Science.gov

Sample records for 99mtc-human serum albumin

  1. Structure of Serum Albumin

    NASA Technical Reports Server (NTRS)

    Carter, Daniel C.; Ho, Joseph X.

    1994-01-01

    Because of its availability, low cost, stability, and unusual ligand-binding properties, serum albumin has been one of the mst extensively studied and applied proteins in biochemistry. However, as a protein, albumin is far from typical, and the widespread interest in and application of albumin have not been balanced by an understanding of its molecular structure. Indeed, for more than 30 years structural information was surmised based solely on techniques such as hydrodynamics, low-angle X-ray scattering, and predictive methods.

  2. Serum albumin: touchstone or totem?

    PubMed

    Margarson, M P; Soni, N

    1998-08-01

    A decrease in serum albumin concentrations is an almost inevitable finding in disease states, and is primarily mediated in the acute phase by alterations in vascular permeability and redistribution. This change is not disease specific but marked changes that persist are generally associated with a poorer prognosis. Critical appraisal of long-standing practices and the availability of alternative colloid solutions have led to a reduction in albumin replacement therapy, and a widespread tolerance of lower albumin concentrations in patients. The factors determining serum albumin concentrations, their measurement and the implications of hypoalbuminaemia are reviewed. The clinical value of serum albumin measurement is discussed. PMID:9797524

  3. Protein Crystal Serum Albumin

    NASA Technical Reports Server (NTRS)

    1998-01-01

    As the most abundant protein in the circulatory system albumin contributes 80% to colloid osmotic blood pressure. Albumin is also chiefly responsible for the maintenance of blood pH. It is located in every tissue and bodily secretion, with extracellular protein comprising 60% of total albumin. Perhaps the most outstanding property of albumin is its ability to bind reversibly to an incredible variety of ligands. It is widely accepted in the pharmaceutical industry that the overall distribution, metabolism, and efficiency of many drugs are rendered ineffective because of their unusually high affinity for this abundant protein. An understanding of the chemistry of the various classes of pharmaceutical interactions with albumin can suggest new approaches to drug therapy and design. Principal Investigator: Dan Carter/New Century Pharmaceuticals

  4. (PCG) Protein Crystal Growth Horse Serum Albumin

    NASA Technical Reports Server (NTRS)

    1995-01-01

    Horse Serum Albumin crystals grown during the USML-1 (STS-50) mission's Protein Crystal Growth Glovebox Experiment. These crystals were grown using a vapor diffusion technique at 22 degrees C. The crystals were allowed to grow for nine days while in orbit. Crystals of 1.0 mm in length were produced. The most abundant blood serum protein, regulates blood pressure and transports ions, metabolites, and therapeutic drugs. Principal Investigator was Edward Meehan.

  5. Preliminary crystallographic studies of four crystal forms of serum albumin

    NASA Technical Reports Server (NTRS)

    Carter, D. C.; Chang, B.; Ho, J. X.; Keeling, K.; Krishnasami, Z.

    1994-01-01

    Several crystal forms of serum albumin suitable for three-dimensional structure determination have been grown. These forms include crystals of recombinant and wild-type human serum albumin, baboon serum albumin, and canine serum albumin. The intrinsic limits of X-ray diffraction for these crystals are in the range 0.28-0.22 nm. Two of the crystal forms produced from human and canine albumin include incorporated long-chain fatty acids. Molecular replacement experiments have been successfully conducted on each crystal form using the previously determined atomic coordinates of human serum albumin illustrating the conserved tertiary structure.

  6. Preliminary crystallographic studies of four crystal forms of serum albumin.

    PubMed

    Carter, D C; Chang, B; Ho, J X; Keeling, K; Krishnasami, Z

    1994-12-15

    Several crystal forms of serum albumin suitable for three-dimensional structure determination have been grown. These forms include crystals of recombinant and wild-type human serum albumin, baboon serum albumin, and canine serum albumin. The intrinsic limits of X-ray diffraction for these crystals are in the range 0.28-0.22 nm. Two of the crystal forms produced from human and canine albumin include incorporated long-chain fatty acids. Molecular replacement experiments have been successfully conducted on each crystal form using the previously determined atomic coordinates of human serum albumin illustrating the conserved tertiary structure. PMID:7813459

  7. Polymerized soluble venom--human serum albumin

    SciTech Connect

    Patterson, R.; Suszko, I.M.; Grammer, L.C.

    1985-03-01

    Extensive previous studies have demonstrated that attempts to produce polymers of Hymenoptera venoms for human immunotherapy resulted in insoluble precipitates that could be injected with safety but with very limited immunogenicity in allergic patients. We now report soluble polymers prepared by conjugating bee venom with human serum albumin with glutaraldehyde. The bee venom-albumin polymer (BVAP) preparation was fractionated on Sephacryl S-300 to have a molecular weight range higher than catalase. /sup 125/I-labeled bee venom phospholipase A was almost completely incorporated into BVAP. Rabbit antibody responses to bee venom and bee venom phospholipase A were induced by BVAP. Human antisera against bee venom were absorbed by BVAP. No new antigenic determinants on BVAP were present as evidenced by absorption of antisera against BVAP by bee venom and albumin. BVAP has potential immunotherapeutic value in patients with anaphylactic sensitivity to bee venom.

  8. Interaction of Citrinin with Human Serum Albumin

    PubMed Central

    Poór, Miklós; Lemli, Beáta; Bálint, Mónika; Hetényi, Csaba; Sali, Nikolett; Kőszegi, Tamás; Kunsági-Máté, Sándor

    2015-01-01

    Citrinin (CIT) is a mycotoxin produced by several Aspergillus, Penicillium, and Monascus species. CIT occurs worldwide in different foods and drinks and causes health problems for humans and animals. Human serum albumin (HSA) is the most abundant plasma protein in human circulation. Albumin forms stable complexes with many drugs and xenobiotics; therefore, HSA commonly plays important role in the pharmacokinetics or toxicokinetics of numerous compounds. However, the interaction of CIT with HSA is poorly characterized yet. In this study, the complex formation of CIT with HSA was investigated using fluorescence spectroscopy and ultrafiltration techniques. For the deeper understanding of the interaction, thermodynamic, and molecular modeling studies were performed as well. Our results suggest that CIT forms stable complex with HSA (logK ~ 5.3) and its primary binding site is located in subdomain IIA (Sudlow’s Site I). In vitro cell experiments also recommend that CIT-HSA interaction may have biological relevance. Finally, the complex formations of CIT with bovine, porcine, and rat serum albumin were investigated, in order to test the potential species differences of CIT-albumin interactions. PMID:26633504

  9. (PCG) Protein Crystal Growth Human Serum Albumin

    NASA Technical Reports Server (NTRS)

    1989-01-01

    (PCG) Protein Crystal Growth Human Serum Albumin. Contributes to many transport and regulatory processes and has multifunctional binding properties which range from various metals, to fatty acids, hormones, and a wide spectrum of therapeutic drugs. The most abundant protein of the circulatory system. It binds and transports an incredible variety of biological and pharmaceutical ligands throughout the blood stream. Principal Investigator on STS-26 was Larry DeLucas.

  10. Serum albumin complexation of acetylsalicylic acid metabolites.

    PubMed

    Jurkowski, Wiktor; Porebski, Grzegorz; Obtułowicz, Krystyna; Roterman, Irena

    2009-06-01

    One possible origin of the type I hypersensitivity reaction is reaction of drugs such as acetylsalicylic acid and its metabolites being complexed with human serum albumin. Albumin, being transporting molecule abundant in blood plasma is able to bind large array of ligands varying from small single carbon particles to long hydrophobic tailed lipidic acids (e.g. myristic acid). This non specificity is possible because of multi domain scaffold and large flexibility of inter-domain loops, which results in serious reorientation of domains. Hypothesis that acetylsalicylic acid metabolites may play indirect role in activation of allergic reaction has been tested. Binding of acetylsalicylic acid metabolites in intra-domain space causes significant increase of liability of domains IIIA and IIIB. One of metabolites, salicyluric acid, once is bound causes distortion and partial unfolding of helices in domains IA, IIB and IIIB. Changed are both directions and amplitude of relative motions as well as intra-domain distances. In result albumin is able to cross-link of adjacent IgE receptors which subsequently starts allergic reaction. PMID:19689242

  11. Trajectories of Serum Albumin Predict Survival of Peritoneal Dialysis Patients

    PubMed Central

    Chiu, Ping-Fang; Tsai, Chun-Chieh; Wu, Chia-Lin; Yang, Tse-Yen; Liou, Hung-Hsiang; Chen, Hung-Lin; Kor, Chew-Teng; Chang, Chia-Chu; Chang, Horng-Rong

    2016-01-01

    Abstract Although initial serum albumin level is highly associated with overall and cardiovascular mortality in peritoneal dialysis (PD) patients, we consider that the dynamic change and trend of albumin after initiation of PD are also essential. We enrolled patients who received PD for more than 3 months from January 1999 to March 2014. We categorized these patients into 2 groups by the difference in serum albumin level (Δalbumin = difference between peak with initial albumin level = peak albumin level − initial albumin level) after PD. The patients with Δalbumin < 0.2 g/dL (median level) were considered as group A (n, number = 238) and those with Δalbumin ≥ 0.2 g/dL were considered as group B (n = 278). Further, we stratified these patients into quartiles: Q1 Δalbumin < −0.2 g/dL; Q2, −0.2 ≦∼ <0.2 g/dL; Q3, 0.2 ≦∼ <0.6 g/dL; and Q4, ≥0.6 g/dL. Regression analysis was performed to determine the correlation of initial albumin and Δalbumin. Group A patients presented with higher levels of serum albumin (3.71 ± 0.54 vs 3.04 ± 0.55 g/dL; P < 0.001) and hematocrit as well as better initial residual renal function. However, those in group A had lower serum albumin increment and downward-sloped trends after dialysis. In contrast, the albumin trend was upward sloped and the increment of albumin was remarkable in group B, despite the high prevalence of cardiovascular diseases and diabetes. Overtime, group A patients had poorer survival and experienced more frequent and longer hospitalizations. Group Q1 patients with least albumin increment had worst survival. Group Q4 patients with lowest initial albumin also had poor survival. Age, diabetes, cardiovascular diseases, BMI, initial albumin, and Δalbumin could affect patient outcomes independently. Regression analysis showed a better outcome can be obtained if the initial albumin level is at least above 3.15 g/dL. (Initial albumin level

  12. Atomic structure and chemistry of human serum albumin

    NASA Technical Reports Server (NTRS)

    He, Xiao M.; Carter, Daniel C.

    1992-01-01

    The three-dimensional structure of human serum albumin has been determined crystallographically to a resolution of 2.8 A. It comprises three homologous domains that assemble to form a heart-shaped molecule. Each domain is a product of two subdomains that possess common structural motifs. The principal regions of ligand binding to human serum albumin are located in hydrophobic cavities in subdomains IIA and ILIA, which exhibit similar chemistry. The structure explains numerous physical phenomena and should provide insight into future pharmacokinetic and genetically engineered therapeutic applications of serum albumin.

  13. Complexes of dendrimers with bovine serum albumin.

    PubMed

    Mandeville, J S; Tajmir-Riahi, H A

    2010-02-01

    We report the complexation of bovine serum albumin (BSA) with several dendrimers of different compositions mPEG-PAMAM (G3), mPEG-PAMAM (G4), and PAMAM (G4) at physiological conditions using constant protein concentration and various dendrimer contents. FTIR, CD, and fluorescence spectroscopic methods were used to analyze polymer binding mode, the binding constant, and the effects of dendrimer complexation on BSA stability and conformation. Structural analysis showed that dendrimers bind BSA via hydrophilic and hydrophobic interactions with a number of bound polymers (n): 1.30 for mPEG-PAMAM-G3, 1.30 for mPEG-PAMAM-G4, and 1.0 for PAMAM-G4. The polymer-BSA binding constants were K(mPEG-G3) = 5.0 (+/-0.8) x 10(3) M(-1), K(mPEG-G4) = 1.0 (+/-0.3) x 10(4) M(-1), and K(PAMAM-G4) = 1.1 (+/-0.4) x 10(4) M(-1). Dendrimer binding altered BSA conformation with a major reduction of alpha-helix and an increase in random coil and turn structures, indicating a partial protein unfolding. PMID:20085247

  14. Interaction of coffee compounds with serum albumins. Part II: Diterpenes.

    PubMed

    Guercia, Elena; Forzato, Cristina; Navarini, Luciano; Berti, Federico

    2016-05-15

    Cafestol and 16-O-methylcafestol are diterpenes present in coffee, but whilst cafestol is found in both Coffea canephora and Coffea arabica, 16-O-methylcafestol (16-OMC) was reported to be specific of only C. canephora. The interactions of such compounds, with serum albumins, have been studied. Three albumins have been considered, namely human serum albumin (HSA), fatty acid free HSA (ffHSA) and bovine serum albumin (BSA). The proteins interact with the diterpenes at the interface between Sudlow site I and the fatty acid binding site 6 in a very peculiar way, leading to a significant change in the secondary structure. The diterpenes do not displace reference binding drugs of site 2, but rather they enhance the affinity of the site for the drugs. They, therefore, may alter the pharmacokinetic profile of albumin - bound drugs. PMID:26776001

  15. Experimental investigation of the serum albumin fascia microstructure

    NASA Astrophysics Data System (ADS)

    Buzoverya, M. E.; Shcherbak, Yu. P.; Shishpor, I. V.

    2012-09-01

    The results of theoretical and experimental investigation of biological liquids are reported. Structural effects observed in fascias are considered with account of the molecular features of albumin and the concept of supramolecular organization of polymers. It is revealed that the morphology of human serum albumin fascias depends on the concentration and quality of the solvent. It is shown that the water-salt fascias of albumin are more structured than water solutions with the same concentration.

  16. [Pulsed radiolysis of aqueous solutions of serum albumin containing naphthoquinones].

    PubMed

    Pribush, A G; Savich, A V

    1987-01-01

    As was shown by the pulse radiolysis method the simultaneous presence of naphthoquinone and human serum albumin molecules in an aqueous solution leads to the adsorption of the former on the surface of the latter. It is suggested that in these conditions the protein tertiary structure changes. New conformation reduces the reactivity of albumin toward the hydrated electron. PMID:3628723

  17. Investigation of bovine serum albumin glycation by THz spectroscopy

    NASA Astrophysics Data System (ADS)

    Cherkasova, Olga P.; Nazarov, Maxim M.; Shkurinov, Alexander P.

    2016-04-01

    Protein glycation is accelerated under hyperglycemic conditions resulting to loss in the structure and biological functions of proteins. The transmission THz spectroscopy has been used for measuring of bovine serum albumin glycation dynamics. It was found that amplitude of albumin THz absorption depends on type of sugars and incubation time.

  18. 99M-technetium labeled macroaggregated human serum albumin pharmaceutical

    DOEpatents

    Winchell, Harry S.; Barak, Morton; Van Fleet, III, Parmer

    1977-05-17

    A reagent comprising macroaggregated human serum albumin having dispersed therein particles of stannous tin and a method for instantly making a labeled pharmaceutical therefrom, are disclosed. The labeled pharmaceutical is utilized in organ imaging.

  19. Glycated Serum Albumin and AGE Receptors.

    PubMed

    Vetter, Stefan W

    2015-01-01

    In vivo modification of proteins by molecules with reactive carbonyl groups leads to intermediate and advanced glycation end products (AGE). Glucose is a significant glycation reagent due to its high physiological concentration and poorly controlled diabetics show increased albumin glycation. Increased levels of glycated and AGE-modified albumin have been linked to diabetic complications, neurodegeneration, and vascular disease. This review discusses glycated albumin formation, structural consequences of albumin glycation on drug binding, removal of circulating AGE by several scavenger receptors, as well as AGE-induced proinflammatory signaling through activation of the receptor for AGE. Analytical methods for quantitative detection of protein glycation and AGE formation are compared. Finally, the use of glycated albumin as a novel clinical marker to monitor glycemic control is discussed and compared to glycated hemoglobin (HbA1c) as long-term indicator of glycemic status. PMID:26471084

  20. Fluorescence lifetime measurements of native and glycated human serum albumin and bovine serum albumin

    NASA Astrophysics Data System (ADS)

    Joshi, Narahari V.; Joshi, Virgina O. d.; Contreras, Silvia; Gil, Herminia; Medina, Honorio; Siemiarczuk, Aleksander

    1999-05-01

    Nonenzymatic glycation, also known as Maillard reaction, plays an important role in the secondary complications of the diabetic pathology and aging, therefore, human serum albumin (HSA) and bovine serum albumin (BSA) were glycated by a conventional method in our laboratory using glucose as the glycating agent. Fluorescence lifetime measurements were carried out with a laser strobe fluorometer equipped with a nitrogen/dye laser and a frequency doubler as a pulsed excitation source. The samples were excited at 295 nm and the emission spectra were recorded at 345 nm. The obtained decay curves were tried for double and triple exponential functions. It has been found that the shorter lifetime increases for glycated proteins as compared with that of the native ones. For example, in the case of glycated BSA the lifetime increased from 1.36 ns to 2.30 ns. Similarly, for HSA, the lifetime increases from 1.58 ns to 2.26 ns. Meanwhile, the longer lifetime changed very slightly for both proteins (from 6.52 ns to 6.72 ns). The increase in the lifetime can be associated with the environmental effect; originated from the attachment of glucose to some lysine residues. A good example is Trp 214 which is in the cage of Lys 225, Lys 212, Lys 233, Lys 205, Lys 500, Lys 199 and Lys 195. If fluorescence lifetime technique is calibrated and properly used it could be employed for assessing glycation of proteins.

  1. Interaction of ergosterol with bovine serum albumin and human serum albumin by spectroscopic analysis.

    PubMed

    Cheng, Zhengjun

    2012-10-01

    This study was designed to examine the interactions of ergosterol with bovine serum albumin (BSA) and human serum albumin (HSA) under physiological conditions with the drug concentrations in the range of 2.99-105.88 μM and the concentration of proteins was fixed at 5.0 μM. The analysis of emission spectra quenching at different temperatures revealed that the quenching mechanism of HSA/BSA by ergosterol was the static quenching. The number of binding sites n and the binding constants K were obtained at various temperatures. The distance r between ergosterol and HSA/BSA was evaluated according to Föster non-radioactive energy transfer theory. The results of synchronous fluorescence, 3D fluorescence, FT-IR, CD and UV-Vis absorption spectra showed that the conformations of HSA/BSA altered in the presence of ergosterol. The thermodynamic parameters, free energy change (ΔG), enthalpy change (ΔH) and entropy change (ΔS) for BSA-ergosterol and HSA-ergosterol systems were calculated by the van't Hoff equation and discussed. Besides, with the aid of three site markers (for example, phenylbutazone, ibuprofen and digitoxin), we have reported that ergosterol primarily binds to the tryptophan residues of BSA/HSA within site I (subdomain II A). PMID:22733490

  2. A high-capacity hydrophobic adsorbent for human serum albumin.

    PubMed

    Belew, M; Peterson, E A; Porath, J

    1985-12-01

    A simple method, based on salting out hydrophobic interaction chromatography, for the efficient removal of trace amounts of serum albumin from partially purified protein preparations is described. The method is also successfully applied for the purification of albumin from Cohn fraction IV, a by-product obtained from the commercial fractionation of human serum proteins by the ethanol precipitation procedure. About 70% of the adsorbed albumin can be eluted by buffer of low ionic strength and can thus be lyophilized directly, if required. The adsorbent can be used for several cycles of adsorption and desorption without affecting its selectivity or capacity. Its adsorption properties and capacity for serum albumin are compared with those of the commercially available adsorbent Blue Sepharose CL-6B. PMID:3879424

  3. THE SECRETORY PATHWAYS OF RAT SERUM GLYCOPROTEINS AND ALBUMIN

    PubMed Central

    Redman, Colvin M.; Cherian, M. George

    1972-01-01

    These studies compare the secretory pathways of newly formed rat serum glycoproteins and albumin by studying their submicrosomal localization at early times after the beginning of their synthesis and also by determining the submicrosomal site of incorporation of N-acetylglucosamine, mannose, galactose, and leucine into protein. N-acetylglucosamine, mannose, and galactose were only incorporated in vitro into proteins from membrane-attached polysomes and not into proteins from free polysomes. Mannose incorporation occurred in the rough endoplasmic reticulum, was stimulated by puromycin but not by cycloheximide, and 90% of the mannose-labeled protein was bound to the membranes. Galactose incorporation, by contrast, occurred in the smooth microsome fraction and 89% of the radioactive protein was in the cisternae. Albumin was mostly recovered (98%) in the cisternae, with negligible amounts in the membranes. To determine whether the radio-active sugars were being incorporated into serum proteins or into membrane protein, the solubilized in vivo-labeled proteins were treated with specific antisera to rat serum proteins or to albumin. Immunoelectrophoresis of the 14C-labeled leucine membrane and cisternal proteins showed that the membranes contained radioactive serum glycoprotein but no albumin, while the cisternal fraction contained all of the radioactive albumin and some glycoproteins. The results indicate that newly formed serum glycoproteins remain attached to the membranes of the rough endoplasmic reticulum after they are released from the membrane-attached polysomes, while albumin passes directly into the cisternae. PMID:5057975

  4. Human serum albumin and its relation with oxidative stress.

    PubMed

    Sitar, Mustafa Erinç; Aydin, Seval; Cakatay, Ufuk

    2013-01-01

    Human serum albumin, a negative acute phase reactant and marker of nutritive status, presents at high concentrations in plasma. Albumin has always been used in many clinical states especially to improve circulatory failure. It has been showed that albumin is involved in many bioactive functions such as regulation of plasma osmotic pressure, binding and transport of various endogenous or exogenous compounds, and finally extracellular antioxidant defenses. Molecules like transferrin, caeruloplasmin, haptoglobin, uric acid, bilirubin, alpha-tocopherol, glucose, and albumin constitute extracellular antioxidant defenses in blood plasma but albumin is the most potent one. Most of the antioxidant properties of albumin can be attributed to its unique biochemical structure. The protein possesses antioxidant properties such as binding copper tightly and iron weakly, scavenging free radicals, e.g., hypochlorous acid (HOCl) and Peroxynitrite (ONOOH) and providing thiol group (-SH). Whether it is chronic or acute, during many pathological conditions, biomarkers of oxidative protein damage increase and this observation continues with considerable oxidation of human serum albumin. There is an important necessity to specify its interactions with Reactive Oxygen Species. Generally, it may lower the availability of pro-oxidants and be preferentially oxidized to protect other macromolecules but all these findings make it necessary that researchers give a more detailed explanation of albumin and its relations with oxidative stress. PMID:24273915

  5. Protein extracts from cultured cells contain nonspecific serum albumin.

    PubMed

    Miyara, Masatsugu; Umeda, Kanae; Ishida, Keishi; Sanoh, Seigo; Kotake, Yaichiro; Ohta, Shigeru

    2016-06-01

    Serum is an important component of cell culture media. The present study demonstrates contamination of intracellular protein extract by bovine serum albumin from the culture media and illustrates how this contamination can cause the misinterpretation of western blot results. Preliminary experiments can prevent the misinterpretation of some experimental results, and optimization of the washing process may enable specific protein detection. PMID:26967711

  6. Serum Albumin Levels and Economic Status in Japanese Older Adults

    PubMed Central

    Ota, Asami; Kondo, Naoki; Murayama, Nobuko; Tanabe, Naohito; Shobugawa, Yugo; Kondo, Katsunori

    2016-01-01

    Background Low serum albumin levels are associated with aging and medical conditions such as cancer, liver dysfunction, inflammation, and malnutrition and might be an independent predictor of long-term mortality in healthy older populations. We tested the hypothesis that economic status is associated with serum albumin levels and explained by nutritional and health status in Japanese older adults. Design We performed a cross-sectional analysis using data from the Japan Gerontological Evaluation study (JAGES). The study participants were 6528 functionally independent residents (3189 men and 3339 women) aged ≥65 years living in four municipalities in Aichi prefecture. We used household income as an indicator of economic status. Multiple linear regression was used to compare serum albumin levels in relation to household income, which was classified as low, middle, and high. Additionally, mediation by nutritional and health-related factors was analyzed in multivariable models. Results With the middle-income group as reference, participants with low incomes had a significantly lower serum albumin level, even after adjustment for sex, age, residential area, education, marital status, and household structure. The estimated mean difference was −0.17 g/L (95% confidence interval, −0.33 to −0.01 g/L). The relation between serum albumin level and low income became statistically insignificant when “body mass index”, “consumption of meat or fish”, “self-rated health”, “presence of medical conditions”, “hyperlipidemia”, or “respiratory disease “was included in the model. Conclusion Serum albumin levels were lower in Japanese older adults with low economic status. The decrease in albumin levels appears to be mediated by nutrition and health-related factors with low household incomes. Future studies are needed to reveal the existence of other pathways. PMID:27276092

  7. Binding of dapsone and its analogues to human serum albumin.

    PubMed

    Karp, W B; Subramanyam, S B; Robertson, A F

    1985-06-01

    The binding of dapsone, 4,4'-sulfonylbis(aniline)(1), and its diacetylated derivative, 4,4"'-sulfonylbis(acetanilide)(2), to human serum albumin is reported. To assess the ability of these compounds to displace 4'-[(4-aminophenyl)sulfonyl]acetanilide (3) from albumin, a dialysis rate technique was used. Competition for the bilirubin binding site on albumin was measured with the peroxidase assay. Compounds 1 and 2 strongly displaced both 3 and bilirubin from human serum albumin. The association constants for 1 and 2 with respect to bilirubin binding were 1.29 X 10(3) and 1.15 X 10(4) M-1, respectively. These results suggest that the binding site for 3 and the bilirubin binding site are similar with respect to 1 and 2 and that the binding of dapsone and its derivatives probably does not involve the amino function. PMID:4020658

  8. Interaction of sulpiride and serum albumin: Modeling from spectrofluorimetric data

    NASA Astrophysics Data System (ADS)

    Fragoso, Viviane Muniz da Silva; Silva, Dilson

    2015-12-01

    We have applied the fluorescence quenching modeling to study the process of interaction of sulpiride with human serum albumin (HSA) and bovine (BSA). Albumin is more abundant protein in blood and it emits fluorescence when excited by 260-295 nm. Sulpiride is an atypical antipsychotic used in the treatment of many psychiatric disorders. As sulpiride is fluorescent, we developed a mathematical model to analyzing the interaction of two fluorescent substances. This model was able to separate the albumin fluorescence from the quencher fluorescence. Results have shown that sulpiride quenches the fluorescence of both albumins by a static process, due to the complex formation drugalbumin. The association constants calculated for sulpiride-HSA was 2.20 (± 0.08) × 104 M-1 at 37° C, and 5.46 (± 0.20) × 104 M-1, 25 ° C, and the primary binding site to sulpiride in the albumin is located closer to the subdomain IB.

  9. PRODUCTION OF UNIFORMLY SIZED SERUM ALBUMIN AND DEXTROSE MICROBUBBLES

    PubMed Central

    Borrelli, Michael J.; O’Brien, William D.; Bernock, Laura J.; Williams, Heather R.; Hamilton, Eric; Wu, Jonah; Oelze, Michael L.; Culp, William C.

    2011-01-01

    Uniformly-sized preparations with average microbubble (MB) diameters from 1 µm to 7 µm were produced reliably by sonicating decafluorobutane-saturated solutions of serum albumin and dextrose. Detailed protocols for producing and size-separating the MBs are presented, along with the effects that changing each production parameter (serum albumin concentration, sonication power, sonication time, etc.) had on MB size distribution and acoustic stability. These protocols can be used to produce MBs for experimental applications or serve as templates for developing new protocols that yield MBs with physical and acoustic properties better suited to specific applications. Size stability and ultrasonic performance quality control tests were developed to assure that successive MB preparations perform identically and to distinguish the physical and acoustic properties of identically sized MBs produced with different serum albumin-dextrose formulations and sonication parameters. MBs can be stored at 5°C for protracted periods (2 weeks to one year depending on formulation). PMID:21689961

  10. Effects of glycation on meloxicam binding to human serum albumin

    NASA Astrophysics Data System (ADS)

    Trynda-Lemiesz, Lilianna; Wiglusz, Katarzyna

    2011-05-01

    The current study reports a binding of meloxicam a pharmacologically important new generation, non-steroidal anti-inflammatory drug to glycated form of the human serum albumin (HSA). The interaction of the meloxicam with nonglycated and glycated albumin has been studied at pH 7.4 in 0.05 M sodium phosphate buffer with 0.1 M NaCl, using fluorescence quenching technique and circular dichroism spectroscopy. Results of the present study have shown that the meloxicam could bind both forms of albumin glycated and nonglycated at a site, which was close to the tryptophan residues. Similarly, how for native albumin glycated form has had one high affinity site for the drug with association constants of the order of 10 5 M -1. The glycation process of the HSA significantly has affected the impact of the meloxicam on the binding of other ligands such as warfarin and bilirubin. The affinity of the glycated albumin for bilirubin as for native albumin has been reduced by meloxicam but observed effect was weaker by half (about 20%) compared with nonglycated albumin. In contrast to the native albumin meloxicam binding to glycated form of the protein only slightly affected the binding of warfarin. It seemed possible that the effects on warfarin binding might be entirely attributable to the Lys 199 modification which was in site I.

  11. A Homogeneous Fluorescent Sensor for Human Serum Albumin

    PubMed Central

    Wang, Rongsheng E.; Tian, Ling; Chang, Yie-Hwa

    2012-01-01

    Human serum albumin is the most abundant protein in the body and is an important biomarker used for disease-related diagnosis. Although the traditional enzyme-linked immunosorbent assay (ELISA) approach can precisely measure the concentration of human serum albumin, the multi-step procedure and time-consuming preparations of ELISA limit its diagnostic applications, preventing accurate point-of-care testing, for example. Herein, we report the recent development of an antibody-based albumin sensor that allows for a homogeneous measurement of albumin concentrations in saliva, urine and serum, in which this type of sensor is validated for the first time. The assay only requires simple mixing, and relies on time-resolved (TR) fluorescence resonance energy transfer (FRET) to produce robust, sensitive signals. The whole process, from sample preparation to final read-out, is expected to take less than one hour and requires only a standard plate-reader, thus making the sensor a convenient and cost-effective tool for albumin analysis. PMID:22326845

  12. Superior serum half life of albumin tagged TNF ligands

    SciTech Connect

    Mueller, Nicole; Schneider, Britta; Pfizenmaier, Klaus; Wajant, Harald

    2010-06-11

    Due to their immune stimulating and apoptosis inducing properties, ligands of the TNF family attract increasing interest as therapeutic proteins. A general limitation of in vivo applications of recombinant soluble TNF ligands is their notoriously rapid clearance from circulation. To improve the serum half life of the TNF family members TNF, TWEAK and TRAIL, we genetically fused soluble variants of these molecules to human serum albumin (HSA). The serum albumin-TNF ligand fusion proteins were found to be of similar bioactivity as the corresponding HSA-less counterparts. Upon intravenous injection (i.v.), serum half life of HSA-TNF ligand fusion proteins, as determined by ELISA, was around 15 h as compared to approximately 1 h for all of the recombinant control TNF ligands without HSA domain. Moreover, serum samples collected 6 or 24 h after i.v. injection still contained high TNF ligand bioactivity, demonstrating that there is only limited degradation/inactivation of circulating HSA-TNF ligand fusion proteins in vivo. In a xenotransplantation model, significantly less of the HSA-TRAIL fusion protein compared to the respective control TRAIL protein was required to achieve inhibition of tumor growth indicating that the increased half life of HSA-TNF ligand fusion proteins translates into better therapeutic action in vivo. In conclusion, our data suggest that genetic fusion to serum albumin is a powerful and generally applicable mean to improve bioavailability and in vivo activity of TNF ligands.

  13. Interaction of purine bases and nucleosides with serum albumin

    NASA Astrophysics Data System (ADS)

    Sułkowska, A.; Michnik, A.

    1997-06-01

    The proton NMR spectra of alkyl derivatives of adenine and adenosine have been studied. High-resolution (400 MHz) proton spectra were recorded at 300 K at increasing concentrations of serum albumin. The dependence of the chemical shifts and the line width of the individual spectral lines on the protein concentration provides some detailed information about the nature of the complexes between the purine derivatives and albumin. Comparison of data for the methylated and non-methylated purine bases and nucleosides indicates the formation of non-specific complexes with serum albumin. However, the presence of the ethyl group in 8-ethyl-9 N-methyladenine means that in the adenine derivative-serum albumin complex the ethyl chain preserves its dominant role in binding. An advantage of our model is that the π-π interaction between the adenine ring and the amino acids of the protein can be replaced by hydrophobic interaction in the case of complexation of the ethyl adenine derivative.

  14. Scaffold materials from glycosylated and PEGylated bovine serum albumin.

    PubMed

    Wang, Kai; David, Allan E; Choi, Young-Suk; Wu, Yonnie; Buschle-Diller, Gisela

    2015-09-01

    Bovine serum albumin has been PEGylated and glycosylated to create mimetic materials for the extracellular matrix (ECM) with potential tissue engineering applications. Different surfaces for cell adhesion were achieved by crosslinking the initial albumin product and forming either a coating or a sponge-like three-dimensional morphology to mimic the mesh structure of natural ECM. The biocompatibility of the albumin matrix with mammalian cells was evaluated using cell culture assays with NIH 3T3 cells. The results indicated that glycoprotein composition and specific morphology of the assembly can improve the cell growth environment. These ECM mimetic structures might eventually be considered to serve as alternatives for the more expensive collagen and elastin based ECM substances currently in use in tissue engineering. PMID:25691091

  15. Binding of several benzodiazepines to bovine serum albumin: Fluorescence study

    NASA Astrophysics Data System (ADS)

    Machicote, Roberta G.; Pacheco, María E.; Bruzzone, Liliana

    2010-10-01

    The interactions of lorazepam, oxazepam and bromazepam with bovine serum albumin (BSA) were studied by fluorescence spectrometry. The Stern-Volmer quenching constants and corresponding thermodynamic parameters Δ H, Δ G and Δ S were calculated. The binding constants and the number of binding sites were also investigated. The distances between the donor (BSA) and the acceptors (benzodiazepines) were obtained according to fluorescence resonance energy transfer and conformational changes of BSA were observed from synchronous fluorescence spectra.

  16. Immunodetection of Serum Albumin Adducts as Biomarkers for Organophosphorus Exposure

    PubMed Central

    Chen, Sigeng; Zhang, Jun; Lumley, Lucille

    2013-01-01

    A major challenge in organophosphate (OP) research has been the identification and utilization of reliable biomarkers for the rapid, sensitive, and efficient detection of OP exposure. Although Tyr 411 OP adducts to human serum albumin (HSA) have been suggested to be one of the most robust biomarkers in the detection of OP exposure, the analysis of HSA-OP adduct detection has been limited to techniques using mass spectrometry. Herein, we describe the procurement of two monoclonal antibodies (mAb-HSA-GD and mAb-HSA-VX) that recognized the HSA Tyr 411 adduct of soman (GD) or S-[2-(diisopropylamino)ethyl]-O-ethyl methylphosphonothioate (VX), respectively, but did not recognize nonphosphonylated HSA. We showed that mAb-HSA-GD was able to detect the HSA Tyr 411 OP adduct at a low level (i.e., human blood plasma treated with 180 nM GD) that could not be detected by mass spectrometry. mAb-HSA-GD and mAb-HSA-VX showed an extremely low-level detection of GD adducted to HSA (on the order of picograms). mAb-HSA-GD could also detect serum albumin OP adducts in blood plasma samples from different animals administered GD, including rats, guinea pigs, and monkeys. The ability of the two antibodies to selectively recognize nerve agents adducted to serum albumin suggests that these antibodies could be used to identify biomarkers of OP exposure and provide a new biologic approach to detect OP exposure in animals. PMID:23192655

  17. The interaction between bovine serum albumin and surfactants.

    PubMed Central

    Jones, M N; Skinner, H A; Tipping, E

    1975-01-01

    1. Potassium n-decyl phosphate binds exothermically to bovine serum albumin at pH 7.0 to form a specific complex containing approx. 60 phosphate anions. 2. The formation of the complex is accompanied by changes in the u.v. difference spectrum of the protein. 3. At higher phosphate concentrations (above 0.4mM) surfactant molecules continue to be bound, and the protein undergoes a gross change in conformation. 4. n-Dodecyltri-methylammonium bromide binds endothermically to bovine serum albumin at pH7.0 but the extent of binding for a given free surfactant concentration is less than for the phosphate surfactant. 5. Binding is accompanied by a small change in the specific viscosity and by changes in the u.v. difference spectrum of the protein. 6. It is suggested that over the surfactant concentration ranges studied n-decyl phosphate ions first bind to the C-terminal part of the protein and then to the more compact N-terminal part whereas n-dodecyltrimethylammonium ions bind only to the C-terminal part of bovine serum albumin. PMID:1180891

  18. Sequences Of Amino Acids For Human Serum Albumin

    NASA Technical Reports Server (NTRS)

    Carter, Daniel C.

    1992-01-01

    Sequences of amino acids defined for use in making polypeptides one-third to one-sixth as large as parent human serum albumin molecule. Smaller, chemically stable peptides have diverse applications including service as artificial human serum and as active components of biosensors and chromatographic matrices. In applications involving production of artificial sera from new sequences, little or no concern about viral contaminants. Smaller genetically engineered polypeptides more easily expressed and produced in large quantities, making commercial isolation and production more feasible and profitable.

  19. Reactions of trimethylphosphine analogues of auranofin with bovine serum albumin

    SciTech Connect

    Isab, A.A.; Shaw, C.F. III; Hoeschele, J.D.; Locke, J.

    1988-10-05

    The reactions of bovine serum albumin (BSA) with (trimethylphosphine)(2,3,4,6-tetra-O-acetyl-1-thio-..beta..-D-glucopyranosato-S)gold(I), Me/sub 3/PAuSAtg, and its chloro analogue, Me/sub 3/PAuCl, were studied to develop insights into the role of the phosphine ligand in the serum chemistry of the related antiarthritic drug auranofin (triethylphosphine)(2,3,4,6-tetra-O-acetyl-1-thio-..beta..-D-glucopyranosato-S)gold(I). /sup 31/P NMR spectroscopy, protein modification, and gel-exclusion chromatography methods were employed. Comparison of the reactions of the methyl derivatives to the previously reported reactions of auranofin and Et/sub 3/PAuCl with BSA demonstrated that similar chemical species are formed but revealed three major differences. Despite these differences, the results for the methyl analogues provide important confirmation for previously developed chemical models of auranofin reactions in serum. Me/sub 3/PO was not observed in reaction mixtures lacking tetraacetylthioglucose (AtgSH); this result affirms the role of AtgSH, displaced by the reaction of Me/sub 3/PAuSAtg at Cys-34, in the generation of the phosphine oxide (an important metabolite in vivo). The weak binding sites on albumin react with Me/sub 3/PAuCl, but not Me/sub 3/PAuSAtg, demonstrating the importance of the strength and reactivity of the anionic ligand-gold bond on the reactions of auranofin analogues. The gold binding capacity of albumin is enhanced after Me/sub 3/PO is formed, consistent with reductive cleavage of albumin disulfide bonds by trimethylphosphine. 24 references, 2 figures, 3 tables.

  20. Tamoxifen and curcumin binding to serum albumin. Spectroscopic study

    NASA Astrophysics Data System (ADS)

    Maciążek-Jurczyk, M.; Maliszewska, M.; Pożycka, J.; Równicka-Zubik, J.; Góra, A.; Sułkowska, A.

    2013-07-01

    Tamoxifen (TMX) is widely used for the breast cancer treatment and is known as chemopreventive agent. Curcumin (CUR) is natural phenolic compound with broad spectrum of biological activity e.g. anti-inflammatory, antimicrobial, antiviral, antifungal and chemopreventive. Combination of tamoxifen and curcumin could be more effective with lower toxicity than each agent alone in use for the treatment or chemoprevention of breast cancer. Binding of drugs to serum albumin is an important factor, which determines toxicity and therapeutic dosage of the drugs. When two drugs are administered together the competition between them for the binding site on albumin can result in a decrease in bound fraction and an increase in the concentration of free biologically active fraction of drug.

  1. Fructosylation generates neo-epitopes on human serum albumin.

    PubMed

    Allarakha, Shaziya; Ahmad, Parvez; Ishtikhar, Mohd; Zaheer, Mohammad Shoaib; Siddiqi, Sheelu Shafiq; Moinuddin; Ali, Asif

    2015-05-01

    Hyperglycemia is the defining feature of diabetes mellitus. The persistently high levels of reducing sugars like glucose and fructose cause glycation of various macromolecules in the body. Human serum albumin (HSA), the most abundant serum protein with a myriad of functions, is prone to glycation and consequent alteration in its structural and biological properties. This study aimed to assess the role of fructose-modified human serum albumin as a marker of diabetic pathophysiology. We carried out modification of HSA with fructose and the changes induced were studied by various physicochemical studies. Fructose modified-HSA showed hyperchromicity in UV spectrum and increased AGE-specific fluorescence as well as quenching of tryptophan fluorescence. In SDS-PAGE protein aggregation was seen. Amadori products were detected by NBT. The fructose modified HSA had higher content of carbonyls along with perturbations in secondary structure as revealed by CD and FT-IR. A greater hydrodynamic radius of fructose-modified HSA was evident by DLS measurement. The fructose-modified HSA induced high titre antibodies in experimental animals exhibiting high specificity towards the immunogen. PMID:25914162

  2. Review: modifications of human serum albumin and their binding effect.

    PubMed

    Lee, Philbert; Wu, Xiaoyang

    2015-01-01

    Human serum albumin (HSA) regulates the transport and availability of numerous chemical compounds and molecules in the blood vascular system. While previous HSA research has found that HSA interacts with specific varieties of ligands, new research efforts aim to expand HSA's ability to interact with more different drugs in order to improve the delivery of various pharmacological drugs. This review will cover fatty acid chain and posttranslational modifications of HSA that potentially modulate how HSA interacts with various pharmacological drugs, including glycation, cysteinylation, S-nitrosylation, S-transnitrosation and S-guanylation. PMID:25732553

  3. Highly sensitive bovine serum albumin biosensor based on liquid crystal

    NASA Astrophysics Data System (ADS)

    Sharma, Vikash; Kumar, Ajay; Ganguly, Prasun; Biradar, A. M.

    2014-01-01

    A highly sensitive liquid crystal (LC) based bovine serum albumin (BSA) protein biosensor is designed. A uniform homeotropic alignment of nematic LC was observed in BSA free substrate which changed into homogeneous in presence of BSA. The change in the LC orientation is found to depend strongly on BSA concentration. This change in the LC alignment is attributed to the modification in the surface conditions which is verified by contact angle measurements. We have detected an ultra low concentration (0.5 μg/ml) of BSA. The present study demonstrates the utilization of LC in the realization of high sensitivity biosensors.

  4. Review: Modifications of Human Serum Albumin and Their Binding Effect

    PubMed Central

    Lee, Philbert; Wu, Xiaoyang

    2015-01-01

    Human serum albumin (HSA) regulates the transport and availability of numerous chemical compounds and molecules in the blood vascular system. While previous HSA research has found that HSA interacts with specific varieties of ligands, new research efforts aim to expand HSA’s ability to interact with more different drugs in order to improve the delivery of various pharmacological drugs. This review will cover fatty acid chain and post-translational modifications of HSA that potentially modulate how HSA interacts with various pharmacological drugs, including glycation, cysteinylation, S-nitrosylation, S-transnitrosation and S-guanylation. PMID:25732553

  5. Experimental evidence on interaction between xenon and bovine serum albumin

    NASA Astrophysics Data System (ADS)

    Wołoszyn, Łukasz; Ilczyszyn, Marek; Ilczyszyn, Maria M.

    Xenon gas interacts with bovine serum albumin (BSA) dissolved in a physiological buffer solution. The fluorescence quenching related to the Trp emission is reversible and depends linearly on the time of saturation by Xe. The most probable site of this interaction is Trp212. The common emission of all BSA fluorophores is also influenced by Xe but this quenching is more complex and suggests: (i) at least two sites occupied by Xe and related to the Tyr and Trp residues; (ii) structural variations of BSA induced by the Xe guest atoms.

  6. Three-dimensional structure of human serum albumin

    NASA Technical Reports Server (NTRS)

    Carter, Daniel C.; He, Xiao-Min; Munson, Sibyl H.; Twigg, Pamela D.; Gernert, Kim M.; Broom, M. Beth; Miller, Teresa Y.

    1989-01-01

    The three-dimensional structure of human serum albumin has been solved at 6.0 A resolution by the method of multiple isomorphous replacement. Crystals were grown from solutions of polyethylene glycol in the infrequently observed space group P42(1)2 and diffracted X-rays to lattice d-spacings of less than 2.9 A. The electron density maps are of high quality and revealed the structure as a predominantly alpha-helical globin protein in which the course of the polypeptide can be traced. The binding loci of several organic compounds have been determined.

  7. Hepatic functional scintigraphic imaging with 99mtechnetium galactosyl serum albumin.

    PubMed

    Kubota, Y; Kitagawa, S; Inoue, K; Ha-Kawa, S K; Kojima, M; Tanaka, Y

    1993-02-01

    99mTc-galactosyl serum albumin (GSA), a specific radiolabeled synthetic ligand for asialoglycoprotein receptors on hepatocytes, was used for functional liver imaging in 18 patients. Six patients had chronic hepatitis, and 12 had liver cirrhosis. Serial scintigraphic images were obtained for 60 minutes after intravenous administration of 1 mg of the ligand. High-quality images of the liver was obtained in all the patients. Dispersed accumulation in the liver in association with delayed clearance of the ligand from the heart was noted in cirrhotic patients. The activity of the entire liver (L) and that of the heart (H) were measured. The capacity of the liver in terms of elimination of the ligand was estimated by calculating [L/H+L] 15 and 30 minutes after the administration. [L/H+L] showed significant differences between patients with chronic hepatitis and those with liver cirrhosis, and also showed significant correlations with laboratory values such as indocyanine green clearance, prothrombin time, hepaplastin test, serum albumin level, and the Child-Turcotte classification score. 99mTc-GSA might be a useful radiopharmaceutical for obtaining hepatic functional images. PMID:8462925

  8. Quantitative determination of biological sulfhydryl groups by postcolumn derivatization and elucidation of microheterogeneity of serum albumins.

    PubMed

    Yasuhara, T; Nokihara, K

    1998-08-15

    A quantitative analytical system for biological sulfhydryl compounds has been developed using an ion-pair reagent with isocratic elution and an on-line postcolumn derivatization with Ellman-type reagents. As human or bovine serum albumin has 35 cysteinyl residues, one cysteinyl residue exists as a free sulfhydryl moiety, and this gives rise to the microheterogeneity in serum albumin. Here we report for the first time the quantitative characterization of the microheterogeneity of serum albumin. Cysteine was found to be the major molecule attached to the sulfydryl group of the serum albumins. Although glutathione could not be detected, the Cys-Gly element of glutathione was found. Freshly prepared human serum albumin from healthy volunteers contained 0.46 nmol of Cys/mL of serum, 0.24 nmol of Cys-Gly/mL of serum, and very small amounts of glutathione (0.02 nmol/mL). PMID:9726170

  9. Surface receptors for serum albumin in group C and G streptococci show three different types of albumin specificity.

    PubMed Central

    Wideback, K; Kronvall, G

    1982-01-01

    A total of 100 bacterial strains were tested for binding uptake of radiolabeled albumin preparations from 15 mammalian species. Three types of surface structures with specific binding sites for albumin were defined. A previously described receptor for albumin was separated into type a in Streptococcus equisimilis strains and in human group G streptococcal strains and type b in bovine group C streptococci. A new type of albumin receptor, type c, was found in Streptococcus dysgalactiae strains, the only receptor type so far with high affinity for bovine serum albumin. Type of albumin receptor correlated with bacterial species. The three receptor types showed high binding capacities; 2 X 10(8) bacterial organisms bound from 5 to 16 micrograms of albumin. All types of albumin receptors were stable to heat treatment at 80 degrees C for 5 min, but susceptible to both pepsin and trypsin treatment. Bacteria-bound albumin preparations were eluted at various concentrations of KSCN, reflecting differences in affinity. Up to 500 micrograms of human fibrinogen or polyclonal human immunoglobulin G had no inhibitory effect on the uptake of albumin, indicating a separate molecular localization of receptors for these proteins. PMID:6295942

  10. In Vivo Labeling of Serum Albumin for PET

    PubMed Central

    Niu, Gang; Lang, Lixin; Kiesewetter, Dale O.; Ma, Ying; Sun, Zhongchan; Guo, Ning; Guo, Jinxia; Wu, Chenxi; Chen, Xiaoyuan

    2015-01-01

    The purpose of this study was to develop a novel in vivo albumin-labeling method to allow PET of cardiac function after myocardial infarction and vascular leakage and increased permeability in inflammatory diseases and malignant tumors. Methods To label albumin in vivo, we synthesized a NOTA (1,4,7-triazacyclononane-N,N′, N″-triacetic acid)-conjugated truncated form of Evans blue (NEB). 18F labeling was achieved by the formation of an 18F-aluminum fluoride (18F-AlF) complex, and 64Cu labeling was obtained by a standard chelation method. Sixty-minute dynamic PET imaging was performed on normal mice to evaluate the distribution of 18F-AlF-NEB, which was compared with in vitro–labeled mouse serum albumin (18F-fluorobenzyl-MSA). Electrocardiography-gated PET imaging was performed in a mouse model of myocardial infarction. Both dynamic and static PET scans were obtained in a mouse inflammation model induced by local injection of turpentine to evaluate vascular leakage. Tumor permeability was studied by dynamic and late-point static PET using 64Cu-NEB in a UM-22B xenograft model. Results NEB was successfully synthesized, and 18F labeling including work-up took about 20–30 min, with a radiochemical purity greater than 95% without the need for high-performance liquid chromatography purification. Most of the radioactivity was retained in the circulation system at 60 min after injection (26.35 ± 1.52 percentage injected dose per gram [%ID/g]). With electrocardiography-gated PET, ventricles of the heart and major arteries were clearly visualized. The myocardial infarction mice showed much lower left ventricular ejection fraction than the control mice. Inflammatory muscles showed significantly higher tracer accumulation than the contralateral healthy ones. UM-22B tumor uptake of 64Cu-NEB gradually increased with time (5.73 ± 1.11 %ID/g at 1 h and 8.03 ± 0.77 %ID/g at 2 h after injection). Conclusion The distribution and local accumulation of serum albumin can be

  11. Biologically active protein fragments containing specific binding regions of serum albumin or related proteins

    NASA Technical Reports Server (NTRS)

    Carter, Daniel C. (Inventor)

    1998-01-01

    In accordance with the present invention, biologically active protein fragments can be constructed which contain only those specific portions of the serum albumin family of proteins such as regions known as subdomains IIA and IIIA which are primarily responsible for the binding properties of the serum albumins. The artificial serums that can be prepared from these biologically active protein fragments are advantageous in that they can be produced much more easily than serums containing the whole albumin, yet still retain all or most of the original binding potential of the full albumin proteins. In addition, since the protein fragment serums of the present invention can be made from non-natural sources using conventional recombinant DNA techniques, they are far safer than serums containing natural albumin because they do not carry the potentially harmful viruses and other contaminants that will be found in the natural substances.

  12. Hydrophobic conjugated microporous polymers for sorption of human serum albumin

    NASA Astrophysics Data System (ADS)

    Zheng, Chunli; Du, Miaomiao; Feng, Shanshan; Sun, Hanxue; Li, An; He, Chi; Zhang, TianCheng; Wang, Qiaorui; Wei, Wei

    2016-02-01

    This paper investigated the sorption of human serum albumin (HSA) from water by three kinds of conjugated microporous polymers (CMPs) with surface hydrophobicity and intrinsic porosity. It was found that the three CMPs captured HSA with fast sorption kinetics and good working capacity. Equilibrium was obtained at 80 min for all the tests, and the maximum sorption quantity (qm) ranged from 0.07 to 0.14 mg/mg. With the increase in the particle external surface area of the CMPs, a greater extent of HSA sorption was achieved. Moreover, promoting the dispersion of CMPs in HSA aqueous solution was also beneficial to the extraction. Attenuated Total Reflection Fourier Transform Infrared spectroscopy verified the interactions between the CMPs and the Nsbnd H, Cdbnd O, and Csbnd N groups of HSA. This paper might provide fundamental guidance for the practical application of CMPs to proteins separation and recovery.

  13. Interaction between fasudil hydrochloride and bovine serum albumin: spectroscopic study.

    PubMed

    Yu, Xianyong; Jiang, Bingfei; Xun, Caifang; Yao, Qing

    2016-06-01

    The interaction between fasudil hydrochloride (FSD) and bovine serum albumin (BSA) was investigated using fluorescence and ultraviolet spectroscopy under imitated physiological conditions. The Stern-Volmer quenching model has been successfully applied and the results revealed that FSD could quench the intrinsic fluorescence of BSA effectively via static quenching. The binding constants and binding sites for the BSA-FSD system were evaluated. The corresponding thermodynamic parameters obtained at different temperatures indicated that hydrophobic force played a major role in the interaction of FSD and BSA. The distance between the donor (BSA) and the acceptor (FSD) was obtained according to fluorescence resonance energy transfer (FRET). Synchronous fluorescence spectroscopy and FT-IR spectra showed that the conformation of BSA was changed in the presence of FSD. Copyright © 2015 John Wiley & Sons, Ltd. PMID:26554343

  14. Structural studies on serum albumins under green light irradiation.

    PubMed

    Comorosan, Sorin; Polosan, Silviu; Popescu, Irinel; Ionescu, Elena; Mitrica, Radu; Cristache, Ligia; State, Alina Elena

    2010-10-01

    This paper presents two new experimental results: the protective effect of green light (GL) on ultraviolet (UV) denaturation of proteins, and the effect of GL on protein macromolecular structures. The protective effect of GL was revealed on two serum albumins, bovine (BSA) and human (HSA), and recorded by electrophoresis, absorption, and circular dichroism spectra. The effect of GL irradiation on protein structure was recorded by using fluorescence spectroscopy and electrophoresis. These new effects were modeled by quantum-chemistry computation using Gaussian 03 W, leading to good fit between theoretical and experimental absorption and circular dichroism spectra. A mechanism for these phenomena is suggested, based on a double-photon absorption process. This nonlinear effect may lead to generation of long-lived Rydberg macromolecular systems, capable of long-range interactions. These newly suggested systems, with macroscopic quantum coherence behaviors, may block the UV denaturation processes. PMID:20473754

  15. Human serum albumin crystals and method of preparation

    NASA Technical Reports Server (NTRS)

    Carter, Daniel C. (Inventor)

    1989-01-01

    Human serum albumin (HSA) crystals are provided in the form of tetragonal plates having the space groups P42(sub 1)2, the crystals being grown to sizes in excess of 0.5 mm in two dimensions and a thickness of 0.1 mm. Growth of the crystals is carried out by a hanging drop method wherein a precipitant solution containing polyethylene glycol (PEG) and a phosphate buffer is mixed with an HSA solution, and a droplet of mixed solution is suspended over a well of precipitant solution. Crystals grow to the desired size in 3 to 7 days. Concentration of reagents, pH and other parameters are controlled within prescribed limits. The resulting crystals exhibit a size and quality such as to allow performance of x ray diffraction studies and enable the conduct of drug binding studies as well as genetic engineering studies.

  16. Role of sensitization to mammalian serum albumin in allergic disease.

    PubMed

    Liccardi, Gennaro; Asero, Riccardo; D'Amato, Maria; D'Amato, Gennaro

    2011-10-01

    Serum albumin (SA) constitutes an intriguing puzzle that is involved in allergic sensitizations from different sources and induces different clinical manifestations. In this article, we describe the role of sensitization to SAs in inducing allergic diseases and the complex interactions and cross-reactivity between SA resulting from its presence in various mammalian tissues and fluids. SAs alone are an uncommon cause of allergic sensitization in airways, but these allergenic proteins likely play a significant role as cross-reacting allergens in individuals sensitized to several types of animal dander. SAs are a minor allergen in milk but a major allergen in meats. Recently, bovine SA has been added to the culture medium of spermatozoids used for artificial insemination. As a consequence, some case reports have shown that bovine SA may be a causative agent in severe anaphylaxis after standard intrauterine insemination or in vitro fertilization. PMID:21809117

  17. Stereoselective interaction of cinchona alkaloid isomers with bovine serum albumin.

    PubMed

    Liu, Yan; Chen, Mingmao; Jiang, Longguang; Song, Ling

    2015-08-15

    The dependence of the interaction between bovine serum albumin (BSA) and two cinchona alkaloids, quinine (QN) and quinidine (QD), on the absolute configuration of these stereoisomers has been comprehensively studied. The FTIR spectra showed that QN and QD interacted with both CO and C-N groups of BSA, resulting in changes to the secondary structure of the protein. Fluorescence quenching of BSA by the stereoisomers revealed lower efficiency for QD in quenching the Trp emission of BSA when compared to QN. Further analysis accurately described the different binding behaviors and recognition discrepancies of QN and QD towards BSA, which was reflected through binding affinities, driving forces, energy changes and conformational changes during the ligand-protein interactions. Synchronous fluorescence further proved that QD was farther from Trp and Tyr than that of QN. This work could provide basic data for clarifying the binding interaction, metabolism and distribution of cinchona alkaloid stereoisomers in vivo. PMID:25794736

  18. Fluorescence quenching of bovine serum albumin by NNMB

    NASA Astrophysics Data System (ADS)

    Jayabharathi, J.; Jayamoorthy, K.; Thanikachalam, V.; Sathishkumar, R.

    2013-05-01

    A new type of fluorophore 2-(naphthalen-1-yl)-1-((naphthalen-1-yl)methyl)-1H-benzimidazole (NNMB) has been prepared and characterized by 1H NMR, 13C NMR, mass and IR spectral analysis. Absorption, fluorescence and synchronous fluorescence spectral studies have been made for the mutual interaction of NNMB with bovine serum albumin (BSA). Absorption spectroscopy proved the formation of a ground state BSA…NNMB complex. Fluorescence spectrum of BSA in the presence of NNMB clearly shows that NNMB acts as a quencher. Based on the theory of Forester's non-radiation energy transfer (FRET) binding distance has been deduced. The Stern-Volmer quenching constant (KSV), binding site number (n), apparent binding constant (KA) and corresponding thermodynamic parameters (ΔG, ΔH and ΔS) were determined.

  19. Heme-based catalytic properties of human serum albumin

    PubMed Central

    Ascenzi, P; di Masi, A; Fanali, G; Fasano, M

    2015-01-01

    Human serum albumin (HSA): (i) controls the plasma oncotic pressure, (ii) modulates fluid distribution between the body compartments, (iii) represents the depot and carrier of endogenous and exogenous compounds, (iv) increases the apparent solubility and lifetime of hydrophobic compounds, (v) affects pharmacokinetics of many drugs, (vi) inactivates toxic compounds, (vii) induces chemical modifications of some ligands, (viii) displays antioxidant properties, and (ix) shows enzymatic properties. Under physiological and pathological conditions, HSA has a pivotal role in heme scavenging transferring the metal-macrocycle from high- and low-density lipoproteins to hemopexin, thus acquiring globin-like reactivity. Here, the heme-based catalytic properties of HSA are reviewed and the structural bases of drug-dependent allosteric regulation are highlighted.

  20. Three-dimensional structure of human serum albumin

    NASA Technical Reports Server (NTRS)

    Carter, Daniel C.; He, Xiao-Min; Twigg, Pamela D.; Casale, Elena

    1991-01-01

    The binding locations to human serum albumin (HSA) of several drug molecules were determined at low resolution using crystallographic methods. The principal binding sites are located within subdomains IIA and IIIA. Preliminary studies suggest that an approach to increasing the in vivo efficacy of drugs which are rendered less effective or ineffective by virtue of their interaction with HSA, would be the use of competitive displacement in drug therapies and/or the development of a general inhibitor to the site within subdomain IIIA. These findings also suggest that the facilitated transfer of various ligands across organ/circulatory interfaces such as liver, kidney, and brain may be associated with binding to the IIIA subdomain.

  1. Neuronal uptake of serum albumin is associated with neuron damage during the development of epilepsy

    PubMed Central

    Liu, Zanhua; Liu, Jinjie; Wang, Suping; Liu, Sibo; Zhao, Yongbo

    2016-01-01

    It is well established that brain blood barrier dysfunction following the onset of seizures may lead to serum albumin extravasation into the brain. However, the effect of albumin extravasation on the development of epilepsy is yet to be fully elucidated. Previous studies have predominantly focused on the effect of albumin absorption by astrocytes; however, the present study investigated the effects of neuronal uptake of albumin in vitro and in kainic acid-induced Sprague-Dawley rat models of temporal lobe epilepsy. In the present study, electroencephalogram recordings were conducted to record seizure onset, Nissl and Evans blue staining were used to detect neuronal damage and albumin extravasation, respectively, and double immunofluorescence was used to explore neuronal absorption of albumin. Cell counting was also conducted in vitro to determine whether albumin contributes to neuronal death. The results of the present study indicated that extravasated serum albumin was absorbed by neurons, and the neurons that had absorbed albumin died and were dissolved 28 days after seizure onset in vivo. Furthermore, significant neuronal death was detected after albumin absorption in vitro in a dose- and time-dependent manner. These results suggested that albumin may be absorbed by neurons following the onset of seizures. Furthermore, the results indicated that neuronal albumin uptake may be associated with neuronal damage and death in epileptic seizures. Therefore, attenuating albumin extravasation following epileptic seizures may reduce brain damage and slow the development of epilepsy. PMID:27446263

  2. Iron absorption in humans: bovine serum albumin compared with beef muscle and egg white

    SciTech Connect

    Hurrell, R.F.; Lynch, S.R.; Trinidad, T.P.; Dassenko, S.A.; Cook, J.D.

    1988-01-01

    We studied the influence of bovine serum albumin and beef meat on nonheme iron absorption in humans and on dialyzable iron in vitro. The addition of serum albumin to a maize gruel had no significant effect on nonheme Fe absorption whereas the addition of beef meat caused a threefold increase. When added to a bread meal, serum albumin caused a modest 60% increase in nonheme Fe absorption and beef meat had no effect. When added to a protein-free meal, serum albumin reduced Fe absorption by 47% compared with a 72% reduction on addition of egg white. The bioavailability of nonheme Fe from meals containing serum albumin was consistently overestimated by the in vitro technique. We conclude that the facilitation of nonheme Fe absorption by meat is not a general property of all animal protein but is better explained by the action of one or more specific animal tissues.

  3. Serum Albumin Domain Structures in Human Blood Serum by Mass Spectrometry and Computational Biology*

    PubMed Central

    Belsom, Adam; Schneider, Michael; Fischer, Lutz; Brock, Oliver; Rappsilber, Juri

    2016-01-01

    Chemical cross-linking combined with mass spectrometry has proven useful for studying protein-protein interactions and protein structure, however the low density of cross-link data has so far precluded its use in determining structures de novo. Cross-linking density has been typically limited by the chemical selectivity of the standard cross-linking reagents that are commonly used for protein cross-linking. We have implemented the use of a heterobifunctional cross-linking reagent, sulfosuccinimidyl 4,4′-azipentanoate (sulfo-SDA), combining a traditional sulfo-N-hydroxysuccinimide (sulfo-NHS) ester and a UV photoactivatable diazirine group. This diazirine yields a highly reactive and promiscuous carbene species, the net result being a greatly increased number of cross-links compared with homobifunctional, NHS-based cross-linkers. We present a novel methodology that combines the use of this high density photo-cross-linking data with conformational space search to investigate the structure of human serum albumin domains, from purified samples, and in its native environment, human blood serum. Our approach is able to determine human serum albumin domain structures with good accuracy: root-mean-square deviation to crystal structure are 2.8/5.6/2.9 Å (purified samples) and 4.5/5.9/4.8Å (serum samples) for domains A/B/C for the first selected structure; 2.5/4.9/2.9 Å (purified samples) and 3.5/5.2/3.8 Å (serum samples) for the best out of top five selected structures. Our proof-of-concept study on human serum albumin demonstrates initial potential of our approach for determining the structures of more proteins in the complex biological contexts in which they function and which they may require for correct folding. Data are available via ProteomeXchange with identifier PXD001692. PMID:26385339

  4. Species Dependence of [64Cu]Cu-Bis(thiosemicarbazone) Radiopharmaceutical Binding to Serum Albumins

    PubMed Central

    Basken, Nathan E.; Mathias, Carla J.; Lipka, Alexander E.; Green, Mark A.

    2008-01-01

    Introduction Interactions of three copper(II) bis(thiosemicarbazone) PET radiopharmaceuticals with human serum albumin, and the serum albumins of four additional mammalian species, were evaluated. Methods 64Cu-labeled diacetyl bis(N4-methylthiosemicarbazonato)copper(II) (Cu-ATSM), pyruvaldehyde bis(N4-methylthiosemicarbazonato)copper(II) (Cu-PTSM), and ethylglyoxal bis(thiosemicarbazonato)copper(II) (Cu-ETS) were synthesized and their binding to human, canine, rat, baboon, and porcine serum albumins quantified by ultrafiltration. Protein binding was also measured for each tracer in human, porcine, rat, and mouse serum. Results The interaction of these neutral, lipophilic copper chelates with serum albumin is highly compound- and species-dependent. Cu-PTSM and Cu-ATSM exhibit particularly high affinity for human serum albumin (HSA), while the albumin binding of Cu-ETS is relatively insensitive to species. At HSA concentrations of 40 mg/mL, “% Free” (non-albumin-bound) levels of radiopharmaceutical were 4.0 ± 0.1%; 5.3 ± 0.2%; and 38.6 ± 0.8% for Cu-PTSM; Cu-ATSM; and Cu-ETS, respectively. Conclusions Species-dependent variations in radiopharmaceutical binding to serum albumin may need to be considered when using animal models to predict the distribution and kinetics of these compounds in humans. PMID:18355683

  5. Glycated serum albumin: a potential disease marker and an intermediate index of diabetes control.

    PubMed

    Raghav, Alok; Ahmad, Jamal

    2014-01-01

    Glycation is a non-enzymatic spontaneous process in proteins which has remarkable impact on its physical and functional aspect. This alteration with addition of carbohydrate residue to human serum albumin leads to several pathological events such as diabetic nephropathy, neuropathy, retinopathy and cardiovascular complications. Human serum albumin is the major protein and is most susceptible to non-enzymatic glycation. Structural and biological properties of functional albumin alter due to the addition of reducing carbohydrate to free amino terminal residues vivo. These irreversible changes in functional albumin are stable which makes this modified albumin as new gold standard future diagnostic marker in diabetes associated complications. Glycated albumin can be used to determine the glycemic control due to short half life than erythrocytes which makes it an alternate reliable disease marker in diabetes. In this review, Human serum albumin glycation has been overviewed, stating concept of glycation and sites that are prone to this modifications. Impact of non-enzymatic addition of carbohydrate to albumin's structural and biological properties has also been elaborated. Accurate measurements of glycated albumin with implications of new highly sensitive techniques have also been described briefly. Interestingly human serum albumin imposed glycation can serve as future tool not for diagnosing diabetes but also its potential in assessment of diabetes associated complications. PMID:25311816

  6. Human serum albumin homeostasis: a new look at the roles of synthesis, catabolism, renal and gastrointestinal excretion, and the clinical value of serum albumin measurements.

    PubMed

    Levitt, David G; Levitt, Michael D

    2016-01-01

    Serum albumin concentration (CP) is a remarkably strong prognostic indicator of morbidity and mortality in both sick and seemingly healthy subjects. Surprisingly, the specifics of the pathophysiology underlying the relationship between CP and ill-health are poorly understood. This review provides a summary that is not previously available in the literature, concerning how synthesis, catabolism, and renal and gastrointestinal clearance of albumin interact to bring about albumin homeostasis, with a focus on the clinical factors that influence this homeostasis. In normal humans, the albumin turnover time of about 25 days reflects a liver albumin synthesis rate of about 10.5 g/day balanced by renal (≈6%), gastrointestinal (≈10%), and catabolic (≈84%) clearances. The acute development of hypoalbuminemia with sepsis or trauma results from increased albumin capillary permeability leading to redistribution of albumin from the vascular to interstitial space. The best understood mechanism of chronic hypoalbuminemia is the decreased albumin synthesis observed in liver disease. Decreased albumin production also accounts for hypoalbuminemia observed with a low-protein and normal caloric diet. However, a calorie- and protein-deficient diet does not reduce albumin synthesis and is not associated with hypoalbuminemia, and CP is not a useful marker of malnutrition. In most disease states other than liver disease, albumin synthesis is normal or increased, and hypoalbuminemia reflects an enhanced rate of albumin turnover resulting either from an increased rate of catabolism (a poorly understood phenomenon) or enhanced loss of albumin into the urine (nephrosis) or intestine (protein-losing enteropathy). The latter may occur with subtle intestinal pathology and hence may be more prevalent than commonly appreciated. Clinically, reduced CP appears to be a result rather than a cause of ill-health, and therapy designed to increase CP has limited benefit. The ubiquitous occurrence of

  7. Human serum albumin homeostasis: a new look at the roles of synthesis, catabolism, renal and gastrointestinal excretion, and the clinical value of serum albumin measurements

    PubMed Central

    Levitt, David G; Levitt, Michael D

    2016-01-01

    Serum albumin concentration (CP) is a remarkably strong prognostic indicator of morbidity and mortality in both sick and seemingly healthy subjects. Surprisingly, the specifics of the pathophysiology underlying the relationship between CP and ill-health are poorly understood. This review provides a summary that is not previously available in the literature, concerning how synthesis, catabolism, and renal and gastrointestinal clearance of albumin interact to bring about albumin homeostasis, with a focus on the clinical factors that influence this homeostasis. In normal humans, the albumin turnover time of about 25 days reflects a liver albumin synthesis rate of about 10.5 g/day balanced by renal (≈6%), gastrointestinal (≈10%), and catabolic (≈84%) clearances. The acute development of hypoalbuminemia with sepsis or trauma results from increased albumin capillary permeability leading to redistribution of albumin from the vascular to interstitial space. The best understood mechanism of chronic hypoalbuminemia is the decreased albumin synthesis observed in liver disease. Decreased albumin production also accounts for hypoalbuminemia observed with a low-protein and normal caloric diet. However, a calorie- and protein-deficient diet does not reduce albumin synthesis and is not associated with hypoalbuminemia, and CP is not a useful marker of malnutrition. In most disease states other than liver disease, albumin synthesis is normal or increased, and hypoalbuminemia reflects an enhanced rate of albumin turnover resulting either from an increased rate of catabolism (a poorly understood phenomenon) or enhanced loss of albumin into the urine (nephrosis) or intestine (protein-losing enteropathy). The latter may occur with subtle intestinal pathology and hence may be more prevalent than commonly appreciated. Clinically, reduced CP appears to be a result rather than a cause of ill-health, and therapy designed to increase CP has limited benefit. The ubiquitous occurrence of

  8. [Amino acid composition and peptide maps of udder and serum albumins in lactating and nonlactating cows].

    PubMed

    Lagodiuk, P Z; Klos, Iu S; Charkin, V A; Kisil', I O

    1983-01-01

    Amino acids and peptides of albumin hydrolyzates from the mammary gland and blood serum were studied for lactating and nonlactating (dry, pregnant 1-4.5 and 4.5-9 months) black-and-white cows. Most pronounced difference between the content of certain amino acids of the mammary gland and blood serum albumins are established for lactating cows and least pronounced for nonlactating dry cows. Dactylography detected 55-57 fragments of products resulted from trypsin hydrolysis of the mammary gland and blood serum albumins of the animals under study. Differences are found in the content and mobility of certain peptides. PMID:6829076

  9. Crystals of Serum Albumin for Use in Genetic Engineering and Rational Drug Design

    NASA Technical Reports Server (NTRS)

    Carter, Daniel C. (Inventor)

    1996-01-01

    Serum albumin crystal forms have been produced which exhibit superior x-ray diffraction quality. The crystals are produced from both recombinant and wild-type human serum albumin, canine, and baboon serum albumin and allow the performance of drug-binding studies as well as genetic engineering studies. The crystals are grown from solutions of polyethylene glycol or ammonium sulphate within prescribed limits during growth times from one to several weeks and include the following space groups: P2(sub 1), C2, P1.

  10. [Spectroscopic studies on the binding of phenazopyridine hydrochloride and bovine serum albumin].

    PubMed

    Zhou, Hong; Chen, Chang-Yun; Xie, An-Jian

    2007-09-01

    The binding of phenazopyridine hydrochloride and bovine serum albumin under physiological conditions was studied by spectroscopic method. The quenching mechanism of the fluorescence of bovine serum albumin by phenazopyridine hydrochloride was studied with fluorescence and absorption spectroscopy. The binding constant Kb and the number of binding sites n were determined at different temperatures according to Scatchard equation, and the main binding force was discussed by thermodynamic equations. The effect of the drug on bovine serum albumin conformation was also studied by using synchronous fluorescence spectroscopy. The quenching mechanism of phenazopyridine hydrochloride to bovine serum albumin is static quenching and non-radiation energy transfer. The binding constants Kb at 15, 25 and 37 degrees C are 2.47 x 10(7), 9.15 x 10(6) and 4.36 x 10(6) mol(-1) with one binding site, respectively. The thermodynamic parameters of the reaction are DeltaH = -71.2 kJ x mol(-1), and DeltaS = 124.8 J x mol(-1) x K(-1). Binding phenazopyridine hydrochloride to bovine serum albumin is a spontaneous inter-molecular interaction in which entropy increases and Gibbs free energy decreases. The binding distance r between phenazopyridine hydrochloride and bovine serum albumin is 1.61 nm according to Forster theory of non-radiation energy transfer. The binding force is electrostatic interaction. Phenazopyridine hydrochloride can be deposited and transported by serum protein in vivo. Phenazopyridine hydrochloride does affect the serum protein conformation. PMID:18051539

  11. Study of the effect of total serum protein and albumin concentrations on canine fructosamine concentration.

    PubMed Central

    Loste, A; Marca, M C

    1999-01-01

    The relationship among serum fructosamine concentration and total serum protein and albumin concentrations were evaluated in healthy and sick dogs (diabetics and dogs with insulinoma were not included). Fructosamine was determined using a commercial colorimetric nitroblue tetrazolium method applied to the Technicon RA-500 (Bayer). Serum fructosamine concentration was not correlated to total protein in normoproteinemic (r = 0.03) and hyperproteinemic dogs (r = 0.29), but there was a high correlation (r = 0.73) in hypoproteinemic dogs. Similar comparison between serum fructosamine and albumin concentrations showed middle correlation (r = 0.49) in normoalbuminemic dogs and high degree of correlation (r = 0.67) in hypoalbuminemic dogs. These results showed the importance of recognizing serum glucose concentration as well as total serum protein and albumin concentrations in the assay of canine serum fructosamine concentration. PMID:10369572

  12. Binding of amifostine to human serum albumin: a biophysical study.

    PubMed

    Sun, Yifu; Wu, Han; Zhao, Guoqing; Shi, Ying

    2015-02-01

    The aim of this present work is to investigate the interaction between amifostine and human serum albumin (HSA) in simulated physiological conditions by spectroscopic methods to reveal potential toxic effects of the drug. The results reflected that amifostine caused fluorescence quenching of HSA through a static quenching process, which was further confirmed by the electrochemical experiments. The binding constants at 290, 297 and 304 K were obtained as 2.53 × 10(5) /M, 8.13 × 10(4) /M and 3.59 × 10(4) /M, respectively. There may be one binding site of amifostine on HSA. The thermodynamic parameters indicated that the interaction between amifostine and HSA was driven mainly by hydrogen bonding and electrostatic forces. Synchronous fluorescence spectra, circular dichroism and Fourier transform infrared spectroscopy results showed amifostine binding slightly changed the conformation of HSA with secondary structural content changes. Förster resonance energy transfer study revealed high possibility of energy transfer with amifostine-Trp-214 distance of 3.48 nm. The results of the present study may provide valuable information for studying the distribution, toxicological and pharmacological mechanisms of amifostine in vivo. PMID:24962599

  13. Interactions of thioflavin T with serum albumins: Spectroscopic analyses

    NASA Astrophysics Data System (ADS)

    Sen, Priyankar; Fatima, Sadaf; Ahmad, Basir; Khan, Rizwan Hasan

    2009-09-01

    The interaction of thioflavin T (ThT) with serum albumins from four different mammalian species i.e. human, bovine, porcine and rabbit, has been investigated by circular dichroism (CD), fluorescence spectroscopy and ITC. The binding constant ( K) for HSA was found to be 9.9 × 10 4 M -1, 4.3 × 10 4 M -1 for RSA, 1.07 × 10 4 M -1 for PSA and 0.3 × 10 4 M -1 for BSA and the number of binding sites ( n) were 1.14, 1.06, 0.94 and 0.8, respectively, which is very significant. By using unfolding pathway of HSA in the presence of urea, domain II of HSA has been assigned to possess binding site of ThT. Its binding constant is comparable to many drugs that bind at domain II of HSA, like salicylate, warfarin, digitoxin, etc. Acting force between HSA and ThT is showing that both hydrophobic and electrostatic forces have contributed for the interaction. Δ Gbinding, Δ H and Δ S were calculated to be -28.46 kJ mol -1, -3.50 kJ mol -1 and 81.04 J K -1 mol -1, respectively. The data described here will help to increase our understanding about the interaction of ThT with native proteins. The results also indicate that care must be taken while using ThT as a probe for detecting amyloid fibrils.

  14. Optimization of bovine serum albumin sorption and recovery by hydrogels.

    PubMed

    Gündüz, Ufuk; Tolga, Asli

    2004-07-25

    Aqueous two-phase systems are composed of aqueous solutions of either two water-soluble polymers, usually polyethylene glycol (PEG) and dextran (Dx), or a polymer and a salt, usually PEG and phosphate or sulfate. Partitioning of proteins in such systems provides a powerful method for separating and purifying mixtures of biomolecules by extraction. If one of the phase forming polymers is a crosslinked gel, then the solution-controlled gel sorption may be considered as a modification of aqueous two-phase extraction. Since PEG/dextran systems are widely used in aqueous two-phase extraction and dextran gels (Sephadex) are common chromatographic media, we choose a PEG/dextran gel system as a model system in this study. The partitioning behavior of pure bovine serum albumin (BSA) in PEG/dextran gel systems is investigated to see the effects of variations in PEG and NaCl concentrations on the partition coefficient K. By making use of the Box-Wilson experimental design, K is shown to be maximized at 9.8 (%, w/w) PEG and 0.2 M NaCl concentrations, respectively, as 182. PMID:15177154

  15. Superhydrophobic Effect on the Adsorption of Human Serum Albumin

    PubMed Central

    Leibner, Evan S.; Barnthip, Naris; Chen, Weinan; Baumrucker, Craig R.; Badding, John V.; Pishko, Michael; Vogler, Erwin A.

    2009-01-01

    Analytical protocol greatly influences measurement of human-serum albumin (HSA) adsorption to commercial expanded polytetrafluororethylene (ePTFE) exhibiting superhydrophobic wetting properties. Degassing of buffer solutions and evacuation of ePTFE adsorbent to remove trapped air immediately prior to contact with protein solutions are shown to be essential. Results obtained with ePTFE as a prototypical superhydrophobic test material suggest that vacuum degassing should be applied in the measurement of protein adsorption to any surface exhibiting superhydrophobicity. Solution depletion quantified using radiometry (I-125 labeled HSA) or electrophoresis yield different measures of adsorption, with nearly four-fold higher surface concentrations of unlabeled HSA measured by the electrophoresis method. This outcome is attributed to the influence of the radiolabel on HSA hydrophilicity which decreases radiolabeled-HSA affinity for a hydrophobic adsorbent in comparison to unlabeled HSA. These results indicate that radiometry underestimates the actual amount of protein adsorbed to a particular material. Removal of radiolabeled HSA adsorbed to ePTFE by 3X serial buffer rinses also shows that the remaining “bound fraction” was about 35% lower than the amount measured by radiometric depletion. This observation implies that measurement of protein bound after surface rinsing significantly underestimates the actual amount of protein concentrated by adsorption into the surface region of a protein-contacting material. PMID:19135420

  16. A novel affinity disks for bovine serum albumin purification.

    PubMed

    Tuzmen, Nalan; Kalburcu, Tülden; Uygun, Deniz Aktaş; Akgol, Sinan; Denizli, Adil

    2015-01-01

    The adsorption characteristics of bovine serum albumin (BSA) onto the supermacroporous poly(hydroxyethylmethacrylate)-Reactive Green 19 [p(HEMA)-RG] cryogel disks have been investigated in this paper. p(HEMA) cryogel disks were prepared by radical polymerization initiated by N,N,N',N'-tetramethylene diamine (TEMED) and ammonium persulfate (APS) pair in an ice bath. Reactive Green (RG) 19 was covalently attached to the p(HEMA) cryogel disks. These disks were used in BSA adsorption studies to interrogate the effects of pH, initial protein concentration, ionic strength, and temperature. BSA adsorption capacity of the p(HEMA)-RG cryogel disk was significantly improved after the incorporation of RG. Adsorption capacity reached a plateau value at about 0.8 mg/mL at pH 4.0. The amount of adsorbed BSA decreased from 37.7 to 13.9 mg/g with increasing NaCl concentration. The enthalpy of BSA adsorption onto the p(HEMA)-RG cryogel disk was calculated as -58.4 kJ/mol. The adsorption equilibrium isotherm was fitted well by the Freundlich model. BSA was desorbed from cryogel disks (over 90 %) using 0.5 M NaSCN, and the purity of desorbed BSA was confirmed by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). The experimental results showed that the p(HEMA)-RG cryogel disks have potential for the quick protein separation and purification process. PMID:25308615

  17. Controlled delivery of bovine serum albumin from carboxymethyl xanthan microparticles.

    PubMed

    Maiti, Sabyasachi; Ray, Somasree; Sa, Biswanath

    2009-01-01

    Bovine serum albumin (BSA)-loaded carboxymethyl xanthan (CMX) microparticles were prepared following gelation of sodium carboxymethyl xanthan (SCMX) gum with different concentrations (1-5%) of aluminium chloride (AlCl3). The microparticles prepared using 1% AlCl3 were subsequently coated with 0.5% aqueous solution of either SCMX gum or sodium alginate. Both uncoated and coated microparticles were characterized for entrapment efficiency, surface morphology, particle size, in vitro release and protein stability. The uncoated microparticles became non-spherical and the mean diameter was found to increase with increasing AlCl3 concentration. Higher concentration of AlCl3 decreased BSA entrapment efficiency of the uncoated microparticles from 86-61%. Furthermore, BSA entrapment in coated microparticles was found lower (78-79%) than uncoated microparticles prepared using 1% AlCl3. Although, the uncoated microparticles released almost half of its content in NaCl-HCl buffer solution (pH 1.2) in 2 h, the alginate and xanthan coated microparticles did not liberate a substantial amount of entrapped protein within the same period and prolonged the release in PBS solution (pH 7.4) up to 10 and 12 h, respectively. The microparticles released the protein via diffusion and swelling of the polymer matrix. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis showed that BSA integrity was well retained in the CMX microparticles. PMID:19562833

  18. Interaction of Human Serum Albumin with Metal Protoporphyrins

    NASA Astrophysics Data System (ADS)

    Hu, Jie; Brancaleon, Lorenzo

    2015-03-01

    Fluorescence spectroscopy is widely used in biotechnology, nanotechnology, and molecular biophysics, since it can provide information on a wide range of molecular processes, e.g. the interactions of solvent molecules with fluorophores, conformational changes, and binding interactions etc. In this study, we present the photophysical properties of the interaction of human serum albumin (HSA) with a series of metal compound of Protoporphyrin IX (PPIX), including ZnPPIX, FePPIX, MgPPIX, MnPPIX and SnPPIX respectively, as well as the free base PPIX. Binding constants were retrieved independently using the Benesi-Hildebrand analysis of the porphyrin emission or absorption spectra and the fluorescence quenching (i.e. Stern-Volmer analysis) and reveal that the two methods yield a difference of approximately one order or magnitude between the two. Fluorescence lifetimes was used to probe whether binding of the porphyrin changes the conformation of the protein or if the interaction places the porphyrin at a location that can prompt resonance energy transfer with the lone Tryptophan residue. In recent years it has been discovered that HSA provides a specific binding site for metal-chelated protoporphyrins in subdomain IA. This has opened a novel field of study over the importance of this site for biomedical applications but it has also created the potential for a series of biotechnological applications of the HSA/protoporphyrin complexes. Our study provides a preliminary investigation of the interaction with metal-chelated protoporphyrins that had not been previously investigated.

  19. Human serum albumin-polyethylenimine nanoparticles for gene delivery.

    PubMed

    Rhaese, Stephanie; von Briesen, Hagen; Rübsamen-Waigmann, Helga; Kreuter, Jörg; Langer, Klaus

    2003-09-19

    Nanoparticles consisting of DNA, human serum albumin (HSA) and polyethylenimine (PEI) were formed and tested for transfection efficiency in vitro with the aim of generating a nonviral gene delivery vehicle. HSA-PEI-DNA nanoparticles containing the pGL3 vector coding for luciferase as reporter gene were formed by charge neutralization. The particles were characterized by gel retardation assay, dynamic light scattering (size) and electrophoretic mobility measurements (charge). Stability was determined by spectrophotometric analysis and transfection efficiency was evaluated in cell culture using human embryonic epithelial kidney 293 cells. HSA-PEI-DNA nanoparticles were prepared by co-encapsulation of PEI as a lysosomotropic agent at varying nitrogen to phosphate (N/P) ratios. An optimum transfection efficiency was achieved when the particles were prepared at N/P ratios between 4.8 and 8.4. Furthermore, they displayed a low cytotoxicity when tested in cell culture. Our results show that HSA-PEI-DNA nanoparticles are a versatile carrier for DNA that may be suitable for i.v. administration. PMID:14499197

  20. Spectroscopic study on binding of rutin to human serum albumin

    NASA Astrophysics Data System (ADS)

    Pastukhov, Alexander V.; Levchenko, Lidiya A.; Sadkov, Anatoli P.

    2007-10-01

    Steady-state and time-resolved fluorescence spectroscopy techniques were used to study the interaction of the flavonoid rutin with human serum albumin (HSA) as well as spectral properties of the protein-bound flavonoid. Both quenching of the intrinsic fluorescence of the protein (Trp214) and the ligand fluorescence, appearing upon complexation with HSA, were used to determine binding parameters. The binding constant determined from the quenching of the Trp214 fluorescence by rutin is equal to 6.87 ± 0.22 × 10 4 M -1 and that obtained from the fluorescence of HSA-bound rutin is 3.8 ± 0.4 × 10 4 M -1. Based on the Job plot analysis, the 1:1 binding stoichiometry for the HSA-rutin complex was determined. The efficient quenching of the Trp214 fluorescence by rutin, fluorescence resonance energy transfer from excited Trp214 to rutin, and competitive binding of warfarin indicate that the binding site for the flavonoid is situated within subdomain IIA of HSA. The presence of the sugar moiety in the flavonoid molecule reduces affinity of rutin for binding to HSA but does not affect the binding stoichiometry and location of the binding site compared with aglycone analogues.

  1. Human Serum Albumin Complexed with Myristate and AZT

    SciTech Connect

    Zhu, Lili; Yang, Feng; Chen, Liqing; Meehan, Edward J.; Huang, Mingdong

    2008-06-16

    3'-Azido-3'-deoxythymidine (AZT) is the first clinically effective drug for the treatment of human immunodeficiency virus infection. The drug interaction with human serum albumin (HSA) has been an important component in understanding its mechanism of action, especially in drug distribution and in drug-drug interaction on HSA in the case of multi-drug therapy. We present here crystal structures of a ternary HSA-Myr-AZT complex and a quaternary HSA-Myr-AZT-SAL complex (Myr, myristate; SAL, salicylic acid). From this study, a new drug binding subsite on HSA Sudlow site 1 was identified. The presence of fatty acid is needed for the creation of this subsite due to fatty acid induced conformational changes of HSA. Thus, the Sudlow site 1 of HSA can be divided into three non-overlapped subsites: a SAL subsite, an indomethacin subsite and an AZT subsite. Binding of a drug to HSA often influences simultaneous binding of other drugs. From the HSA-Myr-AZT-SAL complex structure, we observed the coexistence of two drugs (AZT and SAL) in Sudlow site 1 and the competition between these two drugs in subdomain IB. These results provide new structural information on HSA-drug interaction and drug-drug interaction on HSA.

  2. Cooperative binding of drugs on human serum albumin

    NASA Astrophysics Data System (ADS)

    Varela, L. M.; Pérez-Rodríguez, M.; García, M.

    In order to explain the adsorption isotherms of the amphiphilic penicillins nafcillin and cloxacillin onto human serum albumin (HSA), a cooperative multilayer adsorption model is introduced, combining the Brunauer-Emmet-Teller (BET) adsorption isotherm with an amphiphilic ionic adsorbate, whose chemical potential is derived from Guggenheim's theory. The non-cooperative model has been previously proved to qualitatively predict the measured adsorption maxima of these drugs [Varela, L. M., García, M., Pérez-Rodríguez, M., Taboada, P., Ruso, J. M., and Mosquera, V., 2001, J. chem. Phys., 114, 7682]. The surface interactions among adsorbed drug molecules are modelled in a mean-field fashion, so the chemical potential of the adsorbate is assumed to include a term proportional to the surface coverage, the constant of proportionality being the lateral interaction energy between bound molecules. The interaction energies obtained from the empirical binding isotherms are of the order of tenths of the thermal energy, therefore suggesting the principal role of van der Waals forces in the binding process.

  3. Mechanical characterization of cross-linked serum albumin microcapsules.

    PubMed

    de Loubens, Clément; Deschamps, Julien; Georgelin, Marc; Charrier, Anne; Edwards-Levy, Florence; Leonetti, Marc

    2014-07-01

    Controlling the deformation of microcapsules and capsules is essential in numerous biomedical applications. The mechanical properties of the membrane of microcapsules made of cross-linked human serum albumin (HSA) are revealed by two complementary experiments in the linear elastic regime. The first provides the surfacic shear elastic modulus Gs by the study of small deformations of a single capsule trapped in an elongational flow: Gs varies from 0.002 to 5 N m(-1). The second gives the volumic Young's modulus E of the membrane by shallow and local indentations of the membrane with an AFM probe: E varies from 20 kPa to 1 MPa. The surfacic and volumic elastic moduli increase with the size of the capsule up to three orders of magnitude and with the protein concentration of the membrane. The membrane thickness is evaluated from these two membrane mechanical characteristics and increases with the size and the initial HSA concentration from 2 to 20 μm. PMID:24817568

  4. Bovine serum albumin adsorption on functionalized porous silicon surfaces

    NASA Astrophysics Data System (ADS)

    Tay, Li-Lin; Rowell, Nelson L.; Lockwood, David J.; Boukherroub, Rabah

    2004-10-01

    The large surface area within porous Si (pSi) and its strong room temperature photoluminescence (PL) make it an ideal host for biological sensors. In particular, the development of pSi-based optical sensors for DNA, enzyme and other biochemical molecules have become of great interest. Here, we demonstrate that the in-situ monitoring of the pSi PL behaviour can be used as a positive identification of bovine serum albumin (BSA) protein adsorption inside the porous matrix. Electrochemically prepared pSi films were first functionalized with undecylenic acid to produce an organic monolayer covalently attached to the porous silicon surfaces. The acid terminal group also provided favourable BSA binding sites on the pSi matrix sidewalls. In-situ PL spectra showed a gradual red shift (up to 12 meV) in the PL peak energy due to the protein incorporation into the porous matrix. The PL then exhibited a continuous blue shift after saturation of the protein molecules in the pores. This blue shift of the PL peak frequency and a steady increase in the PL intensity is evidence of surface oxidation. Comparing the specular reflectance obtained by Fourier transform infrared spectroscopy (FTIR) before and after BSA incubation confirmed the adsorption of protein in the pSi matrix.

  5. Photo selective protein immobilization using bovine serum albumin

    NASA Astrophysics Data System (ADS)

    Kim, Wan-Joong; Kim, Ansoon; Huh, Chul; Park, Chan Woo; Ah, Chil Seong; Kim, Bong Kyu; Yang, Jong-Heon; Chung, Kwang Hyo; Choi, Yo Han; Hong, Jongcheol; Sung, Gun Yong

    2012-11-01

    A simple and selective technique which immobilizes protein onto a solid substrate by using UV illumination has been developed. In protein immobilization, a Bovine serum albumin (BSA) performed bifunctional role as a cross-linker between substrate and proteins and as a blocker inhibiting a nonspecific protein adsorption. A new photo-induced protein immobilization process has been investigated at each step by fluorescence microscopy, ellipsometry, and Fourier transform infrared (FT-IR) spectroscopy. A UV photomask has been used to induce selective protein immobilization on target regions of the surface of the SiO2 substrates under UV illumination with negligible nonspecific binding. The UV illumination also showed improved photostability than the conventional methods which employed bifunctional photo-crosslinker molecules of photo-reactive diazirine. This new UV illumination-based photo-addressable protein immobilization provides a new approach for developing novel protein microarrays for multiplexed sensing as well as other types of bio-immobilization in biomedical devices and biotechnologies.

  6. On the mechanical properties of bovine serum albumin (BSA) adhesives.

    PubMed

    Berchane, N S; Andrews, M J; Kerr, S; Slater, N K H; Jebrail, F F

    2008-04-01

    Biological adhesives, natural and synthetic, are of current active interest. These adhesives offer significant advantages over traditional sealant techniques, in particular, they are easier to use, and can play an integral part in the healing mechanism of tissue. Thus, biological adhesives can play a major role in medical applications if they possess adequate mechanical behavior and stability over time. In this work, we report on the method of preparation of bovine serum albumin (BSA) into a biological adhesive. We present quantitative measurements that show the effect of BSA concentration and cross-linker content on the bonding strength of BSA adhesive to wood. A comparison is then made with synthetic poly(glycidyl methacrylate) (PGMA) adhesive, and a commercial cyanoacrylate glue, which was used as a control adhesive. In addition, BSA samples were prepared and characterized for their water content, tensile strength, and elasticity. We show that on dry surface, BSA adhesive exhibits a high bonding strength that is comparable with non-biological commercial cyanoacrylate glues, and synthetic PGMA adhesive. Tensile testing on wet wood showed a slight increase in the bonding strength of BSA adhesive, a considerable decrease in the bonding strength of cyanoacrylate glue, and negligible adhesion of PGMA. Tests performed on BSA samples demonstrate that initial BSA concentration and final water content have a significant effect on the stress-strain behavior of the samples. PMID:18197367

  7. Adsorption of bovine serum albumin on nanosized magnetic particles.

    PubMed

    Peng, Z G; Hidajat, K; Uddin, M S

    2004-03-15

    Adsorption of bovine serum albumin (BSA) on nanosized magnetic particles (Fe(3)O(4)) was carried out in the presence of carbodiimide. The equilibrium and kinetics of the adsorption process were studied. Nanosized magnetic particles (Fe(3)O(4)) were prepared by the chemical precipitation method using Fe2+, Fe3+ salts, and ammonium hydroxide under a nitrogen atmosphere. Characterizations of magnetic particles were carried out using transmission electron microscopy (TEM) and a vibrating sample magnetometer (VSM). Fourier-transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) were used to confirm the attachment of BSA on magnetic particles. Effects of pH and salt concentrations were investigated on the adsorption process. The experimental results show that the adsorption of BSA on magnetic particles was affected greatly by the pH, while the effect of salt concentrations was insignificant at a low concentration range. The adsorption equilibrium isotherm was fitted well by the Langmuir model. The maximum adsorption of BSA on magnetic particles occurred at the isoelectric point of BSA. Adsorption kinetics was analyzed by a linear driving force mass-transfer model. BSA was desorbed from magnetic particles under alkaline conditions, which was confirmed by SDS-PAGE electrophoresis and FTIR results. PMID:14972603

  8. Dynamic and static fluorescence quenching of bovine serum albumin

    NASA Astrophysics Data System (ADS)

    Friday, Jacob; Babcock, Jeremiah; Brancaleon, Lorenzo

    2010-10-01

    Protein folding dynamics studies can benefit from the knowledge of specific binding-site availabilities, which aid the detection of protein structural changes and, possibly, protein structure. Fluorescence quenching (FQ) spectroscopy can be used to detect binding site variations arising from evolving protein conformational changes over time. Use of the Stern-Volmer and modified Stern-Volmer equations shows the divergence of the bimolecular quenching constant from the diffusion-limited constant, which can be indicative of bimolecular binding. The study is part of a larger effort to understand early structural events that lead to the aggregation of partly unfolded proteins. In this study, bovine serum albumin (BSA), a globular alpha-helix plasma transport protein, was complexed with the fluorescent ligand fluorescein in phosphate buffer at pH 7.4 and subjected to FQ spectroscopy. Stern-Volmer plots demonstrated an upward quadratic relationship, indicating the presence of dynamic and static quenching factors. Data-fitting showed that multiple binding sites were available. With these results, further studies will be undertaken, where BSA will be subjected to varied denaturing conditions, including pH changes and urea solvent addition. The change of available binding sites could reveal BSA structural patterns.

  9. Thermodynamic analysis of hydration in human serum heme-albumin

    SciTech Connect

    Baroni, Simona; Pariani, Giorgio; Fanali, Gabriella; Longo, Dario; Ascenzi, Paolo; Aime, Silvio; Fasano, Mauro

    2009-07-31

    Ferric human serum heme-albumin (heme-HSA) shows a peculiar nuclear magnetic relaxation dispersion (NMRD) behavior that allows to investigate structural and functional properties. Here, we report a thermodynamic analysis of NMRD profiles of heme-HSA between 20 and 60 {sup o}C to characterize its hydration. NMRD profiles, all showing two Lorentzian dispersions at 0.3 and 60 MHz, were analyzed in terms of modulation of the zero field splitting tensor for the S = {sup 5}/{sub 2} manifold. Values of correlation times for tensor fluctuation ({tau}{sub v}) and chemical exchange of water molecules ({tau}{sub M}) show the expected temperature dependence, with activation enthalpies of -1.94 and -2.46 {+-} 0.2 kJ mol{sup -1}, respectively. The cluster of water molecules located in the close proximity of the heme is progressively reduced in size by increasing the temperature, with {Delta}H = 68 {+-} 28 kJ mol{sup -1} and {Delta}S = 200 {+-} 80 J mol{sup -1} K{sup -1}. These results highlight the role of the water solvent in heme-HSA structure-function relationships.

  10. Bovine Serum Albumin Nanoparticles Containing Quercetin: Characterization and Antioxidant Activity.

    PubMed

    Antônio, Emilli; Khalil, Najeh Maissar; Mainardes, Rubiana Mara

    2016-02-01

    Quercetin is a flavonoid reported as anti-allergic, anti-inflammatory, antiplatelet, anti-microbial, antioxidant, antineurodegenerative and antitumoral. However, due to its low water solubility, its efficacy is restricted. Nanotechnology can be an importante tool to improve the quercetin properties and increase its bioavailability. In this study, bovine serum albumin (BSA) nanoparticles containing quercetin were developed by desolvation technique, characterized the mean particle size, polydispersity, zeta potential, encapsulation efficiency, physical state of drug in nanoparticles and drug release profile as well as their antioxidant activity was evaluated. The influence of glutaraldehyde percentage in nanoparticles properties was evaluated and did not influence the nanoparticles parameters. Nanoparticles presented a mean size around 130 nm and encapsulation efficiency around 85%. Results from X-ray diffractometry showed that the crystal of the drug was converted to an amorphous state in polymeric matrix. Quercetin release profile demonstrated a biphasic pattern and after 96 h approximately 18% of drug was released. Kinetic models demonstrated that the quercetin release followed a second-order model and the release was governed by Fickian diffusion. After 96 h, quercetin-loaded nanoparticles were more effective than free quercetin for scanvenger of radical ABTS + and hypochlorous acid. BSA nanoparticles represents potential carriers for improve quercetin properties. PMID:27433585

  11. PEGylated Cationic Serum Albumin for Boosting Retroviral Gene Transfer.

    PubMed

    Palesch, David; Boldt, Felix; Müller, Janis A; Eisele, Klaus; Stürzel, Christina M; Wu, Yuzhou; Münch, Jan; Weil, Tanja

    2016-08-17

    Retroviral vectors are common tools for introducing genes into the genome of a cell. However, low transduction rates are a major limitation in retroviral gene transfer, especially in clinical applications. We generated cationic human serum albumin (cHSA) protected by a shell of poly(ethylene glycol) (PEG); this significantly enhanced retroviral gene transduction with potentially attractive pharmacokinetics and low immunogenicity. By screening a panel of chemically optimized HSA compounds, we identified a very potent enhancer that boosted the transduction rates of viral vectors. Confocal microscopy revealed a drastically increased number of viral particles attached to the surfaces of target cells. In accordance with the positive net charge of cationic and PEGylated HSA, this suggests a mechanism of action in which the repulsion of the negatively charged cellular and viral vector membranes is neutralized, thereby promoting attachment and ultimately transduction. Importantly, the transduction-enhancing PEGylated HSA derivative evaded recognition by HSA-specific antibodies and macrophage activation. Our findings hold great promise for facilitating improved retroviral gene transfer. PMID:27239020

  12. Investigation of the interaction between naringin and human serum albumin

    NASA Astrophysics Data System (ADS)

    Zhang, Yaheng; Li, Ying; Dong, Lijun; Li, Jiazhong; He, Wenying; Chen, Xingguo; Hu, Zhide

    2008-03-01

    The interaction between naringin and human serum albumin (HSA) has been thoroughly studied by fluorescence quenching technique in combination with UV absorption spectroscopy, Fourier transform infrared (FT-IR) spectroscopy, circular dichroism (CD) spectroscopy and molecular modeling method. Under the simulative physiological conditions, fluorescence data revealed the presence of the binding site on HSA and its binding constants ( K) are 1.62 × 10 4, 1.68 × 10 4, 1.72 × 10 4, and 1.79 × 10 4 M -1 at 289, 296, 303, and 310 K, respectively. The alterations of protein secondary structure in the presence of naringin aqueous solution were qualitative and quantitative calculated by the evidence from CD and FT-IR spectroscopes. In addition, according to the Van't Hoff equation, the thermodynamic functions standard enthalpy (Δ H0) and standard entropy (Δ S0) for the reaction were calculated to be 3.45 kJ mol -1 and 92.52 J mol -1 K -1. These results indicated that naringin binds to HSA mainly by a hydrophobic interaction. Furthermore, the displacement experiments confirmed that naringin could bind to the site I of HSA, which was also in agreement with the result of the molecular modeling study.

  13. Quercetin Influence on Thermal Denaturation of Bovine Serum Albumin.

    PubMed

    Precupas, Aurica; Sandu, Romica; Popa, Vlad T

    2016-09-01

    The effect of quercetin (QUER) binding on bovine serum albumin (BSA) thermal denaturation was systematically investigated by means of differential scanning calorimetry (DSC). Additional information concerning thermodynamic and structural binding parameters was provided by isothermal titration calorimetry (ITC) and molecular docking. The most relevant effect of QUER is manifested in the modification of the two-step thermal fingerprint of protein denaturation. Higher QUER concentrations result in a single-step denaturation thermogram, ascribed to the interplay between specific and nonspecific binding and enhancement of the solvent unfolding action. Analysis of ITC data indicate sequential binding of two molecules of QUER occurring spontaneously at different binding sites of BSA involving hydrophobic, electrostatic and hydrogen binding forces. Identification of QUER binding sites was possible through corroboration of DSC runs in the presence of site markers and molecular docking. Modeling of ligand-protein interaction confirmed the experimental data. On one hand, a neutral form of QUER binds in a nonplanar conformation to Sudlow's site I, a large hydrophobic cavity of subdomain IIA of BSA and decreases its thermal stability. On the other hand, a second molecule of QUER, the anionic form, is bound in planar conformation to Sudlow's site II, situated in the subdomain IIIA of the folded protein, and increases the thermal stability of the corresponding structural domain of the protein. PMID:27505141

  14. [Study on the interaction between fangchinoline and bovine serum albumin].

    PubMed

    Wu, Qiu-hua; Wang, Chun; Wang, Zhi; Ma, Jing-jun; Zang, Xiao-huan; Qin, Na-xin

    2007-12-01

    The binding reaction of fangchinoline with bovine serum albumin was studied at different temperatures by fluorescence quenching spectra, synchronous fluorescence spectra and ultra-violet spectra. It was shown that fangchinoline has a strong ability of quenching the fluorescence of BSA. The Stern-Volmer curve of the fluorescence quenching of BSA by fangchinoline indicated that the quenching mechanism of fangchinoline to BSA was a static quenching. According to the Förster theory of non-radiation energy transfer, the binding distances (r) at different temperature were 2.51 nm (27 degrees C), 2.72 nm (37 degrees C) and 2.89 nm (47 degrees C), respectively, while the binding constants (KA) were 1.05 x 10(5) L x mol(-1) (27 degrees C), 3.31x 10(5) L x mol(-1) (37 degrees C), and 7.24 x 10(5) L x mol(-1) (47 degrees C), respectively. The thermodynamic parameters showed that the interaction of fangchinoline and BSA was mainly driven by hydrophobic force. Synchronous spectrum was used to investigate the conformational changes of BSA. PMID:18330294

  15. [Isoelectric spectra of liver tissue and blood serum albumin for rabbits of different age].

    PubMed

    Sopkina, D A; Ostolovskiĭ, E M; Ivlev, V N

    1978-01-01

    The isoelectric spectrum of albumin isolated from the liver and blood serum of 30-, 45- and 90-day rabbits was studied. By the method of isoelectric focusing in the boron-borate buffer--mannitol system. It is shown that the liver albumin displays heterogeneity ans is separated into four-five fractions, with pJ 4.8-6.0. Age peculiarities are found for the isoelectric spectrum of this protein. The serum albumin spectrum for rabbits of the studied age groups is characterized by the presence of a homogeneous peak with pJ 5.59, 5.57 and 5.47 corresponding to 30, 45 and 90-day age, respectively. Identity of serum albumin and protein of some liver albumin spectrum components is established by analyzing the pattern of the isoelectric spectrum for a mixture of preparations of 90-day rabbit proteins under comparison. PMID:34911

  16. Effect of processing methods on colouration of human serum albumin preparations.

    PubMed

    McCann, Karl B; Vucica, Yvonne; Famulari, Sandy; Bertolini, Joseph

    2009-01-01

    Human serum albumin is a well tolerated therapeutic for the treatment of hypovolemia. Despite all commercial human albumin preparations being derived from plasma, these products can have a highly variable colour. Albumin samples derived from ethanol precipitation and chromatographic fractionation procedures were evaluated for bilirubin and biliverdin levels and by spectrophotometry. It was shown that albumin derived from a chromatographic process, which had a bilirubin:albumin ratio similar to that observed in plasma, had a vibrant yellow appearance. The albumin derived from ethanol precipitation had undetectable levels of bilirubin, and the amber colour of this product was attributed mainly to residual haem. The presence of bilirubin during pasteurisation led to oxidation to biliverdin, with a resultant colour change from yellow to yellow/green. Given that the antioxidant properties of bilirubin are well established, it is possible that bilirubin helps protect albumin from oxidation during the pasteurisation step. PMID:18948018

  17. Serum albumin analysis for type II diabetes detection using surface-enhanced Raman spectroscopy

    NASA Astrophysics Data System (ADS)

    Lin, Jinyong; Cao, Gang; Lin, Juqiang; Liu, Nenrong; Liao, Fadian; Ruan, Qiuyong; Wu, Shanshan; Huang, Zufang; Li, Ling; Chen, Rong

    2014-09-01

    Surface-enhanced Raman scattering (SERS) spectroscopy combined with membrane electrophoresis (ME) was firstly employed to detect albumin variation in type II diabetic development. Albumin was first purified from human serum by ME and then mixed with silver nanoparticles to perform SERS spectral analysis. SERS spectra were obtained from blood albumin samples of 20 diabetic patients and 19 healthy volunteers. Subtle but discernible changes in the acquired mean spectra of the two groups were observed. Tentative assignment of albumin SERS bands indicated specific structural changes of albumin molecule with diabetic development. Meanwhile, PCA-LDA diagnostic algorithms were employed to classify the two kinds of albumin SERS spectra, yielding the diagnostic sensitivity of 90% and specificity of 94.7%. The results from this exploratory study demonstrated that the EM-SERS method in combination with multivariate statistical analysis has great potential for the label-free detection of albumin variation for improving type II diabetes screening.

  18. Novel Transgenic Mouse Model for Studying Human Serum Albumin as a Biomarker of Carcinogenic Exposure.

    PubMed

    Sheng, Jonathan; Wang, Yi; Turesky, Robert J; Kluetzman, Kerri; Zhang, Qing-Yu; Ding, Xinxin

    2016-05-16

    Albumin is a commonly used serum protein for studying human exposure to xenobiotic compounds, including therapeutics and environmental pollutants. Often, the reactivity of albumin with xenobiotic compounds is studied ex vivo with human albumin or plasma/serum samples. Some studies have characterized the reactivity of albumin with chemicals in rodent models; however, differences between the orthologous peptide sequences of human and rodent albumins can result in the formation of different types of chemical-protein adducts with different interaction sites or peptide sequences. Our goal is to generate a human albumin transgenic mouse model that can be used to establish human protein biomarkers of exposure to hazardous xenobiotics for human risk assessment via animal studies. We have developed a human albumin transgenic mouse model and characterized the genotype and phenotype of the transgenic mice. The presence of the human albumin gene in the genome of the model mouse was confirmed by genomic PCR analysis, whereas liver-specific expression of the transgenic human albumin mRNA was validated by RT-PCR analysis. Further immunoblot and mass spectrometry analyses indicated that the transgenic human albumin protein is a full-length, mature protein, which is less abundant than the endogenous mouse albumin that coexists in the serum of the transgenic mouse. The transgenic protein was able to form ex vivo adducts with a genotoxic metabolite of 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine, a procarcinogenic heterocyclic aromatic amine formed in cooked meat. This novel human albumin transgenic mouse model will facilitate the development and validation of albumin-carcinogen adducts as biomarkers of xenobiotic exposure and/or toxicity in humans. PMID:27028147

  19. Sequence homology between RNAs encoding rat alpha-fetoprotein and rat serum albumin.

    PubMed Central

    Jagodzinski, L L; Sargent, T D; Yang, M; Glackin, C; Bonner, J

    1981-01-01

    We have determined the sequences of the recombinant DNA inserts of three bacterial plasmid cDNA clones containing most of the rat alpha a-fetoprotein mRNA. The resultant nucleotide sequence of alpha-fetoprotein was exhaustively compared to the nucleotide sequence of the mRNA encoding rat serum albumin. These two mRNAs have extensive homology (50%) throughout and the same intron locations. The amino acid sequence of rat alpha-fetoprotein has been deduced from the nucleotide sequence, and its comparison to rat serum albumin's amino acid sequence reveals a 34% homology. The regularly spaced positions of the cysteines found in serum albumin are conserved in rat alpha-fetoprotein, indicating that these two proteins may have a similar secondary folding structure. These homologies indicate that alpha-fetoprotein and serum albumin were derived by duplication of a common ancestral gene and constitute a gene family. PMID:6167988

  20. Binding and hydrolysis of soman by human serum albumin.

    PubMed

    Li, Bin; Nachon, Florian; Froment, Marie-Thérèse; Verdier, Laurent; Debouzy, Jean-Claude; Brasme, Bernardo; Gillon, Emilie; Schopfer, Lawrence M; Lockridge, Oksana; Masson, Patrick

    2008-02-01

    Human plasma and fatty acid free human albumin were incubated with soman at pH 8.0 and 25 degrees C. Four methods were used to monitor the reaction of albumin with soman: progressive inhibition of the aryl acylamidase activity of albumin, the release of fluoride ion from soman, 31P NMR, and mass spectrometry. Inhibition (phosphonylation) was slow with a bimolecular rate constant of 15 +/- 3 M(-1) min (-1). MALDI-TOF and tandem mass spectrometry of the soman-albumin adduct showed that albumin was phosphonylated on tyrosine 411. No secondary dealkylation of the adduct (aging) occurred. Covalent docking simulations and 31P NMR experiments showed that albumin has no enantiomeric preference for the four stereoisomers of soman. Spontaneous reactivation at pH 8.0 and 25 degrees C, measured as regaining of aryl acylamidase activity and decrease of covalent adduct (pinacolyl methylphosphonylated albumin) by NMR, occurred at a rate of 0.0044 h (-1), indicating that the adduct is quite stable ( t1/2 = 6.5 days). At pH 7.4 and 22 degrees C, the covalent soman-albumin adduct, measured by MALDI-TOF mass spectrometry, was more stable ( t1/2 = 20 days). Though the concentration of albumin in plasma is very high (about 0.6 mM), its reactivity with soman (phosphonylation and phosphotriesterase activity) is too slow to play a major role in detoxification of the highly toxic organophosphorus compound soman. Increasing the bimolecular rate constant of albumin for organophosphates is a protein engineering challenge that could lead to a new class of bioscavengers to be used against poisoning by nerve agents. Soman-albumin adducts detected by mass spectrometry could be useful for the diagnosis of soman exposure. PMID:18163544

  1. Influence of Millimeter Electromagnetic Waves on Fluorescence of Water-Saline Solutions of Human Serum Albumin

    NASA Astrophysics Data System (ADS)

    Vardevanyan, P. O.; Antonyan, A. P.; Shahinyan, M. A.; Mikaelyan, M. S.

    2016-07-01

    The effect of electromagnetic waves of the millimeter region on the conformation and fluorescence characteristics of human serum albumin was studied. It is shown that the irradiation of the albumin solution leads to an increase of the fluorescence intensity depending on the duration of irradiation. At an irradiation frequency of 48 GHz the fluorescence intensity of albumin hardly changes at all, while at 41.8 and 51.8 GHz it increases. It is also shown that when the irradiation frequency is 51.8 GHz, the intensity of the albumin solution fluorescence increases with increase of the irradiation time.

  2. Serum albumin coating of demineralized bone matrix results in stronger new bone formation.

    PubMed

    Horváthy, Dénes B; Vácz, Gabriella; Szabó, Tamás; Szigyártó, Imola C; Toró, Ildikó; Vámos, Boglárka; Hornyák, István; Renner, Károly; Klára, Tamás; Szabó, Bence T; Dobó-Nagy, Csaba; Doros, Attila; Lacza, Zsombor

    2016-01-01

    Blood serum fractions are hotly debated adjuvants in bone replacement therapies. In the present experiment, we coated demineralized bone matrices (DBM) with serum albumin and investigated stem cell attachment in vitro and bone formation in a rat calvaria defect model. In the in vitro experiments, we observed that significantly more cells adhere to the serum albumin coated DBMs at every time point. In vivo bone formation with albumin coated and uncoated DBM was monitored biweekly by computed tomography until 11 weeks postoperatively while empty defects served as controls. By the seventh week, the bone defect in the albumin group was almost completely closed (remaining defect 3.0 ± 2.3%), while uncoated DBM and unfilled control groups still had significant defects (uncoated: 40.2 ± 9.1%, control: 52.4 ± 8.9%). Higher density values were also observed in the albumin coated DBM group. In addition, the serum albumin enhanced group showed significantly higher volume of newly formed bone in the microCT analysis and produced significantly higher breaking force and stiffness compared to the uncoated grafts (peak breaking force: uncoated: 15.7 ± 4 N, albumin 46.1 ± 11 N). In conclusion, this investigation shows that implanting serum albumin coated DBM significantly reduces healing period in nonhealing defects and results in mechanically stronger bone. These results also support the idea that serum albumin coating provides a convenient milieu for stem cell function, and a much improved bone grafting success can be achieved without the use of exogenous stem cells. PMID:25677203

  3. Optimization of a colorimetric assay for glycosylated human serum albumin

    SciTech Connect

    Bohney, J.P.; Feldhoff, R.C.

    1986-05-01

    The thiobarbituric acid (TBA) assay has been used for several years to quantitate the amount of glucose which has been non-enzymatically linked to hemoglobin and other proteins. The ketoamine-protein adduct is converted to 5-hydroxymethylfurfural (HMF) by mild hydrolysis with oxalic acid. Reaction of HMF with TBA yields a colored product which has an absorbance maximum at 443 nm. Several modifications of the original procedure has been published, but none permit the unambiguous quantitation of glycosylated human serum albumin (glc-HSA). Problems relate to reagent preparation and stability, the time and temperature of hydrolysis, the choice of standards, and background color corrections. The authors have found that maximum color yield occurs after hydrolysis in an autoclave for 2 h. This increases the sensitivity 3-fold and cuts the assay time in half relative to hydrolysis for 4.5 h at 100/sup 0/C. A NaBH/sub 4/ reduction of a parallel protein sample must be performed to correct for variable background color associated with different sample sources and amounts. HMF can be used as a standard, however, corrections must be made for HMF degradation. Fructose is a better standard, but HMF formation from fructose is faster than formation from glc-HSA. This may result in an underestimate of percent glycosylation. The best standard appears to be glc-HSA prepared with (/sup 3/H)glucose. It appears that with proper controls and standards the TBA assay can be used to determine actual rather than relative percent glycosylation.

  4. Structural basis of transport of lysophospholipids by human serum albumin

    SciTech Connect

    Guo, Shihui; Shi, Xiaoli; Yang, Feng; Chen, Liqing; Meehan, Edward J.; Bian, Chuanbing; Huang, Mingdong

    2010-10-08

    Lysophospholipids play important roles in cellular signal transduction and are implicated in many biological processes, including tumorigenesis, angiogenesis, immunity, atherosclerosis, arteriosclerosis, cancer and neuronal survival. The intracellular transport of lysophospholipids is through FA (fatty acid)-binding protein. Lysophospholipids are also found in the extracellular space. However, the transport mechanism of lysophospholipids in the extracellular space is unknown. HSA (human serum albumin) is the most abundant carrier protein in blood plasma and plays an important role in determining the absorption, distribution, metabolism and excretion of drugs. In the present study, LPE (lysophosphatidylethanolamine) was used as the ligand to analyse the interaction of lysophospholipids with HSA by fluorescence quenching and crystallography. Fluorescence measurement showed that LPE binds to HSA with a K{sub d} (dissociation constant) of 5.6 {micro}M. The presence of FA (myristate) decreases this binding affinity (K{sub d} of 12.9 {micro}M). Moreover, we determined the crystal structure of HSA in complex with both myristate and LPE and showed that LPE binds at Sudlow site I located in subdomain IIA. LPE occupies two of the three subsites in Sudlow site I, with the LPE acyl chain occupying the hydrophobic bottom of Sudlow site I and the polar head group located at Sudlow site I entrance region pointing to the solvent. This orientation of LPE in HSA suggests that HSA is capable of accommodating other lysophospholipids and phospholipids. The study provides structural information on HSA-lysophospholipid interaction and may facilitate our understanding of the transport and distribution of lysophospholipids.

  5. Kinetics of Thermal Denaturation and Aggregation of Bovine Serum Albumin

    PubMed Central

    Borzova, Vera A.; Markossian, Kira A.; Chebotareva, Natalia A.; Kleymenov, Sergey Yu.; Poliansky, Nikolay B.; Muranov, Konstantin O.; Stein-Margolina, Vita A.; Shubin, Vladimir V.; Markov, Denis I.; Kurganov, Boris I.

    2016-01-01

    Thermal aggregation of bovine serum albumin (BSA) has been studied using dynamic light scattering, asymmetric flow field-flow fractionation and analytical ultracentrifugation. The studies were carried out at fixed temperatures (60°C, 65°C, 70°C and 80°C) in 0.1 M phosphate buffer, pH 7.0, at BSA concentration of 1 mg/ml. Thermal denaturation of the protein was studied by differential scanning calorimetry. Analysis of the experimental data shows that at 65°C the stage of protein unfolding and individual stages of protein aggregation are markedly separated in time. This circumstance allowed us to propose the following mechanism of thermal aggregation of BSA. Protein unfolding results in the formation of two forms of the non-native protein with different propensity to aggregation. One of the forms (highly reactive unfolded form, Uhr) is characterized by a high rate of aggregation. Aggregation of Uhr leads to the formation of primary aggregates with the hydrodynamic radius (Rh,1) of 10.3 nm. The second form (low reactive unfolded form, Ulr) participates in the aggregation process by its attachment to the primary aggregates produced by the Uhr form and possesses ability for self-aggregation with formation of stable small-sized aggregates (Ast). At complete exhaustion of Ulr, secondary aggregates with the hydrodynamic radius (Rh,2) of 12.8 nm are formed. At 60°C the rates of unfolding and aggregation are commensurate, at 70°C the rates of formation of the primary and secondary aggregates are commensurate, at 80°C the registration of the initial stages of aggregation is complicated by formation of large-sized aggregates. PMID:27101281

  6. A retrospective analysis of 25% human serum albumin supplementation in hypoalbuminemic dogs with septic peritonitis

    PubMed Central

    Horowitz, Farrah B.; Read, Robyn L.; Powell, Lisa L.

    2015-01-01

    This study describes the influence of 25% human serum albumin (HSA) supplementation on serum albumin level, total protein (TP), colloid osmotic pressure (COP), hospital stay, and survival in dogs with septic peritonitis. Records of 39 dogs with septic peritonitis were evaluated. In the HSA group, initial and post-transfusion TP, albumin, COP, and HSA dose were recorded. In the non-supplemented group, repeated values of TP, albumin, and COP were recorded over their hospitalization. Eighteen dogs survived (53.8% mortality). Repeat albumin values were higher in survivors (mean 23.9 g/L) and elevated repeat albumin values were associated with HSA supplementation. Repeat albumin and TP were higher in the HSA supplemented group (mean 24 g/L and 51.9 g/L, respectively) and their COP increased by 5.8 mmHg. Length of hospitalization was not affected. Twenty-five percent HSA increases albumin, TP, and COP in canine patients with septic peritonitis. Higher postoperative albumin levels are associated with survival. PMID:26028681

  7. The influence of fatty acids on theophylline binding to human serum albumin. Comparative fluorescence study

    NASA Astrophysics Data System (ADS)

    Maciążek-Jurczyk, M.; Sułkowska, A.; Bojko, B.; Równicka-Zubik, J.; Szkudlarek-Haśnik, A.; Zubik-Skupień, I.; Góra, A.; Dubas, M.; Korzonek-Szlacheta, I.; Wielkoszyński, T.; Żurawiński, W.; Sosada, K.

    2012-04-01

    Theophylline, popular diuretic, is used to treat asthma and bronchospasm. In blood it forms complexes with albumin, which is also the main transporter of fatty acids. The aim of the present study was to describe the influence of fatty acids (FA) on binding of theophylline (Th) to human serum albumin (HSA) in the high affinity binding sites. Binding parameters have been obtained on the basis of the fluorescence analysis. The data obtained for the complex of Th and natural human serum albumin (nHSA) obtained from blood of obese patients qualified for surgical removal of stomach was compared with our previous studies on the influence of FA on the complex of Th and commercially available defatted human serum albumin (dHSA).

  8. Exploring the binding mechanism of ondansetron hydrochloride to serum albumins: Spectroscopic approach

    NASA Astrophysics Data System (ADS)

    Sandhya, B.; Hegde, Ashwini H.; K. C., Ramesh; Seetharamappa, J.

    2012-02-01

    The mechanism of interaction of ondansetron hydrochloride (OND) to serum albumins [bovine serum albumin (BSA) and human serum albumin (HSA)] was studied for the first time employing fluorimetric, circular dichroism, FTIR and UV-vis absorption techniques under the simulated physiological conditions. Fluorimetric results were utilized to investigate the binding and conformational characteristics of protein upon interaction with varying concentrations of the drug. Higher binding constant values revealed the strong interaction between the drug and protein while the number of binding sites close to unity indicated single class of binding site for OND in protein. Thermodynamic results revealed that both hydrogen bond and hydrophobic interactions played a major role in stabilizing drug-protein complex. Site marker competitive experiments indicated that the OND bound to albumins at subdomin II A (Sudlow's site I). Further, the binding distance between OND and serum albumin was calculated based on the Förster's theory of non-radioactive energy transfer and found to be 2.30 and 3.41 nm, respectively for OND-BSA and OND-HSA. The circular dichroism data revealed that the presence of OND decreased the α-helix content of serum albumins. 3D-fluorescence results also indicated the conformational changes in protein upon interaction with OND. Further, the effects of some cations have been investigated in the interaction of drug to protein.

  9. Exploring the binding mechanism of ondansetron hydrochloride to serum albumins: spectroscopic approach.

    PubMed

    B, Sandhya; Hegde, Ashwini H; K C, Ramesh; J, Seetharamappa

    2012-02-01

    The mechanism of interaction of ondansetron hydrochloride (OND) to serum albumins [bovine serum albumin (BSA) and human serum albumin (HSA)] was studied for the first time employing fluorimetric, circular dichroism, FTIR and UV-vis absorption techniques under the simulated physiological conditions. Fluorimetric results were utilized to investigate the binding and conformational characteristics of protein upon interaction with varying concentrations of the drug. Higher binding constant values revealed the strong interaction between the drug and protein while the number of binding sites close to unity indicated single class of binding site for OND in protein. Thermodynamic results revealed that both hydrogen bond and hydrophobic interactions played a major role in stabilizing drug-protein complex. Site marker competitive experiments indicated that the OND bound to albumins at subdomin II A (Sudlow's site I). Further, the binding distance between OND and serum albumin was calculated based on the Förster's theory of non-radioactive energy transfer and found to be 2.30 and 3.41 nm, respectively for OND-BSA and OND-HSA. The circular dichroism data revealed that the presence of OND decreased the α-helix content of serum albumins. 3D-fluorescence results also indicated the conformational changes in protein upon interaction with OND. Further, the effects of some cations have been investigated in the interaction of drug to protein. PMID:22112579

  10. Glass transitions in aqueous solutions of protein (bovine serum albumin).

    PubMed

    Shinyashiki, Naoki; Yamamoto, Wataru; Yokoyama, Ayame; Yoshinari, Takeo; Yagihara, Shin; Kita, Rio; Ngai, K L; Capaccioli, Simone

    2009-10-29

    Measurements by adiabatic calorimetry of heat capacities and enthalpy relaxation rates of a 20% (w/w) aqueous solution of bovine serum albumin (BSA) by Kawai, Suzuki, and Oguni [Biophys. J. 2006, 90, 3732] have found several enthalpy relaxations at long times indicating different processes undergoing glass transitions. In a quenched sample, one enthalpy relaxation at around 110 K and another over a wide temperature range (120-190 K) were observed. In a sample annealed at 200-240 K after quenching, three separated enthalpy relaxations at 110, 135, and above 180 K were observed. Dynamics of processes probed by adiabatic calorimetric data are limited to long times on the order of 10(3) s. A fuller understanding of the processes can be gained by probing the dynamics over a wider time/frequency range. Toward this goal, we performed broadband dielectric measurements of BSA-water mixtures at various BSA concentrations over a wide frequency range of thirteen decades from 2 mHz to 1.8 GHz at temperatures from 80 to 270 K. Three relevant relaxation processes were detected. For relaxation times equal to 100 s, the three processes are centered approximately at 110, 135, and 200 K, in good agreement with those observed by adiabatic calorimetry. We have made the following interpretation of the molecular origins of the three processes. The fastest relaxation process having relaxation time of 100 or 1000 s at ca. 110 K is due to the secondary relaxation of uncrystallized water (UCW) in the hydration shell. The intermediate relaxation process with 100 s relaxation time at ca. 135 K is due to ice. The slowest relaxation process having relaxation time of 100 s at ca. 200 K is interpreted to originate from local chain conformation fluctuations of protein slaved by water. Experimental evidence supporting these interpretations include the change of temperature dependence of the relaxation time of the UCW at approximately T(gBSA) approximately = 200 K, the glass transition temperature of

  11. Spectroscopic characterization of effective components anthraquinones in Chinese medicinal herbs binding with serum albumins

    NASA Astrophysics Data System (ADS)

    Bi, Shuyun; Song, Daqian; Kan, Yuhe; Xu, Dong; Tian, Yuan; Zhou, Xin; Zhang, Hanqi

    2005-11-01

    The interactions of serum albumins such as human serum albumin (HSA) and bovine serum albumin (BSA) with emodin, rhein, aloe-emodin and aloin were assessed employing fluorescence quenching and absorption spectroscopic techniques. The results obtained revealed that there are relatively strong binding affinity for the four anthraquinones with HSA and BSA and the binding constants for the interactions of anthraquinones with HSA or BSA at 20 °C were obtained. Anthraquinone-albumin interactions were studied at different temperatures and in the presence of some metal ions. And the competition binding of anthraquinones with serum albumins was also discussed. The Stern-Volmer curves suggested that the quenching occurring in the reactions was the static quenching process. The binding distances and transfer efficiencies for each binding reactions were calculated according to the Föster theory of non-radiation energy transfer. Using thermodynamic equations, the main action forces of these reactions were also obtained. The reasons of the different binding affinities for different anthraquinone-albumin reactions were probed from the point of view of molecular structures.

  12. Oxidative changes in the blood and serum albumin differentiate rats with monoarthritis and polyarthritis.

    PubMed

    Bracht, Adelar; Silveira, Sandra Silva; Castro-Ghizoni, Cristiane Vizioli; Sá-Nakanishi, Anacharis Babeto; Oliveira, Márcia Rosângela Neves; Bersani-Amado, Ciomar Aparecida; Peralta, Rosane Marina; Comar, Jurandir Fernando

    2016-01-01

    Adjuvant arthritis in rats, as rheumatoid arthritis in humans, may be of greater or lesser severity, namely polyarthritis and monoarthritis, respectively. The present study was planned to evaluate the oxidative changes in the blood and specifically in the serum albumin of rats with adjuvant-induced mono- and poly-arthritis. Total antioxidant capacity, thiols, carbonyl groups, albumin, uric acid and ascorbic acid were measured in the total serum. The specific oxidative status of albumin was also measured after separation by affinity chromatography. All serum oxidative parameters were close to normal in monoarthritic rats with the exception of the ascorbic acid concentration, which was 23 % lower, and albumin carbonyl groups, which were 64 % higher. Many modifications were found in polyarthritic rats, specially the ascorbic acid concentration (35 % lower) and albumin carbonyl groups (102 % higher). The results revealed that the levels of ascorbic acid in the serum and carbonyl groups in the albumin molecule can be regarded as indicators of the severity of arthritis since they were modified by both monoarthritis and polyarthritis, but to different degrees. PMID:26835218

  13. Complexation of amphotericin B and curcumin with serum albumins: solubility and effect on erythrocyte membrane damage

    PubMed Central

    Kudva, Avinash K; Manoj, MN; Swamy, Bale M; Ramadoss, Candadai S

    2011-01-01

    Amphotericin and curcumin are known to form complexes with albumins individually. In-silico analysis shows that amphotericin B and curcumin have separate binding regions on human serum albumin and bovine serum albumin. The complex formed with albumin in the presence of both amphotericin and curcumin is water soluble, and it retains antifungal activity. Interestingly, it was found that the presence of curcumin in the complex significantly delayed the red cell lysis by amphotericin B, indicating the possibility of moderating the toxic side effects of the drug using curcumin. Furthermore, since the presumed ternary complex is stable and water soluble, its potential use in the treatment of visceral leishmaniasis (kala azar) and systemic fungal infections needs to be evaluated.

  14. Serum albumin binding of structurally diverse neutral organic compounds: data and models.

    PubMed

    Endo, Satoshi; Goss, Kai-Uwe

    2011-12-19

    Binding to serum albumin has a strong influence on freely dissolved, unbound concentrations of chemicals in vivo and in vitro. For neutral organic solutes, previous studies have suggested a log-log correlation between the albumin-water partition coefficient and the octanol-water partition coefficient (K(ow)) and postulated highly nonspecific binding that is mechanistically analogous to dissolution into solvents. These relationships and concepts were further explored in this study. Bovine serum albumin (BSA)-water partition coefficients (K(BSA/w)) were measured for 83 structurally diverse neutral organic chemicals in consistent experimental conditions. The correlation between log K(BSA/w) and log K(ow) was moderate, with R(2) = 0.76 and SD = 0.43. The log K(BSA/w) of low-polarity compounds including a series of chlorobenzenes and polycyclic aromatic hydrocarbons increased with log K(ow) linearly up to log K(ow) = 4-5, but then the linear relationship apparently broke off, and the increase became gradual. The fitting of polyparameter linear free energy relationship models with five solute descriptors was just comparable to that of the log K(ow) model (R(2) = 0.78-0.79, SD = 0.41-0.42); the relatively high SD obtained suggests that solvent dissolution models are not capable of modeling albumin binding accurately. A size limitation of the binding site(s) of albumin is suggested as a possible reason for the high SD. An equilibrium distribution model indicates that serum albumin generally has high contributions to the binding in the serum of polar compounds and relatively small low-polarity compounds, whereas albumin binding for large low-polarity compounds is outcompeted by the strong partitioning into lipids due to low relative affinity of albumin for these compounds. PMID:22070391

  15. Experimental and theoretical investigation on the interaction between cyclovirobuxine D and human serum albumin

    NASA Astrophysics Data System (ADS)

    Yue, Yuanyuan; Liu, Ren; Liu, Jianming; Dong, Qiao; Fan, Jing

    2014-07-01

    Cyclovirobuxine D is an active compound extracted from the plant Buxux microphylla, and widely available as medications; however, its abuse may casts potential detrimental effects on human health. By using multispectroscopic techniques and molecular modeling, the interaction of cyclovirobuxine D with human serum albumin was investigated. The fluorescence results manifested that static type was the operative mechanism for the interaction with human serum albumin. The structural investigation of the complexed HSA through CD, three-dimensional, FT-IR and synchronous fluorescence shown the polypeptide chain of HSA partially destabilizing. Docking studies revealed the molecule to be bound in the subdomain IIA. Finally, we investigated the distance between the bound ligand and Trp-214 of human serum albumin.

  16. Unexpected Normal Colloid Osmotic Pressure in Clinical States with Low Serum Albumin

    PubMed Central

    Michelis, Regina; Sela, Shifra; Zeitun, Teuta; Geron, Ronit; Kristal, Batya

    2016-01-01

    Background In clinical states associated with systemic oxidative stress (OS) and inflammation such as chronic kidney disease (CKD), oxidative modifications of serum albumin impair its quantification, resulting in apparent hypoalbuminemia. As the maintenance of oncotic pressure/colloid osmotic pressure (COP) is a major function of albumin, this study examined the impact of albumin oxidation on COP, both in-vivo and in-vitro. Methods Patients with proteinuria and patients on chronic hemodialysis (HD) with systemic inflammation and OS were enrolled. Blood samples were collected from 134 subjects: 32 healthy controls (HC), proteinuric patients with high (n = 17) and low (n = 31) systemic inflammation and from 54 patients on chronic hemodialysis (HD) with the highest levels of OS and inflammation. Results In-vitro oxidized albumin showed significantly higher COP values than non-oxidized albumin at identical albumin levels. In vivo, in hypoalbuminemic HD patients with the highest OS and inflammation, COP values were also higher than expected for the low albumin levels. The contribution to COP by other prevalent plasma proteins, such as fibrinogen and immunoglobulins was negligible. We imply that the calculation of COP based on albumin levels should be revisited in face of OS and inflammation. Hence, in hypoalbuminemic proteinuric patients with systemic OS and inflammation the assumption of low COP should be verified by its measurements. PMID:27453993

  17. Alteration of human serum albumin tertiary structure induced by glycation. Spectroscopic study.

    PubMed

    Szkudlarek, A; Maciążek-Jurczyk, M; Chudzik, M; Równicka-Zubik, J; Sułkowska, A

    2016-01-15

    The modification of human serum albumin (HSA) structure by non-enzymatic glycation is one of the underlying factors that contribute to the development of complications of diabetes and neurodegenerative diseases. The aim of the present work was to estimate how glycation of HSA altered its tertiary structure. Changes of albumin conformation were investigated by comparison of glycated (gHSA) and non-glycated human serum albumin (HSA) absorption spectra, red edge excitation shift (REES) and synchronous spectra. Effect of glycation on human serum albumin tertiary structure was also investigated by (1)H NMR spectroscopy. Formation of gHSA Advanced Glycation End-products (AGEs) caused absorption of UV-VIS light between 310 nm and 400 nm while for non-glycated HSA in this region no absorbance has been registered. Analysis of red edge excitation shift effect allowed for observation of structural changes of gHSA in the hydrophobic pocket containing the tryptophanyl residue. Moreover changes in the microenvironment of tryptophanyl and tyrosyl residues brought about AGEs on the basis of synchronous fluorescence spectroscopy have been confirmed. The influence of glycation process on serum albumin binding to 5-dimethylaminonaphthalene-1-sulfonamide (DNSA), 2-(p-toluidino) naphthalene-6-sulfonic acid (TNS), has been studied. Fluorescence analysis showed that environment of both binding site I and II is modified by galactose glycation. PMID:26433342

  18. Alteration of human serum albumin tertiary structure induced by glycation. Spectroscopic study

    NASA Astrophysics Data System (ADS)

    Szkudlarek, A.; Maciążek-Jurczyk, M.; Chudzik, M.; Równicka-Zubik, J.; Sułkowska, A.

    2016-01-01

    The modification of human serum albumin (HSA) structure by non-enzymatic glycation is one of the underlying factors that contribute to the development of complications of diabetes and neurodegenerative diseases. The aim of the present work was to estimate how glycation of HSA altered its tertiary structure. Changes of albumin conformation were investigated by comparison of glycated (gHSA) and non-glycated human serum albumin (HSA) absorption spectra, red edge excitation shift (REES) and synchronous spectra. Effect of glycation on human serum albumin tertiary structure was also investigated by 1H NMR spectroscopy. Formation of gHSA Advanced Glycation End-products (AGEs) caused absorption of UV-VIS light between 310 nm and 400 nm while for non-glycated HSA in this region no absorbance has been registered. Analysis of red edge excitation shift effect allowed for observation of structural changes of gHSA in the hydrophobic pocket containing the tryptophanyl residue. Moreover changes in the microenvironment of tryptophanyl and tyrosyl residues brought about AGEs on the basis of synchronous fluorescence spectroscopy have been confirmed. The influence of glycation process on serum albumin binding to 5-dimethylaminonaphthalene-1-sulfonamide (DNSA), 2-(p-toluidino) naphthalene-6-sulfonic acid (TNS), has been studied. Fluorescence analysis showed that environment of both binding site I and II is modified by galactose glycation.

  19. A novel biosensor for bovine serum albumin based on fluorescent self-assembled sandwich bilayers.

    PubMed

    Sun, Xiangying; Liu, Bin; He, Fei

    2009-01-01

    Fluorescent dyes butyl rhodamine B were assembled via a DL-cystenine intermediate onto quartz wafers whose surface had first adsorbed gold nanoparticles. Hence self-assembled sandwich bilayers with nanocomposite structure were constructed which can be used as a biosensor for bovine serum albumin. The biosensor-based self-assembled monolayers (SAMs) are regenerable and have high sensitivity, five orders of magnitude higher than that of bulk solution phase sensing. The effects of existing forms of dyes on the fluorescence spectra of bilayers in the presence of bovine serum albumin were investigated. PMID:18785615

  20. Crystals of Human Serum Albumin for Use in Genetic Engineering and Rational Drug Design

    NASA Technical Reports Server (NTRS)

    Carter, Daniel C. (Inventor)

    1994-01-01

    This invention pertains to crystals of serum albumin and processes for growing them. The purpose of the invention is to provide crystals of serum albumin which can be studied to determine binding sites for drugs. Form 2 crystals grow in the monoclinic space P2(sub 1), and possesses the following unit cell constraints: a = 58.9 +/- 7, b = 88.3 +/- 7, c = 60.7 +/- 7, Beta = 101.0 +/- 2 degrees. One advantage of the invention is that it will allow rational drug design

  1. Induced Long-Range Attractive Potentials of Human Serum Albumin by Ligand Binding

    SciTech Connect

    Sato, Takaaki; Komatsu, Teruyuki; Nakagawa, Akito; Tsuchida, Eishun

    2007-05-18

    Small-angle x-ray scattering and dielectric spectroscopy investigation on the solutions of recombinant human serum albumin and its heme hybrid revealed that heme incorporation induces a specific long-range attractive potential between protein molecules. This is evidenced by the enhanced forward intensity upon heme binding, despite no hindrance to rotatory Brownian motion, unbiased colloid osmotic pressure, and discontiguous nearest-neighbor distance, confirming monodispersity of the proteins. The heme-induced potential may play a trigger role in recognition of the ligand-filled human serum albumins in the circulatory system.

  2. Competitive binding of phenylbutazone and colchicine to serum albumin in multidrug therapy: A spectroscopic study

    NASA Astrophysics Data System (ADS)

    Sułkowska, A.; Maciążek-Jurczyk, M.; Bojko, B.; Równicka, J.; Zubik-Skupień, I.; Temba, E.; Pentak, D.; Sułkowski, W. W.

    2008-06-01

    The binding sites for phenylbutazone and colchicine were identified in tertiary structure of bovine and human serum albumin with the use of spectrofluorescence analysis. It was found that phenylbutazone has two binding sites in both sera albumins (HSA and BSA), while colchicine has one binding site in BSA as well as in HSA. The comparison of the quenching effect of BSA and HSA fluorescence by phenylbutazone and colchicine allows us to identify subdomain IIA in protein as the binding site for these two drugs. In this subdomain tryptophan 214 is located. The participation of tyrosyl and tryptophanyl residues of protein was also estimated in the drug-albumin complex. The comparison of quenching of fluorescence of HSA and BSA excited at 280 nm with that at 295 nm allowed us to state that the participation of tyrosyl residues of albumin in the phenylbutazone-serum albumin interaction is significant. The analysis of quenching of fluorescence of BSA in the binary and ternary systems showed that phenylbutazone does not affect the complex formed between colchicine and BSA. Similarly, colchicine has no effect on the Phe-BSA complex. However marked differences were observed for the complex with HSA. On the basis of Ka and KQ values it was concluded that colchicine may probably cause displacement of phenylbutazone from its complex with serum albumin (SA). Static and dynamic quenching for the binary and ternary systems is also discussed. The competition of phenylbutazone and colchicine in binding to serum albumin should be taken into account in the multi-drug therapy.

  3. A spectroscopic study of phenylbutazone and aspirin bound to serum albumin in rheumatoid diseases.

    PubMed

    Maciążek-Jurczyk, M; Sułkowska, A; Bojko, B; Równicka-Zubik, J; Sułkowski, W W

    2011-11-01

    Interaction of phenylbutazone (PBZ) and aspirin (ASA), two drugs recommended in rheumatoid diseases (RDs), when binding to human (HSA) and bovine (BSA) serum albumins, has been studied by quenching of fluorescence and proton nuclear magnetic resonance ((1)HNMR) techniques. On the basis of spectrofluorescence measurements high affinity binding sites of PBZ and ASA on albumin as well as their interaction within the binding sites were described. A low affinity binding site has been studied by proton nuclear magnetic resonance spectroscopy. Using fluorescence spectroscopy the location of binding site in serum albumin (SA) for PBZ and ASA was found. Association constants K(a) were determined for binary (i.e. PBZ-SA and ASA-SA) and ternary complexes (i.e. PBZ-[ASA]-SA and ASA-[PBZ]-SA). PBZ and ASA change the affinity of each other to the binding site in serum albumin (SA). The presence of ASA causes the increase of association constants K(aI) of PBZ-SA complex. Similarly, PBZ influences K(aI) of ASA-SA complex. This phenomenon shows that the strength of binding and the stability of the complexes increase in the presence of the second drug. The decrease of K(aII) values suggests that the competition between PBZ and ASA in binding to serum albumin in the second class of binding sites occurs. The analysis of (1)HNMR spectral parameters i.e. changes of chemical shifts and relaxation times of the drug indicate that the presence of ASA weakens the interaction of PBZ with albumin. Similarly PBZ weakens the interaction of ASA with albumin. This conclusion points to the necessity of using a monitoring therapy owning to the possible increase of uncontrolled toxic effects. PMID:21856214

  4. A spectroscopic study of phenylbutazone and aspirin bound to serum albumin in rheumatoid diseases

    NASA Astrophysics Data System (ADS)

    Maciążek-Jurczyk, M.; Sułkowska, A.; Bojko, B.; Równicka-Zubik, J.; Sułkowski, W. W.

    2011-11-01

    Interaction of phenylbutazone (PBZ) and aspirin (ASA), two drugs recommended in rheumatoid diseases (RDs), when binding to human (HSA) and bovine (BSA) serum albumins, has been studied by quenching of fluorescence and proton nuclear magnetic resonance ( 1HNMR) techniques. On the basis of spectrofluorescence measurements high affinity binding sites of PBZ and ASA on albumin as well as their interaction within the binding sites were described. A low affinity binding site has been studied by proton nuclear magnetic resonance spectroscopy. Using fluorescence spectroscopy the location of binding site in serum albumin (SA) for PBZ and ASA was found. Association constants Ka were determined for binary (i.e. PBZ-SA and ASA-SA) and ternary complexes (i.e. PBZ-[ASA]-SA and ASA-[PBZ]-SA). PBZ and ASA change the affinity of each other to the binding site in serum albumin (SA). The presence of ASA causes the increase of association constants KaI of PBZ-SA complex. Similarly, PBZ influences KaI of ASA-SA complex. This phenomenon shows that the strength of binding and the stability of the complexes increase in the presence of the second drug. The decrease of KaII values suggests that the competition between PBZ and ASA in binding to serum albumin in the second class of binding sites occurs. The analysis of 1HNMR spectral parameters i.e. changes of chemical shifts and relaxation times of the drug indicate that the presence of ASA weakens the interaction of PBZ with albumin. Similarly PBZ weakens the interaction of ASA with albumin. This conclusion points to the necessity of using a monitoring therapy owning to the possible increase of uncontrolled toxic effects.

  5. Effects of non-enzymatic glycation in human serum albumin. Spectroscopic analysis.

    PubMed

    Szkudlarek, A; Sułkowska, A; Maciążek-Jurczyk, M; Chudzik, M; Równicka-Zubik, J

    2016-01-01

    Human serum albumin (HSA), transporting protein, is exposed during its life to numerous factors that cause its functions become impaired. One of the basic factors --glycation of HSA--occurs in diabetes and may affect HSA-drug binding. Accumulation of advanced glycation end-products (AGEs) leads to diseases e.g. diabetic and non-diabetic cardiovascular diseases, Alzheimer disease, renal disfunction and in normal aging. The aim of the present work was to estimate how non-enzymatic glycation of human serum albumin altered its tertiary structure using fluorescence technique. We compared glycated human serum albumin by glucose (gHSA(GLC)) with HSA glycated by fructose (gHSA(FRC)). We focused on presenting the differences between gHSA(FRC) and nonglycated (HSA) albumin used acrylamide (Ac), potassium iodide (KI) and 2-(p-toluidino)naphthalene-6-sulfonic acid (TNS). Changes of the microenvironment around the tryptophan residue (Trp-214) of non-glycated and glycated proteins was investigated by the red-edge excitation shift method. Effect of glycation on ligand binding was examined by the binding of phenylbutazone (PHB) and ketoprofen (KP), which a primary high affinity binding site in serum albumin is subdomain IIA and IIIA, respectively. At an excitation and an emission wavelength of λex 335nm and λem 420nm, respectively the increase of fluorescence intensity and the blue-shift of maximum fluorescence was observed. It indicates that the glycation products decreases the polarity microenvironment around the fluorophores. Analysis of red-edge excitation shift method showed that the red-shift for gHSA(FRC) is higher than for HSA. Non-enzymatic glycation also caused, that the Trp residue of gHSA(FRC) becomes less accessible for the negatively charged quencher (I(-)), KSV value is smaller for gHSA(FRC) than for HSA. TNS fluorescent measurement demonstrated the decrease of hydrophobicity in the glycated albumin. KSV constants for gHSA-PHB systems are higher than for the

  6. Effects of non-enzymatic glycation in human serum albumin. Spectroscopic analysis

    NASA Astrophysics Data System (ADS)

    Szkudlarek, A.; Sułkowska, A.; Maciążek-Jurczyk, M.; Chudzik, M.; Równicka-Zubik, J.

    2016-01-01

    Human serum albumin (HSA), transporting protein, is exposed during its life to numerous factors that cause its functions become impaired. One of the basic factors - glycation of HSA - occurs in diabetes and may affect HSA-drug binding. Accumulation of advanced glycation end-products (AGEs) leads to diseases e.g. diabetic and non-diabetic cardiovascular diseases, Alzheimer disease, renal disfunction and in normal aging. The aim of the present work was to estimate how non-enzymatic glycation of human serum albumin altered its tertiary structure using fluorescence technique. We compared glycated human serum albumin by glucose (gHSAGLC) with HSA glycated by fructose (gHSAFRC). We focused on presenting the differences between gHSAFRC and nonglycated (HSA) albumin used acrylamide (Ac), potassium iodide (KI) and 2-(p-toluidino)naphthalene-6-sulfonic acid (TNS). Changes of the microenvironment around the tryptophan residue (Trp-214) of non-glycated and glycated proteins was investigated by the red-edge excitation shift method. Effect of glycation on ligand binding was examined by the binding of phenylbutazone (PHB) and ketoprofen (KP), which a primary high affinity binding site in serum albumin is subdomain IIA and IIIA, respectively. At an excitation and an emission wavelength of λex 335 nm and λem 420 nm, respectively the increase of fluorescence intensity and the blue-shift of maximum fluorescence was observed. It indicates that the glycation products decreases the polarity microenvironment around the fluorophores. Analysis of red-edge excitation shift method showed that the red-shift for gHSAFRC is higher than for HSA. Non-enzymatic glycation also caused, that the Trp residue of gHSAFRC becomes less accessible for the negatively charged quencher (I-), KSV value is smaller for gHSAFRC than for HSA. TNS fluorescent measurement demonstrated the decrease of hydrophobicity in the glycated albumin. KSV constants for gHSA-PHB systems are higher than for the unmodified serum

  7. Effect of baseline serum albumin concentration on outcome of resuscitation with albumin or saline in patients in intensive care units: analysis of data from the saline versus albumin fluid evaluation (SAFE) study

    PubMed Central

    Study Investigators, SAFE

    2006-01-01

    Objective To determine whether outcomes of resuscitation with albumin or saline in the intensive care unit depend on patients' baseline serum albumin concentration. Design Analysis of data from a double blind, randomised controlled trial. Setting Intensive care units of 16 hospitals in Australia and New Zealand. Participants 6045 participants in the saline versus albumin fluid evaluation (SAFE) study. Interventions Fluid resuscitation with 4% albumin or saline in patients with a baseline serum albumin concentration of 25 g/l or less or more than 25 g/l. Main outcome measures Primary outcome was all cause mortality at 28 days. Secondary outcomes were length of stay in the intensive care unit, length of stay in hospital, duration of renal replacement therapy, and duration of mechanical ventilation. Main results The odds ratios for death for albumin compared with saline for patients with a baseline serum albumin concentration of 25 g/l or less and more than 25 g/l were 0.87 and 1.09, respectively (ratio of odds ratios 0.80, 95% confidence interval 0.63 to 1.02); P=0.08 for heterogeneity. No significant interaction was found between baseline serum albumin concentration as a continuous variable and the effect of albumin and saline on mortality. No consistent interaction was found between baseline serum albumin concentration and treatment effects on length of stay in the intensive care unit, length of hospital stay, duration of renal replacement therapy, or duration of mechanical ventilation. Conclusion The outcomes of resuscitation with albumin and saline are similar irrespective of patients' baseline serum albumin concentration. Trial registration ISRCTN76588266. PMID:17040925

  8. Association between Serum Albumin Concentration and Ketosis Risk in Hospitalized Individuals with Type 2 Diabetes Mellitus

    PubMed Central

    2016-01-01

    Objective. This study examined the association between serum albumin concentration and ketosis risk in hospitalized individuals with type 2 diabetes mellitus (T2DM). Methods. A retrospective cross-sectional study was conducted at a medical center in Taiwan. Inclusion criteria were endocrinology ward inpatients exceeding 21 years of age, with preexisting diagnosis of T2DM, and blood glucose above 13.9 millimoles per liter (mmol/L) at admission. Individuals without measurement of serum albumin, urine ketone, or hemoglobin A1C, or harboring active infection, myocardial infarction, cerebrovascular event, cirrhosis, malignancy, or overt proteinuria were excluded. Using serum albumin concentration below 3.0 grams per deciliter to define hypoalbuminemia, 151 hypoalbuminemic cases and 104 normoalbuminemic controls were enrolled. The presence of ketones in urine established ketosis. Results. The prevalence of ketonuria was 48% in hypoalbuminemic subjects compared to 30% in normoalbuminemic controls (odds ratio (OR): 2.15; 95% confidence interval (CI): 1.26–3.57; P = 0.004). Moreover, among the 156 subjects with serum beta-hydroxybutyrate measurement in addition to urine ketone, 33% of the hypoalbuminemic individuals had ketonemia exceeding 3 mmol/L compared to 19% of those with normoalbuminemia (OR: 2.12, 95% CI: 0.99–4.48, P = 0.051). Conclusions. Serum albumin concentration is inversely associated with ketosis risk in hospitalized individuals with T2DM. PMID:27504458

  9. Serum Albumin Stimulates Protein Kinase G-dependent Microneme Secretion in Toxoplasma gondii.

    PubMed

    Brown, Kevin M; Lourido, Sebastian; Sibley, L David

    2016-04-29

    Microneme secretion is essential for motility, invasion, and egress in apicomplexan parasites. Although previous studies indicate that Ca(2+) and cGMP control microneme secretion, little is known about how these pathways are naturally activated. Here we have developed genetically encoded indicators for Ca(2+) and microneme secretion to better define the signaling pathways that regulate these processes in Toxoplasma gondii We found that microneme secretion was triggered in vitro by exposure to a single host protein, serum albumin. The natural agonist serum albumin induced microneme secretion in a protein kinase G-dependent manner that correlated with increased cGMP levels. Surprisingly, serum albumin acted independently of elevated Ca(2+) and yet it was augmented by artificial agonists that raise Ca(2+), such as ethanol. Furthermore, although ethanol elevated intracellular Ca(2+), it alone was unable to trigger secretion without the presence of serum or serum albumin. This dichotomy was recapitulated by zaprinast, a phosphodiesterase inhibitor that elevated cGMP and separately increased Ca(2+) in a protein kinase G-independent manner leading to microneme secretion. Taken together, these findings reveal that microneme secretion is centrally controlled by protein kinase G and that this pathway is further augmented by elevation of intracellular Ca(2.) PMID:26933037

  10. Complexation of serum albumins and triton X-100: Quenching of tryptophan fluorescence and analysis of the rotational diffusion of complexes

    NASA Astrophysics Data System (ADS)

    Vlasova, I. M.; Vlasov, A. A.; Saletskii, A. M.

    2016-07-01

    The polarized and nonpolarized fluorescence of bovine serum albumin and human serum albumin in Triton X-100 solutions is studied at different pH values. Analysis of the constants of fluorescence quenching for BSA and HSA after adding Triton X-100 and the hydrodynamic radii of BSA/HSA-detergent complexes show that the most effective complexation between both serum albumins and Triton X-100 occurs at pH 5.0, which lies near the isoelectric points of the proteins. Complexation between albumin and Triton X-100 affects the fluorescence of the Trp-214 residing in the hydrophobic pockets of both BSA and HSA.

  11. Identification of albumin-bound fatty acids as the major factor in serum-induced lipid accumulation by cultured cells.

    PubMed

    Mackenzie, C G; Mackenzie, J B; Reiss, O K; Wisneski, J A

    1970-11-01

    Factors responsible for the high lipogenic activity of rabbit serum were investigated using an assay procedure based on the gravimetric determination of the 24 hr increase in cell lipid. Cellular synthesis of fatty acids was inhibited by the presence of serum in the assay medium. Approximately 90% of the increase in cell lipid produced by serum fractions was due to triglyceride accumulation. Fractionation of rabbit serum by precipitation with ammonium sulfate or by ultracentrifugation in high density medium, both indicated that three-quarters of its lipogenic activity was associated with albumin. The lipoproteins prepared by ultracentrifugation also exhibited about one-half the activity of whole serum. The lipogenic activity of albumin was confirmed by the high potency of the albumin isolated in a nearly pure form from proteins of d>1.21 by precipitation with trichloroacetic acid and extraction with ethanol. As judged from chemical and isotopic analysis, neither the lipid content nor the lipid composition of the albumin was appreciably altered during its isolation. Of the albumin-bound lipids, only the free fatty acids, as determined by DEAE column chromatography, were present in an amount sufficient to account for the observed increase in cell triglycerides. In control experiments with horse serum of low lipogenic activity, the proteins of d>1.21 also possessed low activity in conjunction with a low content of free fatty acid. However, the albumin isolated from the latter preparation exhibited the high lipogenic activity of rabbit serum albumin. Chemical and isotopic analysis of the recovered horse serum albumin revealed that its free fatty acid content was the same as that of rabbit serum albumin. These results indicated that the isolation of horse serum albumin was attended by a substantial increase in its free fatty acid content. When the rabbit serum and horse serum content of media were adjusted to provide equivalent concentrations of albumin-bound fatty

  12. In vivo photoacoustic molecular imaging of the distribution of serum albumin in rat burned skin.

    PubMed

    Tsunoi, Yasuyuki; Sato, Shunichi; Kawauchi, Satoko; Ashida, Hiroshi; Saitoh, Daizoh; Terakawa, Mitsuhiro

    2013-11-01

    Information on the state of edema is important for treating severe burn injuries, but a method for noninvasive real-time quantitative diagnosis of edema is not available. Thus, in vivo spatiotemporal characteristics of serum albumin, which would behave differently from water in burned tissue, are not fully understood. In this study, we used a photoacoustic (PA) imaging method to visualize depth distribution of albumin in a rat deep burn model, for which Evans blue was used as a nontoxic molecular probe. Water content in the tissue and urine volume were also measured for reference. We performed PA imaging of albumin in three regions in the rats, burn and nonburn regions and their boundary, and the imaging showed that albumin started to leak out of the vessels in the boundary and diffused within the burned tissue. Diffusion of albumin into the nonburn region, where water content was increased, was limited. In the burn and boundary regions, albumin-originating PA signal increased in two phases: immediately after making burns and from 24 to 72 h after burn. The second increase is attributable to the selective return of water to the vessels, resulting in increased concentration of albumin in extravascular tissue. PMID:23597848

  13. The quantitative effect of serum albumin, serum urea, and valproic acid on unbound phenytoin concentrations in children.

    PubMed

    ter Heine, Rob; van Maarseveen, Erik M; van der Westerlaken, Monique M L; Braun, Kees P J; Koudijs, Suzanne M; Berg, Maarten J Ten; Malingré, Mirte M

    2014-06-01

    Dosing of phenytoin is difficult in children because of its variable pharmacokinetics and protein binding. Possible covariates for this protein binding have mostly been univariately investigated in small, and often adult, adult populations. We conducted a study to identify and quantify these covariates in children. We extracted data on serum phenytoin concentrations, albumin, triglycerides, urea, total bilirubin and creatinine concentrations and data on coadministration of valproic acid or carbamazepine in 186 children. Using nonlinear mixed effects modeling the effects of covariates on the unbound phenytoin fraction were investigated. Serum albumin, serum urea concentrations, and concomitant valproic acid use significantly influenced the unbound phenytoin fraction. For clinical practice, we recommend that unbound phenytoin concentrations are measured routinely. However, if this is impossible, we suggest to use our model to calculate the unbound concentration. In selected children, close treatment monitoring and dose reductions should be considered to prevent toxicity. PMID:23670246

  14. Gold nanoparticles with different amino acid surfaces: serum albumin adsorption, intracellular uptake and cytotoxicity.

    PubMed

    Cai, Huanxin; Yao, Ping

    2014-11-01

    Gold nanoparticles with aspartate, glycine, leucine, lysine, and serine surfaces were produced from the mixed solutions of HAuCl4 and respective amino acids via UV irradiation. The amino acids bind to the nanoparticle surfaces via amine groups and their carboxylic groups extend out to stabilize the nanoparticles. The nanoparticles have diameters of 15-47 nm in pH 7.4 aqueous solution and have diameters of 62-73 nm after 48 h incubation in cell culture containing serum. The nanoparticles adsorb human and bovine serum albumins on their surfaces by specific interactions, characterized by the intrinsic fluorescence quenching of the albumins. The albumin adsorption effectively decreases the aggregation of the nanoparticles in cell culture and also decreases the intracellular uptake of the nanoparticles. The gold nanoparticles produced from leucine and lysine, which have amphiphilic groups on their surfaces, present better biocompatibility than the other gold nanoparticles. PMID:25466455

  15. Growth Status and Its Relationship with Serum Lipids and Albumin in Children with Cystic Fibrosis.

    PubMed

    Fallahi, Gholam Hossein; Latifi, Sahar; Mahmoudi, Maryam; Kushki, Davood; Haghhi Ashtiani, Mohammad Taghi; Morteza, Afsaneh; Rezaei, Nima

    2016-04-01

    Cystic fibrosis (CF) is an autosomal recessive disease, which affects many organs as it impairs chloride channel. This study was performed to evaluate growth status and its relationship with some laboratory indices such as Cholesterol (chol), Triglyceride (TG), albumin and total protein in children with CF referred to pediatrics center. This study was designed as a cross-sectional study in one year section. Demographic features were compared with standard percentiles curves. Chol, TG, albumin, total protein, prothrombin time, and hemoglobin were measured. Stool exams were also performed. A questionnaire was designed to obtain a history of the first presentation of disease, birth weight, type of labor and parent relativity. In 52% of patients, failure to thrive (FTT) was the first presentation. Steatorrhea and respiratory infections were the first presentations, which were seen in 13.7% and 33% of the cases, respectively. The weight of 88% of patients was below the 15th percentile while 82% had a height percentile below 15th. Head circumference in 53% of patients was below the 15th percentile. There was a significant association between weight percentile and serum albumin and total protein (P=0.03 and P=0.007, respectively). There was also a significant relationship between height percentile and serum albumin and total protein (P<0.001 and P<0.000, respectively). The relationships between head circumference and serum albumin and total protein were also significant (P=0.006 and P<0.000, respectively). There was also a significant association between height percentile and hemoglobin. The decrease in anthropometric percentiles leads to decreased serum albumin and total protein. PMID:27309270

  16. Optical signaling in biofluids: a nondenaturing photostable molecular probe for serum albumins.

    PubMed

    Dey, Gourab; Gaur, Pankaj; Giri, Rajanish; Ghosh, Subrata

    2016-01-31

    The systematic investigation of the interaction of a new class of molecular materials with proteins through structure-optical signaling relationship studies has led to the development of efficient fluorescent probes that can detect and quantify serum albumins in biofluids without causing any denaturation. PMID:26675447

  17. Bovine serum albumin adsorption onto functionalized polystyrene lattices: A theoretical modeling approach and error analysis

    NASA Astrophysics Data System (ADS)

    Beragoui, Manel; Aguir, Chadlia; Khalfaoui, Mohamed; Enciso, Eduardo; Torralvo, Maria José; Duclaux, Laurent; Reinert, Laurence; Vayer, Marylène; Ben Lamine, Abdelmottaleb

    2015-03-01

    The present work involves the study of bovine serum albumin adsorption onto five functionalized polystyrene lattices. The adsorption measurements have been carried out using a quartz crystal microbalance. Poly(styrene-co-itaconic acid) was found to be an effective adsorbent for bovine serum albumin molecule adsorption. The experimental isotherm data were analyzed using theoretical models based on a statistical physics approach, namely monolayer, double layer with two successive energy levels, finite multilayer, and modified Brunauer-Emmet-Teller. The equilibrium data were then analyzed using five different non-linear error analysis methods and it was found that the finite multilayer model best describes the protein adsorption data. Surface characteristics, i.e., surface charge density and number density of surface carboxyl groups, were used to investigate their effect on the adsorption capacity. The combination of the results obtained from the number of adsorbed layers, the number of adsorbed molecules per site, and the thickness of the adsorbed bovine serum albumin layer allows us to predict that the adsorption of this protein molecule can also be distinguished by monolayer or multilayer adsorption with end-on, side-on, and overlap conformations. The magnitudes of the calculated adsorption energy indicate that bovine serum albumin molecules are physisorbed onto the adsorbent lattices.

  18. Serum albumin and muscle measures in a cohort of healthy young and old participants.

    PubMed

    Reijnierse, E M; Trappenburg, M C; Leter, M J; Sipilä, S; Stenroth, L; Narici, M V; Hogrel, J Y; Butler-Browne, G; McPhee, J S; Pääsuke, M; Gapeyeva, H; Meskers, C G M; Maier, A B

    2015-10-01

    Consensus on clinically valid diagnostic criteria for sarcopenia requires a systematical assessment of the association of its candidate measures of muscle mass, muscle strength, and physical performance on one side and muscle-related clinical parameters on the other side. In this study, we systematically assessed associations between serum albumin as a muscle-related parameter and muscle measures in 172 healthy young (aged 18-30 years) and 271 old participants (aged 69-81 year) from the European MYOAGE study. Muscle measures included relative muscle mass, i.e., total- and appendicular lean mass (ALM) percentage, absolute muscle mass, i.e., ALM/height(2) and total lean mass in kilograms, handgrip strength, and walking speed. Muscle measures were standardized and analyzed in multivariate linear regression models, stratified by age. Adjustment models included age, body composition, C-reactive protein and lifestyle factors. In young participants, serum albumin was positively associated with lean mass percentage (p = 0.007) and with ALM percentage (p = 0.001). In old participants, serum albumin was not associated with any of the muscle measures. In conclusion, the association between serum albumin and muscle measures was only found in healthy young participants and the strongest for measures of relative muscle mass. PMID:26310888

  19. Peroxidase mediated conjugation of corn fibeer gum and bovine serum albumin to improve emulsifying properties

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The emulsifying properties of corn fiber gum (CFG), a naturally-occurring polysaccharide protein complex, were improved by kinetically controlled formation of hetero-covalent linkages with bovine serum albumin (BSA), using horseradish peroxidase. The formation of hetero-crosslinked CFG-BSA conjugate...

  20. Binding study of tetracyclines to human serum albumin using difference spectrophotometry.

    PubMed

    Zia, H; Price, J C

    1976-02-01

    The binding of several tetracyclines to human serum albumin was studied using difference spectrophotometry and a spectrophotometric probe, 2-(4'-hydroxybenzeneazo)benzoic acid. Difference spectra observed for the interaction between the probe and human serum albumin were similar to probe-bovine serum albumin spectra but were less intense for a given concentration of probe and did not reach saturation as quickly. Difference spectra for the tetracyclines were dependent on the characteristics of the ring substituents. More hydrophobic substituents on the D and C rings tended to give more intense difference spectra, but charge-transfer complexing may also have been involved since methacycline with a methylene group in the 6-position showed the most intense spectra of the compounds studied. Solvent perturbation, pH, and urea studies tended to confirm that something other than hydrophobic binding of the tetracyclines was involved. Drug-probe displacement studies showed that methacycline gave the greatest probe displacement followed by doxycycline, chlortetracycline, oxytetracycline, and tetracycline. This order of displacement of the anionic probe indicates that both hydrophobic and charge-transfer binding are involved. Experiments with calcium ion and ethylenediaminetetraacetic acid showed that the difference spectra obtained with the tetracyclines and human serum albumin were not the result of metallic bridge-chelate formation. PMID:3641

  1. Interaction of triprolidine hydrochloride with serum albumins: thermodynamic and binding characteristics, and influence of site probes.

    PubMed

    Sandhya, B; Hegde, Ashwini H; Kalanur, Shankara S; Katrahalli, Umesha; Seetharamappa, J

    2011-04-01

    The interaction between triprolidine hydrochloride (TRP) to serum albumins viz. bovine serum albumin (BSA) and human serum albumin (HSA) has been studied by spectroscopic methods. The experimental results revealed the static quenching mechanism in the interaction of TRP with protein. The number of binding sites close to unity for both TRP-BSA and TRP-HSA indicated the presence of single class of binding site for the drug in protein. The binding constant values of TRP-BSA and TRP-HSA were observed to be 4.75 ± 0.018 × 10(3) and 2.42 ± 0.024 × 10(4)M(-1) at 294 K, respectively. Thermodynamic parameters indicated that the hydrogen bond and van der Waals forces played the major role in the binding of TRP to proteins. The distance of separation between the serum albumin and TRP was obtained from the Förster's theory of non-radioactive energy transfer. The metal ions viz., K(+), Ca(2+), Co(2+), Cu(2+), Ni(2+), Mn(2+) and Zn(2+) were found to influence the binding of the drug to protein. Displacement experiments indicated the binding of TRP to Sudlow's site I on both BSA and HSA. The CD, 3D fluorescence spectra and FT-IR spectral results revealed the changes in the secondary structure of protein upon interaction with TRP. PMID:21215548

  2. Adsorbed serum albumin is permissive to macrophage attachment to perfluorocarbon polymer surfaces in culture.

    PubMed

    Godek, M L; Michel, R; Chamberlain, L M; Castner, D G; Grainger, D W

    2009-02-01

    Monocyte/macrophage adhesion to biomaterials, correlated with foreign body response, occurs through protein-mediated surface interactions. Albumin-selective perfluorocarbon (FC) biomaterials are generally poorly cell-conducive because of insufficient receptor-mediated surface interactions, but macrophages bind to albumin-coated substrates and also preferentially to highly hydrophobic fluorinated surfaces. Bone marrow macrophages (BMMO) and IC-21, RAW 264.7, and J774A.1 monocyte/macrophage cells were cultured on FC surfaces. Protein deposition onto two distinct FC surfaces from complex and single-component solutions was tracked using fluorescence and time-of-flight secondary ion mass spectrometry (ToF-SIMS) methods. Cell adhesion and growth on protein pretreated substrates were compared by light microscopy. Flow cytometry and integrin-directed antibody receptor blocking were used to assess integrins critical for monocyte/macrophage adhesion in vitro. Albumin predominantly adsorbs onto both FC surfaces from 10% serum. In cultures preadsorbed with albumin or serum-dilutions, BMMO responded similar to IC-21 at early time points. Compared with Teflon AF, plasma-polymerized FC was less permissive to extended cell proliferation. The beta(2) integrins play major roles in macrophage adhesion to FC surfaces: antibody blocking significantly disrupted cell adhesion. Albumin-mediated cell adhesion mechanisms to FC surfaces could not be clarified. Primary BMMO and secondary IC-21 macrophages behave similarly on FC surfaces, regardless of preadsorbed protein biasing, with respect to adhesion, cell morphology, motility, and proliferation. PMID:18306309

  3. Adsorbed serum albumin is permissive to macrophage attachment to perfluorocarbon polymer surfaces in culture

    PubMed Central

    Godek, M.L.; Michel, R.; Chamberlain, L. M.; Castner, D. G.; Grainger, D.W.

    2013-01-01

    Monocyte/macrophage adhesion to biomaterials, correlated with foreign body response, occurs through protein-mediated surface interactions. Albumin-selective perfluorocarbon (FC) biomaterials are generally poorly cell-conducive due to insufficient receptor-mediated surface interactions, but macrophages bind to albumin-coated substrates and also preferentially to highly hydrophobic fluorinated surfaces. Bone marrow macrophages (BMMO) and IC-21, RAW 264.7 and J774A.1 monocyte/macrophage cells were cultured on FC surfaces. Protein deposition onto two distinct FC surfaces from complex and single-component solutions was tracked using fluorescence and time-of-flight secondary ion mass spectrometry (ToF-SIMS) methods. Cell adhesion and growth on protein pre-treated substrates were compared by light microscopy. Flow cytometry and integrin-directed antibody receptor blocking assessed integrins critical for monocyte/macrophage adhesion in vitro. Albumin predominantly adsorbs onto both FC surfaces from 10% serum. In cultures pre-adsorbed with albumin or serum-dilutions, BMMO responded similar to IC-21 at early time points. Compared to Teflon® AF, plasma-polymerized FC was less permissive to extended cell proliferation. The β2 integrins play major roles in macrophage adhesion to FC surfaces: antibody blocking significantly disrupted cell adhesion. Albumin-mediated cell adhesion mechanisms to FC surfaces could not be clarified. Primary BMMO and secondary IC-21 macrophages behave similarly on FC surfaces, regardless of pre-adsorbed protein biasing, with respect to adhesion, cell morphology, motility and proliferation. PMID:18306309

  4. Relationship Between Serum Albumin Levels and Infections in Newborn Late Preterm Infants

    PubMed Central

    Yang, Chunyan; Liu, Zhaoguo; Tian, Min; Xu, Ping; Li, Baoyun; Yang, Qiaozhi; Yang, Yujun

    2016-01-01

    Background We aimed to evaluate the clinical value of serum albumin levels for the evaluation and prognosis of late preterm infants with infections. Material/Methods This was a retrospective study performed in late preterm infants admitted at the neonatal intensive care unit (NICU) of the Liaocheng People’s Hospital between July 2012 and March 2013. Data, including laboratory test results, neonatal critical illness score (NCIS), perinatal complications and prognosis, were analyzed. The newborn infants were divided into 3 groups according to their serum albumin levels, (≥30 g/L, 25–30 g/L and ≤25 g/L for high, moderate, and low, respectively). Results Among 257 patients, birth weight was 2003±348 g, gestational age was 35.7±2.3 weeks, and 59.1% were male. In addition, 127 (49.4%) were in the low albumin group. There were 32 patients with sepsis, 190 with infections, and 35 without infection, and their rates of hypoalbuminemia were 86.0%, 50.5%, and 30.7%, respectively (P<0.05). Albumin levels of the patients who survived were higher than those of the patients who died. In the low albumin group, the number of individual-event-critical NCIS cases and the frequency of multiple organs injuries were 63.8% and 28.3%, respectively, and were higher than in the 2 other groups. Mortality was higher in patients with sepsis. Hypoalbuminemia was associated with severe adverse outcomes (odds ratio=6.3, 95% confidence interval: 3.7–10.9, P<0.001). Conclusions Hypoalbuminemia was frequent among neonates with sepsis. Lower albumin levels might be associated with a poorer prognosis. Albumin levels could be appropriate for the diagnosis and prognosis of late preterm neonates with infections. PMID:26747243

  5. Interactions Between Sirolimus and Anti-Inflammatory Drugs: Competitive Binding for Human Serum Albumin

    PubMed Central

    Khodaei, Arash; Bolandnazar, Soheila; Valizadeh, Hadi; Hasani, Leila; Zakeri-Milani, Parvin

    2016-01-01

    Purpose: The aim of the present study was investigating the effects of three anti-inflammatory drugs, on Sirolimus protein biding. The binding site of Sirolimus on human serum albumin (HSA) was also determined. Methods: Six different concentrations of Sirolimus were separately exposed to HSA at pH 7.4 and 37°C. Ultrafiltration method was used for separating free drug; then free drug concentrations were measured by HPLC. Finally, Sirolimus protein binding parameters was calculated using Scatchard plots. The same processes were conducted in the presence of NSAIDs at lower concentration of albumin and different pH conditions. To characterize the binding site of Sirolimus on albumin, the free concentration of warfarin sodium and Diazepam, site I and II specific probes, bound to albumin were measured upon the addition of increasing Sirolimus concentrations. Results: Based on the obtained results presence of Diclofenac, Piroxicam and Naproxen, could significantly decrease the percentage of Sirolimus protein binding. The Binding reduction was the most in the presence of Piroxicam. Sirolimus-NSAIDs interactions were increased in higher pH values and also in lower albumin concentrations. Probe displacement study showed that Sirolimus may mainly bind to site I on albumin molecule. Conclusion: More considerations in co-administration of NSAIDs and Sirolimus is recommended. PMID:27478785

  6. Lack of an effect of dietary selenium on serum albumin, glucose and urea nitrogen in ewes.

    PubMed Central

    Sugden, E A; Hidiroglou, M; Mitchell, D

    1978-01-01

    The results of a study on the effect of dietary selenium administered with vitamin E on serum levels of albumin, glucose and urea nitrogen in ewes are reported. In October, at the onset of breeding, after ten months on a dystrophogenic diet, mean serum levels of albumin (g/dl), glucose (mg/dl) and urea nitrogen (mg/dl) were respectively 3.5, 52.9 and 12.8, in 65 Se-deficient ewes and 3.6, 51.7 and 14.3 in 65 Se-adequate ewes. Despite a significant difference in the serum level of urea nitrogen between Se-deficient and Se-adequate groups, no consistent effect of dietary selenium was apparent. PMID:688079

  7. Determination of the binding properties of the uremic toxin phenylacetic acid to human serum albumin.

    PubMed

    Saldanha, Juliana F; Yi, Dan; Stockler-Pinto, Milena B; Soula, Hédi A; Chambert, Stéphane; Fouque, Denis; Mafra, Denise; Soulage, Christophe O

    2016-06-01

    Uremic toxins are compounds normally excreted in urine that accumulate in patients with chronic kidney disease as a result of decreased renal clearance. Phenylacetic acid (PAA) has been identified as a new protein bound uremic toxin. The purpose of this study was to investigate in vitro the interaction between PAA and human serum albumin (HSA) at physiological and pathological concentrations. We used ultrafiltration to show that there is a single high-affinity binding site for PAA on HSA, with a binding constant on the order of 3.4 × 10(4) M(-1) and a maximal stoichiometry of 1.61 mol per mole. The PAA, at the concentration reported in end-stage renal patients, was 26% bound to albumin. Fluorescent probe competition experiments demonstrated that PAA did not bind to Sudlow's site I (in subdomain IIA) and only weakly bind to Sudlow's site II (in subdomain IIIA). The PAA showed no competition with other protein-bound uremic toxins such as p-cresyl-sulfate or indoxyl sulfate for binding to serum albumin. Our results provide evidence that human serum albumin can act as carrier protein for phenylacetic acid. PMID:26945842

  8. Serum albumin acts as a shuttle to enhance cholesterol efflux from cells[S

    PubMed Central

    Sankaranarayanan, Sandhya; de la Llera-Moya, Margarita; Drazul-Schrader, Denise; Phillips, Michael C.; Kellner-Weibel, Ginny; Rothblat, George H.

    2013-01-01

    An important mechanism contributing to cell cholesterol efflux is aqueous transfer in which cholesterol diffuses from cells into the aqueous phase and becomes incorporated into an acceptor particle. Some compounds can enhance diffusion by acting as shuttles transferring cholesterol to cholesterol acceptors, which act as cholesterol sinks. We have examined whether particles in serum can enhance cholesterol efflux by acting as shuttles. This task was accomplished by incubating radiolabeled J774 cells with increasing concentrations of lipoprotein-depleted sera (LPDS) or components present in serum as shuttles and a constant amount of LDL, small unilamellar vesicles, or red blood cells (RBC) as sinks. Synergistic efflux was measured as the difference in fractional efflux in excess of that predicted by the addition of the individual efflux values of sink and shuttle alone. Synergistic efflux was obtained when LPDS was incubated with cells and LDL. When different components of LPDS were used as shuttles, albumin produced synergistic efflux, while apoA-I did not. A synergistic effect was also obtained when RBC was used as the sink and albumin as shuttle. The previously observed negative association of albumin with coronary artery disease might be linked to reduced cholesterol shuttling that would occur when serum albumin levels are low. PMID:23288948

  9. Crystal structure of equine serum albumin in complex with cetirizine reveals a novel drug binding site.

    PubMed

    Handing, Katarzyna B; Shabalin, Ivan G; Szlachta, Karol; Majorek, Karolina A; Minor, Wladek

    2016-03-01

    Serum albumin (SA) is the main transporter of drugs in mammalian blood plasma. Here, we report the first crystal structure of equine serum albumin (ESA) in complex with antihistamine drug cetirizine at a resolution of 2.1Å. Cetirizine is bound in two sites--a novel drug binding site (CBS1) and the fatty acid binding site 6 (CBS2). Both sites differ from those that have been proposed in multiple reports based on equilibrium dialysis and fluorescence studies for mammalian albumins as cetirizine binding sites. We show that the residues forming the binding pockets in ESA are highly conserved in human serum albumin (HSA), and suggest that binding of cetirizine to HSA will be similar. In support of that hypothesis, we show that the dissociation constants for cetirizine binding to CBS2 in ESA and HSA are identical using tryptophan fluorescence quenching. Presence of lysine and arginine residues that have been previously reported to undergo nonenzymatic glycosylation in CBS1 and CBS2 suggests that cetirizine transport in patients with diabetes could be altered. A review of all available SA structures from the PDB shows that in addition to the novel drug binding site we present here (CBS1), there are two pockets on SA capable of binding drugs that do not overlap with fatty acid binding sites and have not been discussed in published reviews. PMID:26896718

  10. Serum albumin and fixation failure with cannulated hip screws in undisplaced intracapsular femoral neck fracture.

    PubMed

    Riaz, O; Arshad, R; Nisar, S; Vanker, R

    2016-07-01

    Introduction Internal fixation of undisplaced intracapsular femoral neck fractures with cannulated hip screws is a widely accepted surgical technique, despite reported failure rates of 12%-19%. This study determined whether preoperative serum albumin levels are linked to fixation failure. Methods We retrospectively reviewed 251 consecutive undisplaced intracapsular femoral neck fracture patients treated with cannulated hip screws in a district general hospital. Preoperative albumin levels were measured, and the fixation technique, classification and posterior tilt on radiography assessed. Fixation failure was defined as a screw cut, avascular necrosis (AVN) or non-union. Results Of the patients, 185 were female and 66 male. The mean age was 77 years (range 60-101 years). Thirty seven (15%) patients had fixation failure: 10 (4%) due to AVN; 12 (5%) due to non-union; and 15 (6%) due to fixation collapse. Low serum albumin levels were significantly associated with failure (p=0.01), whereas gender (p=0.56), operated side (p=0.62), age (p=0.34) and screw configuration (p=0.42) were not. A posterior tilt angle greater than 20° on lateral radiography significantly predicted failure (p=0.002). Conclusions Preoperative serum albumin is an independent predictor of cannulated hip screw fixation failure in undisplaced femoral neck fractures. Nutritional status should therefore be considered when deciding between surgical fixation and arthroplasty to avoid the possibility of revision surgery, along with an increased risk of morbidity and mortality. PMID:27055409

  11. Interaction of silicon nanoparticles with the molecules of bovine serum albumin in aqueous solutions

    SciTech Connect

    Anenkova, K A; Sergeeva, I A; Petrova, G P; Fedorova, K V; Osminkina, L A; Timoshenko, Viktor Yu

    2011-05-31

    Using the method of photon-correlation spectroscopy, the coefficient of translational diffusion D{sub t} and the hydrodynamic radius R of the particles in aqueous solutions of the bovine serum albumin, containing silicon nanoparticles, are determined. The character of the dependence of these parameters on the concentration of the protein indicates the absence of interaction between the studied particles in the chosen range of albumin concentrations 0.2 - 1.0 mg mL{sup -1}. (optical technologies in biophysics and medicine)

  12. Nanoencapsulation of ultra-small superparamagnetic particles of iron oxide into human serum albumin nanoparticles

    PubMed Central

    Altinok, Mahmut; Urfels, Stephan; Bauer, Johann

    2014-01-01

    Summary Human serum albumin nanoparticles have been utilized as drug delivery systems for a variety of medical applications. Since ultra-small superparamagnetic particles of iron oxide (USPIO) are used as contrast agents in magnetic resonance imaging, their encapsulation into the protein matrix enables the synthesis of diagnostic and theranostic agents by surface modification and co-encapsulation of active pharmaceutical ingredients. The present investigation deals with the surface modification and nanoencapsulation of USPIO into an albumin matrix by using ethanolic desolvation. Particles of narrow size distribution and with a defined particle structure have been achieved. PMID:25551054

  13. Serum albumin perturbations in cyanotics after cardiac surgery: Patterns and predictions

    PubMed Central

    Kapoor, Poonam Malhotra; Narula, Jitin; Chowdhury, Ujjwal Kumar; Kiran, Usha; Taneja, Sameer

    2016-01-01

    Introduction: Hypoalbuminemia is a well-recognized predictor of general surgical risk and frequently occurs in patients with cyanotic congenital heart disease (CCHD). Moreover, cardiopulmonary bypass (CPB)-induced an inflammatory response, and the overall surgical stress can effect albumin concentration greatly. The objective of his study was to track CPB-induced changes in albumin concentration in patients with CCHD and to determine the effect of hypoalbuminemia on postoperative outcomes. Materials and Methods: Prospective observational study conducted in 150 patients, Group 1 ≤18 years (n = 75) and Group 2 >18 years (n = 75) of age. Albumin levels were measured preoperatively (T1), after termination of CPB (T2) and 48 h post-CPB (T3). Primary parameters (mortality, duration of postoperative ventilation, duration of inotropes and duration of Intensive Care Unit [ICU] stay) and secondary parameters (urine output, oliguria, arrhythmias, and hemodynamic parameters) were recorded. Results: The albumin levels in Group 1 at T1, T2, and T3 were 3.8 ± 0.48, 3.2 ± 0.45 and 2.6 ± 0.71 mg/dL; and in Group 2 were 3.7 ± 0.50, 3.2 ± 0.49 and 2.7 ± 0.62 mg/dL respectively. All patients showed a significant decrease in albumin concentration 48 h after surgery (P < 0.01). Analysis between the groups, however, showed no statistical difference. Eleven patients expired during the study period, and nonsurvivors showed significantly lower serum albumin concentration 48 h after surgery 2.3 ± 0.62 mg/dL versus 3.7 ± 0.56 mg/dL in the survivors (P < 0.05). Receiver operating characteristic curve showed that a baseline albumin cut-off value of 3.3 g/dL predicts mortality with a positive predictive value 47.6% and a negative predictive value of 99.2% (P < 0.05). A strong correlation was seen between albumin levels at 48 h with duration of CPB (r2 = 0.6321), ICU stay (r2 = 0.7447) and incidence of oliguria (r2 = 0.8803). Conclusions: The study demonstrated similar fall in albumin

  14. Bovine Serum Albumin binding to CoCrMo nanoparticles and the influence on dissolution

    NASA Astrophysics Data System (ADS)

    Simoes, T. A.; Brown, A. P.; Milne, S. J.; Brydson, R. M. D.

    2015-10-01

    CoCrMo alloys exhibit good mechanical properties, excellent biocompatibility and are widely utilised in orthopaedic joint replacements. Metal-on-metal hip implant degradation leads to the release of metal ions and nanoparticles, which persist through the implant's life and could be a possible cause of health complications. This study correlates preferential binding between proteins and metal alloy nanoparticles to the alloy's corrosion behaviour and the release of metal ions. TEM images show the formation of a protein corona in all particles immersed in albumin containing solutions. Only molybdenum release was significant in these tests, suggesting high dissolution of this element when CoCrMo alloy nanoparticles are produced as wear debris in the presence of serum albumin. The same trend was observed during extended exposure of molybdenum reference nanoparticles to albumin.

  15. Cigarette smoke induces alterations in the drug-binding properties of human serum albumin.

    PubMed

    Clerici, Marco; Colombo, Graziano; Secundo, Francesco; Gagliano, Nicoletta; Colombo, Roberto; Portinaro, Nicola; Giustarini, Daniela; Milzani, Aldo; Rossi, Ranieri; Dalle-Donne, Isabella

    2014-04-01

    Albumin is the most abundant plasma protein and serves as a transport and depot protein for numerous endogenous and exogenous compounds. Earlier we had shown that cigarette smoke induces carbonylation of human serum albumin (HSA) and alters its redox state. Here, the effect of whole-phase cigarette smoke on HSA ligand-binding properties was evaluated by equilibrium dialysis and size-exclusion HPLC or tryptophan fluorescence. The binding of salicylic acid and naproxen to cigarette smoke-oxidized HSA resulted to be impaired, unlike that of curcumin and genistein, chosen as representative ligands. Binding of the hydrophobic fluorescent probe 4,4'-bis(1-anilino-8-naphtalenesulfonic acid) (bis-ANS), intrinsic tryptophan fluorescence, and susceptibility to enzymatic proteolysis revealed slight changes in albumin conformation. These findings suggest that cigarette smoke-induced modifications of HSA may affect the binding, transport and bioavailability of specific ligands in smokers. PMID:24388826

  16. The effects of Hespan on serum and lymphatic albumin, globulin, and coagulant protein.

    PubMed Central

    Lucas, C E; Denis, R; Ledgerwood, A M; Grabow, D

    1988-01-01

    The effects of hydroxyethyl starch (Hespan) resuscitation on serum and lymphatic proteins following hemorrhagic shock were studied in 34 splenectomized dogs. Following shock, five randomly assigned treatment groups received the shed blood plus 50 mL/kg of salt solution (RL) or RL with varying concentrations (0.22-1.5 gm/kg) of Hespan. Each dog received 50 ml/kg/d of the test solution for three days after shock. Prothrombin time, partial thromboplastin time, thrombin time, total serum protein, albumin, globulin, and coagulant protein activity of fibrinogen, prothrombin, and factor VIII were measured before shock, at the end of shock, following resuscitation, and on day 3; thoracic duct lymph values were obtained on day 3. Hespan-supplemented resuscitation lowered all serum proteins including albumin, globulin and coagulant proteins; concomitantly, the lymph protein rose after Hespan resuscitation. This decrease in serum proteins and rise in lymph proteins parallels similar results after albumin resuscitation in man and animals and suggests that Hespan induces an oncotically controlled extravascular protein relocation. Further studies on the significance of these findings need to be conducted. PMID:2451485

  17. Calorimetric investigation of diclofenac drug binding to a panel of moderately glycated serum albumins.

    PubMed

    Indurthi, Venkata S K; Leclerc, Estelle; Vetter, Stefan W

    2014-08-01

    Glycation alters the drug binding properties of serum proteins and could affect free drug concentrations in diabetic patients with elevated glycation levels. We investigated the effect of bovine serum albumin glycation by eight physiologically relevant glycation reagents (glucose, ribose, carboxymethyllysine, acetoin, methylglyoxal, glyceraldehyde, diacetyl and glycolaldehyde) on diclofenac drug binding. We used this non-steroidal anti-inflammatory drug diclofenac as a paradigm for acidic drugs with high serum binding and because of its potential cardiovascular risks in diabetic patients. Isothermal titration calorimetry showed that glycation reduced the binding affinity Ka of serum albumin and diclofenac 2 to 6-fold by reducing structural rigidity of albumin. Glycation affected the number of drug binding sites in a glycation reagent dependent manner and lead to a 25% decrease for most reagent, expect for ribose, with decreased by 60% and for the CML-modification, increased the number of binding sites by 60%. Using isothermal titration calorimetry and differential scanning calorimetry we derived the complete thermodynamic characterization of diclofenac binding to all glycated BSA samples. Our results suggest that glycation in diabetic patients could significantly alter the pharmacokinetics of the widely used over-the-counter NSDAI drug diclofenac and with possibly negative implications for patients. PMID:24751671

  18. Serum albumin level as a risk factor for mortality in burn patients

    PubMed Central

    Alejandra Aguayo-Becerra, Olivia; Torres-Garibay, Carlos; Dassaejv Macías-Amezcua, Michel; Fuentes-Orozco, Clotilde; de Guadalupe Chávez-Tostado, Mariana; Andalón-Dueñas, Elizabeth; Espinosa Partida, Arturo; Álvarez-Villaseñor, Andrea Del Socorro; Cortés-Flores, Ana Olivia; Alejandro González-Ojeda

    2013-01-01

    OBJECTIVE: Hypoalbuminemia is a common clinical deficiency in burn patients and is associated with complications related to increased extravascular fluid, including edema, abnormal healing, and susceptibility to sepsis. Some prognostic scales do not include biochemical parameters, whereas others consider them together with comorbidities. The purpose of this study was to determine whether serum albumin can predict mortality in burn patients. METHODS: We studied burn patients ≥16 years of age who had complete clinical documentation, including the Abbreviated Burn Severity Index, serum albumin, globulin, and lipids. Sensitivity and specificity analyses were performed to determine the cut-off level of albumin that predicts mortality. RESULTS: In our analysis of 486 patients, we found that mortality was higher for burns caused by flame (p = 0.000), full-thickness burns (p = 0.004), inhalation injuries (p = 0.000), burns affecting >30% of the body surface area (p = 0.001), and burns associated with infection (p = 0.008). Protein and lipid levels were lower in the patients who died (p<0.05). Albumin levels showed the highest sensitivity and specificity (84% and 83%, respectively), and the area under the receiver-operating characteristic curve (0.869) had a cut-off of 1.95 g/dL for mortality. CONCLUSION: Patients with albumin levels <2 g/dL had a mortality risk of >80%, with 84% sensitivity and 83% specificity. At admission, the albumin level could be used as a sensitive and specific marker of burn severity and an indicator of mortality. PMID:23917657

  19. Comparison Between Measured and Calculated Free Calcium Values at Different Serum Albumin Concentrations

    PubMed Central

    Mir, Altaf Ahmad; Goyal, Bela; Datta, Sudip Kumar; Ikkurthi, Saidaiah; Pal, Arnab

    2016-01-01

    Introduction: Free ionic calcium is the metabolically active component of total calcium (TCa) in blood. However, most laboratories report TCa levels that are dependent on serum albumin concentration. Hence, several formulae have evolved to calculate free calcium levels from TCa after adjustment for albumin. However, free calcium can directly be measured using direction selective electrodes rather than spectrophotometric methods used in autoanalyzers. Objectives: This study compares the levels of free calcium obtained by measurement by direct ion selective electrode (ISE) and the one calculated as a function of TCa by formulae. Materials and Methods: A total of 254 serum samples submitted to clinical biochemistry laboratory of a tertiary care hospital were analyzed for total protein, albumin, and TCa by standard spectrophotometric methods and for free calcium by direct ISE. Three commonly used formulae viz. Orrell, Berry et al. and Payne et al. were used to calculate adjusted TCa. Calculated free calcium was obtained by taking 50% of these values. Results: A significant difference (P < 0.05) was observed between calculated free calcium by all the three formulae and measured free calcium estimated by direct ISE using paired t-test and Bland–Altman plots. Conclusion: Formulae for predicting free calcium by estimating TCa and albumin lacks consistency in prediction and free calcium should be evaluated by direct measurement. PMID:27365914

  20. Immobilization of Bovine Serum Albumin Upon Multiwall Carbon Nanotube for High Speed Humidity Sensing Application.

    PubMed

    Bhattacharya, Sankhya; Sasmal, Milan

    2016-01-01

    We present a high-speed humidity sensor based on immobilization of bovine serum albumin upon multiwall carbon nanotube (IBC). A simple and versatile drop casting technique was employed to make the humidity sensor using novel material IBC at room temperature. IBC was synthesized using easy solution process technique. The working principle of the IBC humidity sensor depends upon the variation of output current or conductance with the exposure of different humidity level. Humidity sensing properties of our device is explained on the basis of charge transfer from water molecules to IBC and bovine serum albumin to multiwall carbon nanotube (MWCNT). Our sensor exhibits faster response time around 1.2 s and recovery time 1.5 s respectively. PMID:26841403

  1. Bovine serum albumin nanoparticles as controlled release carrier for local drug delivery to the inner ear

    PubMed Central

    2014-01-01

    Nanoparticles have attracted increasing attention for local drug delivery to the inner ear recently. Bovine serum albumin (BSA) nanoparticles were prepared by desolvation method followed by glutaraldehyde fixation or heat denaturation. The nanoparticles were spherical in shape with an average diameter of 492 nm. The heat-denatured nanoparticles had good cytocompatibility. The nanoparticles could adhere on and penetrate through the round window membrane of guinea pigs. The nanoparticles were analyzed as drug carriers to investigate the loading capacity and release behaviors. Rhodamine B was used as a model drug in this paper. Rhodamine B-loaded nanoparticles showed a controlled release profile and could be deposited on the osseous spiral lamina. We considered that the bovine serum albumin nanoparticles may have potential applications in the field of local drug delivery in the treatment of inner ear disorders. PMID:25114637

  2. ACCURACY OF SERUM - ASCITES ALBUMIN GRADIENT IN THE AETIOLOGICAL DIAGNOSIS OF ASCITES.

    PubMed

    Seth, A K; Rangarao, R; Pakhetra, R; Baskaran, V; Rana, Pvs; Rajamani, S

    2002-04-01

    50 adults with ascites admitted to our hospital were studied. Simultaneous samples of ascitic fluid and blood were collected and subjected to analysis including ascitic fluid total protein and serum ascites albumin gradient The cut off value of serum-ascites albumin gradient for differentiating between high and low gradient was taken as 1.1 gm % and of ascitic fluid protein for differentiating exudate and transudate as 2.5 gm%. The sensitivity, specificity, positive predictive value and negative predictive value of high gradient and transudative ascites in diagnosing portal hypertension were 943%, 60%, 84.6%, 81.8% and 62.9%, 133%, 91.7% and 50% respectively. High gradient ascites is a sensitive test in the diagnosis of portal hypertension as a cause of ascites. The exudate-transudate approach has severe limitations in the differential diagnosis of ascites. PMID:27407357

  3. Spectral Fluorescence Properties of an Anionic Oxacarbocyanine Dye in Complexes with Human Serum Albumin

    NASA Astrophysics Data System (ADS)

    Pronkin, P. G.; Tatikolov, A. S.

    2015-07-01

    The spectral fluorescence properties of the anionic oxacarbocyanine dye 3,3'-di-(γ-sulfopropyl)-5,5'-diphenyl-9-ethyloxacarbocyanine betaine (OCC) were studied in solutions and in complexes with human serum albumin (HSA). Interaction with HSA leads to a significant increase in the fluorescence of the dye. We studied quenching of the fluorescence of OCC in a complex with HSA by ibuprofen and warfarin. Data on quenching of fluorescence by ibuprofen indicate binding of the dye to binding site II of subdomain IIIA in the HSA molecule. Synchronous fluorescence spectra of human serum albumin in the presence of OCC showed that complexation with OCC does not lead to appreciable rearrangement of the protein molecule at the binding site.

  4. Comparative studies of the effects of copper sulfate and zinc sulfate on serum albumins

    NASA Astrophysics Data System (ADS)

    Plotnikova, O. A.; Melnikov, G. V.; Melnikov, A. G.; Kovalenko, A. V.

    2016-04-01

    The work is devoted to the study of the interaction of heavy metals with bovine serum albumin (BSA) and human serum albumin (HSA), by quenching of the intrinsic fluorescence of proteins and fluorescent probe pyrene by heavy metal ions. Sulfates of copper and zinc (CuSO4, ZnSO4) were taken as the metal salts. The value of the Stern-Volmer constants of quenching of intrinsic fluorescence of proteins and fluorescence probe pyrene reduced from Cu (II) to the Zn (II). It was experimentally found that the copper ions have a greater ability to fluorescence quenching, which is probably associated with the greater availability of protein chromophore groups to copper ions and with adsorbed fluorescent probe pyrene in the protein globule.

  5. Bovine serum albumin nanoparticles as controlled release carrier for local drug delivery to the inner ear

    NASA Astrophysics Data System (ADS)

    Yu, Zhan; Yu, Min; Zhang, Zhibao; Hong, Ge; Xiong, Qingqing

    2014-07-01

    Nanoparticles have attracted increasing attention for local drug delivery to the inner ear recently. Bovine serum albumin (BSA) nanoparticles were prepared by desolvation method followed by glutaraldehyde fixation or heat denaturation. The nanoparticles were spherical in shape with an average diameter of 492 nm. The heat-denatured nanoparticles had good cytocompatibility. The nanoparticles could adhere on and penetrate through the round window membrane of guinea pigs. The nanoparticles were analyzed as drug carriers to investigate the loading capacity and release behaviors. Rhodamine B was used as a model drug in this paper. Rhodamine B-loaded nanoparticles showed a controlled release profile and could be deposited on the osseous spiral lamina. We considered that the bovine serum albumin nanoparticles may have potential applications in the field of local drug delivery in the treatment of inner ear disorders.

  6. Isotachophoretic zone formation of serum albumin in different free fluid electrophoresis instruments.

    PubMed

    Thormann, W; Firestone, M A; Sloan, J E; Long, T D; Mosher, R A

    1990-04-01

    The isotachophoretic behavior of a model protein, serum albumin, was examined (i) by computer simulation, (ii) by capillary isotachophoresis in HPE 100 and Tachophor 2127, (iii) by continuous flow isotachophoresis in Elphor VaP 22 and the BIO-STREAM Separator and (iv) by recycling isotachophoresis in an apparatus of our own design. Variations in monitored zone shapes can be explained by differences in engineering aspects and fluid stabilization principles of the instruments. PMID:2340824

  7. Role of admission serum albumin levels in patients with intracerebral hemorrhage.

    PubMed

    Limaye, Kaustubh; Yang, Ju Dong; Hinduja, Archana

    2016-03-01

    Low serum albumin levels have been reported to be an independent predictor of increased morbidity and mortality in multiple disease conditions. The aim of our study was to identify the impact of low serum albumin levels on mortality and outcomes at discharge in patients with intracerebral hemorrhage. We retrospectively reviewed our prospective database of patients with intracerebral hemorrhage from January 2010 to December 2011. Patients were dichotomized into two groups based on their serum albumin levels upon admission. Hypoalbuminemia was defined as serum albumin levels ≤3.4 g/dl. The two groups were compared using Fisher's exact test for categorical variables and t test for continuous variables. Poor outcome was defined as death or discharge to a long-term nursing facility (modified Rankin Score 4-6). Out of 97 patients admitted with intracerebral hemorrhage, 90 met our inclusion criteria (42 had normal levels and 48 had hypoalbuminemia). The baseline characteristics, risk factors, etiology, location and volume of intracerebral hemorrhage, admission blood glucose, white cell count, length of hospital stay, length of intensive care unit stay, and complications were similar between both groups. Although admission hypoalbuminemia did not impact in-hospital mortality (28 vs 24 %, p = 0.635), there was a significant increase in poor outcomes at discharge (59 vs 31 %, p = 0.009) (OR 1.8; 95 % CI; 1.2-2.8). Similar to other diseases, hypoalbuminemia was associated with poor functional outcomes in patients with intracerebral hemorrhage. This will need to be confirmed in larger prospective studies before adopting therapeutic and preventive strategies in future. PMID:26133948

  8. Spectroscopic studies on the interaction between phycocyanin and bovine serum albumin

    NASA Astrophysics Data System (ADS)

    Kathiravan, A.; Chandramohan, M.; Renganathan, R.; Sekar, S.

    2009-02-01

    Bluish phycocyanin was obtained from the cyanobacteria namely Spirulina sp. (marine form). The interaction between phycocyanin and bovine serum albumin (BSA) was studied by using absorption, FT-IR, steady-state, time resolved and synchronous fluorescence spectroscopy. Phycocyanin effectively quenched the intrinsic fluorescence of BSA. The number of binding sites ( n) and binding constant ( K) was measured by fluorescence quenching method. The interaction between phycocyanin and BSA occurs through static quenching and conformational changes of BSA were observed.

  9. Doxorubicin-loaded glycyrrhetinic acid modified recombinant human serum albumin nanoparticles for targeting liver tumor chemotherapy.

    PubMed

    Qi, Wen-Wen; Yu, Hai-Yan; Guo, Hui; Lou, Jun; Wang, Zhi-Ming; Liu, Peng; Sapin-Minet, Anne; Maincent, Philippe; Hong, Xue-Chuan; Hu, Xian-Ming; Xiao, Yu-Ling

    2015-03-01

    Due to overexpression of glycyrrhetinic acid (GA) receptor in liver cancer cells, glycyrrhetinic acid modified recombinant human serum albumin (rHSA) nanoparticles for targeting liver tumor cells may result in increased therapeutic efficacy and decreased adverse effects of cancer therapy. In this study, doxorubicin (DOX) loaded and glycyrrhetinic acid modified recombinant human serum albumin nanoparticles (DOX/GA-rHSA NPs) were prepared for targeting therapy for liver cancer. GA was covalently coupled to recombinant human serum albumin nanoparticles, which could efficiently deliver DOX into liver cancer cells. The resultant GA-rHSA NPs exhibited uniform spherical shape and high stability in plasma with fixed negative charge (∼-25 mV) and a size about 170 nm. DOX was loaded into GA-rHSA NPs with a maximal encapsulation efficiency of 75.8%. Moreover, the targeted NPs (DOX/GA-rHSA NPs) showed increased cytotoxic activity in liver tumor cells compared to the nontargeted NPs (DOX/rHSA NPs, DOX loaded recombinant human serum albumin nanoparticles without GA conjugating). The targeted NPs exhibited higher cellular uptake in a GA receptor-positive liver cancer cell line than nontargeted NPs as measured by both flow cytometry and confocal laser scanning microscopy. Biodistribution experiments showed that DOX/GA-rHSA NPs exhibited a much higher level of tumor accumulation than nontargeted NPs at 1 h after injection in hepatoma-bearing Balb/c mice. Therefore, the DOX/GA-rHSA NPs could be considered as an efficient nanoplatform for targeting drug delivery system for liver cancer. PMID:25584860

  10. Forster resonance energy transfer in the system of human serum albumin-xanthene dyes

    NASA Astrophysics Data System (ADS)

    Kochubey, V. I.; Pravdin, A. B.; Melnikov, A. G.; Konstantinova, I.; Alonova, I. V.

    2016-04-01

    The processes of interaction of fluorescent probes: eosin and erythrosine with human serum albumin (HSA) were studied by the methods of absorption and fluorescence spectroscopy. Extinction coefficients of probes were determined. Critical transfer radius and the energy transfer efficiency were defined by fluorescence quenching of HSA. Analysis of the excitation spectra of HSA revealed that the energy transfer process is carried out mainly between tryptophanyl and probes.

  11. Spectral Changes of Erythrosin B Luminescence Upon Binding to Bovine Serum Albumin

    NASA Astrophysics Data System (ADS)

    Sablin, N. V.; Gerasimova, M. A.; Nemtseva, E. V.

    2016-04-01

    Changes in absorption, fluorescence, phosphorescence, and delayed fluorescence spectra of erythrosin B are studied in the presence of bovine serum albumin at room temperature. Spectral and chronoscopic characteristics of the observed photophysical processes are defined. The binding of erythrosin B with the protein followed by spectral changes is demonstrated. Absorption and fluorescence spectra of the dye in the bound state are described, the binding mechanism is analyzed. The binding parameters of the dye-protein complex are estimated.

  12. Patterns of the adsorption of bovine serum albumin on carboxymethyl dextran and carboxymethyl cellulose films

    NASA Astrophysics Data System (ADS)

    Paribok, I. V.; Solomyanskii, A. E.; Zhavnerko, G. K.

    2016-02-01

    Patterns of the adsorption of bovine serum albumin on carboxymethyl dextran and carboxymethyl cellulose films are studied by means of microcontact printing, atomic force microscopy, and quartz crystal microbalance. It is shown that both the charge of polysaccharide macromolecules and the technique for deposition of their films onto the surface (via adsorption from a solution or covalent cross-linking) are factors that determine the degree of nonspecific adsorption of the protein on such films.

  13. Synthesis of Fluorine-18 Radio-labeled Serum Albumins for PET Blood Pool Imaging

    PubMed Central

    Basuli, Falguni; Li, Changhui; Xu, Biying; Williams, Mark; Wong, Karen; Coble, Vincent L; Vasalatiy, Olga; Seidel, Jurgen; Green, Michael V.; Griffiths, Gary L.; Choyke, Peter L.; Jagoda, Elaine M.

    2015-01-01

    We sought to develop a practical, reproducible and clinically translatable method of radiolabeling serum albumins with fluorine-18 for use as a PET blood pool imaging agent in animals and man. Fluorine-18 radiolabeled fluoronicotinic acid-2,3,5,6-tetrafluorophenyl ester, [18F]F-Py-TFP was prepared first by the reaction of its quaternary ammonium triflate precursor with [18F]tetrabutylammonium fluoride ([18F]TBAF) according to a previously published method for peptides, with minor modifications. The incubation of [18F]F-Py-TFP with rat serum albumin (RSA) in phosphate buffer (pH 9) for 15 min at 37–40 °C produced fluorine-18-radiolabeled RSA and the product was purified using a mini-PD MiniTrap G-25 column. The overall radiochemical yield of the reaction was 18–35% (n = 30, uncorrected) in a 90-min synthesis. This procedure, repeated with human serum albumin (HSA), yielded similar results. Fluorine-18-radiolabeled RSA demonstrated prolonged blood retention (biological half-life of 4.8 hours) in healthy awake rats. The distribution of major organ radioactivity remained relatively unchanged during the 4 hour observation periods either by direct tissue counting or by dynamic PET whole-body imaging except for a gradual accumulation of labeled metabolic products in the bladder. This manual method for synthesizing radiolabeled serum albumins uses fluorine-18, a widely available PET radionuclide, and natural protein available in both pure and recombinant forms which could be scaled up for widespread clinical applications. These preclinical biodistribution and PET imaging results indicate that [18F]RSA is an effective blood pool imaging agent in rats and might, as [18F]HSA, prove similarly useful as a clinical imaging agent. PMID:25533724

  14. Detection and analysis of tupaia hepatocytes via mAbs against tupaia serum albumin

    PubMed Central

    Liu, Xuan; Yuan, Lunzhi; Yuan, Quan; Zhang, Yali; Wu, Kun; Zhang, Tianying; Wu, Yong; Hou, Wangheng; Wang, Tengyun; Liu, Pingguo; Shih, James Wai Kuo; Cheng, Tong; Xia, Ningshao

    2015-01-01

    On the basis of its close phylogenetic relationship with primates, the development of Tupaia belangeri as an infection animal model and drug metabolism model could provide a new option for preclinical studies, especially in hepatitis virus research. As a replacement for primary human hepatocytes (PHHs), primary tupaia hepatocytes (PTHs) have been widely used. Similar to human serum albumin, tupaia serum albumin (TSA) is the most common liver synthesis protein and is an important biomarker for PTHs and liver function. However, no detection or quantitative method for TSA has been reported. In this study, mouse monoclonal antibodies (mAbs) 4G5 and 9H3 against TSA were developed to recognize PTHs, and they did not show cross-reactivity with serum albumin from common experimental animals, such as the mouse, rat, cow, rabbit, goat, monkey, and chicken. The two mAbs also exhibited good performance in fluorescence activated cell sorting (FACS) analysis and immunofluorescence (IF) detection of PTHs. A chemiluminescent enzyme immune assay method using the two mAbs, with a linear range from 96.89 pg/ml to 49,609.38 pg/ml, was developed for the quantitative detection of TSA. The mAbs and the CLEIA method provide useful tools for research on TSA and PTHs. PMID:26597317

  15. Detection and analysis of tupaia hepatocytes via mAbs against tupaia serum albumin.

    PubMed

    Liu, Xuan; Yuan, Lunzhi; Yuan, Quan; Zhang, Yali; Wu, Kun; Zhang, Tianying; Wu, Yong; Hou, Wangheng; Wang, Tengyun; Liu, Pingguo; Shih, James Wai Kuo; Cheng, Tong; Xia, Ningshao

    2016-05-20

    On the basis of its close phylogenetic relationship with primates, the development of Tupaia belangeri as an infection animal model and drug metabolism model could provide a new option for preclinical studies, especially in hepatitis virus research. As a replacement for primary human hepatocytes (PHHs), primary tupaia hepatocytes (PTHs) have been widely used. Similar to human serum albumin, tupaia serum albumin (TSA) is the most common liver synthesis protein and is an important biomarker for PTHs and liver function. However, no detection or quantitative method for TSA has been reported. In this study, mouse monoclonal antibodies (mAbs) 4G5 and 9H3 against TSA were developed to recognize PTHs, and they did not show cross-reactivity with serum albumin from common experimental animals, such as the mouse, rat, cow, rabbit, goat, monkey, and chicken. The two mAbs also exhibited good performance in fluorescence activated cell sorting (FACS) analysis and immunofluorescence (IF) detection of PTHs. A chemiluminescent enzyme immune assay method using the two mAbs, with a linear range from 96.89 pg/ml to 49,609.38 pg/ml, was developed for the quantitative detection of TSA. The mAbs and the CLEIA method provide useful tools for research on TSA and PTHs. PMID:26597317

  16. Equilibrium Sorption of Structurally Diverse Organic Ions to Bovine Serum Albumin.

    PubMed

    Henneberger, Luise; Goss, Kai-Uwe; Endo, Satoshi

    2016-05-17

    Reliable partitioning data are essential for assessing the bioaccumulation potential and the toxicity of chemicals. In contrast to neutral organic chemicals, the partitioning behavior of ionogenic organic chemicals (IOCs) is still a black box for environmental scientists. Partitioning to serum albumin, the major protein in blood plasma, strongly influences the freely dissolved concentration of many chemicals (including IOCs), which affects their transport and distribution in the body. Because consistent data sets for partitioning of IOCs are rarely available, bovine serum albumin-water partition coefficients (KBSA/w) were measured in this study for 45 anionic and 4 cationic organic chemicals, including various substituted benzoic and naphthoic acids, sulfonates and several pesticides and pharmaceuticals. The results of this study suggest that binding to BSA is substantially influenced by the three-dimensional structure of the chemicals and the position of substitutions on the sorbing molecules. For example, we found a difference of >1.5 log units between isomeric chemicals such as 3,4-dichlorobenzoic acid and 2,6-dichlorobenzoic acid, and 1-naphthoic acid and 2-naphthoic acid. Conventional modeling approaches (e.g., based on octanol-water partition coefficients) poorly predict log KBSA/w of organic ions (R(2) ≤ 0.5), partially because they do not capture the observed steric effects. Hence, alternative modeling strategies will be required for accurate prediction of serum albumin-water partition coefficients of organic ions. PMID:27098963

  17. Spectroscopic studies of the interaction between tetra-substituted aluminum phthalocyanines and bovine serum albumin

    NASA Astrophysics Data System (ADS)

    He, Yipeng; Zheng, Liqin; Huang, Yide; Lin, Pingping; Yang, Hongqin; Peng, Yiru

    2014-11-01

    Serum albumin, the most abundant plasma protein in mammalian blood, shows significant effects on delivery and therapeutic efficacy of drugs, therefore, the investigation of binding interaction between serum albumin and drugs is vital and necessary. In the present study, the binding interaction of two aluminum (III) phthalocyanine (AlPc) derivatives, tetrasulfonate- and tetra-(p-sulfoazophenyl-4-aminosulfonyl)-substituted AlPc (complexes 1 and 2), with bovine serum albumin (BSA) was investigated by UV-Vis and fluorescence spectroscopy. Adding BSA to the Pc complexes in water caused remarkable changes in the Q-band of the Pc complexes, indicating an altered aggregation behavior. When titrating these AlPcs with BSA in PBS, the intrinsic fluorescence of BSA was significantly quenched through a static quenching process. The binding of Pc complexes to BSA might change its conformation, evidenced by the red shift of maximum emission wavelength. Furthermore, binding constants and binding sites were obtained and binding ability between the Pc complexes and BSA was assessed. Our results suggest that complexes 1 and 2 readily interact with BSA whereas the latter shows more affinity (with higher binding constant value) to BSA, implying the stretched amphiphilic substituents of complex 2 may contribute to their transportation in the blood.

  18. Water-soluble noncovalent adducts of the heterometallic copper subgroup complexes and human serum albumin with remarkable luminescent properties.

    PubMed

    Chelushkin, P S; Krupenya, D V; Tseng, Yu-Jui; Kuo, Ting-Yi; Chou, Pi-Tai; Koshevoy, I O; Burov, S V; Tunik, S P

    2014-01-25

    Novel water-soluble noncovalent adducts of the heterometallic copper subgroup complexes and human serum albumin (HSA) display strong phosphorescence, internalize into HeLa cells and can be used in time-resolved fluorescent imaging. PMID:24296768

  19. Identification of cross-reactive single-domain antibodies against serum albumin using next-generation DNA sequencing.

    PubMed

    Henry, Kevin A; Tanha, Jamshid; Hussack, Greg

    2015-10-01

    Antibodies that cross-react with multiple isoforms or homologue of a given protein are often desirable, especially in therapeutic applications. Here, we report the identification of several unique, clonally unrelated, single-domain antibodies (sdAbs) that bind to multiple serum albumin orthologues (human, rhesus, rat and mouse) with low-to-medium nanomolar affinity from a llama immunized only with human serum albumin. Using single-round panning of a phage-displayed sdAb library against serum albumins and next-generation DNA sequencing, we were able to predict patterns of sdAb reactivity to the albumins of different species with ∼90% accuracy. We expect this strategy to be generally applicable for identifying cross-reactive sdAbs, particularly when these exist at low frequency and/or are poorly enriched by panning. Moreover, the sdAbs identified here are of potential interest for serum half-life extension of biologics. PMID:26319004

  20. Surface-enhanced Raman spectroscopy study of the interaction of antitumoral drug Paclitaxel with human serum albumin

    NASA Astrophysics Data System (ADS)

    Yan, Tianxiu; Gu, Huaimin; Yuan, Xiaojuan; Wu, Jiwei; Wei, Huajiang

    2008-12-01

    SERS spectroscopy was employed to study the interaction of the antitumoral drug paclitaxel with human serum albumin. The normal Raman spectrum of the paclitaxel was shown in this study for the first time. There were some differences existing in the surface-enhanced Raman scattering (SERS) spectrum of paclitaxel and its human serum albumin (HSA), which demonstrated that there was high bioaffinity of paclitaxel to human serum albumin. And it was also found that there existed some differences in the SERS of the paclitaxel/HSA complexes at different pH values, which may indicated some significant information on the binding site, by which paclitaxel binds to human serum albumin. It can provide significant instruction in the synthesis of the drug and in improving the therapeutic efficacy of this drug.

  1. Interaction of some cardiovascular drugs with bovine serum albumin at physiological conditions using glassy carbon electrode: A new approach.

    PubMed

    Afsharan, Hadi; Hasanzadeh, Mohammad; Shadjou, Nasrin; Jouyban, Abolghasem

    2016-08-01

    In this report, for the first time, the non-modified glassy carbon electrode was used for detection of cardiovascular drug interaction with bovine serum albumin (BSA). These interactions were tested at physiological conditions (T=37°C and pH=7.4 phosphate buffer solution) in different incubation times (0-4h) by cyclic voltammetry (CV), differential pulse voltammetry (DPV) and square wave voltammetry (SWV). The applications of DPV for quantitative investigation of some cardiovascular drug interaction with BSA (as a model of serum albumin proteins) were discussed. The herein described approach is expected to promote the exploitation of electrochemically-based methods for the study of drug-serum albumin protein interaction which is necessary in biochemical and biosensing studies. This report may open a new window to application of electrochemical sensors towards interactions of cardiovascular drugs with BSA and human serum albumin (HAS) in the near future. PMID:27157732

  2. Circular dichroism study of the interaction between mutagens and bilirubin bound to different binding sites of serum albumins.

    PubMed

    Orlov, Sergey; Goncharova, Iryna; Urbanová, Marie

    2014-05-21

    Although recent investigations have shown that bilirubin not only has a negative role in the organism but also exhibits significant antimutagenic properties, the mechanisms of interactions between bilirubin and mutagens are not clear. In this study, interaction between bilirubin bound to different binding sites of mammalian serum albumins with structural analogues of the mutagens 2-aminofluorene, 2,7-diaminofluorene and mutagen 2,4,7-trinitrofluorenone were investigated by circular dichroism and absorption spectroscopy. Homological human and bovine serum albumins were used as chiral matrices, which preferentially bind different conformers of bilirubin in the primary binding sites and make it observable by circular dichroism. These molecular systems approximated a real system for the study of mutagens in blood serum. Differences between the interaction of bilirubin bound to primary and to secondary binding sites of serum albumins with mutagens were shown. For bilirubin bound to secondary binding sites with low affinity, partial displacement and the formation of self-associates were observed in all studied mutagens. The associates of bilirubin bound to primary binding sites of serum albumins are formed with 2-aminofluorene and 2,4,7-trinitrofluorenone. It was proposed that 2,7-diaminofluorene does not interact with bilirubin bound to primary sites of human and bovine serum albumins due to the spatial hindrance of the albumins binding domains. The spatial arrangement of the bilirubin bound to serum albumin along with the studied mutagens was modelled using ligand docking, which revealed a possibility of an arrangement of the both bilirubin and 2-aminofluorene and 2,4,7-trinitrofluorenone in the primary binding site of human serum albumin. PMID:24589992

  3. Dependence of the solubility of natural flavonoids in water on the concentration of miramistin, polyvinylpyrrolidone, and human serum albumin

    NASA Astrophysics Data System (ADS)

    Lipkovska, N. A.; Barvinchenko, V. N.; Fedyanina, T. V.

    2014-05-01

    In organized media of the cationic surfactant miramistin and the polymers polyvinylpyrrolidone and human serum albumin, the solubility of natural flavonoids quercetin and rutin increased by one or two orders of magnitude. The increase was more significant for hydrophobic quercetin than for hydrophilic rutin. The solubility also depended on the structure and self-organization of molecules in organized media and the site of flavonoids in them. The calculated binding constants increased in the series polyvinylpyrrolidone < miramistin < human serum albumin.

  4. Allosteric Sensing of Fatty Acid Binding by NMR: Application to Human Serum Albumin.

    PubMed

    Jafari, Naeimeh; Ahmed, Rashik; Gloyd, Melanie; Bloomfield, Jonathon; Britz-McKibbin, Philip; Melacini, Giuseppe

    2016-08-25

    Human serum albumin (HSA) serves not only as a physiological oncotic pressure regulator and a ligand carrier but also as a biomarker for pathologies ranging from ischemia to diabetes. Moreover, HSA is a biopharmaceutical with a growing repertoire of putative clinical applications from hypovolemia to Alzheimer's disease. A key determinant of the physiological, diagnostic, and therapeutic functions of HSA is the amount of long chain fatty acids (LCFAs) bound to HSA. Here, we propose to utilize (13)C-oleic acid for the NMR-based assessment of albumin-bound LCFA concentration (CONFA). (13)C-Oleic acid primes HSA for a LCFA-dependent allosteric transition that modulates the frequency separation between the two main (13)C NMR peaks of HSA-bound oleic acid (ΔνAB). On the basis of ΔνAB, the overall [(12)C-LCFA]Tot/[HSA]Tot ratio is reproducibly estimated in a manner that is only minimally sensitive to glycation, albumin concentration, or redox potential, unlike other methods to quantify HSA-bound LCFAs such as the albumin-cobalt binding assay. PMID:27429126

  5. Fluorescence Spectroscopic Studies on the Complexation of Antidiabetic Drugs with Glycosylated Serum Albumin

    NASA Astrophysics Data System (ADS)

    Seedher, N.; Kanojia, M.

    2013-11-01

    Glycosylation decreases the association constant values and hence the binding affinity of human serum albumin (HSA) for the antidiabetic drugs under study. The percentage of HAS-bound drug at physiological temperature was only about 21-38 % as compared to 46-74 % for non-glycosylated HSA. Thus the percentage of free drug available for an antihyperglycemic effect was about double (62-79 %) compared to the values for non-glycosylated HSA. Much higher free drug concentrations available for pharmacological effect can lead to the risk of hypoglycemia. Hydrophobic interactions were predominantly involved in the binding. In the binding of gliclazide, hydrogen bonding and electrostatic interactions were involved. Site specificity for glycosylated HSA was the same as that for non-glycosylated HSA; gliclazide and repaglinide bind only at site II whereas glimepiride and glipizide bind at both sites I and II. Glycosylation, however, caused conformational changes in albumin, and the binding region within site II was different for glycosylated and non-glycosylated albumin. Stern-Volmer analysis also indicated the conformational changes in albumin as a result of glycosylation and showed that the dynamic quenching mechanism was valid for fluorescence of both glycosylated and non-glycosylated HSA.

  6. Influence of serum albumin on intracellular delivery of drug-loaded hyaluronan polymeric micelles.

    PubMed

    Nešporová, Kristina; Šógorková, Jana; Šmejkalová, Daniela; Kulhánek, Jaromír; Huerta-Angeles, Gloria; Kubala, Lukáš; Velebný, Vladimír

    2016-09-10

    Polymeric micelles are attractive drug delivery systems for intravenously administered nonpolar drugs. Although physical parameters like size, shape and loading capacity are considered as the most important for their efficiency, here we demonstrate that the effects of serum protein interaction and characteristics of loaded compound cannot be neglected during the micelle development and design of experimental set up. Polymeric micelles prepared from amphiphilic hyaluronic acid grafted with short (hexanoic) and long fatty acids (oleic) were tested after loading with two different hydrophobic models, Nile red and curcumin. The composition of micelles affected mainly the loading capacity. Both encapsulated compounds behaved differently in the in vitro cell uptake, which was also influenced by serum concentration, where serum albumin was found to be the primary destabilizing component. This destabilization was found to be influenced by polymeric micelle concentration. Thus, the chemical structure of micelle, the properties of non-covalently loaded substance and serum albumin/polymeric micelle ratio modulate the in vitro intracellular uptake of drugs loaded in nanocarriers. PMID:27473277

  7. Locations of the three primary binding sites for long-chain fatty acids on bovine serum albumin

    SciTech Connect

    Hamilton, J.A.; Era, S.; Bhamidipati, S.P. ); Reed, R.G. )

    1991-03-15

    Binding of {sup 13}C-enriched oleic acid to bovine serum albumin and to three large proteolytic fragments of albumin - two complementary fragments corresponding to the two halved of albumin and one fragment corresponding to the carboxyl-terminal domain - yielded unique patterns of NMR resonances (chemical shifts and relative intensities) that were used to identify the locations of binding of the first 5 mol of oleic acid to the multidomain albumin molecule. The first 3 mol of oleic acid added to intact albumin generated three distinct NMR resonances as a result of simultaneous binding of oleic acid to three heterogeneous sites (primary sites). This distribution suggests albumin to be a less symmetrical binding molecule than theoretical models predict. This work also demonstrates the power of NMR for the study of microenvironments of individual fatty acid binding sites in specific domain.

  8. Polypharmacotherapy in rheumatology: 1H NMR analysis of binding of phenylbutazone and methotrexate to serum albumin

    NASA Astrophysics Data System (ADS)

    Maciążek-Jurczyk, M.; Sułkowska, A.; Równicka-Zubik, J.; Bojko, B.; Szkudlarek-Haśnik, A.; Knopik, M.; Sułkowski, W. W.

    2011-05-01

    The influence of phenylbutazone (Phe) and methotrexate (MTX) on binding of MTX and Phe to human (HSA) and bovine (BSA) serum albumin in the low-affinity binding sites is investigated. The strength and kind of interactions between serum albumin (SA) and drugs used in combination therapy were found using 1H NMR spectroscopy. A stoichiometric molar ratios for Phe-SA and MTX-SA complexes are 36:1 and 31:1, respectively. It appeared these molar ratios are higher for the ternary systems than it were in the binary ones. The presence of the additional drug (MTX or Phe) causes the increase of an affinity of albumin towards Phe and MTX. It was found that the aliphatic groups of MTX are more resistant to the influence of Phe on the MTX-SA complex than the aromatic rings. The results showed the important impact of another drug (MTX or Phe) on the affinity of SA towards Phe and MTX in the low-affinity binding sites. This work is a subsequent part of the spectroscopic study on Phe-MTX-SA interactions (Maciążek-Jurczyk, 2009 [1]).

  9. Alteration of methotrexate binding to human serum albumin induced by oxidative stress. Spectroscopic comparative study

    NASA Astrophysics Data System (ADS)

    Maciążek-Jurczyk, M.; Sułkowska, A.; Równicka-Zubik, J.

    2016-01-01

    Changes of oxidative modified albumin conformation by comparison of non-modified (HSA) and modified (oHSA) human serum albumin absorption spectra, Red Edge Excitation Shift (REES) effect and fluorescence synchronous spectra were investigated. Studies of absorption spectra indicated that changes in the value of absorbance associated with spectral changes in the region from 200 to 250 nm involve structural alterations related to variations in peptide backbone conformation. Analysis of the REES effect allowed for the observation of changes caused by oxidation in the region of the hydrophobic pocket containing the tryptophanyl residue. Synchronous fluorescence spectroscopy confirmed changes of the position of the tryptophanyl and tyrosil residues fluorescent band. Effect of oxidative stress on binding of methotrexate (MTX) was investigated by spectrofluorescence, UV-VIS and 1HNMR spectroscopy. MTX caused the fluorescence quenching of non-modified (HSA) and modified (oHSA) human serum albumin molecule. The values of binding constants, Hill's coefficients and a number of binding sites in the protein molecule in the high affinity binding site were calculated for the binary MTX-HSA and MTX-oHSA systems. For these systems, qualitative analysis in the low affinity binding sites was performed with the use of the 1HNMR technique.

  10. Carbamylation of Serum Albumin as a Risk Factor for Mortality in Patients with Kidney Failure

    PubMed Central

    Berg, Anders H.; Drechsler, Christiane; Wenger, Julia; Buccafusca, Roberto; Hod, Tammy; Kalim, Sahir; Ramma, Wenda; Parikh, Samir M.; Steen, Hanno; Friedman, David J.; Danziger, John; Wanner, Christoph; Thadhani, Ravi; Karumanchi, S. Ananth

    2013-01-01

    Urea, the toxic end-product of protein catabolism, is elevated in end-stage renal disease (ESRD), although it is unclear whether or how it contributes to disease. Urea can promote the carbamylation of proteins on multiple lysine side chains, including human albumin, which has a predominant carbamylation site on lysine 549. The proportion of serum albumin carbamylated on Lys-549 (%C-Alb) correlated with time-averaged blood urea concentrations and was twice as high in ESRD patients than in non-uremic subjects (0.90% vs. 0.42%, P<0.0001). Baseline %C-Alb was higher in ESRD subjects who died within 1-year than in those who survived longer than 1 year (1.01% vs. 0.77%, P<0.001) and was associated with an increased risk of death within 1 year (HR of 3.76, 95% CI: 2.20–6.43, P<0.0001). These findings were validated in an independent cohort of diabetic ESRD subjects (HR 3.73, 95% CI: 2.00–6.96, P<0.001). Decreased concentrations of serum amino acids correlated with higher %C-Alb in ESRD patients, and mice with diet-induced amino acid deficiencies exhibited greater susceptibility to albumin carbamylation than did chow-fed mice. In vitro studies showed that amino acids such as cysteine, histidine, arginine, lysine, as well as other nucleophiles such as taurine, inhibited cyanate-induced C-Alb formation at physiologic pH and temperature. Together, these results suggest that chronically elevated urea promotes carbamylation of proteins in ESRD, and that serum amino acid concentrations may modulate this protein modification. In summary, we have identified serum %C-Alb as a risk factor for mortality in patients with ESRD and propose that this risk factor may be modifiable with supplemental amino acid therapy. PMID:23467560

  11. Maternal serum ischemia modified albumin as a marker for hypertensive disorders of pregnancy: a pilot study

    PubMed Central

    Vyakaranam, Sapna; Bhongir, Aparna Varma; Patlolla, Dakshayani; Chintapally, Rekha

    2015-01-01

    Background Hypoxia driven oxidative stress of the placenta contributes to the pathogenesis of preeclampsia. Serum Ischemia Modified Albumin (IMA) has recently emerged as an oxidative stress marker, used in diagnosis of cardiac ischemia. Aim: To determine the efficiency of serum IMA in differentiating hypertensive disorders of pregnancy (pregnancy induced hypertension, preeclampsia) from normal pregnancy. Methods It was a case control study. Pregnant women ≥32 weeks of gestation. Study population were included 3 groups, 19 Normotensive Pregnant (NP) women as controls, 18 pregnant women with Pregnancy Induced Hypertension (PIH) and 19 with preeclampsia (PE). Serum IMA was estimated by Enzyme Linked Immune Sorbent Assay (ELISA). Results were analyzed by student ‘t’test. Critical values for serum IMA were obtained by Receiver Operation Characteristics (ROC) curves. Results Serum IMA levels were significantly elevated in PE (56.84 ± 21.57 ng/ml) when compared with PIH (36.24 ± 14.51 ng/ml) and NP (35.47 ± 11.58 ng/ml) (P value <0.001). With a cutoff of 38.33 ng/ml, sensitivity and specificity for preeclampsia was 88.9% and 73.7% respectively. Conclusions Our study demonstrated that serum IMA, an oxidative stress marker is elevated in PE & PIH. Hence serum IMA can undergo further evaluation as a marker of PE. PMID:26636109

  12. Investigation of Bovine Serum Albumin (BSA) Attachment onto Self-Assembled Monolayers (SAMs) Using Combinatorial Quartz Crystal Microbalance with Dissipation (QCM-D) and Spectroscopic Ellipsometry (SE)

    PubMed Central

    Phan, Hanh T. M.; Bartelt-Hunt, Shannon; Rodenhausen, Keith B.; Schubert, Mathias; Bartz, Jason C.

    2015-01-01

    Understanding protein adsorption kinetics to surfaces is of importance for various environmental and biomedical applications. Adsorption of bovine serum albumin to various self-assembled monolayer surfaces including neutral and charged hydrophilic and hydrophobic surfaces was investigated using in-situ combinatorial quartz crystal microbalance with dissipation and spectroscopic ellipsometry. Adsorption of bovine serum albumin varied as a function of surface properties, bovine serum albumin concentration and pH value. Charged surfaces exhibited a greater quantity of bovine serum albumin adsorption, a larger bovine serum albumin layer thickness, and increased density of bovine serum albumin protein compared to neutral surfaces at neutral pH value. The quantity of adsorbed bovine serum albumin protein increased with increasing bovine serum albumin concentration. After equilibrium sorption was reached at pH 7.0, desorption of bovine serum albumin occurred when pH was lowered to 2.0, which is below the isoelectric point of bovine serum albumin. Our data provide further evidence that combinatorial quartz crystal microbalance with dissipation and spectroscopic ellipsometry is a sensitive analytical tool to evaluate attachment and detachment of adsorbed proteins in systems with environmental implications. PMID:26505481

  13. Association of a high normalized protein catabolic rate and low serum albumin level with carpal tunnel syndrome in hemodialysis patients.

    PubMed

    Huang, Wen-Hung; Hsu, Ching-Wei; Weng, Cheng-Hao; Yen, Tzung-Hai; Lin, Jui-Hsiang; Lee, Meng

    2016-06-01

    Carpal tunnel syndrome (CTS) is the most common mononeuropathy in patients with end-stage renal disease (ESRD). The association between chronic inflammation and CTS in hemodialysis (HD) patients has rarely been investigated. HD patients with a high normalized protein catabolic rate (nPCR) and low serum albumin level likely have adequate nutrition and inflammation. In this study, we assume that a low serum albumin level and high nPCR is associated with CTS in HD patients. We recruited 866 maintenance hemodialysis (MHD) patients and divided them into 4 groups according to their nPCR and serum albumin levels: (1) nPCR <1.2 g/kg/d and serum albumin level <4 g/dL; (2) nPCR ≥1.2 g/kg/d and serum albumin level <4 g/dL; (3) nPCR <1.2 g/kg/d and serum albumin level ≥4 g/dL; and (4) nPCR ≥1.2 g/kg/d and serum albumin level ≥4 g/dL. After adjustment for related variables, HD duration and nPCR ≥1.2 g/kg/d and serum albumin level <4 g/dL were positively correlated with CTS. By calculating the area under the receiver-operating characteristic curve, we calculated that the nPCR and HD duration cut-off points for obtaining the most favorable Youden index were 1.29 g/kg/d and 7.5 years, respectively. Advance multivariate logistic regression analysis revealed that in MHD patients, nPCR ≥1.29 g/kg/d and serum albumin <4 g/dL, and also HD duration >7.5 years were associated with CTS. A high nPCR and low serum albumin level, which likely reflect adequate nutrition and inflammation, were associated with CTS in MHD patients. PMID:27368039

  14. Association of a high normalized protein catabolic rate and low serum albumin level with carpal tunnel syndrome in hemodialysis patients

    PubMed Central

    Huang, Wen-Hung; Hsu, Ching-Wei; Weng, Cheng-Hao; Yen, Tzung-Hai; Lin, Jui-Hsiang; Lee, Meng

    2016-01-01

    Abstract Carpal tunnel syndrome (CTS) is the most common mononeuropathy in patients with end-stage renal disease (ESRD). The association between chronic inflammation and CTS in hemodialysis (HD) patients has rarely been investigated. HD patients with a high normalized protein catabolic rate (nPCR) and low serum albumin level likely have adequate nutrition and inflammation. In this study, we assume that a low serum albumin level and high nPCR is associated with CTS in HD patients. We recruited 866 maintenance hemodialysis (MHD) patients and divided them into 4 groups according to their nPCR and serum albumin levels: (1) nPCR <1.2 g/kg/d and serum albumin level <4 g/dL; (2) nPCR ≥1.2 g/kg/d and serum albumin level <4 g/dL; (3) nPCR <1.2 g/kg/d and serum albumin level ≥4 g/dL; and (4) nPCR ≥1.2 g/kg/d and serum albumin level ≥4 g/dL. After adjustment for related variables, HD duration and nPCR ≥1.2 g/kg/d and serum albumin level <4 g/dL were positively correlated with CTS. By calculating the area under the receiver-operating characteristic curve, we calculated that the nPCR and HD duration cut-off points for obtaining the most favorable Youden index were 1.29 g/kg/d and 7.5 years, respectively. Advance multivariate logistic regression analysis revealed that in MHD patients, nPCR ≥1.29 g/kg/d and serum albumin <4 g/dL, and also HD duration >7.5 years were associated with CTS. A high nPCR and low serum albumin level, which likely reflect adequate nutrition and inflammation, were associated with CTS in MHD patients. PMID:27368039

  15. Characterizing Active Pharmaceutical Ingredient Binding to Human Serum Albumin by Spin-Labeling and EPR Spectroscopy.

    PubMed

    Hauenschild, Till; Reichenwallner, Jörg; Enkelmann, Volker; Hinderberger, Dariush

    2016-08-26

    Drug binding to human serum albumin (HSA) has been characterized by a spin-labeling and continuous-wave (CW) EPR spectroscopic approach. Specifically, the contribution of functional groups (FGs) in a compound on its albumin-binding capabilities is quantitatively described. Molecules from different drug classes are labeled with EPR-active nitroxide radicals (spin-labeled pharmaceuticals (SLPs)) and in a screening approach CW-EPR spectroscopy is used to investigate HSA binding under physiological conditions and at varying ratios of SLP to protein. Spectral simulations of the CW-EPR spectra allow extraction of association constants (KA ) and the maximum number (n) of binding sites per protein. By comparison of data from 23 SLPs, the mechanisms of drug-protein association and the impact of chemical modifications at individual positions on drug uptake can be rationalized. Furthermore, new drug modifications with predictable protein binding tendency may be envisaged. PMID:27460503

  16. Role of Serum Interleukin 6, Albumin and C-Reactive Protein in COPD Patients

    PubMed Central

    Emami Ardestani, Mohammad

    2015-01-01

    Background: Chronic obstructive pulmonary disease (COPD) is a non-specific inflammation, which involves the airways, lung parenchyma and pulmonary vessels. The inflammation causes the activation of inflammatory cells and the release of various inflammatory mediators such as interleukin-8 (IL-8), IL-6 and tumor necoris factor alpha (TNF-a). The purpose of the present study was to measure serum IL-6, C-reactive protein (CRP) (as a positive phase reactant) and albumin level (as a negative phase reactant) in COPD patients (only due to cigarette smoking not bio-mass), non COPD smokers and healthy subjects using enzyme-linked immunosorbent assay (ELISA); we compared the differences in inflammatory factors among groups. Materials and Methods: A total of 180 males were enrolled in this study and divided into three equal groups. The first group was 60 smokers who had COPD. The second group included 60 smokers without COPD and the third group consisted of people who were not smokers and did not have COPD; 5 mL of venous blood was taken from all participants and it was collected in a test tube containing anticoagulant and then centrifuged at 3000 rpm for 10 minutes. Serum was separated and used to measure the amount of IL-6, CRP and albumin. Spirometry was performed according to the criteria set by the American Thoracic Society. Results: The mean serum level of IL-6 was 83.2±7.5 pg/mL in group I, 54.9±24.3 pg/mL in group II and 46.9±10.4 pg/mL in group III. There was a significant difference among the three groups (P<0.001). The mean serum level of CRP was 28.9±14.9 mg/dL in the first group, 19.9±8.5 mg/dL in the second group and 4.2±2.3 mg/dL in the third group (P=0.02). But by controlling the confounding effects of age, this difference was not significant (P=0.49). The mean serum level of albumin was I 4.1±0.57 mg/dL in group I, 4.3±0.56 mg/dL in group II and 4.1±0.53 mg/dL in group III. There was no significant difference among the three groups in this regard (P=0

  17. Study on the interaction of the toxic food additive carmoisine with serum albumins: a microcalorimetric investigation.

    PubMed

    Basu, Anirban; Kumar, Gopinatha Suresh

    2014-05-30

    The interaction of the synthetic azo dye and food colorant carmoisine with human and bovine serum albumins was studied by microcalorimetric techniques. A complete thermodynamic profile of the interaction was obtained from isothermal titration calorimetry studies. The equilibrium constant of the complexation process was of the order of 10(6)M(-1) and the binding stoichiometry was found to be 1:1 with both the serum albumins. The binding was driven by negative standard molar enthalpy and positive standard molar entropy contributions. The binding affinity was lower at higher salt concentrations in both cases but the same was dominated by mostly non-electrostatic forces at all salt concentrations. The polyelectrolytic forces contributed only 5-8% of the total standard molar Gibbs energy change. The standard molar enthalpy change enhanced whereas the standard molar entropic contribution decreased with rise in temperature but they compensated each other to keep the standard molar Gibbs energy change almost invariant. The negative standard molar heat capacity values suggested the involvement of a significant hydrophobic contribution in the complexation process. Besides, enthalpy-entropy compensation phenomenon was also observed in both the systems. The thermal stability of the serum proteins was found to be remarkably enhanced on binding to carmoisine. PMID:24742664

  18. Effects of perfluorooctane sulfonate on the conformation and activity of bovine serum albumin.

    PubMed

    Wang, Yanqing; Zhang, Hongmei; Kang, Yijun; Cao, Jian

    2016-06-01

    Perfluorooctane sulfonate (PFOS) is among the most prominent contaminates in human serum and has been reported to possess potential toxicity to the human body. In this study, the effects of PFOS on the conformation and activity of bovine serum albumin (BSA) were investigated in vitro. The results indicated that the binding interaction of PFOS with BSA destroyed the tertiary and secondary structures of protein with the loss of α-helix structure and the increasing of hydrophobic microenvironment of the Trp or Tyr residues. During the thermal denaturation protein, PFOS increases the protein stability of BSA. The proportion of α-helix decreased on increasing the PFOS concentration and the microenvironment of the Trp or Tyr residues becomes more hydrophobic. The results from molecular modeling indicated that BSA had not only one possible binding site to bind with PFOS by the polar interaction, hydrogen bonds and hydrophobic forces. In addition, the BSA relative activities were decreased with the increase of PFOS concentration. Such loss of BSA activity in the presence of PFOS indicated that one of the binding sites in BSA is located in subdomain IIIA, which is in good agreement with the fluorescence spectroscopic experiments and molecular modeling results. This study offers a comprehensive picture of the interactions of PFOS with serum albumin and provides insights into the toxicological effect of perfluoroalkylated substances. PMID:27031195

  19. Spectroscopic and molecular modelling studies of binding mechanism of metformin with bovine serum albumin

    NASA Astrophysics Data System (ADS)

    Sharma, Deepti; Ojha, Himanshu; Pathak, Mallika; Singh, Bhawna; Sharma, Navneet; Singh, Anju; Kakkar, Rita; Sharma, Rakesh K.

    2016-08-01

    Metformin is a biguanide class of drug used for the treatment of diabetes mellitus. It is well known that serum protein-ligand binding interaction significantly influence the biodistribution of a drug. Current study was performed to characterize the binding mechanism of metformin with serum albumin. The binding interaction of the metformin with bovine serum albumin (BSA) was examined using UV-Vis absorption spectroscopy, fluorescence, circular dichroism, density functional theory and molecular docking studies. Absorption spectra and fluorescence emission spectra pointed out the weak binding of metformin with BSA as was apparent from the slight change in absorbance and fluorescence intensity of BSA in presence of metformin. Circular dichroism study implied the significant change in the conformation of BSA upon binding with metformin. Density functional theory calculations showed that metformin has non-planar geometry and has two energy states. The docking studies evidently signified that metformin could bind significantly to the three binding sites in BSA via hydrophobic, hydrogen bonding and electrostatic interactions. The data suggested the existence of non-covalent specific binding interaction in the complexation of metformin with BSA. The present study will certainly contribute to the development of metformin as a therapeutic molecule.

  20. Interaction of phenylbutazone and colchicine in binding to serum albumin in rheumatoid therapy: 1H NMR study

    NASA Astrophysics Data System (ADS)

    Maciążek-Jurczyk, M.; Sułkowska, A.; Bojko, B.; Równicka-Zubik, J.; Sułkowski, W. W.

    2009-09-01

    The monitoring of drug concentration in blood serum is necessary in multi-drug therapy. Mechanism of drug binding with serum albumin (SA) is one of the most important factors which determine drug concentration and its transport to the destination tissues. In rheumatoid diseases drugs which can induce various adverse effects are commonly used in combination therapy. Such proceeding may result in the enhancement of those side effects due to drug interaction. Interaction of phenylbutazone and colchicine in binding to serum albumin and competition between them in gout has been studied by proton nuclear magnetic resonance ( 1H NMR) technique. The aim of the study was to determine the low affinity binding sites, the strength and kind of interaction between serum albumin and drugs used in combination therapy. The study of competition between phenylbutazone and colchicine in binding to serum albumin points to the change of their affinity to serum albumin in the ternary systems. This should be taken into account in multi-drug therapy. This work is a subsequent part of the spectroscopic study on Phe-COL-SA interactions [A. Sułkowska, et al., J. Mol. Struct. 881 (2008) 97-106].

  1. Epicatechin breaks preformed glycated serum albumin and reverses the retinal accumulation of advanced glycation end products.

    PubMed

    Kim, Junghyun; Kim, Chan-Sik; Moon, Min Kyong; Kim, Jin Sook

    2015-02-01

    The accumulation of advanced glycation end products (AGEs) is associated with many of the complications of diabetes mellitus, including diabetic retinopathy. AGE-breakers, such as N-phenacylthiazolium and alagebrium, have been proposed as therapeutic agents for reversing the increase in protein crosslinking in diabetes. (-)-Epicatechin is a major dietary flavonoid with a wide range of health-promoting biological activities. The aim of this study was to determine the potential effect of (-)-epicatechin in reducing the burden of AGEs in vitro and in vivo and to evaluate whether the reduced AGE burden could translate into improvement in retinal vascular function in exogenously AGE-injected rats. Glycated human serum albumin was purified from patients with diabetes. The breakdown of the already formed AGEs was studied by treating glycated human serum albumin with (-)-epicatechin. To study the effect of (-)-epicatechin on retinal vascular function, exogenously AGE-injected rats were treated with (-)-epicatechin (50 and 100 mg/kg i.p.) for two weeks. Apoptosis of retinal vascular cells was quantified using TUNEL staining. The AGE load in the retinas was determined via immunohistochemical staining and western blot analysis. (-)-Epicatechin was able to break preformed glycated human serum albumin in vitro as well as reduce AGE accumulation in retinas in vivo in a dose dependent manner. In exogenously AGE-injected rats, treatment with (-)-epicatechin was evidenced by an improved retinal vascular apoptosis. AGE burden in retinas was also reduced upon treatment. This study suggests that (-)-epicatechin could represent a valuable drug for the treatment of diabetic retinopathy by reducing the AGE burden. PMID:25530268

  2. Imatinib binding to human serum albumin modulates heme association and reactivity.

    PubMed

    Di Muzio, Elena; Polticelli, Fabio; Trezza, Viviana; Fanali, Gabriella; Fasano, Mauro; Ascenzi, Paolo

    2014-10-15

    Imatinib, an inhibitor of the Bcr-Abl tyrosine kinase, is approximately 95% bound to plasma proteins, α1-acid glycoprotein (AGP) being the primary carrier. However, human serum albumin (HSA) may represent the secondary carrier of imatinib in pathological states characterized by low AGP levels, such as pancreatic cancer, hepatic cirrhosis, hepatitis, hyperthyroidism, nephrotic syndrome, malnutrition, and cachexia. Here, thermodynamics of imatinib binding to full-length HSA and its recombinant Asp1-Glu382 truncated form (containing only the FA1, FA2, FA6, and FA7 binding sites; trHSA), in the absence and presence of ferric heme (heme-Fe(III)), and the thermodynamics of heme-Fe(III) binding to HSA and trHSA, in the absence and presence of imatinib, has been investigated. Moreover, the effect of imatinib on kinetics of peroxynitrite detoxification by ferric human serum heme-albumin (HSA-heme-Fe(III)) and ferric truncated human serum heme-albumin (trHSA-heme-Fe(III)) has been explored. All data were obtained at pH 7.0, and 20.0 °C and 37.0 °C. Imatinib binding to the FA7 site of HSA and trHSA inhibits allosterically heme-Fe(III) association to the FA1 site and vice versa, according to linked functions. Moreover, imatinib binding to the secondary FA2 site of HSA-heme-Fe(III) inhibits allosterically peroxynitrite detoxification. Docking simulations and local structural comparison with other imatinib-binding proteins support functional data indicating the preferential binding of imatinib to the FA1 and FA7 sites of HSA, and to the FA2 and FA7 sites of HSA-heme-Fe(III). Present results highlight the allosteric coupling of the FA1, FA2, and FA7 sites of HSA, and may be relevant in modulating ligand binding and reactivity properties of HSA in vivo. PMID:25057771

  3. Determination of protein-ligand binding affinity by NMR: observations from serum albumin model systems.

    PubMed

    Fielding, Lee; Rutherford, Samantha; Fletcher, Dan

    2005-06-01

    The usefulness of bovine serum albumin (BSA) as a model protein for testing NMR methods for the study of protein-ligand interactions is discussed. Isothermal titration calorimetry established the binding affinity and stoichiometry of the specific binding site for L-tryptophan, D-tryptophan, naproxen, ibuprofen, salicylic acid and warfarin. The binding affinities of the same ligands determined by NMR methods are universally weaker (larger KD). This is because the NMR methods are susceptible to interference from additional non-specific binding. The L-tryptophan-BSA and naproxen-BSA systems were the best behaved model systems. PMID:15816062

  4. Effect of zeta potentials on bovine serum albumin adsorption to hydroxyapatite surfaces.

    PubMed

    Miyake, Nahoko; Sato, Toru; Maki, Yoshinobu

    2013-01-01

    The aim of the present study was to examine the adsorption of bovine serum albumin (BSA) to hydroxyapatite surfaces by means of zeta potential. The electrophoretic mobility of both hydroxyapatite and BSA were negative, with BSA itself less negative than hydroxyapatite. The zeta potential of the surface of BSA-adsorbed hydroxyapatite was significantly more negative than that of hydroxyapatite alone (p<0.0001). The BSA histogram indicated two negative peaks, and the zeta potential of BSA-adsorbed hydroxyapatite also showed two similar negative peaks. These results suggest that BSA adsorption to hydroxyapatite surfaces is related to electrostatic interaction. PMID:23903580

  5. Interaction of lipid vesicle with silver nanoparticle-serum albumin protein corona

    NASA Astrophysics Data System (ADS)

    Chen, Ran; Choudhary, Poonam; Schurr, Ryan N.; Bhattacharya, Priyanka; Brown, Jared M.; Chun Ke, Pu

    2012-01-01

    The physical interaction between a lipid vesicle and a silver nanoparticle (AgNP)-human serum albumin (HSA) protein "corona" has been examined. Specifically, the binding of AgNPs and HSA was analyzed by spectrophotometry, and the induced conformational changes of the HSA were inferred from circular dichroism spectroscopy. The fluidity of the vesicle, a model system for mimicking cell membrane, was found to increase with the increased exposure to AgNP-HSA corona, though less pronounced compared to that induced by AgNPs alone. This study offers additional information for understanding the role of physical forces in nanoparticle-cell interaction and has implications for nanomedicine and nanotoxicology.

  6. Is Iron Chelation Important in Preventing Glycation of Bovine Serum Albumin in Vitro?

    PubMed

    Galiniak, Sabina; Bartosz, Grzegorz; Sadowska-Bartosz, Izabela

    2015-12-01

    The role of metal (especially) iron ions has been postulated to play a prominent role in protein glycation, suggesting antiglycating effectiveness of metal chelators. However, this rule may not apply to all model glycation systems. We found that metal chelators are not effective in prevention of glycation of bovine serum albumin (BSA) in vitro, and there is no correlation between the antiglycating effects of 32 compounds and their iron chelation activity as measured with the ferrozine test. These data indicate that the glycation of BSA in vitro is iron-independent and is not a proper system to study the role of metals in protein glycation. PMID:26146126

  7. Direct interactions in the recognition between the environmental estrogen bisphenol AF and human serum albumin.

    PubMed

    Yang, Lijun; Lv, Junna; Wang, Xin; Zhang, Jing; Li, Qi; Zhang, Tingting; Zhang, Zhenzhen; Zhang, Lei

    2015-08-01

    Bisphenol AF (BPAF) was used as a model compound to investigate the binding mechanism between the endocrine disrupting compound and human serum albumin (HSA) using multispectroscopic techniques and molecular modeling method at the protein level. The results indicated that BPAF was indeed bound to HSA and located in the hydrophobic pocket of HSA on subdomain IIA through hydrogen bond and van der Waals interactions. The fluorescence quenching data showed that the binding of BPAF and HSA quenched the intrinsic fluorescence of HSA, and the static quenching constants were acquired. PMID:25694370

  8. Photophysical investigations of squaraine and cyanine dyes and their interaction with bovine serum albumin

    NASA Astrophysics Data System (ADS)

    Saikiran, M.; Sato, D.; Pandey, S. S.; Kato, T.

    2016-04-01

    A model far-red sensitive symmetrical squaraine dye (SQ-3) and unsymmetrical near infra-red sensitive cyanine dye (UCD-1) bearing direct–COOH functionalized indole ring were synthesized, characterized and subjected to photophysical investigations including their interaction with bovine serum albumin (BSA) as a model protein in phosphate buffer solution (PBS). Both of the dyes exhibit strong interaction with BSA in phosphate buffer with high apparent binding constant. A judicious tuning of hydrophobic main backbone with reactive functionality for associative interaction with active site of BSA has been found to be necessary for BSA detection in PBS.

  9. Studies of interaction between colchicine and bovine serum albumin by fluorescence quenching method

    NASA Astrophysics Data System (ADS)

    Hu, Yan-Jun; Liu, Yi; Zhang, Li-Xia; Zhao, Ru-Ming; Qu, Song-Sheng

    2005-08-01

    We investigated the interaction between colchicine and bovine serum albumin (BSA) by fluorescence and UV-Vis absorption spectroscopy. In the mechanism discussion, it was proved that the fluorescence quenching of BSA by colchicine is a result of the formation of colchicine-BSA complex; van der Waals interactions and hydrogen bonds play a major role in stabilizing the complex. The modified Stern-Volmer quenching constant Ka and corresponding thermodynamic parameters ΔH, ΔG, ΔS at different temperatures were calculated. The distance r between donor (BSA) and acceptor (colchicine) was obtained according to fluorescence resonance energy transfer (FRET).

  10. Bull serum albumin coated Au@Agnanorods as SERS probes for ultrasensitive osteosarcoma cell detection.

    PubMed

    Yue, Ji; Liu, Zhen; Cai, Xingyu; Ding, Xianting; Chen, Shouhui; Tao, Ke; Zhao, Tingbao

    2016-04-01

    Surface-Enhanced Raman scattering (SERS) has been widely used for imaging and sensing. However, limited reports are currently available on SERS-based cancer cell targeting strategy due to the challenge of synthesizing highly sensitive, reproducible and biocompatible SERS probe. Herein, we developed novel SERS probes, based on BSA (Bull Serum Albumin) coated gold-silver core-shell nanorods modified with Raman reporter 5,5-dithiobis 2-nitrobenzoic acid (DTNB) (Au@AgNRs@BSA@Anti-MICA), for in vitro cancer cell detection. Our results demonstrate that the SERS probe is very robust for cancer cell ultrasensitive detection with good biocompatibility and strong SERS signal. PMID:26838436

  11. Perturbed angular correlation experiments on the pressure-induced structural modification of bovine serum albumin.

    PubMed

    Ceolín, M

    2000-09-11

    The hydrodynamic behaviour of the bovine serum albumin (BSA) was studied by means of the Perturbed Angular Correlation (PAC) technique as a function of the hydrostatic pressure (up to 4.1 kbar) applied to the sample. The results have clearly shown that at moderated pressures (around 1.5 kbar) the BSA molecule suffers structural modifications which produces an increase of the molecular volume and the rotational correlation time of the molecule. About the reversibility of the process, our results indicate that the changes are fully irreversible. Our experiments are the first devoted to the study of the high-pressure behaviour of biological molecules using the PAC technique. PMID:10989128

  12. Layer-by-layer films from tartrazine dye with bovine serum albumin

    NASA Astrophysics Data System (ADS)

    de Souza, Nara C.; Flores, Júlio C. Johner; Silva, Josmary R.

    2009-12-01

    We report on the preparation and study of the adsorption process of layer-by-layer films of tartrazine alternated with bovine serum albumin. UV-Vis spectroscopy indicated that the films form J-aggregates of tartrazine. Adsorption kinetics was fitted by the Johnson-Mehl-Avrami equation and surface morphological analyses by atomic force microscopy suggested that the J-aggregates were column-shaped, which was attributed to the column-like symmetry of the tartrazine molecules. The columnar structures that formed probably arose from the juxtaposition of smaller aggregates that were already present at the beginning of film growth.

  13. Neo-epitopes on methylglyoxal modified human serum albumin lead to aggressive autoimmune response in diabetes.

    PubMed

    Jyoti; Mir, Abdul Rouf; Habib, Safia; Siddiqui, Sheelu Shafiq; Ali, Asif; Moinuddin

    2016-05-01

    Glyco-oxidation of proteins has implications in the progression of diabetes type 2. Human serum albumin is prone to glyco-oxidative attack by sugars and methylglyoxal being a strong glycating agent may have severe impact on its structure and consequent role in diabetes. This study has probed the methylglyoxal mediated modifications of HSA, the alterations in its immunological characteristics and possible role in autoantibody induction. We observed an exposure of chromophoric groups, loss in the fluorescence intensity, generation of AGEs, formation of cross-linked products, decrease in α-helical content, increase in hydrophobic clusters, FTIR band shift, attachment of methylglyoxal to HSA and the formation of N(ε)-(carboxyethyl) lysine in the modified HSA, when compared to the native albumin. MG-HSA was found to be highly immunogenic with additional immunogenicity invoking a highly specific immune response than its native counterpart. The binding characteristics of circulating autoantibodies in type 2 diabetes mellitus (DM) patients showed the generation of anti-MG-HSA auto-antibodies in the these patients, that are preferentially recognized by the modified albumin. We propose that MG induced structural perturbations in HSA, result in the generation of neo-epitopes leading to an aggressive auto-immune response and may contribute to the immunopathogenesis of diabetes type 2 associated complications. PMID:26861824

  14. Association between serum uric acid, urinary albumin excretion, and glycated hemoglobin in Type 2 diabetic patient

    PubMed Central

    Neupane, Sunita; Dubey, Raju Kumar; Gautam, Narayan; Agrawal, Krishna Kumar; Jayan, Archana; Shrestha, Sujata; Jha, Amit Chandra

    2016-01-01

    Background: Diabetes mellitus (DM) is a chronic disease characterized by insulin deficiency or peripheral resistance resulting in hyperglycemia. Poor glycemic control leads to diabetic complications. Hyperuricemia has been reported with increased risk of renal insufficiency. The aim of this study was to evaluate the relationship between serum uric acid concentration, degree of urinary albumin excretion (UAE) and glycated hemoglobin (HbA1c) in Type 2 DM (T2DM) patients. Materials and Methods: Serum uric acid concentrations, urine microalbumin, and HbA1c were measured in fifty T2DM patients. We then evaluated relationship between uric acid concentrations, degree of UAE and glycemic control as well as other confounding variables. Results: Serum uric acid concentration correlated positively with UAE (r = 0.323, P < 0.05), age (r = 0.337, P < 0.05), age at onset (r = 0.341, P < 0.05), and duration of DM (r = 0.312, P < 0.05). Multiple regression analysis demonstrated that serum uric acid concentration (β = 0.293, P < 0.0001), duration of DM (β = 0.261, P < 0.0001), HbA1c (β = 0.173, P < 0.005), and systolic blood pressure (β = 0.268, P < 0.005) were independent determinants of UAE. Conclusions: Serum uric acid concentration is associated with microalbuminuria and HbA1c in T2DM patients. PMID:27226687

  15. Probing the interaction of a new synthesized CdTe quantum dots with human serum albumin and bovine serum albumin by spectroscopic methods.

    PubMed

    Bardajee, Ghasem Rezanejade; Hooshyar, Zari

    2016-05-01

    A novel CdTe quantum dots (QDs) were prepared in aqueous phase via a facile method. At first, poly (acrylic amide) grafted onto sodium alginate (PAAm-g-SA) were successfully synthesized and then TGA capped CdTe QDs (CdTe-TGA QDs) were embed into it. The prepared CdTe-PAAm-g-SA QDs were optimized and characterized by transmission electron microscopy (TEM), thermo-gravimetric (TG) analysis, Fourier transform infrared (FT-IR), UV-vis and fluorescence spectroscopy. The characterization results indicated that CdTe-TGA QDs, with particles size of 2.90 nm, were uniformly dispersed on the chains of PAAm-g-SA biopolymer. CdTe-PAAm-g-SA QDs also exhibited excellent UV-vis absorption and high fluorescence intensity. To explore biological behavior of CdTe-PAAm-g-SA QDs, the interactions between CdTe-PAAm-g-SA QDs and human serum albumin (HSA) (or bovine serum albumin (BSA)) were investigated by cyclic voltammetry, FT-IR, UV-vis, and fluorescence spectroscopic. The results confirmed the formation of CdTe-PAAm-g-SA QDs-HSA (or BSA) complex with high binding affinities. The thermodynamic parameters (ΔG<0, ΔH<0 and ΔS<0) were indicated that binding reaction was spontaneous and van der Waals interactions and hydrogen-bond interactions played a major role in stabilizing the CdTe-PAAm-g-SA QDs-HSA (or BSA) complexes. The binding distance between CdTe-PAAm-g-SA QDs and HSA (or BSA)) was calculated about 1.37 nm and 1.27 nm, respectively, according to Forster non-radiative energy transfer theory (FRET). Analyzing FT-IR spectra showed that the formation of QDs-HSA and QDs-BSA complexes led to conformational changes of the HSA and BSA proteins. All these experimental results clarified the effective transportation and elimination of CdTe-PAAm-g-SA QDs in the body by binding to HSA and BSA, which could be a useful guideline for the estimation of QDs as a drug carrier. PMID:26952487

  16. In vivo uptake of heterologous alphafetoprotein and serum albumin by ependymal cells of developing chick embryos.

    PubMed

    Moro, R; Fielitz, W; Esteves, A; Grunberg, J; Uriel, J

    1984-01-01

    The in vivo uptake by neuroepithelial cells of rat serum proteins injected into the mesencephalic cavity of developing chicken was demonstrated by immunohistochemical methods. It was found that 48 h after inoculation, rat alphafetoprotein (AFP) and serum albumin (SA) localize in the same places as do chicken AFP and SA. No labelling was present for rat or chicken IgG. We also present evidence showing that chicken ovalbumin, which is not normally found inside ependymal cells is not internalized even when injected into the cerebrospinal fluid at 30-fold its physiological concentration. The existence of transient specific receptors which could be responsible for this protein uptake is proposed. The possible implications in relation to developmental biology are discussed. PMID:24873957

  17. Interaction of chlorogenic acids and quinides from coffee with human serum albumin.

    PubMed

    Sinisi, Valentina; Forzato, Cristina; Cefarin, Nicola; Navarini, Luciano; Berti, Federico

    2015-02-01

    Chlorogenic acids and their derivatives are abundant in coffee and their composition changes between coffee species. Human serum albumin (HSA) interacts with this family of compounds with high affinity. We have studied by fluorescence spectroscopy the specific binding of HSA with eight compounds that belong to the coffee polyphenols family, four acids (caffeic acid, ferulic acid, 5-O-caffeoyl quinic acid, and 3,4-dimethoxycinnamic acid) and four lactones (3,4-O-dicaffeoyl-1,5-γ-quinide, 3-O-[3,4-(dimethoxy)cinnamoyl]-1,5-γ-quinide, 3,4-O-bis[3,4-(dimethoxy)cinnamoyl]-1,5-γ-quinide, and 1,3,4-O-tris[3,4-(dimethoxy)cinnamoyl]-1,5-γ-quinide), finding dissociation constants of the albumin-chlorogenic acids and albumin-quinides complexes in the micromolar range, between 2 and 30μM. Such values are comparable with those of the most powerful binders of albumin, and more favourable than the values obtained for the majority of drugs. Interestingly in the case of 3,4-O-dicaffeoyl-1,5-γ-quinide, we have observed the entrance of two ligand molecules in the same binding site, leading up to a first dissociation constant even in the hundred nanomolar range, which is to our knowledge the highest affinity ever observed for HSA and its ligands. The displacement of warfarin, a reference drug binding to HSA, by the quinide has also been demonstrated. PMID:25172718

  18. Data set for mass spectrometric analysis of recombinant human serum albumin from various expression systems.

    PubMed

    Smith, Daryl G S; Frahm, Grant E; Kane, Anita; Lorbetskie, Barry; Girard, Michel; Johnston, Michael J W; Cyr, Terry D

    2015-09-01

    Human serum albumin (HSA) is a versatile and important protein for the pharmaceutical industry (Fanali et al., Mol. Aspects Med. 33(3) (2012) 209-290). Due to the potential transmission of pathogens from plasma sourced albumin, numerous expression systems have been developed to produce recombinant HSA (rHSA) (Chen et al., Biochim. Biophys. Acta (BBA)-Gen. Subj. 1830(12) (2013) 5515-5525; Kobayashi, Biologicals 34(1) (2006) 55-59). Based on our previous study showing increased glycation of rHSA expressed in Asian rice (Frahm et al., J. Phys. Chem. B 116(15) (2012) 4661-4670), both supplier-to-supplier and lot-to-lot variability of rHSAs from a number of expression systems were evaluated using reversed phase liquid chromatography linked with MS and MS/MS analyses. The data are associated with the research article 'Determination of Supplier-to-Supplier and Lot-to-Lot Variability in Glycation of Recombinant Human Serum Albumin Expressed in Oryza sativa' where further analysis of rHSA samples with additional biophysical methods can be found (Frahm et al., PLoS ONE 10(9) (2014) e109893). We determined that all rHSA samples expressed in rice showed elevated levels of arginine and lysine hexose glycation compared to rHSA expressed in yeast, suggesting that the extensive glycation of the recombinant proteins is a by-product of either the expression system or purification process and not a random occurrence. PMID:26322323

  19. Surface modification of PLGA nanoparticles via human serum albumin conjugation for controlled delivery of docetaxel

    PubMed Central

    2013-01-01

    Background Poly lactic-co-glycolic acid (PLGA) based nanoparticles are considered to be a promising drug carrier in tumor targeting but suffer from the high level of opsonization by reticuloendothelial system due to their hydrophobic structure. As a result surface modification of these nanoparticles has been widely studied as an essential step in their development. Among various surface modifications, human serum albumin (HSA) possesses advantages including small size, hydrophilic surface and accumulation in leaky vasculature of tumors through passive targeting and a probable active transport into tumor tissues. Methods PLGA nanoparticles of docetaxel were prepared by emulsification evaporation method and were surface conjugated with human serum albumin. Fourier transform infrared spectrum was used to confirm the conjugation reaction where nuclear magnetic resonance was utilized for conjugation ratio determination. In addition, transmission electron microscopy showed two different contrast media in conjugated nanoparticles. Furthermore, cytotoxicity of free docetaxel, unconjugated and conjugated PLGA nanoparticles was studied in HepG2 cells. Results Size, zeta potential and drug loading of PLGA nanoparticles were about 199 nm, −11.07 mV, and 4%, respectively where size, zeta potential and drug loading of conjugated nanoparticles were found to be 204 nm, −5.6 mV and 3.6% respectively. Conjugated nanoparticles represented a three-phasic release pattern with a 20% burst effect for docetaxel on the first day. Cytotoxicity experiment showed that the IC50 of HSA conjugated PLGA nanoparticles (5.4 μg) was significantly lower than both free docetaxel (20.2 μg) and unconjugated PLGA nanoparticles (6.2 μg). Conclusion In conclusion surface modification of PLGA nanoparticles through HSA conjugation results in more cytotoxicity against tumor cell lines compared with free docetaxel and unconjugated PLGA nanoparticles. Albumin conjugated PLGA nanoparticles may

  20. Bacillus anthracis co-opts nitric oxide and host serum albumin for pathogenicity in hypoxic conditions.

    PubMed

    St John, Stephen; Blower, Ryan; Popova, Taissia G; Narayanan, Aarthi; Chung, Myung-Chul; Bailey, Charles L; Popov, Serguei G

    2013-01-01

    Bacillus anthracis is a dangerous pathogen of humans and many animal species. Its virulence has been mainly attributed to the production of Lethal and Edema toxins as well as the antiphagocytic capsule. Recent data indicate that the nitric oxide (NO) synthase (baNOS) plays an important pathogenic role at the early stage of disease by protecting bacteria from the host reactive species and S-nytrosylating the mitochondrial proteins in macrophages. In this study we for the first time present evidence that bacteria-derived NO participates in the generation of highly reactive oxidizing species which could be abolished by the NOS inhibitor L - NAME, free thiols, and superoxide dismutase but not catalase. The formation of toxicants is likely a result of the simultaneous formation of NO and superoxide leading to a labile peroxynitrite and its stable decomposition product, nitrogen dioxide. The toxicity of bacteria could be potentiated in the presence of bovine serum albumin. This effect is consistent with the property of serum albumin to serves as a trap of a volatile NO accelerating its reactions. Our data suggest that during infection in the hypoxic environment of pre-mortal host the accumulated NO is expected to have a broad toxic impact on host cell functions. PMID:23730627

  1. The interaction between cepharanthine and two serum albumins: multiple spectroscopic and chemometric investigations.

    PubMed

    Cheng, Zhengjun; Liu, Rong; Jiang, Xiaohui; Xu, Qianyong

    2014-08-01

    The binding modes of cepharanthine (CEPT) with bovine serum albumin (BSA) and human serum albumin (HSA) have been established by reproducing physiological conditions, which is very important to understand the pharmacokinetics and toxicity of CEPT. These spectral data were further analyzed by the multivariate curve resolution-alternating least squares method. Moreover, the concentration profiles and pure spectra of three species (BSA/HSA, CEPT and CEPT-BSA/HSA) and the apparent equilibrium constants K(app) were evaluated. The experimental results showed that CEPT could quench the fluorescence intensity of BSA/HSA by a combined quenching (static and dynamic) procedure. The binding constant (K), the thermodynamic parameters (ΔG, ΔH and ΔS) and binding subdomain were measured, and indicated that CEPT could spontaneously bind to BSA/HSA on subdomain IIA through the hydrophobic interactions. The effect of CEPT on the secondary structure of proteins has been analyzed by circular dichroism, 3D fluorescence and Fourier transform infrared spectra. The binding distance between CEPT and tryptophan of BSA/HSA was 2.305/1.749 nm, which is based on the Förster resonance energy transfer theory. PMID:24123839

  2. 1HNMR study of methotrexate serum albumin (MTX SA) binding in rheumatoid arthritis

    NASA Astrophysics Data System (ADS)

    Sułkowska, A.; Maciążek-Jurczyk, M.; Bojko, B.; Równicka, J.; Sułkowski, W. W.

    2008-11-01

    Rheumatoid arthritis (RA) is an immunologically depended disease. It is characterized by a chronic, progressive inflammatory process. Methotrexate (4-amino-10-methylfolic acid, MTX) is the modifying drug used to treat RA. The aim of the presented studies is to determine the low affinity binding site of MTX in bovine (BSA) and human (HSA) serum albumin with the use of proton nuclear magnetic resonance ( 1HNMR) spectroscopy. The analysis of 1HNMR spectra of MTX in the presence of serum albumin (SA) allows us to observe the interactions between aromatic rings of the drug and the rings of amino acids located in the hydrophobic subdomains of the protein. On the basis of the chemical shifts σ [ppm] and the relaxation times T1 [s] of drug protons the hydrophobic interaction between MTX-SA and the stoichiometric molar ratio of the complex was evaluated. This work is a part of a spectroscopic study on MTX-SA interactions [A. Sułkowska, M. Maciążek, J. Równicka, B. Bojko, D. Pentak, W.W. Sułkowski, J. Mol. Struct. 834-836 (2007) 162-169].

  3. A Fluorescence Quenching Study of the Interaction of Nebivolol Hydrochloride with Bovine and Human Serum Albumin

    NASA Astrophysics Data System (ADS)

    Abdel-Aziz, L.; Abdel-Fattah, L.; El-Kosasy, A.; Gaied, M.

    2015-09-01

    The interaction of nebivolol hydrochloride (NH), a β1-blocker, with bovine serum albumin (BSA) has been investigated at different pH values using the fluorescence quenching technique. The effect of different temperatures was studied at physiological pH 7.4. The binding constants of NH with BSA at 288, 298, and 309 K were found to be 2.691 × 1011, 1.38 × 1010, and 6.27 × 108 M-1, respectively. From the Arrhenius plot, the thermodynamic parameters, ΔH0 and ΔS0, were estimated to be -204.48 kJ/mol and -491.42 J/mol × K, respectively. This indicates that Van der Waals interactions and hydrogen bonds play a major role in the reaction. The effect of some inorganic divalent cations (Cu2+, Ni2+, and Zn2+) on binding of NH to BSA was also studied at physiological pH 7.4. Conformational investigation of BSA was done using synchronous fluorescence, showing the change in the microenvironment of the tryptophan residues. Fluorescence quenching reactions of NH to human serum albumin (HSA) and to γ-globulins were investigated and the binding parameters were obtained.

  4. Assessment of Binding Affinity between Drugs and Human Serum Albumin Using Nanoporous Anodic Alumina Photonic Crystals.

    PubMed

    Nemati, Mahdieh; Santos, Abel; Law, Cheryl Suwen; Losic, Dusan

    2016-06-01

    In this study, we report an innovative approach aiming to assess the binding affinity between drug molecules and human serum albumin by combining nanoporous anodic alumina rugate filters (NAA-RFs) modified with human serum albumin (HSA) and reflectometric interference spectroscopy (RIfS). NAA-RFs are photonic crystal structures produced by sinusoidal pulse anodization of aluminum that present two characteristic optical parameters, the characteristic reflection peak (λPeak), and the effective optical thickness of the film (OTeff), which can be readily used as sensing parameters. A design of experiments strategy and an ANOVA analysis are used to establish the effect of the anodization parameters (i.e., anodization period and anodization offset) on the sensitivity of HSA-modified NAA-RFs toward indomethacin, a model drug. To this end, two sensing parameters are used, that is, shifts in the characteristic reflection peak (ΔλPeak) and changes in the effective optical thickness of the film (ΔOTeff). Subsequently, optimized NAA-RFs are used as sensing platforms to determine the binding affinity between a set of drugs (i.e., indomethacin, coumarin, sulfadymethoxine, warfarin, and salicylic acid) and HSA molecules. Our results verify that the combination of HSA-modified NAA-RFs with RIfS can be used as a portable, low-cost, and simple system for establishing the binding affinity between drugs and plasma proteins, which is a critical factor to develop efficient medicines for treating a broad range of diseases and medical conditions. PMID:27128744

  5. Spectroscopic studies on the interaction between tetrandrine and two serum albumins by chemometrics methods

    NASA Astrophysics Data System (ADS)

    Cheng, Zhengjun; Liu, Rong; jiang, Xiaohui

    2013-11-01

    The binding interactions of tetrandrine (TETD) with bovine serum albumin (BSA) and human serum albumin (HSA) have been investigated by spectroscopic methods. These experimental data were further analyzed using multivariate curve resolution-alternating least squares (MCR-ALS) method, and the concentration profiles and pure spectra for three species (BSA/HSA, TETD and TETD-BSA/HSA) existed in the interaction procedure, as well as, the apparent equilibrium constants Kapp were evaluated. The binding sites number n and the binding constants K were obtained at various temperatures. The binding distance between TETD and BSA/HSA was 1.455/1.451 nm. The site markers competitive experiments indicated that TETD primarily bound to the tryptophan residue of BSA/HSA within site I. The thermodynamic parameters (ΔG, ΔH and ΔS) calculated on the basis of different temperatures revealed that the binding of TETD-BSA was mainly depended on the hydrophobic interaction strongly and electrostatic interaction, and yet the binding of TETD-HSA was strongly relied on the hydrophobic interaction. The results of synchronous fluorescence, 3D fluorescence and FT-IR spectra show that the conformation of proteins has altered in the presence of TETD. In addition, the effect of some common ions on the binding constants between TETD and proteins were also discussed.

  6. A study on human serum albumin influence on glycation of fibrinogen

    SciTech Connect

    Kielmas, Martyna; Szewczuk, Zbigniew; Stefanowicz, Piotr

    2013-09-13

    Highlights: •The glycation of fibrinogen was investigated by isotopic labeling method. •The potential glycation sites in fibrinogen were identified. •Human serum albumin (HSA) inhibits the glycation of fibrinogen. •The effect of HSA on fibrinogen glycation is sequence-dependent. -- Abstract: Although in vivo glycation proceeds in complex mixture of proteins, previous studies did not take in consideration the influence of protein–protein interaction on Maillard reaction. The aim of our study was to test the influence of human serum albumin (HSA) on glycation of fibrinogen. The isotopic labeling using [{sup 13}C{sub 6}] glucose combined with LC-MS were applied as tool for identification possible glycation sites in fibrinogen and for evaluation the effect of HSA on the glycation level of selected amino acids in fibrinogen. The obtained data indicate that the addition of HSA protects the fibrinogen from glycation. The level of glycation in presence of HSA is reduced by 30–60% and depends on the location of glycated residue in sequence of protein.

  7. Characterisation of molten globule-like state of sheep serum albumin at physiological pH.

    PubMed

    Dar, Mohammad Aasif; Wahiduzzaman; Haque, Md Anzarul; Islam, Asimul; Hassan, Md Imtaiyaz; Ahmad, Faizan

    2016-08-01

    Sheep serum albumin (SSA) is a 583 amino acid residues long multidomain monomeric protein which is rich in cysteine and low in tryptophan content. The serum albumins (from human, bovine and sheep) play a vital role among all proteins investigated until now, as they are the most copious circulatory proteins. We have purified SSA from sheep kidneys by a simple and efficient two-step purification procedure. Further, we have studied urea-induced denaturation of SSA by monitoring changes in the difference absorption coefficient at 287nm (Δε287), intrinsic fluorescence emission intensity at 347nm (F347) and mean residue ellipticity at 222nm ([θ]222) at pH 7.4 and 25°C. The coincidence of denaturation curves of these optical properties suggests that urea-induced denaturation is a bi-phasic process (native (N) state↔intermediate (X) state↔denatured (D) state) with a stable intermediate populated around 4.2-4.7M urea. The intermediate (X) state was further characterized by the far-UV and near-UV CD, dynamic light scattering (DLS) and fluorescence using 1-anilinonaphthalene-8-sulfonic acid (ANS) binding method. All denaturation curves were analyzed for Gibbs free energy changes associated with the equilibria, N state↔X state and X state↔D state in the absence of urea. PMID:27180298

  8. Renal targeted delivery of triptolide by conjugation to the fragment peptide of human serum albumin.

    PubMed

    Yuan, Zhi-xiang; Wu, Xiao-juan; Mo, Jingxin; Wang, Yan-li; Xu, Chao-qun; Lim, Lee Yong

    2015-08-01

    We have previously demonstrated that peptide fragments (PFs) of the human serum albumin could be developed as potential renal targeting carriers, in particular, the peptide fragment, PF-A299-585 (A299-585 representing the amino acid sequence of the human serum albumin). In this paper, we conjugated triptolide (TP), the anti-inflammatory Chinese traditional medicine, to PF-A299-585 via a succinic acid spacer to give TPS-PF-A299-585 (TP loading 2.2% w/w). Compared with the free TP, TPS-PF-A299-585 exhibited comparable anti-inflammatory activity in the lipopolysaccharide stimulated MDCK cells, but was significantly less cytotoxic than the free drug. Accumulation of TPS-PF-A299-585 in the MDCK cells in vitro and in rodent kidneys in vivo was demonstrated using FITC-labeled TPS-PF-A299-585. Renal targeting was confirmed in vivo in a membranous nephropathic (MN) rodent model, where optical imaging and analyses of biochemical markers were combined to show that TPS-PF-A299-585 was capable of alleviating the characteristic symptoms of MN. The collective data affirm PF-A299-585 to be a useful carrier for targeting TP to the kidney. PMID:26117184

  9. Research of the interaction between kangai injection and human serum albumin by fluorescence spectroscopy

    NASA Astrophysics Data System (ADS)

    Ye, Changbin; Lin, Xiaogang; Zhu, Hao; Li, Wenchao; Wu, Jie

    2015-10-01

    The interaction between drugs and serum albumin is the theoretical basis of pharmacology research. Kangai injection with invigorating Qi, enhancing the immune function, is widely used for a variety of malignant tumor treatment. Fluorescence spectroscopy was adopted due to its high sensitivity and other advantages. The interaction between kangai injection and human serum albumin (HSA) in physiological buffer (pH 7.4) was investigated by fluorescence spectroscopy and UV-Vis absorption spectroscopy. The results of fluorescence spectrum at three temperature (296K, 303K and 310K) showed the degree of binding at 310K is the highest. Also, the maximum emission peak has a slight blue shift, which indicates that the interaction between kangai injection and HSA has an effect on the conformation of HSA. That is, the microenvironment of tryptophan increase hydrophobic due to the increase of the concentration of kangai injection. Results obtained from analysis of fluorescence spectrum and fluorescence intensity indicated that kangai injection has a strong ability to quench the intrinsic fluorescence of HSA. And according to the Stern-Volume equation, the quenching mechanism is static quenching, which is further proved by the UV-Vis absorption spectroscopy.

  10. Bacillus anthracis co-opts nitric oxide and host serum albumin for pathogenicity in hypoxic conditions

    PubMed Central

    St. John, Stephen; Blower, Ryan; Popova, Taissia G.; Narayanan, Aarthi; Chung, Myung-Chul; Bailey, Charles L.; Popov, Serguei G.

    2013-01-01

    Bacillus anthracis is a dangerous pathogen of humans and many animal species. Its virulence has been mainly attributed to the production of Lethal and Edema toxins as well as the antiphagocytic capsule. Recent data indicate that the nitric oxide (NO) synthase (baNOS) plays an important pathogenic role at the early stage of disease by protecting bacteria from the host reactive species and S-nytrosylating the mitochondrial proteins in macrophages. In this study we for the first time present evidence that bacteria-derived NO participates in the generation of highly reactive oxidizing species which could be abolished by the NOS inhibitor L - NAME, free thiols, and superoxide dismutase but not catalase. The formation of toxicants is likely a result of the simultaneous formation of NO and superoxide leading to a labile peroxynitrite and its stable decomposition product, nitrogen dioxide. The toxicity of bacteria could be potentiated in the presence of bovine serum albumin. This effect is consistent with the property of serum albumin to serves as a trap of a volatile NO accelerating its reactions. Our data suggest that during infection in the hypoxic environment of pre-mortal host the accumulated NO is expected to have a broad toxic impact on host cell functions. PMID:23730627

  11. Kinetic studies of bovine serum albumin interaction with PG and TBHQ using surface plasmon resonance.

    PubMed

    Fathi, Farzaneh; Ezzati Nazhad Dolatanbadi, Jafar; Rashidi, Mohammad-Reza; Omidi, Yadollah

    2016-10-01

    Propyl gallate (PG) and tert-butylhydroquinone (TBHQ) are examples of phenolic antioxidant agents, which have widespread uses in food industry. In this study, for the first time, we report on the interaction of PG and TBHQ with bovine serum albumin (BSA) using surface plasmon resonance (SPR). In order to modify Au slide with carboxyl functional group, 11-mercaptoundecanoic acid (MUA) was used. After activation of carboxylic groups, BSA was immobilized onto the MUA through both covalent amide bond and electrostatic binding formation. The SPR analysis showed dose-response sensograms of BSA upon increasing concentration of PG and TBHQ. At pH 4.5, the equilibrium dissociation constant or affinity unit (KD) for PG and TBHQ were 1.89e(-10) and 1.49e(-10) and at pH 7.5 were 4.74e(-10) and 1.83e(-9), respectively. The smaller amount of KD demonstrated high food additive molecules affinity to BSA. Based on these findings, it can be concluded that PG and TBHQ molecules can interact with BSA and effectively distributed within the body. Besides, SPR can be considered as useful automatic tool for quantification of PG and TBHQ interaction with serum albumin and it can deliver precise real-time kinetic data. PMID:27327906

  12. Synthesis and characterization of imprinted sorbent for separation of gramine from bovine serum albumin.

    PubMed

    Luliński, Piotr; Klejn, Dorota; Maciejewska, Dorota

    2016-08-01

    The aim of this study was to develop an efficient sorbent for separation of N,N-dimethyl-3-aminomethylindole (gramine) from bovine serum albumin. An imprinting technology was involved in the synthesis of polymers from nine different functional monomers in the presence of ethylene glycol dimethacrylate as a cross-linker. The analysis of binding capacities showed that the highest specificity towards gramine was achieved when 4-vinylbenzoic acid was used as the functional monomer in methanol to form the bulk imprinted polymer, MIP1 (imprinting factor equal to 21.3). The Scatchard analysis of MIP1 showed two classes of binding sites with the dissociation constants Kd equal to 0.105 and 6.52μmolL(-1). The composition and morphology of polymers were defined by (13)C CP/MAS NMR, BET and SEM-EDS analyses. The recognition mechanism of MIP1 was tested using the structurally related bioanalytes, and the dominant role of indole moiety and ethylamine side chain was revealed. A new MISPE protocol was optimized for separation of gramine. The total recoveries on MIP1 were equal to 94±12 % from standard solutions and 85±11 % from bovine serum albumin. PMID:27157767

  13. Comparative studies on the interaction of cefixime with bovine serum albumin by fluorescence quenching spectroscopy and synchronous fluorescence spectroscopy.

    PubMed

    Zhang, Lihui; Liu, Baosheng; Li, Zhiyun; Guo, Ying

    2015-08-01

    Under simulated physiological conditions, the reaction mechanism between cefixime and bovine serum albumin at different temperatures (293, 303 and 310 K) was investigated using a fluorescence quenching method and synchronous fluorescence method, respectively. The results indicated that the fluorescence intensity and synchronous fluorescence intensity of bovine serum albumin decreased regularly on the addition of cefixime. In addition, the quenching mechanism, binding constants, number of binding sites, type of interaction force and energy-transfer parameters of cefixime with bovine serum albumin obtained from two methods using the same equation were consistent. The results indicated that the synchronous fluorescence spectrometry could be used to study the binding mechanism between drug and protein, and was a useful supplement to the conventional method. PMID:25351241

  14. Isolation and purification of cat albumin from cat serum by copper ion affinity chromatography: further analysis of its primary structure.

    PubMed

    Dandeu, J P; Rabillon, J; Guillaume, J L; Camoin, L; Lux, M; David, B

    1991-02-22

    Proteins, regardless of their origin, have to be highly purified, particularly from the immunochemical point of view, if they are to be used to study their allergenicity. It is shown that cat albumin, a highly potent allergen for cat-sensitive humans, can be isolated and purified from cat serum using immobilized metal ion affinity chromatography (copper ions) instead of a salting-out process or precipitation with alcohol, techniques generally used for the preparation of serum proteins. During the process described, immunoglobulins are concomitantly isolated in a relatively pure form. Cat albumin amino acid composition and sequence were analysed after an ultimate purification by ion-exchange chromatography. The highest homology (greater than 80%) was found with the rat serum albumin. PMID:2045457

  15. O{sub 2}-mediated oxidation of ferrous nitrosylated human serum heme-albumin is limited by nitrogen monoxide dissociation

    SciTech Connect

    Ascenzi, Paolo; Gullotta, Francesca; Gioia, Magda; Coletta, Massimo; Fasano, Mauro

    2011-03-04

    Research highlights: {yields} Human serum heme-albumin displays globin-like properties. {yields} O{sub 2}-mediated oxidation of ferrous nitrosylated human serum heme-albumin. {yields} Allosteric modulation of human serum heme-albumin reactivity. {yields} Rifampicin is an allosteric effector of human serum heme-albumin. {yields} Human serum heme-albumin is a ROS and NOS scavenger. -- Abstract: Human serum heme-albumin (HSA-heme-Fe) displays globin-like properties. Here, kinetics of O{sub 2}-mediated oxidation of ferrous nitrosylated HSA-heme-Fe (HSA-heme-Fe(II)-NO) is reported. Values of the first-order rate constants for O{sub 2}-mediated oxidation of HSA-heme-Fe(II)-NO (i.e., for ferric HSA-heme-Fe formation) and for NO dissociation from HSA-heme-Fe(II)-NO (i.e., for NO replacement by CO) are k = 9.8 x 10{sup -5} and 8.3 x 10{sup -4} s{sup -1}, and h = 1.3 x 10{sup -4} and 8.5 x 10{sup -4} s{sup -1}, in the absence and presence of rifampicin, respectively, at pH = 7.0 and T = 20.0 {sup o}C. The coincidence of values of k and h indicates that NO dissociation represents the rate limiting step of O{sub 2}-mediated oxidation of HSA-heme-Fe(II)-NO. Mixing HSA-heme-Fe(II)-NO with O{sub 2} does not lead to the formation of the transient adduct(s), but leads to the final ferric HSA-heme-Fe derivative. These results reflect the fast O{sub 2}-mediated oxidation of ferrous HSA-heme-Fe and highlight the role of drugs in modulating allosterically the heme-Fe-atom reactivity.

  16. Study of interaction of proton transfer probe 1-hydroxy-2-naphthaldehyde with serum albumins: a spectroscopic study.

    PubMed

    Balia Singh, Rupashree; Mahanta, Subrata; Guchhait, Nikhil

    2008-04-25

    In the present work, we have studied the interaction of proton transfer probe 1-hydroxy-2-naphthaldehyde (HN12) with Human Serum Albumin (HSA) and Bovine Serum Albumin (BSA) by steady state absorption and emission spectroscopy combined with time resolved fluorescence measurements. The measured binding constant (K) and free energy change (DeltaG) indicate a stronger affinity of HN12 molecule for HSA than BSA. Steady state anisotropy, excitation anisotropy and fluorescence resonance energy transfer (FRET) studies indicate that the probe molecule resides at the hydrophobic site of the protein environment. PMID:18296059

  17. A Comprehensive Spectroscopic and Computational Investigation to Probe the Interaction of Antineoplastic Drug Nordihydroguaiaretic Acid with Serum Albumins

    PubMed Central

    Nusrat, Saima; Siddiqi, Mohammad Khursheed; Zaman, Masihuz; Zaidi, Nida; Ajmal, Mohammad Rehan; Alam, Parvez; Qadeer, Atiyatul; Abdelhameed, Ali Saber

    2016-01-01

    Exogenous drugs that are used as antidote against chemotheray, inflammation or viral infection, gets absorbed and interacts reversibly to the major serum transport protein i.e. albumins, upon entering the circulatory system. To have a structural guideline in the rational drug designing and in the synthesis of drugs with greater efficacy, the binding mechanism of an antineoplastic and anti-inflammatory drug Nordihydroguaiaretic acid (NDGA) with human and bovine serum albumins (HSA & BSA) were examined by spectroscopic and computational methods. NDGA binds to site II of HSA with binding constant (Kb) ~105 M-1 and free energy (ΔG) ~ -7.5 kcal.mol-1. It also binds at site II of BSA but with lesser binding affinity (Kb) ~105 M-1 and ΔG ~ -6.5 kcal.mol-1. The negative value of ΔG, ΔH and ΔS for both the albumins at three different temperatures confirmed that the complex formation process between albumins and NDGA is spontaneous and exothermic. Furthermore, hydrogen bonds and hydrophobic interactions are the main forces involved in complex formation of NDGA with both the albumins as evaluated from fluorescence and molecular docking results. Binding of NDGA to both the albumins alter the conformation and causes minor change in the secondary structure of proteins as indicated by the CD spectra. PMID:27391941

  18. A Comprehensive Spectroscopic and Computational Investigation to Probe the Interaction of Antineoplastic Drug Nordihydroguaiaretic Acid with Serum Albumins.

    PubMed

    Nusrat, Saima; Siddiqi, Mohammad Khursheed; Zaman, Masihuz; Zaidi, Nida; Ajmal, Mohammad Rehan; Alam, Parvez; Qadeer, Atiyatul; Abdelhameed, Ali Saber; Khan, Rizwan Hasan

    2016-01-01

    Exogenous drugs that are used as antidote against chemotheray, inflammation or viral infection, gets absorbed and interacts reversibly to the major serum transport protein i.e. albumins, upon entering the circulatory system. To have a structural guideline in the rational drug designing and in the synthesis of drugs with greater efficacy, the binding mechanism of an antineoplastic and anti-inflammatory drug Nordihydroguaiaretic acid (NDGA) with human and bovine serum albumins (HSA & BSA) were examined by spectroscopic and computational methods. NDGA binds to site II of HSA with binding constant (Kb) ~105 M-1 and free energy (ΔG) ~ -7.5 kcal.mol-1. It also binds at site II of BSA but with lesser binding affinity (Kb) ~105 M-1 and ΔG ~ -6.5 kcal.mol-1. The negative value of ΔG, ΔH and ΔS for both the albumins at three different temperatures confirmed that the complex formation process between albumins and NDGA is spontaneous and exothermic. Furthermore, hydrogen bonds and hydrophobic interactions are the main forces involved in complex formation of NDGA with both the albumins as evaluated from fluorescence and molecular docking results. Binding of NDGA to both the albumins alter the conformation and causes minor change in the secondary structure of proteins as indicated by the CD spectra. PMID:27391941

  19. Enhanced Gene Silencing through Human Serum Albumin-Mediated Delivery of Polyethylenimine-siRNA Polyplexes

    PubMed Central

    Nicolì, Elena; Syga, Marie Isabel; Bosetti, Michela; Shastri, V. Prasad

    2015-01-01

    Small interfering RNA (siRNA) targeted therapeutics (STT) offers a compelling alternative to tradition medications for treatment of genetic diseases by providing a means to silence the expression of specific aberrant proteins, through interference at the expression level. The perceived advantage of siRNA therapy is its ability to target, through synthetic antisense oligonucleotides, any part of the genome. Although STT provides a high level of specificity, it is also hindered by poor intracellular uptake, limited blood stability, high degradability and non-specific immune stimulation. Since serum proteins has been considered as useful vehicles for targeting tumors, in this study we investigated the effect of incorporation of human serum albumin (HSA) in branched polyethylenimine (bPEI)-siRNA polyplexes in their internalization in epithelial and endothelial cells. We observed that introduction of HSA preserves the capacity of bPEI to complex with siRNA and protect it against extracellular endonucleases, while affording significantly improved internalization and silencing efficiency, compared to bPEI-siRNA polyplexes in endothelial and metastatic breast cancer epithelial cells. Furthermore, the uptake of the HSA-bPEI-siRNA ternary polyplexes occurred primarily through a caveolae-mediated endocytosis, thus providing evidence for a clear role for HSA in polyplex internalization. These results provide further impetus to explore the role of serum proteins in delivery of siRNA. PMID:25856158

  20. Spectroscopic study on the interaction of bovine serum albumin with zinc(II) phthalocyanine.

    PubMed

    Li, Yejing; Wang, Yi; Wang, Ao; Lu, Shan; Zhou, Lin; Zhou, Jiahong; Lin, Yun; Wei, Shaohua

    2015-12-01

    The interaction between the photosensitive antitumour drug, 2(3),9(10),16(17),23(24)-tetra-(((2-aminoethylamino)methyl)phenoxy)phthalocyaninato-zinc(II) (ZnPc) and bovine serum albumin (BSA) has been investigated using various spectroscopic methods. This work may provide some useful information for understanding the interaction mechanism of anticancer drug-albumin binding and gain insight into the biological activity and metabolism of the drug in blood. Based on analysis of the fluorescence spectra, ZnPc could quench the intrinsic fluorescence of BSA and the quenching mechanism was static by forming a ground state complex. Meanwhile, the Stern-Volmer quenching constant (KSV), binding constant (Kb), number of binding sites (n) and thermodynamic parameters were obtained. Results showed that the interaction of ZnPc with BSA occurred spontaneously via hydrogen bond and van der Waal's force. According to Foster's non-radioactive energy transfer theory, the energy transfer from BSA to ZnPc occurred with high possibility. Synchronous fluorescence and circular dichroism (CD) spectra also demonstrated that ZnPc induced the secondary structure of and conformation changes in BSA, especially α helix. PMID:25829360

  1. Microglial cell death induced by glycated bovine serum albumin: nitric oxide involvement.

    PubMed

    Khazaei, Mohammad R; Habibi-Rezaei, Mehran; Karimzadeh, Fereshteh; Moosavi-Movahedi, Ali Akbar; Sarrafnejhad, Abdo Alfattah; Sabouni, Farzaneh; Bakhti, Mostafa

    2008-08-01

    Nonenzymatic glycation results in the formation of advanced glycation end products (AGEs) through a nonenzymatic multistep reaction of reducing sugars with proteins. AGEs have been suspected to be involved in the pathogenesis of several chronic clinical neurodegenerative complications including Alzheimer's disease, which is characterized with the activation of microglial cells in neuritic plaques. To find out the consequence of this activation on microglial cells, we treated the cultured microglial cells with different glycation levels of Bovine Serum Albumin (BSA) which were prepared in vitro. Extent of glycation of protein has been characterized during 16 weeks of incubation with glucose. Treatment of microglial cells with various levels of glycated albumin induced nitric oxide (NO) production and consequently cell death. We also tried to find out the mode of death in AGE-activated microglial cells. Altogether, our results suggest that AGE treatment causes microglia to undergo NO-mediated apoptotic and necrotic cell death in short term and long term, respectively. NO production is a consequence of iNOS expression in a JNK dependent RAGE signalling after activation of RAGE by AGE-BSA. PMID:18463114

  2. Bovine serum albumin-sodium alkyl sulfates bioconjugates as drug delivery systems.

    PubMed

    Benkő, M; Varga, N; Sebők, D; Bohus, G; Juhász, Á; Dékány, I

    2015-06-01

    Precipitation of bovine serum albumin (BSA) by anionic surfactants with alkyl chains of increasing lengths (octyl, decyl, dodecyl sulfates) was studied at room temperature, at pH 3.0, in isotonic sodium chloride solution. The particle size of albumin, the zeta potential, the surface charge and fluorescent properties of BSA-surfactant composites were investigated concerning addition of increasing amount of surfactant. The thermal stability of the systems was monitored by calorimetric analysis (DSC). The formation of the well-ordered structure in the self-assembly process in liquid phase was studied by XRD measurement. The structure of the precipitated BSA-surfactant nanocomposites was characterized by small-angle X-ray scattering (SAXS). Finally, ibuprofen (IBU) molecules were enclosed in BSA-surfactant bioconjugate systems and the release properties of the drug were investigated. It has been found out that, as a consequence to the increasing number of carbon atoms in the alkyl chains of the surfactant, the structure and the fluorescent properties of the aggregates formed can be controlled due to the increase in the hydrophobicity of BSA-surfactant composites. The bioconjugates are well applicable as carrier to realize controlled release of drug molecules. PMID:25935562

  3. Interaction with Serum Albumin As a Factor of the Photodynamic Efficacy of Novel Bacteriopurpurinimide Derivatives

    PubMed Central

    Akimova, Akimova; Rychkov, G. N.; Grin, M. A.; Filippova, N. A.; Golovina, G. V.; Durandin, N. A.; Vinogradov, A. M.; Kokrashvili, T. A.; Mironov, A. F.; Shtil, A. A.; Kuzmin, V. A.

    2015-01-01

    Optimization of the chemical structure of antitumor photosensitizers (PSs) is aimed at increasing their affinity to a transport protein, albumin and irreversible light-induced tumor cell damage. Bacteriopurpurinimide derivatives are promising PSs thanks to their ability to absorb light in the near infrared spectral region. Using spectrophotometry, we show that two new bacteriopurpurinimide derivatives with different substituents at the N atoms of the imide exocycle and the pyrrole ring A are capable of forming non-covalent complexes with human serum albumin (HSA). The association constant (calculated with the Benesi-Hildebrand equation) for N-ethoxybacteriopurpurinimide ethyloxime (compound 1) is higher than that for the methyl ether of methoxybacteriopurpurinimide (compound 2) (1.18×105 M-1 vs. 1.26×104 M-1, respectively). Molecular modeling provides details of the atomic interactions between 1 and 2 and amino acid residues in the FA1 binding site of HSA. The ethoxy group stabilizes the position of 1 within this site due to hydrophobic interaction with the protein. The higher affinity of 1 for HSA makes this compound more potent than 2 in photodynamic therapy for cultured human colon carcinoma cells. Photoactivation of 1 and 2 in cells induces rapid (within a few minutes of irradiation) necrosis. This mechanism of cell death may be efficient for eliminating tumors resistant to other therapies. PMID:25927008

  4. Serum albumin level during intestinal exfoliative rejection: a potential predictor of graft recovery and patient outcome.

    PubMed

    Zambernardi, Agustina; Gondolesi, Gabriel; Cabanne, Ana; Martinez, María I; Solar, Héctor; Rumbo, Martín; Rumbo, Carolina

    2013-01-01

    Exfoliative rejection is a severe complication after intestinal transplant. The assessment of mucosa histology is restricted to the area reached by endoscopy. We aim to evaluate the serum albumin (SA) value as a parameter of graft damage and clinical prognosis in intestinal exfoliative rejection (ExR). The present study is a retrospective analysis of 11 episodes of ExR occurred in a cohort of 26 patients. SA levels were measured 24 h after diagnosis and twice a week thereafter and then correlated with parameters of clinical and graft histological recovery (HR). During ExR, all patients had very low SA levels, reaching a minimum average of 1.9 ± 0.3 g/dL. According to the value of albumin levels at ExR diagnosis, the patients were grouped finding a correlation with their clinical evolution. Six ExR episodes presented with severe hipoalbuminemia (<2.2 g/dL; p < 0.05) that correlated with worse patient and graft outcome, ranging from graft loss and need for re-transplantation to delayed clinical and HR. SA at ExR diagnosis may be an indicator of the severity of the ExR process, and it could also be used as an early predictor of patient and graft outcome. PMID:23351092

  5. Study on the interaction between novel spiro pyrrolidine and bovine serum albumin by spectroscopic techniques

    NASA Astrophysics Data System (ADS)

    Yu, Xianyong; Yang, Ying; Zou, Xin; Tao, Hongwen; Ling, Yulin; Yao, Qing; Zhou, Hu; Yi, Pinggui

    Spiro pyrrolidines, which were proved with diverse and potent biological activities and they were discovered widespread in nature. In this paper, using fluorescence and ultraviolet spectroscopy, we investigated the interactions between novel spiro pyrrolidine (NSP) and bovine serum albumin (BSA) under the imitated physiological condition. The results show that the NSP binds to BSA molecules. Static quenching and non-radiation energy transfer are the main reasons for fluorescence quenching. We calculated the binding constant (Ka) and binding sites (n) at different temperatures and obtained the binding distance between the tryptophan residue in BSA and the NSP based on the Förster theory of non-radiation energy transfer. In addition, using synchronous fluorescence spectra, we demonstrated conformation changes of BSA caused by NSP. The comparison of binding potency of NSP and BSA suggests that the substituent on the benzene ring influences the binding ability of NSP and BSA.

  6. Interaction of human serum albumin with novel imidazole derivatives studied by spectroscopy and molecular docking.

    PubMed

    Yue, Yuanyuan; Sun, Yangyang; Dong, Qiao; Liu, Ren; Yan, Xuyang; Zhang, Yajie; Liu, Jianming

    2016-05-01

    This study was a detailed characterization of the interaction of a series of imidazole derivatives with a model transport protein, human serum albumin (HSA). Fluorescence and time-resolved fluorescence results showed the existence of a static quenching mode for the HSA-imidazole derivative interaction. The binding constant at 296 K was in the order of 10(4) M(-1) , showing high affinity between the imidazole derivatives and HSA. A site marker competition study combined with molecular docking revealed that the imidazole derivatives bound to subdomain IIA of HSA (Sudlow's site I). Furthermore, the results of synchronous, 3D, Fourier transform infrared, circular dichroism and UV-vis spectroscopy demonstrated that the secondary structure of HSA was altered in the presence of the imidazole derivatives. The specific binding distance, r, between the donor and acceptor was obtained according to fluorescence resonance energy transfer. Copyright © 2015 John Wiley & Sons, Ltd. PMID:26364804

  7. Capsaicin-Coated Silver Nanoparticles Inhibit Amyloid Fibril Formation of Serum Albumin.

    PubMed

    Anand, Bibin G; Dubey, Kriti; Shekhawat, Dolat Singh; Kar, Karunakar

    2016-06-21

    We have synthesized capsaicin-coated silver nanoparticles (AgNPs(Cap)) and have tested their anti-amyloid activity, considering serum albumin (BSA) as a model protein. We found that amyloid formation of BSA was strongly suppressed in the presence of AgNPs(Cap). However, isolated capsaicin and uncapped control nanoparticles did not show such an inhibition effect. Bioinformatics analysis reveals CH-π and H-bonding interactions between capsaicin and BSA in the formation of the protein-ligand complex. These results suggest the significance of surface functionalization of nanoparticles with capsaicin, which probably allows capsaicin to effectively interact with the key residues of the amyloidogenic core of BSA. PMID:27243335

  8. Impact of condensed tannin size as individual and mixed polymers on bovine serum albumin precipitation.

    PubMed

    Harbertson, James F; Kilmister, Rachel L; Kelm, Mark A; Downey, Mark O

    2014-10-01

    Condensed tannins composed of epicatechin from monomer to octamer were isolated from cacao (Theobroma cacao, L.) seeds and added to bovine serum albumin (BSA) individually and combined as mixtures. When added to excess BSA the amount of tannin precipitated increased with tannin size. The amount of tannin required to precipitate BSA varied among the polymers with the trimer requiring the most to precipitate BSA (1000 μg) and octamer the least (50 μg). The efficacy of condensed tannins for protein precipitation increased with increased degree of polymerisation (or size) from trimers to octamers (monomers and dimers did not precipitate BSA), while mixtures of two sizes primarily had an additive effect. This study demonstrates that astringent perception is likely to increase with increasing polymer size. Further research to expand our understanding of astringent perception and its correlation with protein precipitation would benefit from sensory analysis of condensed tannins across a range of polymer sizes. PMID:24799203

  9. Use of Lanthanide-Containing Polyoxometalates to Sensitise the Emission of Fluorescent Labelled Serum Albumin.

    PubMed

    Holmes-Smith, A Sheila; Crisp, Jacob; Hussain, Firasat; Patzke, Greta R; Hungerford, Graham

    2016-02-01

    Monitoring the interaction of biomolecules is important, and the use of energy transfer is a principal technique in elucidating nanoscale interactions. Lanthanide compounds are promising luminescent probes for biological samples as their emission is longer-lived than any native autofluorescence. Polyoxometalates (POMs) are interesting structural motifs to incorporate lanthanides, offering low toxicity and a size pertinent for biological applications. Here, we employ iso-structured POMs containing either terbium or europium and assess their interaction with serum albumin by sensitisation of a fluorescent tag on the protein via LRET (luminescence resonance energy transfer) by exciting the lanthanide. Time-resolved measurements showed energy transfer with an efficiency of over 90% for the POM-protein systems. The Tb-POM results were relatively straightforward, while those with the iso-structured Eu-POM were complicated by the effect of protein shielding from the aqueous environment. PMID:26642428

  10. Fluorescence spectrometric study on the interaction of tamibarotene with bovine serum albumin.

    PubMed

    Ye, Huazhen; Qiu, Bin; Lin, Zhenyu; Chen, Guonan

    2011-01-01

    The interaction between tamibarotene and bovine serum albumin (BSA) was studied using fluorescence quenching technique and ultraviolet-visible spectrophotometry. The results of experiments showed that tamibarotene could strongly quench the intrinsic fluorescence of BSA by a dynamic quenching mechanism. The apparent binding constant, number of binding site and corresponding thermodynamic parameters at different temperatures were calculated respectively, and the main interaction force between tamibarotene and BSA was proved to be hydrophobic force. Synchronous fluorescence spectra showed that tamibarotene changed the molecular conformation of BSA. When BSA concentration was 1.00 × 10⁻⁶mol L⁻¹, the quenched fluorescence ΔF had a good linear relationship with the concentration of tamibarotene in the range 1.00 × 10⁻⁶ to 12.00 × 10⁻⁶ mol L⁻¹ with the detection limit of 6.52 × 10⁻⁷  mol L⁻¹. PMID:22021245

  11. Controlled ultraviolet resonance energy transfer between bovine serum albumin donors and cadmium sulfide quantum dots acceptors

    NASA Astrophysics Data System (ADS)

    Ghali, Mohsen; El-Kemary, Maged; Ramadan, Mahmoud

    2015-08-01

    We report on Förester resonance nergy transfer (FRET) within a bioconjugated system composed of cadmium sulfide (CdS) quantum dots (QDs) and transport protein bovine serum albumin (BSA). The optical properties of these two elements of the bioconjugate were exploited to produce FRET in the ultraviolet (UV) region with a maximum efficiency of 22% from BSA donors to QD acceptors. In contrast to previous studies, which were limited to FRET in the visible light, we used 2.6 nm CdS QDs because they emit light with a shorter wavelength (∼370 nm) that facilitates the UV-FRET process. UV-FRET was controlled by tuning the spectral overlap between BSA and CdS QDs.

  12. Study on the interaction between bovine serum albumin and starch nanoparticles prepared by isoamylolysis and recrystallization.

    PubMed

    Ji, Na; Qiu, Chao; Li, Xiaojing; Xiong, Liu; Sun, Qingjie

    2015-04-01

    The current study primarily investigated the interaction of bovine serum albumin (BSA) with starch nanoparticles (SNPs) prepared by isoamylolysis and recrystallization using UV-vis, fluorescence, transmission electron microscopy (TEM), Fourier transform infrared (FTIR) and circular dichroism (CD). The enhanced absorbance observed by UV-vis spectroscopy and decreased intensity of fluorescence spectroscopy suggested that BSA could bind to SNPs and form a BSA-SNP complex. The synchronous fluorescence spectra revealed that the emission maximum of Tyr residue (at Δλ=15nm) was red-shifted at the investigated concentrations range, indicating that the conformation of BSA was changed. Quenching parameters showed that the quenching effect of SNPs was static quenching. TEM images showed that the SNPs were surrounded by protein coronae, indicating that nanoparticle-protein complexes had formed. The FTIR and CD characterization indicated that the SNPs induced structural changes in the secondary structure of BSA. PMID:25805153

  13. Characterization of the binding of 2-mercaptobenzimidazole to bovine serum albumin.

    PubMed

    Teng, Yue; Zou, Luyi; Huang, Ming; Zong, Wansong

    2015-04-01

    2-Mercaptobenzimidazole (MBI) is widely utilized as a corrosion inhibitor, copper-plating brightener and rubber accelerator. The residue of MBI in the environment is potentially harmful to human health. In this article, the interaction of MBI with bovine serum albumin (BSA) was explored using spectroscopic and molecular docking methods under physiological conditions. The positively charged MBI can spontaneously bind with the negatively charged BSA through electrostatic forces with one binding site. The site marker competition experiments and the molecular docking study revealed that MBI bound into site II (subdomain IIIA) of BSA, which further led to some secondary structure and microenvironmental changes of BSA. This work provides useful information on understanding the toxicological actions of MBI at the molecular level. PMID:25683240

  14. Enantioselective separation of chiral arylcarboxylic acids on an immobilized human serum albumin chiral stationary phase.

    PubMed

    Andrisano, V; Booth, T D; Cavrini, V; Wainer, I W

    1997-01-01

    A series of 12 chiral arylcarboxylic acids were chromatographed on an immobilized human serum albumin chiral stationary phase (HSA-CSP). The effects of solute structure on chromatographic retentions and enantioselective separations were examined by linear regression analysis and the construction of quantitative structure-enantioselective retention relationships. Competitive displacement studies were also conducted using R-ibuprofen as the displacing agent. The results indicate that the enantioselective retention of the solutes takes place at the indole-benzodiazepine site (site II) on the HSA molecule and that chiral recognition is affected by the hydrophobicity and steric volume of the solutes. The displacement studies also identified a cooperative allosteric interaction induced by the binding of R-ibuprofen to site II. PMID:9134695

  15. Fluorescence study on the interaction of human serum albumin with Butein in liposomes

    NASA Astrophysics Data System (ADS)

    Toprak, Mahmut

    2016-02-01

    The interaction of Butein with human serum albumin in L-egg lecithin phosphatidycholine (PC) liposome has been investigated by fluorescence and absorption spectroscopy. The results of the fluorescence measurement indicated that Butein effectively quenched the intrinsic fluorescence of HSA via static quenching. The Stern-Volmer plots in all the liposome solutions showed a positive deviation from the linearity. According to the thermodynamic parameters, the hydrophobic interactions appeared be the major interaction forces between Butein and HSA. The effect of Butein on the conformation of HSA was also investigated by the synchronous fluorescence under the same experimental conditions. In addition, the partition coefficient of the Butein in the PC liposomes was also determined by using the fluorescence quenching process. The obtained results can be of biological significance in pharmacology and clinical medicine.

  16. Synthesis of Three Rimantadine Schiff Bases and Their Biological Effects on Serum Albumin

    PubMed Central

    Liu, Bing-Mi; Ma, Ping; Wang, Xin; Kong, Yu-Mei; Zhang, Li-Ping; Liu, Bin

    2014-01-01

    Three new rimantadine Schiff bases (RSBs) were prepared, and then the interaction of RSBs with bovine serum albumin (BSA) was investigated using fluorescence, synchronous fluorescence, UV-vis absorption spectroscopy under physiological conditions. The results showed that the three RSBs effectively quenched the intrinsic fluorescence of BSA via static quenching. Binding constant (Ka), number of binding sites (n), and the binding distance (r) between three RSBs and BSA were calculated by Stern-Volmer equation and Förster’s theory in this study. According to the results of displacement experiments of site probes, it was considered that the binding sites were located in hydrophobic cavities in sub-domains IIA of BSA. What is more, synchronous fluorescence studies indicated that the hydrophobicity around tryptophan residues was increased with the addition of rimantadine-o-vanillin (ROV) and rimantadine-4-methoxy-salicylaldehyde (RMS), while there was no apparent change with the addition of rimantadine-salicylaldehyde (RS). PMID:25587306

  17. Experimental immune complex glomerulonephritis and the nephrotic syndrome in cats immunised with cationised bovine serum albumin.

    PubMed

    Nash, A S; Mohammed, N A; Wright, N G

    1990-11-01

    Membranous nephropathy was induced in four cats by repeated intravenous injections of 120 mg cationic bovine serum albumin (BSA, pI 9.5). All four cats developed diffuse granular deposits of IgG and C3 along the glomerular capillary walls as early as five weeks which persisted until the end of the experiment at 17 weeks. Ultrastructural studies revealed many subepithelial electron dense deposits. Two cats developed severe proteinuria and the nephrotic syndrome characterised by hypoalbuminaemia and oedema. An additional four cats received repeated injections of unmodified native BSA (pI 4.5) and remained basically normal. This is the first report of membranous nephropathy and the nephrotic syndrome in an experimental animal model which, unlike other animal models, is subject to the spontaneously occurring disease. PMID:2148430

  18. New insights into in vitro amyloidogenic properties of human serum albumin suggest considerations for therapeutic precautions.

    PubMed

    Sharma, Neetu; Sivalingam, Vishwanath; Maurya, Sonalika; Prasad, Archana; Khandelwal, Puneet; Yadav, Subhash Chandra; Patel, Basant K

    2015-12-21

    Amyloid aggregates display striking features of detergent stability and self-seeding. Human serum albumin (HSA), a preferred drug-carrier molecule, can also aggregate in vitro. So far, key amyloid properties of stability against ionic detergents and self-seeding, are unclear for HSA aggregates. Precautions against amyloid contamination would be required if HSA aggregates were self-seeding. Here, we show that HSA aggregates display detergent sarkosyl stability and have self-seeding potential. HSA dimer is preferable for clinical applications due to its longer retention in circulation and lesser oedema owing to its larger molecular size. Here, HSA was homodimerized via free cysteine-34, without any potentially immunogenic cross-linkers that are usually pre-requisite for homodimerization. Alike the monomer, HSA dimers also aggregated as amyloid, necessitating precautions while using for therapeutics. PMID:26554815

  19. Investigation of thermal denaturation of solid bovine serum albumin by terahertz dielectric spectroscopy

    NASA Astrophysics Data System (ADS)

    Li, Xiangjun; Fu, Xiuhua; Liu, Jianjun; Du, Yong; Hong, Zhi

    2013-10-01

    We investigate the thermal denaturation of solid bovine serum albumin (BSA) using terahertz time domain spectroscopy (THz-TDS). When the protein is heated up from 25 °C to 107 °C and cooled down to 25 °C again, an irreversible decrease in its THz absorption coefficient and refractive index is observed. The corresponding frequency-dependent permittivity during heating is fitted by the Debye model with single relaxation time. The relaxation times during temperature rising agree very well with Arrhenius equation with the activation energy of 6.52 kJ/(K·mol), which can be an indicator for the stability of BSA during thermal denaturation process.

  20. The investigation of the interaction between NCP-EDA and bovine serum albumin by spectroscopic approaches.

    PubMed

    Yu, Xianyong; Lu, Shiyu; Yang, Ying; Li, Xiaofang; Yi, Pinggui

    2011-12-01

    The fluorescence and ultraviolet spectroscopies were explored to study the interaction between N-confused porphyrins-edaravone diad (NCP-EDA) and bovine serum albumin (BSA) under simulative physiological condition at different temperatures. The experimental results show that the fluorescence quenching mechanism between NCP-EDA and BSA is a combined quenching (dynamic and static quenching). The binding constants, binding sites and the corresponding thermodynamic parameters (ΔG, ΔH, and ΔS) of the interaction system were calculated at different temperatures. According to Förster non-radiation energy transfer theory, the binding distance between NCP-EDA and BSA was calculated to be 3.63 nm. In addition, the effect of NCP-EDA on the conformation of BSA was analyzed using synchronous fluorescence spectroscopy. PMID:21963191

  1. The investigation of the interaction between NCP-EDA and bovine serum albumin by spectroscopic approaches

    NASA Astrophysics Data System (ADS)

    Yu, Xianyong; Lu, Shiyu; Yang, Ying; Li, Xiaofang; Yi, Pinggui

    2011-12-01

    The fluorescence and ultraviolet spectroscopies were explored to study the interaction between N-confused porphyrins-edaravone diad (NCP-EDA) and bovine serum albumin (BSA) under simulative physiological condition at different temperatures. The experimental results show that the fluorescence quenching mechanism between NCP-EDA and BSA is a combined quenching (dynamic and static quenching). The binding constants, binding sites and the corresponding thermodynamic parameters (Δ G, Δ H, and Δ S) of the interaction system were calculated at different temperatures. According to Förster non-radiation energy transfer theory, the binding distance between NCP-EDA and BSA was calculated to be 3.63 nm. In addition, the effect of NCP-EDA on the conformation of BSA was analyzed using synchronous fluorescence spectroscopy.

  2. Spectroscopic investigation of the interaction between riboflavin and bovine serum albumin

    NASA Astrophysics Data System (ADS)

    Guo, Xing-Jia; Sun, Xiu-Dan; Xu, Shu-Kun

    2009-08-01

    The mutual interaction of riboflavin (RF) with bovine serum albumin (BSA) was investigated using fluorescence spectroscopy under simulative physiological conditions. The fluorescence quenching mechanism of BSA by RF should belong to dynamic quenching according to the Stern-Volmer equation, but also the effect of ground complex formation and energy transfer could not be completely precluded in BSA-RF system. The binding constants and the corresponding thermodynamic parameters at different temperatures were calculated, which indicated the presence of hydrophobic forces between RF and BSA. The averaged binding distance between riboflavin and BSA was also obtained based on the theory of FÖrster's non-radiation energy transfer. Moreover, the effect of riboflavin on the conformation of BSA was analyzed using synchronous fluorescence. The effects of some common ions Cu 2+, Zn 2+, Ca 2+, and Mg 2+ on the binding constant between riboflavin and BSA were also examined.

  3. Spectrometry researches on interaction and sonodynamic damage of riboflavin (RF) to bovine serum albumin (BSA)

    NASA Astrophysics Data System (ADS)

    Wang, Zhiqiu; Li, Jushi; Wang, Jun; Zou, Mingming; Wang, Siyu; Li, Ying; Kong, Yumei; Xia, Lixin

    2012-02-01

    In this paper, the riboflavin (RF) was used to study the interaction and sonodynamic damage to bovine serum albumin (BSA) by fluorescence and UV-vis spectroscopy. The results showed that the RF could efficiently bind to BSA in aqueous solution. Under ultrasonic irradiation, the RF could obviously damage the BSA. In addition, synchronous fluorescence spectroscopy revealed that the RF showed more accessible to tryptophan (Trp) residues than to tyrosine (Tyr) residues. Also, it damaged Trp residues more seriously than Tyr residues under ultrasonic irradiation. At last, the generation of reactive oxygen species (ROS) in sonodynamic process was estimated by the method of Oxidation-Extraction Spectrometry (OES). And then, several radical scavengers were used to determine the kind of ROS. It was found that at least the singlet oxygen ( 1O 2) and hydroxyl radicals ( rad OH) were generated.

  4. Interaction of bovine serum albumin protein with self assembled monolayer of mercaptoundecanoic acid

    NASA Astrophysics Data System (ADS)

    Poonia, Monika; Agarwal, Hitesh; Manjuladevi, V.; Gupta, R. K.

    2016-05-01

    Detection of proteins and other biomolecules in liquid phase is the essence for the design of a biosensor. The sensitivity of a sensor can be enhanced by the appropriate functionalization of the sensing area so as to establish the molecular specific interaction. In the present work, we have studied the interaction of bovine serum albumin (BSA) protein with a chemically functionalized surface using a quartz crystal microbalance (QCM). The gold-coated quartz crystals (AT-cut/5 MHz) were functionalized by forming self-assembled monolayer (SAM) of 11-Mercaptoundecanoic acid (MUA). The adsorption characteristics of BSA onto SAM of MUA on quartz crystal are reported. BSA showed the highest affinity for SAM of MUA as compared to pure gold surface. The SAM of MUA provides carboxylated surface which enhances not only the adsorption of the BSA protein but also a very stable BSA-MUA complex in the liquid phase.

  5. A calorimetric study on interactions of colchicine with human serum albumin

    NASA Astrophysics Data System (ADS)

    Zhao, Qiang; Xu, Xiang-Yu; Sun, Xiang-Jun; Liu, Min; Sun, De-Zhi; Li, Lin-Wei

    2009-08-01

    Interaction of colchicine (COL) with human serum albumin (HSA) in buffer solutions (pH 7.2) has been investigated by isothermal titration calorimetry (ITC) combined with circular dichroism (CD) and UV-vis spectra. Heats of the interactions have been determined at 298.15 K. Based on the calorimetric data and reasonable suppositions for the bio-macromolecule - ligand binding process, the equilibrium constants, standard changes of enthalpy, entropy and Gibbs free energy of the processes are obtained. The results show that there are two classes of ligand binding sites. The first-class binding is mainly driven by entropy, while the second-class binding is synergistically driven by entropy and enthalpy. Circular dichroism (CD) and UV-vis spectra show that COL can change the secondary structure of HSA molecule.

  6. Affinity of rosmarinic acid to human serum albumin and its effect on protein conformation stability.

    PubMed

    Peng, Xin; Wang, Xiangchao; Qi, Wei; Su, Rongxin; He, Zhimin

    2016-02-01

    Rosmarinic acid (RA) is a natural polyphenol contained in many aromatic plants with promising biological activities. The interaction between RA and human serum albumin (HSA) was investigated by multi-spectroscopic, electrochemistry, molecular docking and molecular dynamics simulation methods. The fluorescence emission of HSA was quenched by RA through a combined static and dynamic quenching mechanism, but the static quenching was the major constituent. Fluorescence experiments suggested that RA was bound to HSA with moderately strong binding affinity through hydrophobic interaction. The probable binding location of RA was located near site I of HSA. Additionally, as shown by the Fourier transform infrared (FT-IR) and circular dichroism (CD) spectra, RA can result in conformational and structural alterations of HSA. Furthermore, the molecular dynamics studies were used to investigate the stability of the HSA and HSA-RA system. Altogether, the results can provide an important insight for the applications of RA in the food industry. PMID:26304336

  7. Binding properties of drospirenone with human serum albumin and lysozyme in vitro

    NASA Astrophysics Data System (ADS)

    Wang, Qing; Ma, Xiangling; He, Jiawei; Sun, Qiaomei; Li, Yuanzhi; Li, Hui

    2016-01-01

    The interaction of drospirenone (DP) with human serum albumin (HSA)/lysozyme (LYZ) was investigated using different optical techniques and molecular models. Results from the emission and time resolved fluorescence studies revealed that HSA/LYZ emission quenching with DP was initiated by static quenching mechanism. The LYZ-DP system was more easily influenced by temperature than the HSA-DP system. Displacement experiments demonstrated that the DP binding site was mainly located in site 1 of HSA. Based on the docking methods, DP was mainly bound in the active site hinge region where Trp-62 and Trp-63 are located. Conformation study showed that DP had different effects on the local conformation of HSA and LYZ molecules.

  8. Studying the denaturation of bovine serum albumin by a novel approach of difference-UV analysis.

    PubMed

    Nikolaidis, Athanasios; Moschakis, Thomas

    2017-01-15

    A novel approach in the analysis of difference-UV spectrophotometric data for determining the heat denaturation degree of bovine serum albumin (BSA) was assessed. Five different parameters of difference-UV spectra were obtained by subtracting spectra of unheated and denatured protein solutions at different temperature-time combinations. BSA was found to exhibit a maximum degree of heat denaturation of about 17% compared to the complete unfolding caused by 6M guanidine hydrochloride. This low degree of heat denaturation is probably caused by the aggregation of the initially unfolded protein molecules. The kinetic analysis exhibited discontinuities in the Arrhenius plots, distinguishing the unfolding and aggregation phases of the denaturation process, whereas such a discrimination could not be obtained by differential scanning calorimetry analyses. The proposed method is accurate, fast, simple and sensitive enough to detect changes in the protein heat denaturation even at short temperature-time intervals. PMID:27542472

  9. Evaluation of the enantioselective binding of imazalil to human serum albumin by capillary electrophoresis.

    PubMed

    Asensi-Bernardi, Lucía; Martín-Biosca, Yolanda; Escuder-Gilabert, Laura; Sagrado, Salvador; Medina-Hernández, María José

    2015-11-01

    In this work, a methodology for the evaluation of enantioselective binding of imazalil (IMA) enantiomers to human serum albumin (HSA) that does not require the separation of free and bound to HSA fractions is developed. This methodology comprises the incubation of IMA-HSA designed mixtures for 30 min directly in the capillary electrophoresis system and the subsequent direct injection and chiral separation of IMA employing highly sulfated β-cyclodextrin as chiral selector and the complete filling technique. Two mathematical approaches were used to estimate apparent affinity constants (K1), protein binding and enantioselectivity (ES) for both enantiomers of IMA. Moderate enantioselective binding of IMA enantiomers to HSA (ES = 2.0) was shown by the 1:1 stoichiometry and log K1 values of 3.4 ± 0.4 and 3.1 ± 0.3 for the first and second eluted enantiomers, respectively. PMID:25857268

  10. Glycation of bovine serum albumin by ascorbate in vitro: Possible contribution of the ascorbyl radical?

    PubMed Central

    Sadowska-Bartosz, Izabela; Stefaniuk, Ireneusz; Galiniak, Sabina; Bartosz, Grzegorz

    2015-01-01

    Ascorbic acid (AA) has been reported to be both pro-and antiglycating agent. In vitro, mainly proglycating effects of AA have been observed. We studied the glycation of bovine serum albumin (BSA) induced by AA in vitro. BSA glycation was accompanied by oxidative modifications, in agreement with the idea of glycoxidation. Glycation was inhibited by antioxidants including polyphenols and accelerated by 2,​2′-​azobis-​2-​methyl-​propanimidamide and superoxide dismutase. Nitroxides, known to oxidize AA, did not inhibit BSA glycation. A good correlation was observed between the steady-state level of the ascorbyl radical in BSA samples incubated with AA and additives and the extent of glycation. On this basis we propose that ascorbyl radical, in addition to further products of AA oxidation, may initiate protein glycation. PMID:26202868

  11. Glycation of bovine serum albumin by ascorbate in vitro: Possible contribution of the ascorbyl radical?

    PubMed

    Sadowska-Bartosz, Izabela; Stefaniuk, Ireneusz; Galiniak, Sabina; Bartosz, Grzegorz

    2015-12-01

    Ascorbic acid (AA) has been reported to be both pro-and antiglycating agent. In vitro, mainly proglycating effects of AA have been observed. We studied the glycation of bovine serum albumin (BSA) induced by AA in vitro. BSA glycation was accompanied by oxidative modifications, in agreement with the idea of glycoxidation. Glycation was inhibited by antioxidants including polyphenols and accelerated by 2,​2'-​azobis-​2-​methyl-​propanimidamide and superoxide dismutase. Nitroxides, known to oxidize AA, did not inhibit BSA glycation. A good correlation was observed between the steady-state level of the ascorbyl radical in BSA samples incubated with AA and additives and the extent of glycation. On this basis we propose that ascorbyl radical, in addition to further products of AA oxidation, may initiate protein glycation. PMID:26202868

  12. The complexity of condensed tannin binding to bovine serum albumin--An isothermal titration calorimetry study.

    PubMed

    Kilmister, Rachel L; Faulkner, Peta; Downey, Mark O; Darby, Samuel J; Falconer, Robert J

    2016-01-01

    Isothermal titration calorimetry was applied to study the binding of purified proanthocyanidin oligomers to bovine serum albumin (BSA). The molecular weight of the proanthocyanidin oligomer had a major impact on its binding to BSA. The calculated change in enthalpy (ΔH) and association constant (Ka) became greater as the oligomer size increased then plateaued at the heptameric oligomer. These results support a model for precipitation of proteins by proanthocyanidin where increased oligomer size enhanced the opportunity for cross linkages between proteins ultimately forming sediment-able complexes. The authors suggest tannin binding to proteins is opportunistic and involves multiple sites, each with a different Ka and ΔH of binding. The ΔH of binding comprises both an endothermic hydrophobic interaction and exothermic hydrogen bond component. This suggests the calculated entropy value (ΔS) for tannin-protein interactions is subject to a systematic error and should be interpreted with caution. PMID:26212957

  13. Interaction of diuron to human serum albumin: Insights from spectroscopic and molecular docking studies.

    PubMed

    Chen, Huilun; Rao, Honghao; Yang, Jian; Qiao, Yongxiang; Wang, Fei; Yao, Jun

    2016-01-01

    This investigation was undertaken to determine the interaction of diuron with human serum albumin (HSA) was studied by monitoring the spectral behavior of diuron-HSA system. The fluorescence of HSA at 340 nm excited at 230 nm was obviously quenched by diuron due to dynamic collision and the quenching constant was of the order of 10(4) L mol(-1) at 310 K. However, no fluorescence quenching was observed when excited at 280 nm. Thermodynamic investigations revealed that the combination between diuron and HSA was entropy driven by predominantly hydrophobic interactions. The binding of diuron induced the drastic reduction in α-helix conformation and the significant enhancement in β-turn conformation of HSA. In addition, both sites marker competition study and molecular modeling simulation evidenced the binding of diuron to HSA primarily took place in subdomain IIIA (Sudlow's site II). PMID:26671830

  14. Prevention of Serum Albumin Glycation/Fibrillation by β-Cyclodextrin Functionalized Magnetic Nanoparticles.

    PubMed

    Ansari, Mojtaba; Habibi-Rezaei, Mehran; Salahshour-Kordestani, Soheila; Movahedi, Ali A Moosavi; Poursasan, Najmeh

    2015-01-01

    Nowadays, glycation induced protein aggregation and related opposing strategies have received much attention. We present the effect of functionalized magnetic core-shell nanoparticles of Fe3O4 (MNPs) with β-cyclodextrin (β-CD) on the aggregation/fibrillation of bovine serum albumin (BSA) under diabetic condition known as amyloidogenesis. To confirm the β-CD conjugation on MNP, Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermogravimetric analysis (TGA), transmission electron microscopy (TEM) and vibrating sample magnetometer (VSM) methods were applied. Moreover, spectrofluorimetry and spectropolarimetry were utilized to analyze the effect of β-CD/Fe3O4 MNPs on the aggregation and amyloidogenesis of BSA through glycation. The BSA amyloidogenesis was significantly inhibited by interfering β-CD-MNPs that may present the possible diagnostic and preventive applications against the degenerative effects of protein glycation/fibrillation under diabetes. PMID:26100685

  15. Interaction of lipid vesicle with silver nanoparticle-serum albumin protein corona

    PubMed Central

    Chen, Ran; Choudhary, Poonam; Schurr, Ryan N.; Bhattacharya, Priyanka; Brown, Jared M.; Chun Ke, Pu

    2012-01-01

    The physical interaction between a lipid vesicle and a silver nanoparticle (AgNP)-human serum albumin (HSA) protein “corona” has been examined. Specifically, the binding of AgNPs and HSA was analyzed by spectrophotometry, and the induced conformational changes of the HSA were inferred from circular dichroism spectroscopy. The fluidity of the vesicle, a model system for mimicking cell membrane, was found to increase with the increased exposure to AgNP-HSA corona, though less pronounced compared to that induced by AgNPs alone. This study offers additional information for understanding the role of physical forces in nanoparticle-cell interaction and has implications for nanomedicine and nanotoxicology. PMID:22271932

  16. Serum Albumin-Alginate Microparticles Prepared by Transacylation: Relationship between Physicochemical, Structural and Functional Properties.

    PubMed

    Hadef, Imane; Rogé, Barbara; Edwards-Lévy, Florence

    2015-08-10

    Our laboratory develops a method of microencapsulation using a transacylation reaction in a water-in-oil (W/O) emulsion. The method is based on the creation of amide bonds between free amine functions of a protein (human serum albumin (HSA)) and ester groups of propylene glycol alginate (PGA) in the inner aqueous phase after alkalization. The aim of this work is to study the influence of physicochemical properties of HSA-PGA mixtures on microparticle characteristics. Microparticles were prepared varying the concentrations of PGA and HSA, then characterized (inner structure, size, swelling rate, release kinetics). PGA and each polymer mixture used in the microencapsulation procedure were examined in order to elucidate the mechanism of microstructure formation. It was found that the morphology and functional properties of HSA-alginate microparticles were related to the two polymer concentrations in the aqueous solution. Actually, the polymer concentration variations led to physicochemical changes, which affected the microparticle structure and functional properties. PMID:26121308

  17. Binding of Citreoviridin to Human Serum Albumin: Multispectroscopic and Molecular Docking

    PubMed Central

    Hou, Haifeng; Qu, Xiaolan; Li, Yuqin; Kong, Yueyue; Jia, Baoxiu; Yao, Xiaojun; Jiang, Baofa

    2015-01-01

    Citreoviridin (CIT), a mycotoxin produced by Penicillium citreonigrum, is a common contaminant of wide range of agriproducts and detrimental to human and animal health. In this study, the interaction of CIT with human serum albumin (HSA) is researched by steady-state fluorescence, ultraviolet-visible (UV-Vis) absorption, circular dichroism (CD) methods, and molecular modeling. The association constants, binding site numbers, and corresponding thermodynamic parameters are used to investigate the quenching mechanism. The alternations of HSA secondary structure in the presence of CIT are demonstrated with UV-Vis, synchronous fluorescence, and CD spectra. The molecular modeling results reveal that CIT can bind with hydrophobic pocket of HSA with hydrophobic and hydrogen bond force. Moreover, an apparent distance of 3.25 nm between Trp214 and CIT is obtained via fluorescence resonance energy transfer method. PMID:25977915

  18. Size-dependent denaturing kinetics of bovine serum albumin adsorbed onto gold nanospheres

    NASA Astrophysics Data System (ADS)

    Teichroeb, J. H.; Forrest, J. A.; Jones, L. W.

    2008-08-01

    We have used localized surface plasmon resonance (LSPR) to monitor the kinetics of thermal denaturing of bovine serum albumin (BSA) adsorbed onto gold nanospheres of size 5nm-100nm. The effect of the protein on the LSPR was monitored by visible extinction spectroscopy. The wavelength of the peak extinction (resonance) is affected by the conformation of the adsorbed protein layer, and as such can be used as a very sensitive probe of thermal denaturing that is specific to the adsorbed (as opposed to free) protein. The time dependence of the denaturing is measured in the temperature range 60 °C - 70 °C , and the lifetimes are used to calculate an activation barrier for thermal denaturing. The results show that thermally activated denaturing of proteins adsorbed onto nanoparticles has a nanoparticle-size-dependent activation barrier, and this barrier increases for decreasing particle size. This may have important implications for other protein-nanoparticle interactions.

  19. A colorimetric and ratiometric fluorescent probe for quantification of bovine serum albumin.

    PubMed

    Zeng, Xiaodan; Zhang, Xiaoling; Zhu, Baocun; Jia, Hongying; Li, Yamin; Xue, Juan

    2011-10-01

    A 4-aminonaphthalimide-based ratiometric fluorescent probe 1 employing the internal charge transfer (ICT) mechanism was designed and synthesized to detect bovine serum albumin (BSA). The interaction of 1 and BSA was investigated by fluorescence and UV-vis absorption spectroscopy. Upon treatment with BSA, the probe successfully exhibited a ratiometric fluorescent response at 540 nm and 480 nm. The fluorescent intensity ratio at 540 nm and 480 nm (F(540)/F(480)) increases linearly with BSA concentration in the range of 0-75.0 μg mL(-1) and the detection limit was about 2.4 ng mL(-1). Our strategy is expected to provide a methodology to quantify BSA either by a normal or by a ratiometric and colorimetric way with high sensitivity. PMID:21858298

  20. Kinetic Analyses of Data from a Human Serum Albumin Assay Using the liSPR System

    PubMed Central

    Henseleit, Anja; Pohl, Carolin; Kaltenbach, Hans-Michael; Hettwer, Karina; Simon, Kirsten; Uhlig, Steffen; Haustein, Natalie; Bley, Thomas; Boschke, Elke

    2015-01-01

    We used the interaction between human serum albumin (HSA) and a high-affinity antibody to evaluate binding affinity measurements by the bench-top liSPR system (capitalis technology GmbH). HSA was immobilized directly onto a carboxylated sensor layer, and the mechanism of interaction between the antibody and HSA was investigated. The bivalence and heterogeneity of the antibody caused a complex binding mechanism. Three different interaction models (1:1 binding, heterogeneous analyte, bivalent analyte) were compared, and the bivalent analyte model best fit the curves obtained from the assay. This model describes the interaction of a bivalent analyte with one or two ligands (A + L ↔ LA + L ↔ LLA). The apparent binding affinity for this model measured 37 pM for the first reaction step, and 20 pM for the second step. PMID:25607476

  1. Investigation of the interaction between amodiaquine and human serum albumin by fluorescence spectroscopy and molecular modeling.

    PubMed

    Samari, Fayezeh; Shamsipur, Mojtaba; Hemmateenejad, Bahram; Khayamian, Taghi; Gharaghani, Sajjad

    2012-08-01

    The interaction of amodiaquine (AQ) with human serum albumin (HSA) has been studied by fluorescence spectroscopy. Based on the sign and magnitude of the enthalpy and entropy changes (ΔH(0) = -43.27 kJ mol(-1) and ΔS(0) = -50.03 J mol(-1) K(-1)), hydrogen bond and van der Waals forces were suggested as the main interacting forces. Moreover, the efficiency of energy transfer and distance between HSA and acceptor AQ was calculated. Finally, the binding of AQ to HSA was modeled by molecular docking and molecular dynamic simulation methods. Excellent agreement was found between the experimental and theoretical results. Both experimental results and modeling methods suggested that AQ binds mainly to the sub-domain IIA of HSA. PMID:22658498

  2. [Study on the interaction between ICT fluorescence probe and bovine serum albumins].

    PubMed

    Liu, Yu-Fang; Li, Jian-Qing; Xu, Zhi-Cheng; Wei, Yan-Li; Shuang, Shao-Min; Dong, Chuan

    2008-04-01

    The present article studied the interaction between intramolecular charge transfer fluorescence probe-1-keto-2-(p-dimethylaminobenzal)-tetrohydronaphthalene (KDTN) and bovine serum albumins (BSA). With the concentration of KDTN increasing, the fluorescence of BSA rapidly quenched and the fluorescence peak gradually blue-shifted. The result indicated that they were bound mainly by hydrophobic interaction. The binding sites is 0.94 (3 degrees C) and the equilibrium constant K is 3.27 x 10(4) L x mol(-1). Temperature increment is advantageous to the combination. It is a single static quenching process that the fluorescence of BSA quenches, which is induced by the combination of KDTN and BSA. Further study showed that different substances had different effects on the combination of KDTN and BSA. PMID:18619322

  3. Investigation on the interaction of pyrene with bovine serum albumin using spectroscopic methods

    NASA Astrophysics Data System (ADS)

    Xu, Chengbin; Gu, Jiali; Ma, Xiping; Dong, Tian; Meng, Xuelian

    This paper was designed to investigate the interaction of pyrene with bovine serum albumin (BSA) under physiological condition by spectroscopic methods. Spectroscopic analysis of the emission quenching revealed that the quenching mechanism of BSA by pyrene was static. The binding sites and constants of pyrene-BSA complex were observed to be 1.20 and 2.63 × 106 L mol-1 at 298 K, respectively. The enthalpy change (ΔH) and entropy change (ΔS) revealed that van der Waals forces and hydrogen bonds stabilized the pyrene-BSA complex. Energy transfer from tryptophan to pyrene occurred by a FRET (fluorescence resonance energy transfer) mechanism, and the distance (r = 2.72 nm) had been determined. The results of synchronous, three-dimensional fluorescence, and circular dichroism spectra showed that the pyrene induced conformational changes of BSA.

  4. Spectroscopic analyses on interaction of bovine serum albumin with novel spiro[cyclopropane-pyrrolizin

    NASA Astrophysics Data System (ADS)

    Yu, Xianyong; Liao, Zhixi; Jiang, Bingfei; Hu, Xiaolian; Li, Xiaofang

    2015-02-01

    The interaction between novel spiro[cyclopropane-pyrrolizin] (NSCP) and bovine serum albumin (BSA) was analyzed by fluorescence and ultraviolet-visible (UV-Vis) spectroscopy at 298 K, 304 K and 310 K under simulative physiological conditions. The results showed that NSCP can effectively quench the intrinsic fluorescence of BSA via static quenching. The binding constants, binding sites of NSCP with BSA were calculated. Hydrogen binds and van der Waals force played a major role in stabilizing the complex and the binding reaction were spontaneous. According to the Förster non-radiation energy transfer theory, the average binding distances between NSCP and BSA were obtained. What is more, the synchronous fluorescence spectra indicated that the conformation of BSA has been changed.

  5. Binding of caffeine, theophylline, and theobromine with human serum albumin: A spectroscopic study

    NASA Astrophysics Data System (ADS)

    Zhang, Hong-Mei; Chen, Ting-Ting; Zhou, Qiu-Hua; Wang, Yan-Qing

    2009-12-01

    The interaction between three purine alkaloids (caffeine, theophylline, and theobromine) and human serum albumin (HSA) was investigated using UV/vis absorption, circular dichroism (CD), fluorescence, synchronous fluorescence, and three-dimensional fluorescence spectra techniques. The results revealed that three alkaloids caused the fluorescence quenching of HSA by the formation of alkaloid-HSA complex. The binding site number n and apparent binding constant KA, corresponding thermodynamic parameters the free energy change (Δ G), enthalpy change (Δ H), and entropy change (Δ S) at different temperatures were calculated. The hydrophobic interaction plays a major role in stabilizing the complex. The distance r between donor (HSA) and acceptor (alkaloids) was obtained according to fluorescence resonance energy transfer. The effect of alkaloids on the conformation of HSA was analyzed using circular dichroism (CD), UV/vis absorption, synchronous fluorescence and three-dimensional fluorescence spectra techniques.

  6. Spectrometric studies on the interaction of fluoroquinolones and bovine serum albumin

    NASA Astrophysics Data System (ADS)

    Ni, Yongnian; Su, Shaojing; Kokot, Serge

    2010-02-01

    The interaction between fluoroquinolones (FQs), ofloxacin and enrofloxacin, and bovine serum albumin (BSA) was investigated by fluorescence and UV-vis spectroscopy. It was demonstrated that the fluorescence quenching of BSA by FQ is a result of the formation of the FQ-BSA complex stabilized, in the main, by hydrogen bonds and van der Waals forces. The Stern-Volmer quenching constant, KSV, and the corresponding thermodynamic parameters, Δ H, Δ S and Δ G, were estimated. The distance, r, between the donor, BSA, and the acceptor, FQ, was estimated from fluorescence resonance energy transfer (FRET). The effect of FQ on the conformation of BSA was analyzed with the aid of UV-vis absorbance spectra and synchronous fluorescence spectroscopy. Spectral analysis showed that the two FQs affected the conformation of the BSA but in a different manner. Thus, with ofloxacin, the polarity around the tryptophan residues decreased and the hydrophobicity increased, while for enrofloxacin, the opposite effect was observed.

  7. [Interaction between ambroxol hydrochloride and human serum albumin studied by spectroscopic and molecular modeling methods].

    PubMed

    Liang, Jing; Feng, Su-Ling

    2011-04-01

    In the present paper, the interaction between ambroxol hydrochloride (ABX) and human serum albumin (HSA) was studied under simulative physiological condition by spectroscopy and molecular modeling method. Stern-Volmer curvers at different temperatures and UV-Vis absorption spectroscopy showed that ABX quenched the fluorescence of HSA mainly through dynamic quenching mode. On the basis of the thermodynamic data, the main binding force between them is hydrophobic interaction. According to the theory of Forster non-radiation energy transfer, the binding distance between the donor and the acceptor was 3.01 nm. The effect of ABX on the conformation of HSA was analyzed by the synchronous and three-dimensional fluorescence spectroscopy. Furthermore, using the molecular modeling method, the interaction between them was predicted from molecular angle: ABX might locate in the subdomain III A of HSA. PMID:21714251

  8. Synthesis of three rimantadine schiff bases and their biological effects on serum albumin.

    PubMed

    Liu, Bing-Mi; Ma, Ping; Wang, Xin; Kong, Yu-Mei; Zhang, Li-Ping; Liu, Bin

    2014-01-01

    Three new rimantadine Schiff bases (RSBs) were prepared, and then the interaction of RSBs with bovine serum albumin (BSA) was investigated using fluorescence, synchronous fluorescence, UV-vis absorption spectroscopy under physiological conditions. The results showed that the three RSBs effectively quenched the intrinsic fluorescence of BSA via static quenching. Binding constant (K a), number of binding sites (n), and the binding distance (r) between three RSBs and BSA were calculated by Stern-Volmer equation and Förster's theory in this study. According to the results of displacement experiments of site probes, it was considered that the binding sites were located in hydrophobic cavities in sub-domains IIA of BSA. What is more, synchronous fluorescence studies indicated that the hydrophobicity around tryptophan residues was increased with the addition of rimantadine-o-vanillin (ROV) and rimantadine-4-methoxy-salicylaldehyde (RMS), while there was no apparent change with the addition of rimantadine-salicylaldehyde (RS). PMID:25587306

  9. Quenching of tryptophan fluorescence of bovine serum albumin under the effect of ions of heavy metals

    NASA Astrophysics Data System (ADS)

    Plotnikova, O. A.; Mel'nikov, A. G.; Mel'nikov, G. V.; Gubina, T. I.

    2016-01-01

    The interaction of heavy metals with bovine serum albumin (BSA) has been studied using data of quenching of intrinsic fluorescence of the protein by the ions of the heavy metals. Under the assumption of static quenching with formation of nonfluorescent complexes of fluorophores of BSA with heavy metals, conclusions have been drawn on the peculiarities of binding of the heavy metals to the protein. The values of the Stern-Volmer constants of association and those of the constants of BSA binding to the heavy metals decrease in the order Cu(II) > Pb(II) > Cd(II). It has been experimentally found that the copper ions have greater capacity to bind to the protein with the formation of the nonfluorescent complexes, which results in a significant decrease in the fluorescence intensity of the protein.

  10. Sentinel lymph nodes fluorescence detection and imaging using Patent Blue V bound to human serum albumin

    PubMed Central

    Tellier, Franklin; Steibel, Jérôme; Chabrier, Renée; Blé, François Xavier; Tubaldo, Hervé; Rasata, Ravelo; Chambron, Jacques; Duportail, Guy; Simon, Hervé; Rodier, Jean-François; Poulet, Patrick

    2012-01-01

    Patent Blue V (PBV), a dye used clinically for sentinel lymph node detection, was mixed with human serum albumin (HSA). After binding to HSA, the fluorescence quantum yield increased from 5 × 10−4 to 1.7 × 10−2, which was enough to allow fluorescence detection and imaging of its distribution. A detection threshold, evaluated in scattering test objects, lower than 2.5 nmol × L−1 was obtained, using a single-probe setup with a 5-mW incident light power. The detection sensitivity using a fluorescence imaging device was in the µmol × L−1 range, with a noncooled CCD camera. Preclinical evaluation was performed on a rat model and permitted to observe inflamed nodes on all animals. PMID:23024922

  11. Synthesis of imidazole derivatives and the spectral characterization of the binding properties towards human serum albumin

    NASA Astrophysics Data System (ADS)

    Yue, Yuanyuan; Dong, Qiao; Zhang, Yajie; Li, Xiaoge; Yan, Xuyang; Sun, Yahui; Liu, Jianming

    2016-01-01

    Small molecular drugs that can combine with target proteins specifically, and then block relative signal pathway, finally obtain the purpose of treatment. For this reason, the synthesis of novel imidazole derivatives was described and this study explored the details of imidazole derivatives binding to human serum albumin (HSA). The data of steady-state and time-resolved fluorescence showed that the conjugation of imidazole derivatives with HSA yielded quenching by a static mechanism. Meanwhile, the number of binding sites, the binding constants, and the thermodynamic parameters were also measured; the raw data indicated that imidazole derivatives could spontaneously bind with HSA through hydrophobic interactions and hydrogen bonds which agreed well with the results from the molecular modeling study. Competitive binding experiments confirmed the location of binding. Furthermore, alteration of the secondary structure of HSA in the presence of the imidazole derivatives was tested.

  12. Probing the binding sites and the effect of berbamine on the structure of bovine serum albumin

    NASA Astrophysics Data System (ADS)

    Cheng, Xiao-Xia; Lui, Yi; Zhou, Bo; Xiao, Xiao-He; Liu, Yi

    2009-06-01

    Berbamine, a naturally occurring isoquinoline alkaloid extracted from Berberis sp., is the active constituent of some Chinese herbal medicines and exhibits a variety of pharmacological activities. The effects of berbamine on the structure of bovine serum albumin (BSA) were investigated by circular dichroism, fluorescence and absorption spectroscopy under physiological conditions. Berbamine caused a static quenching of the intrinsic fluorescence of BSA, and the quenching data were analyzed by application of the Stern-Volmer equation. There was a single primary berbamine-binding site on BSA with a binding constant of 2.577 × 10 4 L mol -1 at 298 K. The thermodynamic parameters, enthalpy change (Δ H0) and entropy change (Δ S0) for the reaction were -76.5 kJ mol -1 and -173.4 J mol -1 K -1 according to the van't Hoff equation. The results showed that the hydrogen bond and van der Waals interaction were the predominant forces in the binding process. Competitive experiments revealed a displacement of warfarin by berbamine, indicating that the binding site was located at Drug sites I. The distance r between the donor (BSA) and the acceptor (berbamine) was obtained according to the Förster non-radiation energy transfer theory. The results of three-dimensional fluorescence spectra, UV-vis absorption difference spectra and circular dichroism of BSA in the presence of berbamine showed that the conformation of BSA was changed. The results provide a quantitative understanding of the effect of berbamine on the structure of bovine serum albumin, providing a useful guideline for further drug design.

  13. Reciprocal Allosteric Modulation of Carbon Monoxide and Warfarin Binding to Ferrous Human Serum Heme-Albumin

    PubMed Central

    Bocedi, Alessio; De Sanctis, Giampiero; Ciaccio, Chiara; Tundo, Grazia R.; Di Masi, Alessandra; Fanali, Gabriella; Nicoletti, Francesco P.; Fasano, Mauro; Smulevich, Giulietta; Ascenzi, Paolo; Coletta, Massimo

    2013-01-01

    Human serum albumin (HSA), the most abundant protein in human plasma, could be considered as a prototypic monomeric allosteric protein, since the ligand-dependent conformational adaptability of HSA spreads beyond the immediate proximity of the binding site(s). As a matter of fact, HSA is a major transport protein in the bloodstream and the regulation of the functional allosteric interrelationships between the different binding sites represents a fundamental information for the knowledge of its transport function. Here, kinetics and thermodynamics of the allosteric modulation: (i) of carbon monoxide (CO) binding to ferrous human serum heme-albumin (HSA-heme-Fe(II)) by warfarin (WF), and (ii) of WF binding to HSA-heme-Fe(II) by CO are reported. All data were obtained at pH 7.0 and 25°C. Kinetics of CO and WF binding to the FA1 and FA7 sites of HSA-heme-Fe(II), respectively, follows a multi-exponential behavior (with the same relative percentage for the two ligands). This can be accounted for by the existence of multiple conformations and/or heme-protein axial coordination forms of HSA-heme-Fe(II). The HSA-heme-Fe(II) populations have been characterized by resonance Raman spectroscopy, indicating the coexistence of different species characterized by four-, five- and six-coordination of the heme-Fe atom. As a whole, these results suggest that: (i) upon CO binding a conformational change of HSA-heme-Fe(II) takes place (likely reflecting the displacement of an endogenous ligand by CO), and (ii) CO and/or WF binding brings about a ligand-dependent variation of the HSA-heme-Fe(II) population distribution of the various coordinating species. The detailed thermodynamic and kinetic analysis here reported allows a quantitative description of the mutual allosteric effect of CO and WF binding to HSA-heme-Fe(II). PMID:23555601

  14. Studies on interaction of colloidal Ag nanoparticles with Bovine Serum Albumin (BSA).

    PubMed

    Ravindran, Aswathy; Singh, Anupam; Raichur, Ashok M; Chandrasekaran, N; Mukherjee, Amitava

    2010-03-01

    Biofunctionalization of noble metal nanoparticles like Ag, Au is essential to obtain biocompatibility for specific biomedical applications. Silver nanoparticles are being increasingly used in bio-sensing applications owing to excellent optoelectronic properties. Among the serum albumins, the most abundant proteins in plasma, a wide range of physiological functions of Bovine Serum Albumin (BSA) has made it a model system for biofunctionalization. In absence of adequate prior reports, this study aims to investigate the interaction between silver nanoparticles and BSA. The interaction of BSA [0.05-0.85% concentrations] with Ag nanoparticles [50ppm concentration] in aqueous dispersion was studied through UV-vis spectral changes, morphological and surface structural changes. At pH 7, which is more than the isoelectric point of BSA, a decrease in absorbance at plasmon peak of uninteracted nanoparticles (425nm) was noted till 0.45% BSA, beyond that a blue shift towards 410nm was observed. The blue shift may be attributed to enhanced electron density on the particle surfaces. Increasing pH to 12 enhanced the blue shift further to 400nm. The conformational changes in BSA at alkaline pH ranges and consequent hydrophobic interactions also played an important role. The equilibrium adsorption data fitted better to Freundlich isotherm compared to Langmuir curve. The X-ray diffraction study revealed complete coverage of Ag nanoparticles by BSA. The scanning electron microscopic study of the interacted nanoparticles was also carried out to decipher morphological changes. This study established that tailoring the concentration of BSA and pH of the interaction it was possible to reduce aggregation of nanoparticles. Biofunctionalized Ag nanoparticles with reduced aggregation will be more amenable towards bio-sensing applications. PMID:19896812

  15. [Clinical application of 99mTc-DTPA-galactosyl serum albumin in hepatobiliary disease].

    PubMed

    Ohno, K; Itoh, K; Nagao, K; Katoh, H; Okushiba, T; Satoh, M; Tomiyama, M; Hiraguchi, E; Tanabe, T

    1993-02-01

    A clinical study with 99mTc-DTPA-galactosyl serum albumin (99mTc-GSA) was performed in 10 patients with hepatobiliary disease. In this study, scintigraphic data and images with 99mTc-GSA were compared with several serological liver function tests, the hepatic blood perfusion index and image quality using 99mTc-DTPA-human serum albumin (99mTc-HSA). Dynamic and serial hepatic images were obtained over a 20 min period after 99mTc-GSA injection, and time activity curves from the heart and liver were generated. The blood clearance index (HH15), and the hepatic uptake index (LHL15) were calculated from each curve of the heart and liver, respectively. In addition, using two compartment fitting, the blood clearance (KH1, KH2) index was calculated, and using exponential fitting, the hepatic uptake index (KL) was calculated. The mean HH15 in LC group and non-LC group was 0.81 +/- 0.05, 0.64 +/- 0.10, respectively. The mean LHL15 in LC group and non-LC group was 0.79 +/- 0.04, 0.91 +/- 0.06, respectively. There were significant differences between non-LC group and LC group in HH15, and LHL15, KH1 and KL. There were also significant correlations of KH1 with HH15, and KL with LHL15. Parameters of 99mTc-GSA showed significant correlations with various liver functions. 99mTc-GSA scintigraphy showed clearer liver images in hepatobiliary diseases than 99mTc-HSA. These results suggest that 99mTc-GSA scintigraphy is useful in estimating preserved liver function and hepatic morphology. PMID:8468807

  16. Human serum albumin-TRAIL conjugate for the treatment of rheumatoid arthritis.

    PubMed

    Byeon, Hyeong Jun; Min, Sun Young; Kim, Insoo; Lee, Eun Seong; Oh, Kyung Taek; Shin, Beom Soo; Lee, Kang Choon; Youn, Yu Seok

    2014-12-17

    Albumin conjugation is viewed as an effective means of protracting short in vivo lifespans of proteins and targeting rheumatoid arthritis (RA). In this study, we present a human serum albumin (HSA) conjugate linked with tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) via a bifunctional PEG derivative (HSA-TRAIL). Prepared HSA-TRAIL was found to have a larger molecular size (∼240 kDa, 15.4 nm) than TRAIL (∼66 kDa, 6.2 nm), and its bioactivity (apoptosis, cytotoxicity, and antiproliferation) was well preserved in Mia Paca-2 cells and mouse splenocytes. The enhanced therapeutic efficacy of HSA-TRAIL was demonstrated in collagen-induced arthritis (CIA) mice. The incidence and clinical scores, expressed as degree of erythema and swelling in HSA-TRAIL-treated mice, were remarkably lower than those of TRAIL-treated mice. The serum levels of pro-inflammatory cytokines IFN-γ, TNF-α, IL-1β, and IL-2 in HSA-TRAIL-treated mice were significantly lower than those of TRAIL-treated mice. Furthermore, HSA-TRAIL accumulated in the hind paws of CIA mice, not in naïve TRAIL mice. Pharmacokinetic profiles of HSA-TRAIL were greatly improved in comparison to those of TRAIL (AUCinf: 844.1 ± 130.0 vs 36.0 ± 1.2 ng·h/mL; t1/2: 6.20 ± 0.72 vs 0.23 ± 0.01 h, respectively). The HSA-TRAIL conjugate, which presents clear advantages of targeting RA and long systemic circulation by HSA and unique anti-inflammatory efficacy by TRAIL, has potential as a novel treatment for rheumatoid arthritis. PMID:25387356

  17. Time differential perturbed angular correlation of 111In-EDTA linked to the single free cysteine of bovine serum albumin.

    PubMed

    Ceolín, M; Martínez, J A; Ermácora, M R

    1997-09-25

    By means of a facile chemical modification of the bovine serum albumin molecule, it was possible to measure its hydrodynamic radius with high accuracy (approximately 3%) using the TDPAC technique. The new approach presented here allows a wide use of the TDPAC technique to perform high precision studies of backbone dynamics of almost any protein. PMID:9350519

  18. Interaction of BODIPY dyes with bovine serum albumin: a case study on the aggregation of a click-BODIPY dye.

    PubMed

    Jameson, Laramie P; Smith, Nicholas W; Annunziata, Onofrio; Dzyuba, Sergei V

    2016-06-01

    The fluorescence of BODIPY and click-BODIPY dyes was found to substantially increase in the presence of bovine serum albumin (BSA). BSA acted as a solubilizer for dye aggregates, in addition to being a conventional binding scaffold for the click-BODIPY dyes, indicating that disaggregation of fluorophores should be considered when evaluating dye-protein interactions. PMID:27173791

  19. Investigation of Cu(II) Binding to Bovine Serum Albumin by Potentiometry with an Ion Selective Electrode

    ERIC Educational Resources Information Center

    Jie Liu

    2004-01-01

    A laboratory project that investigates Cu(II) bind to bovine serum albumin (BSA) in an aqueous solution is developed to assist undergraduate students in gaining better understanding of the interaction of ligands with biological macromolecule. Thus, students are introduced to investigation of Cu(II) binding to BSA by potentiometry with the Cu(II)…

  20. Evaluation of the binding interaction between bovine serum albumin and dimethyl fumarate, an anti-inflammatory drug by multispectroscopic methods.

    PubMed

    Jattinagoudar, Laxmi; Meti, Manjunath; Nandibewoor, Sharanappa; Chimatadar, Shivamurti

    2016-03-01

    The information of the quenching reaction of bovine serum albumin with dimethyl fumarate is obtained by multi-spectroscopic methods. The number of binding sites, n and binding constants, KA were determined at different temperatures. The effect of increasing temperature on Stern-Volmer quenching constants (KD) indicates that a dynamic quenching mechanism is involved in the interaction. The analysis of thermodynamic quantities namely, ∆H° and ∆S° suggested hydrophobic forces playing a major role in the interaction between dimethyl fumarate and bovine serum albumin. The binding site of dimethyl fumarate on bovine serum albumin was determined by displacement studies, using the site probes viz., warfarin, ibuprofen and digitoxin. The determination of magnitude of the distance of approach for molecular interactions between dimethyl fumarate and bovine serum albumin is calculated according to the theory of Förster energy transfer. The CD, 3D fluorescence spectra, synchronous fluorescence measurements and FT-IR spectral results were indicative of the change in secondary structure of the protein. The influence of some of the metal ions on the binding interaction was also studied. PMID:26688208

  1. Evaluation of the binding interaction between bovine serum albumin and dimethyl fumarate, an anti-inflammatory drug by multispectroscopic methods

    NASA Astrophysics Data System (ADS)

    Jattinagoudar, Laxmi; Meti, Manjunath; Nandibewoor, Sharanappa; Chimatadar, Shivamurti

    2016-03-01

    The information of the quenching reaction of bovine serum albumin with dimethyl fumarate is obtained by multi-spectroscopic methods. The number of binding sites, n and binding constants, KA were determined at different temperatures. The effect of increasing temperature on Stern-Volmer quenching constants (KD) indicates that a dynamic quenching mechanism is involved in the interaction. The analysis of thermodynamic quantities namely, ∆H° and ∆S° suggested hydrophobic forces playing a major role in the interaction between dimethyl fumarate and bovine serum albumin. The binding site of dimethyl fumarate on bovine serum albumin was determined by displacement studies, using the site probes viz., warfarin, ibuprofen and digitoxin. The determination of magnitude of the distance of approach for molecular interactions between dimethyl fumarate and bovine serum albumin is calculated according to the theory of Förster energy transfer. The CD, 3D fluorescence spectra, synchronous fluorescence measurements and FT-IR spectral results were indicative of the change in secondary structure of the protein. The influence of some of the metal ions on the binding interaction was also studied.

  2. epi-Fluorescence imaging at the air-water interface of fibrillization of bovine serum albumin and human insulin.

    PubMed

    Sessions, Kristen; Sacks, Stuart; Li, Shanghao; Leblanc, Roger M

    2014-08-18

    Protein fibrillization is associated with many devastating neurodegenerative diseases. This process has been studied using spectroscopic and microscopic methods. In this study, epi-fluorescence at the air-water interface was developed as an innovative technique for observing fibrillization of bovine serum albumin and human insulin. PMID:24976597

  3. Effects of Fatty Acids and Glycation on Drug Interactions with Human Serum Albumin.

    PubMed

    Anguizola, Jeanethe A; Basiaga, Sara B G; Hage, David S

    2013-09-01

    The presence of elevated glucose concentrations in diabetes is a metabolic change that leads to an increase in the amount of non-enzymatic glycation that occurs for serum proteins. One protein that is affected by this process is the main serum protein, human serum albumin (HSA), which is also an important carrier agent for many drugs and fatty acids in the circulatory system. Sulfonylureas drugs, used to treat type 2 diabetes, are known to have significant binding to HSA. This study employed ultrafiltration and high-performance affinity chromatography to examine the effects of HSA glycation on the interactions of several sulfonylurea drugs (i.e., acetohexamide, tolbutamide and gliclazide) with fatty acids, whose concentrations in serum are also affected by diabetes. Similar overall changes in binding were noted for these drugs with normal HSA or glycated HSA and in the presence of the fatty acids. For most of the tested drugs, the addition of physiological levels of the fatty acids to normal HSA and glycated HSA produced weaker binding. At low fatty acid concentrations, many of these systems followed a direct competition model while others involved a mixed-mode interaction. In some cases, there was a change in the interaction mechanism between normal HSA and glycated HSA, as seen with linoleic acid. Systems with only direct competition also gave notable changes in the affinities of fatty acids at their sites of drug competition when comparing normal HSA and glycated HSA. This research demonstrated the importance of considering how changes in the concentrations and types of metabolites (e.g., in this case, glucose and fatty acids) can alter the function of a protein such as HSA and its ability to interact with drugs or other agents. PMID:24349966

  4. Effects of Fatty Acids and Glycation on Drug Interactions with Human Serum Albumin

    PubMed Central

    Anguizola, Jeanethe A.; Basiaga, Sara B. G.; Hage, David S.

    2013-01-01

    The presence of elevated glucose concentrations in diabetes is a metabolic change that leads to an increase in the amount of non-enzymatic glycation that occurs for serum proteins. One protein that is affected by this process is the main serum protein, human serum albumin (HSA), which is also an important carrier agent for many drugs and fatty acids in the circulatory system. Sulfonylureas drugs, used to treat type 2 diabetes, are known to have significant binding to HSA. This study employed ultrafiltration and high-performance affinity chromatography to examine the effects of HSA glycation on the interactions of several sulfonylurea drugs (i.e., acetohexamide, tolbutamide and gliclazide) with fatty acids, whose concentrations in serum are also affected by diabetes. Similar overall changes in binding were noted for these drugs with normal HSA or glycated HSA and in the presence of the fatty acids. For most of the tested drugs, the addition of physiological levels of the fatty acids to normal HSA and glycated HSA produced weaker binding. At low fatty acid concentrations, many of these systems followed a direct competition model while others involved a mixed-mode interaction. In some cases, there was a change in the interaction mechanism between normal HSA and glycated HSA, as seen with linoleic acid. Systems with only direct competition also gave notable changes in the affinities of fatty acids at their sites of drug competition when comparing normal HSA and glycated HSA. This research demonstrated the importance of considering how changes in the concentrations and types of metabolites (e.g., in this case, glucose and fatty acids) can alter the function of a protein such as HSA and its ability to interact with drugs or other agents. PMID:24349966

  5. Cell cytotoxicity and serum albumin binding capacity of the morin-Cu(ii) complex and its effect on deoxyribonucleic acid.

    PubMed

    Roy, Atanu Singha; Samanta, Sintu Kumar; Ghosh, Pooja; Tripathy, Debi Ranjan; Ghosh, Sudip Kumar; Dasgupta, Swagata

    2016-08-16

    The dietary components, flavonoids, are important for their anti-oxidant properties and the ability to act as metal ion chelators. The characterization of the morin-Cu(ii) complex is executed using elemental analysis, FTIR and mass spectroscopy. DNA cleaving and cell cytotoxicity properties followed by serum albumin binding have been investigated in this report. The morin-Cu(ii) complex was found to cleave plasmid pBR322 DNA via an oxidative pathway as revealed by agarose gel based assay performed in the presence of some scavengers and reactive oxygen species. The breaking of the deoxyribose ring of calf thymus DNA (ct-DNA) was also confirmed by the formation of thiobarbituric acid reacting species (TBARS) between thiobarbituric acid and malonaldehyde. The morin-Cu(ii) complex is able to inhibit the growth of human HeLa cells. Fluorescence studies revealed that the morin-Cu(ii) complex can quench the intrinsic fluorescence of serum albumins (SAs) via a static quenching method. The binding constants were found to be in the order of 10(5) M(-1) and observed to increase with temperature. Both ΔH° and ΔS° are positive for the binding of the morin-Cu(ii) complex with serum albumins which indicated the presence of hydrophobic forces. Site-selectivity studies reveal that the morin-Cu(ii) complex binds to both site 1 (subdomain IIA) and site 2 (subdomain IIIA) of human serum albumin (HSA) and bovine serum albumin (BSA). Circular dichroism (CD) studies showed the structural perturbation of SAs during binding with the morin-Cu(ii) complex. The results from binding studies confirmed that after complexation with the Cu(ii) ion, morin alters its mode of interaction with SAs which could have differential implications on its other biological and pharmaceutical properties. PMID:27345944

  6. Residual bovine serum albumin (BSA) quantitation in vaccines using automated Capillary Western technology.

    PubMed

    Loughney, John W; Lancaster, Catherine; Ha, Sha; Rustandi, Richard R

    2014-09-15

    Bovine serum albumin (BSA) is a major component of fetal bovine serum (FBS), which is commonly used as a culture medium during vaccine production. Because BSA can cause allergic reactions in humans the World Health Organization (WHO) has set a guidance of 50 ng or less residual BSA per vaccine dose. Vaccine manufacturers are expected to develop sensitive assays to detect residual BSA. Generally, sandwich enzyme-linked immunosorbent assays (ELISA) are used in the industry to detect these low levels of BSA. We report the development of a new improved method for residual BSA detection using the SimpleWestern technology to analyze residual BSA in an attenuated virus vaccine. The method is based on automated Capillary Western and has linearity of two logs, >80% spike recovery (accuracy), intermediate precision of CV <15%, and LOQ of 5.2 ng/ml. The final method was applied to analyze BSA in four lots of bulk vaccine products and was used to monitor BSA clearance during vaccine process purification. PMID:24841366

  7. Human serum albumin reduces the potency of acetylcholinesterase inhibitor based drugs for Alzheimer's disease.

    PubMed

    Islam, Mullah Muhaiminul; Gurung, Arun Bahadur; Bhattacharjee, Atanu; Aguan, Kripamoy; Mitra, Sivaprasad

    2016-04-01

    Human serum albumin (HSA) induced modulation of acetylcholinesterase (AChE) inhibition activity of four well-known cholinergic inhibitors like tacrine hydrochloride (TAC), donepezil hydrochloride monohydrate (DON), (-) Huperzine A (HuPA), eserine (ESE) was monitored quantitatively by Ellman's method. Kinetic analysis of enzyme hydrolysis reaction revealed that while the mechanism of inhibition does not change significantly, the inhibition efficiency changes drastically in presence of HSA, particularly for DON and TAC. However, interestingly, no notable difference was observed in the cases of HuPA and/or ESE. For example, the IC50 value of AChE inhibition increases by almost 135% in presence of ∼250 μM HSA (IC50 = 159 ± 8 nM) while comparing with aqueous buffer solution of pH 8.0 (IC50 = 68 ± 4 nM) in DON. On the other hand, the change is almost insignificant (<10%) in case of HuPA under the similar condition. The experimentally observed difference in the extent of modulatory effect was correlated with the sequestration ability of HSA towards different drugs predicted from molecular docking calculations. The result in this study demonstrates the importance to consider the plasma protein binding tendency of a newly synthesized AD drug before claiming its potency over the existing one. Further, development of new and intelligent delivery medium that shields the administered drugs from serum adsorption may reduce the optimal drug dose requirement. PMID:26902639

  8. The Process of Separating Bovine Serum Albumin Using Hydroxyapatite and Active Babassu Coal (Orbignya martiana)

    PubMed Central

    Zuñiga, Abraham Damian Giraldo; Sousa, Rita de Cássia Superbi; Zacchi Scolforo, Carmelita

    2016-01-01

    Bovine serum albumin is one of the major serum proteins; it plays an important role as a result of its functional and nutritional properties which have bioactive peptides. Adsorption method was used to separate protein, which involves hydroxyapatite, synthetic hydroxyapatite, and active babassu coal. Initially, characterization was carried out using the zeta potential of the adsorbents. Kinetic pseudo-first- and pseudo-second-order models were applied. For isotherms, equilibrium data studies were carried out using the Langmuir and Freundlich models, in addition to determining the efficiency of adsorptive process. The results of the zeta potential showed loads ranging from +6.9 to −42.8 mV. The kinetic data were better represented in the pseudo-second-order model with chemisorption characteristics. The adsorption capacity of the adsorbents decreased as pH increased, indicating that the electrostatic bonds and some functional groups of active babassu coal contributed to the reduction of adsorption, especially oxygen linked to carbon atoms. The value of pH 4.0 showed the best results of adsorption, being obtained as the maximum adsorption capacity (qm) and yield (%) (where qm = 87.95 mg g−1 and 74.2%; 68.26 mg g−1 and 68.6%; and 36.18 mg g−1, 37.4%) of hydroxyapatite, synthetic hydroxyapatite, and active babassu coal, respectively. PMID:27376149

  9. Cabazitaxel-loaded human serum albumin nanoparticles as a therapeutic agent against prostate cancer

    PubMed Central

    Qu, Na; Lee, Robert J; Sun, Yating; Cai, Guangsheng; Wang, Junyang; Wang, Mengqiao; Lu, Jiahui; Meng, Qingfan; Teng, Lirong; Wang, Di; Teng, Lesheng

    2016-01-01

    Cabazitaxel-loaded human serum albumin nanoparticles (Cbz-NPs) were synthesized to overcome vehicle-related toxicity of current clinical formulation of the drug based on Tween-80 (Cbz-Tween). A salting-out method was used for NP synthesis that avoids the use of chlorinated organic solvent and is simpler compared to the methods based on emulsion-solvent evaporation. Cbz-NPs had a narrow particle size distribution, suitable drug loading content (4.9%), and superior blood biocompatibility based on in vitro hemolysis assay. Blood circulation, tumor uptake, and antitumor activity of Cbz-NPs were assessed in prostatic cancer xenograft-bearing nude mice. Cbz-NPs exhibited prolonged blood circulation and greater accumulation of Cbz in tumors along with reduced toxicity compared to Cbz-Tween. Moreover, hematoxylin and eosin histopathological staining of organs revealed consistent results. The levels of blood urea nitrogen and serum creatinine in drug-treated mice showed that Cbz-NPs were less toxic than Cbz-Tween to the kidneys. In conclusion, Cbz-NPs provide a promising therapeutic for prostate cancer. PMID:27555767

  10. Locating the Binding Sites of Pb(II) Ion with Human and Bovine Serum Albumins

    PubMed Central

    Belatik, Ahmed; Hotchandani, Surat; Carpentier, Robert; Tajmir-Riahi, Heidar-Ali

    2012-01-01

    Lead is a potent environmental toxin that has accumulated above its natural level as a result of human activity. Pb cation shows major affinity towards protein complexation and it has been used as modulator of protein-membrane interactions. We located the binding sites of Pb(II) with human serum (HSA) and bovine serum albumins (BSA) at physiological conditions, using constant protein concentration and various Pb contents. FTIR, UV-visible, CD, fluorescence and X-ray photoelectron spectroscopic (XPS) methods were used to analyse Pb binding sites, the binding constant and the effect of metal ion complexation on HSA and BSA stability and conformations. Structural analysis showed that Pb binds strongly to HSA and BSA via hydrophilic contacts with overall binding constants of KPb-HSA = 8.2 (±0.8)×104 M−1 and KPb-BSA = 7.5 (±0.7)×104 M−1. The number of bound Pb cation per protein is 0.7 per HSA and BSA complexes. XPS located the binding sites of Pb cation with protein N and O atoms. Pb complexation alters protein conformation by a major reduction of α-helix from 57% (free HSA) to 48% (metal-complex) and 63% (free BSA) to 52% (metal-complex) inducing a partial protein destabilization. PMID:22574219

  11. Quantification of total content of non-esterified fatty acids bound to human serum albumin.

    PubMed

    Pavićević, Ivan D; Jovanović, Vesna B; Takić, Marija M; Aćimović, Jelena M; Penezić, Ana Z; Mandić, Ljuba M

    2016-09-10

    Non-esterified fatty acids bound to the human serum albumin (HSA) contribute to several HSAs properties of special concern in pathologies, for instance to the reactivity of the free HSA-Cys34 thiol group (important antioxidative thiol pool in plasma), and to the affinity for binding of molecules and ions (for example cobalt as a prominent biomarker in heart ischemia). Therefore, the method for determination of FAs bound to HSA was developed. FAs were released from HSA (previously isolated from serum by ammonium sulfate precipitation) using acidic copper(II) sulfate in phosphoric acid, extracted by n-heptane-chloroform (4:1, v/v) mixture, spotted on TL silica-gel and then developed with n-heptane-chloroform-acetic acid (5:3:0.3, v/v/v). Common office flatbed scanner and software solution for densitometric image analysis, developed in R, were used. The linearity of calibration curve in concentration range from 0.1 to 5.0mmol/L stearic acid was achieved. The method was proved to be precise (with RSD of 1.4-4.7%) and accurate. Accuracy was examined by standard addition method (recoveries 97.2-102.5%) and by comparison to results of GC. The method is sample saving, technically less demanding, and cheap, and therefore suitable for determination of FAs/HSA ratio when elevated concentrations of free FAs are reliable diagnostic/risk parameter of pathological states. PMID:27394177

  12. Cabazitaxel-loaded human serum albumin nanoparticles as a therapeutic agent against prostate cancer.

    PubMed

    Qu, Na; Lee, Robert J; Sun, Yating; Cai, Guangsheng; Wang, Junyang; Wang, Mengqiao; Lu, Jiahui; Meng, Qingfan; Teng, Lirong; Wang, Di; Teng, Lesheng

    2016-01-01

    Cabazitaxel-loaded human serum albumin nanoparticles (Cbz-NPs) were synthesized to overcome vehicle-related toxicity of current clinical formulation of the drug based on Tween-80 (Cbz-Tween). A salting-out method was used for NP synthesis that avoids the use of chlorinated organic solvent and is simpler compared to the methods based on emulsion-solvent evaporation. Cbz-NPs had a narrow particle size distribution, suitable drug loading content (4.9%), and superior blood biocompatibility based on in vitro hemolysis assay. Blood circulation, tumor uptake, and antitumor activity of Cbz-NPs were assessed in prostatic cancer xenograft-bearing nude mice. Cbz-NPs exhibited prolonged blood circulation and greater accumulation of Cbz in tumors along with reduced toxicity compared to Cbz-Tween. Moreover, hematoxylin and eosin histopathological staining of organs revealed consistent results. The levels of blood urea nitrogen and serum creatinine in drug-treated mice showed that Cbz-NPs were less toxic than Cbz-Tween to the kidneys. In conclusion, Cbz-NPs provide a promising therapeutic for prostate cancer. PMID:27555767

  13. Synthetic cationic antimicrobial peptides bind with their hydrophobic parts to drug site II of human serum albumin

    PubMed Central

    2014-01-01

    Background Many biologically active compounds bind to plasma transport proteins, and this binding can be either advantageous or disadvantageous from a drug design perspective. Human serum albumin (HSA) is one of the most important transport proteins in the cardiovascular system due to its great binding capacity and high physiological concentration. HSA has a preference for accommodating neutral lipophilic and acidic drug-like ligands, but is also surprisingly able to bind positively charged peptides. Understanding of how short cationic antimicrobial peptides interact with human serum albumin is of importance for developing such compounds into the clinics. Results The binding of a selection of short synthetic cationic antimicrobial peptides (CAPs) to human albumin with binding affinities in the μM range is described. Competitive isothermal titration calorimetry (ITC) and NMR WaterLOGSY experiments mapped the binding site of the CAPs to the well-known drug site II within subdomain IIIA of HSA. Thermodynamic and structural analysis revealed that the binding is exclusively driven by interactions with the hydrophobic moieties of the peptides, and is independent of the cationic residues that are vital for antimicrobial activity. Both of the hydrophobic moieties comprising the peptides were detected to interact with drug site II by NMR saturation transfer difference (STD) group epitope mapping (GEM) and INPHARMA experiments. Molecular models of the complexes between the peptides and albumin were constructed using docking experiments, and support the binding hypothesis and confirm the overall binding affinities of the CAPs. Conclusions The biophysical and structural characterizations of albumin-peptide complexes reported here provide detailed insight into how albumin can bind short cationic peptides. The hydrophobic elements of the peptides studied here are responsible for the main interaction with HSA. We suggest that albumin binding should be taken into careful

  14. Rosin Surfactant QRMAE Can Be Utilized as an Amorphous Aggregate Inducer: A Case Study of Mammalian Serum Albumin

    PubMed Central

    Ishtikhar, Mohd; Chandel, Tajjali Ilm; Ahmad, Aamir; Ali, Mohd Sajid; Al-lohadan, Hamad A.; Atta, Ayman M.; Khan, Rizwan Hasan

    2015-01-01

    Quaternary amine of diethylaminoethyl rosin ester (QRMAE), chemically synthesized biocompatible rosin based cationic surfactant, has various biological applications including its use as a food product additive. In this study, we examined the amorphous aggregation behavior of mammalian serum albumins at pH 7.5, i.e., two units above their isoelectric points (pI ~5.5), and the roles played by positive charge and hydrophobicity of exogenously added rosin surfactant QRMAE. The study was carried out on five mammalian serum albumins, using various spectroscopic methods, dye binding assay, circular dichroism and electron microscopy. The thermodynamics of the binding of mammalian serum albumins to cationic rosin modified surfactant were established using isothermal titration calorimetry (ITC). It was observed that a suitable molar ratio of protein to QRMAE surfactant enthusiastically induces amorphous aggregate formation at a pH above two units of pI. Rosin surfactant QRMAE-albumins interactions revealed a unique interplay between the initial electrostatic and the subsequent hydrophobic interactions that play an important role towards the formation of hydrophobic interactions-driven amorphous aggregate. Amorphous aggregation of proteins is associated with varying diseases, from the formation of protein wine haze to the expansion of the eye lenses in cataract, during the expression and purification of recombinant proteins. This study can be used for the design of novel biomolecules or drugs with the ability to neutralize factor(s) responsible for the aggregate formation, in addition to various other industrial applications. PMID:26418451

  15. Fluorescence analysis of competition of phenylbutazone and methotrexate in binding to serum albumin in combination treatment in rheumatology

    NASA Astrophysics Data System (ADS)

    Maciążek-Jurczyk, M.; Sułkowska, A.; Bojko, B.; Równicka, J.; Sułkowski, W. W.

    2009-04-01

    Combination of several drugs is often necessary especially during long-them therapy. The competition between drugs can cause a decrease of the amount of a drug bound to albumin. This results in an increase of the free, biological active fraction of the drug. The aim of the presented study was to describe the competition between phenylbutazone (Phe) and methotrexate (MTX), two drugs recommended for the treatment of rheumatology in binding to bovine (BSA) and human (HSA) serum albumin in the high affinity binding site. Fluorescence analysis was used to estimate the effect of drugs on the protein fluorescence and to define the binding and quenching properties of drugs-serum albumin complexes. The effect of the displacement of one drug from the complex of the other with serum albumin has been described on the basis of the comparison of the quenching curves and binding constants for the binary and ternary systems. The conclusion that both Phe and MTX form a binding site in the same subdomain (IIA) points to the necessity of using a monitoring therapy owning to the possible increase of the uncontrolled toxic effects.

  16. Extending the Serum Half-Life of G-CSF via Fusion with the Domain III of Human Serum Albumin

    PubMed Central

    Zhao, Shuqiang; Zhang, Yu; Tian, Hong; Chen, Xiaofei; Cai, Di; Yao, Wenbing; Gao, Xiangdong

    2013-01-01

    Protein fusion technology is one of the most commonly used methods to extend the half-life of therapeutic proteins. In this study, in order to prolong the half-life of Granulocyte colony stimulating factor (G-CSF), the domain III of human serum albumin (3DHSA) was genetically fused to the N-terminal of G-CSF. The 3DHSA-G-CSF fusion gene was cloned into pPICZαA along with the open reading frame of the α-factor signal under the control of the AOX1 promoter. The recombinant expression vector was transformed into Pichia pastoris GS115, and the recombinant strains were screened by SDS-PAGE. As expected, the 3DHSA-G-CSF showed high binding affinity with HSA antibody and G-CSF antibody, and the natural N-terminal of 3DHSA was detected by N-terminal sequencing. The bioactivity and pharmacokinetic studies of 3DHSA-G-CSF were respectively determined using neutropenia model mice and human G-CSF ELISA kit. The results demonstrated that 3DHSA-G-CSF has the ability to increase the peripheral white blood cell (WBC) counts of neutropenia model mice, and the half-life of 3DHSA-G-CSF is longer than that of native G-CSF. In conclusion, 3DHSA can be used to extend the half-life of G-CSF. PMID:24151579

  17. PEGylated human serum albumin (HSA) nanoparticles: preparation, characterization and quantification of the PEGylation extent

    NASA Astrophysics Data System (ADS)

    Fahrländer, E.; Schelhaas, S.; Jacobs, A. H.; Langer, K.

    2015-04-01

    Modification with poly(ethylene glycol) (PEG) is a widely used method for the prolongation of plasma half-life of colloidal carrier systems such as nanoparticles prepared from human serum albumin (HSA). However, the quantification of the PEGylation extent is still challenging. Moreover, the influence of different PEG derivatives, which are commonly used for nanoparticle conjugation, has not been investigated so far. The objective of the present study is to develop a method for the quantification of PEG and to monitor the influence of diverse PEG reagents on the amount of PEG linked to the surface of HSA nanoparticles. A size exclusion chromatography method with refractive index detection was established which enabled the quantification of unreacted PEG in the supernatant. The achieved results were confirmed using a fluorescent PEG derivative, which was detected by photometry and fluorimetry. Additionally, PEGylated HSA nanoparticles were enzymatically digested and the linked amount of fluorescently active PEG was directly determined. All the analytical methods confirmed that under optimized PEGylation conditions a PEGylation efficiency of up to 0.5 mg PEG per mg nanoparticle could be achieved. Model calculations made a ‘brush’ conformation of the PEG chains on the particle surface very likely. By incubating the nanoparticles with fetal bovine serum the reduced adsorption of serum proteins on PEGylated HSA nanoparticles compared to non-PEGylated HSA nanoparticles was demonstrated using sodium dodecylsulfate polyacrylamide gel electrophoresis. Finally, the positive effect of PEGylation on plasma half-life was demonstrated in an in vivo study in mice. Compared to unmodified nanoparticles the PEGylation led to a four times larger plasma half-life.

  18. PEGylated human serum albumin (HSA) nanoparticles: preparation, characterization and quantification of the PEGylation extent.

    PubMed

    Fahrländer, E; Schelhaas, S; Jacobs, A H; Langer, K

    2015-04-10

    Modification with poly(ethylene glycol) (PEG) is a widely used method for the prolongation of plasma half-life of colloidal carrier systems such as nanoparticles prepared from human serum albumin (HSA). However, the quantification of the PEGylation extent is still challenging. Moreover, the influence of different PEG derivatives, which are commonly used for nanoparticle conjugation, has not been investigated so far. The objective of the present study is to develop a method for the quantification of PEG and to monitor the influence of diverse PEG reagents on the amount of PEG linked to the surface of HSA nanoparticles. A size exclusion chromatography method with refractive index detection was established which enabled the quantification of unreacted PEG in the supernatant. The achieved results were confirmed using a fluorescent PEG derivative, which was detected by photometry and fluorimetry. Additionally, PEGylated HSA nanoparticles were enzymatically digested and the linked amount of fluorescently active PEG was directly determined. All the analytical methods confirmed that under optimized PEGylation conditions a PEGylation efficiency of up to 0.5 mg PEG per mg nanoparticle could be achieved. Model calculations made a 'brush' conformation of the PEG chains on the particle surface very likely. By incubating the nanoparticles with fetal bovine serum the reduced adsorption of serum proteins on PEGylated HSA nanoparticles compared to non-PEGylated HSA nanoparticles was demonstrated using sodium dodecylsulfate polyacrylamide gel electrophoresis. Finally, the positive effect of PEGylation on plasma half-life was demonstrated in an in vivo study in mice. Compared to unmodified nanoparticles the PEGylation led to a four times larger plasma half-life. PMID:25789544

  19. Interaction of cucurbitacins with human serum albumin: Thermodynamic characteristics and influence on the binding of site specific ligands.

    PubMed

    Abou-Khalil, Rony; Jraij, Alia; Magdalou, Jacques; Ouaini, Naïm; Tome, Daniel; Greige-Gerges, Hélène

    2009-06-01

    Cucurbitacins (Cuc) are cytotoxic oxygenated triterpenes. Their binding to albumin may control their diffusion and consequently their biological effects. The specific binding site of Cuc to albumin is important to be defined as it could determine some of the drug interactions of the compounds. This paper deals with the interaction between human serum albumin and a series of four cucurbitacins (B, D, E and I) measured by fluorescence and circular dichroism spectroscopies. Cuc B and E at C25, are the acetylated forms of Cuc D and I. The binding parameters (K(a) and n) of Cuc B, D and E to albumin were determined at 288, 293, 298 and 303K. Cuc B possesses the higher binding constant (K(a)) values followed by Cuc E and D. The thermodynamic parameters DeltaH, DeltaG and DeltaS were calculated. They indicated hydrophobic and electrostatic interactions for Cuc B, hydrophobic interaction for Cuc E, hydrophobic and hydrogen bond interactions for Cuc D. In addition to bilirubin, Cuc B, D, and E increased the binding constant values for warfarin to albumin, whereas they did not affect the binding of other ligands of site I such as chloroform and salicylate. The increase of the K(a) values of warfarin and bilirubin was associated with an increase of the binding constant value of cucurbitacin to albumin. Cuc I did not bind to albumin and could be considered less capable to affect the interaction of ligands to albumin than Cuc B, D and E. CD spectra indicated that Cuc binding to HSA was not associated with substantial structural changes of the protein. PMID:19380237

  20. Characterization of methylene diphenyl diisocyanate haptenated human serum albumin and hemoglobin

    PubMed Central

    Mhike, Morgen; Chipinda, Itai; Hettick, Justin M.; Simoyi, Reuben H.; Lemons, Angela; Green, Brett J.; Siegel, Paul D.

    2013-01-01

    Protein haptenation by polyurethane industrial intermediate methylene diphenyl diisocyanate (MDI) is thought to be an important step in the development of diisocyanate (dNCO)-specific allergic sensitization; however, MDI haptenated albumins used to screen specific antibody are often poorly characterized. Recently, the need to develop standardized immunoassays using a consistent, well characterized dNCO-haptenated protein to screen for the presence of MDI-specific IgE and IgG from workers’ sera has been emphasized and recognized. This has been challenging to achieve due to the bivalent, electrophilic nature of dNCO leading to the capability to produce multiple cross-linked protein species and polymeric additions to proteins. In the present study, MDI was reacted with human serum albumin (HSA) and hemoglobin (Hb) at molar ratios ranging from 1:1 to 40:1 MDI: protein. Adducts were characterized by (1) loss of available trinitrobenzene sulfonic acid (TNBS) binding to primary amines, (2) electrophoretic migration in polyacrylamide gels, (3) quantification of methylene diphenyl diamine following acid hydrolysis and (4) immunoassay. Concentration dependent changes in all the above noted parameters were observed demonstrating increase in both number and complexity of conjugates formed with increasing MDI concentration. In conclusion, a series of bio-analytical assays should be performed to standardize MDI-antigen preparations across lots and laboratories for measurement of specific antibody in exposed workers which in total indicate degree of intra- and inter-molecular cross-linking, number of dNCO bound, number of different specific binding sites on the protein and degree of immuno-reactivity. PMID:23743149

  1. Fluorescence and Docking Studies of the Interaction between Human Serum Albumin and Pheophytin.

    PubMed

    Chaves, Otávio Augusto; Amorim, Ana Paula de O; Castro, Larissa H E; Sant'Anna, Carlos Mauricio R; de Oliveira, Márcia C C; Cesarin-Sobrinho, Dari; Netto-Ferreira, José Carlos; Ferreira, Aurélio B B

    2015-01-01

    In the North of Brazil (Pará and Amazonas states) the leaves of the plant Talinum triangulare (popular: cariru) replace spinach as food. From a phytochemical point of view, they are rich in compounds of the group of pheophytins. These substances, related to chlorophyll, have photophysical properties that give them potential application in photodynamic therapy. Human serum albumin (HSA) is one of the main endogenous vehicles for biodistribution of molecules by blood plasma. Association constants and thermodynamic parameters for the interaction of HSA with pheophytin from Talinum triangulare were studied by UV-Vis absorption, fluorescence techniques, and molecular modeling (docking). Fluorescence quenching of the HSA's internal fluorophore (tryptophan) at temperatures 296 K, 303 K, and 310 K, resulted in values for the association constants of the order of 10⁴ L∙mol(-1), indicating a moderate interaction between the compound and the albumin. The negative values of ΔG° indicate a spontaneous process; ΔH° = 15.5 kJ∙mol(-1) indicates an endothermic process of association and ΔS° = 0.145 kJ∙mol(-1)∙K(-1) shows that the interaction between HSA and pheophytin occurs mainly by hydrophobic factors. The observed Trp fluorescence quenching is static: there is initial non-fluorescent association, in the ground state, HSA:Pheophytin. Possible solution obtained by a molecular docking study suggests that pheophytin is able to interact with HSA by means of hydrogen bonds with three lysine and one arginine residues, whereas the phytyl group is inserted in a hydrophobic pocket, close to Trp-214. PMID:26516829

  2. Relation between the serum albumin level and nutrition supply in patients with pressure ulcers: retrospective study in an acute care setting.

    PubMed

    Sugino, Hirotaka; Hashimoto, Ichiro; Tanaka, Yuka; Ishida, Soshi; Abe, Yoshiro; Nakanishi, Hideki

    2014-01-01

    This retrospective study examined the validity of the commonly used serum albumin level as an indicator of nutrition status of patients with pressure ulcer(s), particularly because the serum albumin level is affected by various factors and may not be specific to malnutrition. Specifically, we investigated whether nutrition supply or inflammation affects the serum albumin level in 82 patients with pressure ulcers(s) (29 in whom pressure ulcer was present upon admission and 53 in whom pressure ulcer developed after hospital admission). Serum albumin levels, blood test including C-reactive protein (CRP) levels and blood count, caloric intake, and depth and healing of pressure ulcers were compared between various subgroups of patients. Serum albumin levels correlated with red blood cell counts and hemoglobin and CRP levels but not with caloric intake. The correlation with CRP before and after several weeks of pressure ulcer treatment was negative. The serum albumin level upon admission was higher in patients in whom the ulcer healed than in those in whom it did not heal as well as in patients who were discharged than in those who died in the hospital. The serum albumin level appears to reflect inflammation, wound healing, and disease severity rather than nutrition supply in patients with pressure ulcer. J. Med. Invest. 61: 15-21, February, 2014. PMID:24705743

  3. Ibuprofen Impairs Allosterically Peroxynitrite Isomerization by Ferric Human Serum Heme-Albumin*

    PubMed Central

    Ascenzi, Paolo; di Masi, Alessandra; Coletta, Massimo; Ciaccio, Chiara; Fanali, Gabriella; Nicoletti, Francesco P.; Smulevich, Giulietta; Fasano, Mauro

    2009-01-01

    Human serum albumin (HSA) participates in heme scavenging; in turn, heme endows HSA with myoglobin-like reactivity and spectroscopic properties. Here, the allosteric effect of ibuprofen on peroxynitrite isomerization to NO3− catalyzed by ferric human serum heme-albumin (HSA-heme-Fe(III)) is reported. Data were obtained at 22.0 °C. HSA-heme-Fe(III) catalyzes peroxynitrite isomerization in the absence and presence of CO2; the values of the second order catalytic rate constant (kon) are 4.1 × 105 and 4.5 × 105 m−1 s−1, respectively. Moreover, HSA-heme-Fe(III) prevents peroxynitrite-mediated nitration of free added l-tyrosine. The pH dependence of kon (pKa = 6.9) suggests that peroxynitrous acid reacts preferentially with the heme-Fe(III) atom, in the absence and presence of CO2. The HSA-heme-Fe(III)-catalyzed isomerization of peroxynitrite has been ascribed to the reactive pentacoordinated heme-Fe(III) atom. In the absence and presence of CO2, ibuprofen impairs dose-dependently peroxynitrite isomerization by HSA-heme-Fe(III) and facilitates the nitration of free added l-tyrosine; the value of the dissociation equilibrium constant for ibuprofen binding to HSA-heme-Fe(III) (L) ranges between 7.7 × 10−4 and 9.7 × 10−4 m. Under conditions where [ibuprofen] is ≫L, the kinetics of HSA-heme-Fe(III)-catalyzed isomerization of peroxynitrite is superimposable to that obtained in the absence of HSA-heme-Fe(III) or in the presence of non-catalytic HSA-heme-Fe(III)-cyanide complex and HSA. Ibuprofen binding impairs allosterically peroxynitrite isomerization by HSA-heme-Fe(III), inducing the hexacoordination of the heme-Fe(III) atom. These results represent the first evidence for peroxynitrite isomerization by HSA-heme-Fe(III), highlighting the allosteric modulation of HSA-heme-Fe(III) reactivity by heterotropic interaction(s), and outlining the role of drugs in modulating HSA functions. The present results could be relevant for the drug-dependent protective role

  4. Investigation of the Interaction of Naringin Palmitate with Bovine Serum Albumin: Spectroscopic Analysis and Molecular Docking

    PubMed Central

    Zhang, Xia; Li, Lin; Xu, Zhenbo; Liang, Zhili; Su, Jianyu; Huang, Jianrong; Li, Bing

    2013-01-01

    Background Bovine serum albumin (BSA) contains high affinity binding sites for several endogenous and exogenous compounds and has been used to replace human serum albumin (HSA), as these two compounds share a similar structure. Naringin palmitate is a modified product of naringin that is produced by an acylation reaction with palmitic acid, which is considered to be an effective substance for enhancing naringin lipophilicity. In this study, the interaction of naringin palmitate with BSA was characterised by spectroscopic and molecular docking techniques. Methodology/Principal Findings The goal of this study was to investigate the interactions between naringin palmitate and BSA under physiological conditions, and differences in naringin and naringin palmitate affinities for BSA were further compared and analysed. The formation of naringin palmitate-BSA was revealed by fluorescence quenching, and the Stern-Volmer quenching constant (KSV) was found to decrease with increasing temperature, suggesting that a static quenching mechanism was involved. The changes in enthalpy (ΔH) and entropy (ΔS) for the interaction were detected at −4.11±0.18 kJ·mol−1 and −76.59±0.32 J·mol−1·K−1, respectively, which indicated that the naringin palmitate-BSA interaction occurred mainly through van der Waals forces and hydrogen bond formation. The negative free energy change (ΔG) values of naringin palmitate at different temperatures suggested a spontaneous interaction. Circular dichroism studies revealed that the α-helical content of BSA decreased after interacting with naringin palmitate. Displacement studies suggested that naringin palmitate was partially bound to site I (subdomain IIA) of the BSA, which was also substantiated by the molecular docking studies. Conclusions/Significance In conclusion, naringin palmitate was transported by BSA and was easily removed afterwards. As a consequence, an extension of naringin applications for use in food, cosmetic and medicinal

  5. Serum albumin as a probe for testing the selectivity of irreversible cysteine protease inhibitors: The case of vinyl sulfones.

    PubMed

    Regazzoni, Luca; Colombo, Simone; Mazzolari, Angelica; Vistoli, Giulio; Carini, Marina

    2016-05-30

    Vinyl sulfones are used for drug design of irreversible inhibitors of cysteine proteases since they are able to alkylate cysteine thiols inside the catalytic pocket of this class of enzymes. Some authors have reported the lack of reactivity towards glutathione as sufficient evidence of the selectivity of such a mechanism. Herein, we demonstrate that some simple molecules containing a vinyl sulfone moiety are not thiol-specific alkylants since they react with some albumin nucleophiles including side chains of Cys34 and His146. Such side-reactions are not desirable for any drug candidate since they limit serum stability, bioavailability and they possibly trigger toxicity mechanisms. In silico predictions, indicate that the compounds tested share similar structural features with reported inhibitors of cysteine proteases, as well as similar poses around the main albumin nucleophiles. Altogether, the data suggest that albumin is better than glutathione for the setup of early in vitro tests probing the selectivity of cysteine protease inhibitors. PMID:26970985

  6. Luminescent spectral characteristics of eosin in solutions of human serum albumin when denatured by treatment with sodium dodecyl sulfate

    NASA Astrophysics Data System (ADS)

    Vlasova, I. M.; Zemlyanskii, A. Yu.; Saletskii, A. M.

    2006-09-01

    From analysis of the fluorescence spectra of eosin molecules in a solution with human serum albumin (HSA), we have obtained information about the dynamics of protein conformational rearrangements during denaturing of the protein when treated with sodium dodecyl sulfate (SDS) for different pH values of the solution. We hypothesize that HSA denaturing in the presence of SDS occurs in two stages: the first stage is loosening of the protein globules, and the second stage is complete unfolding of the protein molecules. We have shown that denaturating of the protein in the presence of SDS passes through both stages for a solution pH below the isoelectric point of the albumin, while the denaturing stops in the first stage for a solution pH above the isoelectric point of the albumin.

  7. Selective electrochemical sensing of human serum albumin by semi-covalent molecular imprinting.

    PubMed

    Cieplak, Maciej; Szwabinska, Katarzyna; Sosnowska, Marta; Chandra, Bikram K C; Borowicz, Pawel; Noworyta, Krzysztof; D'Souza, Francis; Kutner, Wlodzimierz

    2015-12-15

    We devised and prepared a conducting molecularly imprinted polymer (MIP) for human serum albumin (HSA) determination using semi-covalent imprinting. The bis(2,2'-bithien-5-yl)methane units constituted the MIP backbone. This MIP was deposited as a thin film on an Au electrode by oxidative potentiodynamic electropolymerization to fabricate an electrochemical chemosensor. The HSA template imprinting, and then its releasing from the MIP was confirmed by the differential pulse voltammetry (DPV), electrochemical impedance spectroscopy (EIS), XPS, and PM-IRRAS measurements as well as by AFM imaging. Semi-covalent imprinting provided a very well defined locations of recognition sites in the MIP molecular cavities. These sites populated the imprinted cavities or the MIP surface only. The DPV and EIS response of the MIP film coated electrode to the HSA analyte was linear in the range of 0.8 to 20 and 4 to 80 µg/mL HSA, respectively, with the limit of detection of 16.6 and 800 ng/mL, respectively. The impressively high imprinting factor reached, exceeding 20, strongly confirmed that semi-covalent imprinting resulted in formation of a large number of very well defined molecular cavities with high affinity to the HSA molecules. The MIP selectivity against low-(molecular weight) interferences, common for physiological fluids, such as blood and urea, was very high. There was no response to the presence of these interferences at concentrations encountered in the samples analyzed. Moreover, the chemosensor selectivity to the myoglobin and cytochrome c interferences was excellent while that to lysozyme was slightly lower but still high. The chemosensor was useful for determination of abnormal HSA concentration in a control blood serum. PMID:26258876

  8. Study of interaction between human serum albumin and three phenanthridine derivatives: Fluorescence spectroscopy and computational approach

    NASA Astrophysics Data System (ADS)

    Liu, Jianming; Yue, Yuanyuan; Wang, Jing; Yan, Xuyang; Liu, Ren; Sun, Yangyang; Li, Xiaoge

    2015-06-01

    Over the past decades, phenanthridine derivatives have captured the imagination of many chemists due to their wide applications. In the present work, the interaction between phenanthridine derivatives benzo [4,5]imidazo[1,2-a]thieno[2,3-c]quinoline (BTQ), benzo[4,5]imidazo[1,2-a]furo[2,3-c]quinoline (BFQ), 5,6-dimethylbenzo[4,5]imidazo[1,2-a]furo[2,3-c]quinoline (DFQ) and human serum albumin (HSA) were investigated by molecular modeling techniques and spectroscopic methods. The results of molecular modeling simulations revealed that the phenanthridine derivatives could bind on both site I in HSA. Fluorescence data revealed that the fluorescence quenching of HSA by phenanthridine derivatives were the result of the formation of phenanthridine derivatives-HSA complex, and the binding intensity between three phenanthridine derivatives and HSA was BTQ > BFQ > DFQ. Thermodynamics confirmed that the interaction were entropy driven with predominantly hydrophobic forces. The effects of some biological metal ions and toxic ions on the binding affinity between phenanthridine derivatives and HSA were further examined.

  9. [Cooperative interaction of serum albumin with quaternized poly-4-vinyl pyridine and structure of the complexes].

    PubMed

    Kabanov, V A; Evdakov, V P; Mustafaev, M I; Antipina, A D

    1977-01-01

    Interaction of bovine serum albumin (BSA) with quaternized poly-4-vinyl pyridine (PE) in aqueous solutions at pH 7 was studied. It was shown that in a wide range of the ratios of the components (nBSA/nPE) soluble stable cooperative complexes were formed. At the same time a certain critical content of the protein exists at which the system loses its homogeneity. Complex formation is not accompanied by protein denaturation. At smaller nBSA/nPE ratios non-homogeneous distribution of protein globulas among polyelectrolite macromolecules was found; this corresponded to the "all or none" principle. Using ultracentrifugation technique viscosimetric measurements and electron microscopy it was shown that the soluble complexes exist in the form of rode-like particles consisting of protein globules stabilized by polycation chains. Such particle can be considered as a model of nucleoprotein complex. At certain crytical nBSA/nPE rations the rod-like particles aggregate with additional number of BSA-molecules and form more complicate soluble and insoluble cooperative complexes. Possible structural models of the complexes described were suggested and the thermodinamic and kinetic cryteria of their self-assembly were discussed. PMID:37435

  10. Spectroscopy characterization of the interaction between brevifolin carboxylic acid and bovine serum albumin.

    PubMed

    Tian, Jianniao; Xie, Yuhuan; Zhao, Yanchun; Li, Caifeng; Zhao, Shulin

    2011-01-01

    Themechanism of binding of the antivirus drug, brevifolin carboxylic acid (BCA) with bovine serum albumin (BSA) was investigated by steady-state and time-resolved fluorescence, circular dichroism (CD), Fourier transform infrared (FT-IR) and Raman spectroscopy under pseudo-physiological conditions for the first time. A strong fluorescence quenching was observed and the quenching mechanism was considered as static quenching. Various binding parameters were evaluated. The quantitative analysis of CD spectral data revealed that the a-helical content of BSA increased from 48.91% (in free BSA) to 52.46% (in bound form) in the presence of BCA. Based on the Förster's theory of non-radiation energy transfer, the relation of the binding average distance r between the donor (BSA) and acceptor (BCA) and acceptor concentration was determined. The changes in association constants of BCA-BSA in the presence of the common ions are also discussed. From the CD, FT-IR, time-resolved fluorescence and Raman spectroscopic results, it is apparent that the interaction of BCA with BSA causes a conformational change in the protein, and the Trp and Tyr residues are buried in more hydrophobic surroundings. BCA mainly binds to residue Trp 212 located in domain II of BSA by hydrophobic interaction and hydrogen bond. PMID:20737652

  11. Comparison of interactions between human serum albumin and silver nanoparticles of different sizes using spectroscopic methods.

    PubMed

    Zhang, Wanju; Zhang, Qingbo; Wang, Fang; Yuan, Lian; Xu, Ziqiang; Jiang, Fenglei; Liu, Yi

    2015-06-01

    Three different sizes (15.9 ± 2.1 nm, 26.4 ± 3.2 nm and 39.8 ± 4.0 nm, respectively) of citrate-coated silver nanoparticles (SNPs) have been synthesized and characterized. The interactions of the synthesized SNPs with human serum albumin (HSA) at physiological pH have been systematically studied by UV-vis absorption spectroscopy, fluorescence spectroscopy, synchronous fluorescence spectroscopy, three-dimensional fluorescence spectroscopy and circular dichroism (CD) spectroscopy. The results indicate that the SNPs can bind to HSA with high affinity and quench the intrinsic fluorescence of HSA. The binding constants and quenching rate constants were calculated. The apparent association constants (Kapp ) values are 2.14 × 10(4) M(-1) for 15.9 nm SNP, 1.65 × 10(4) M(-1) for 26.4 nm SNP and 1.37 × 10(4) M(-1) for 39.8 nm SNP, respectively. The values of binding constant obtained from the fluorescence quenching data match well with that determined from the absorption spectral changes. These results suggest that the smaller SNPs have stronger interactions to HSA than the larger ones at the same concentrations. Synchronous fluorescence, three-dimensional fluorescence and CD spectroscopy studies show that the synthesized SNPs can induce slight conformational changes in HSA. PMID:25103628

  12. Study on the binding of colloidal zinc oxide nanoparticles with bovine serum albumin

    NASA Astrophysics Data System (ADS)

    Kathiravan, A.; Paramaguru, G.; Renganathan, R.

    2009-09-01

    The interaction between colloidal zinc oxide (ZnO) nanoparticles and bovine serum albumin (BSA) was studied by using absorption, fluorescence, Fourier transform infrared, synchronous and time resolved fluorescence spectroscopic measurements. The apparent association constant has been deduced ( Kapp = 1.1 × 10 4 M -1) from the absorption spectral changes of BSA-colloidal ZnO nanoparticles using Benesi-Hildebrand equation. Addition of colloidal ZnO nanoparticles effectively quenched the intrinsic fluorescence of BSA. The number of binding sites ( n = 1.06) and apparent binding constant ( K = 2.5 × 10 4 M -1) were calculated by relevant fluorescence data. Based on Forster's non-radiation energy transfer theory, distance between the donor (BSA) and acceptor (ZnO) ( r0 = 2.88 nm) as well as the critical energy transfer distance ( R0 = 2.49 nm) has also been calculated. The interaction between colloidal ZnO and BSA occurs through static quenching mechanism. The effect of colloidal ZnO nanoparticles on the conformation of BSA has been analyzed by means of UV-visible absorption spectra and synchronous fluorescence spectra.

  13. Interaction of glutathione with bovine serum albumin: Spectroscopy and molecular docking.

    PubMed

    Jahanban-Esfahlan, Ali; Panahi-Azar, Vahid

    2016-07-01

    This study aims to investigate the interaction between glutathione and bovine serum albumin (BSA) using ultraviolet-visible (UV-vis) absorption, fluorescence spectroscopies under simulated physiological conditions (pH 7.4) and molecular docking methods. The results of fluorescence spectroscopy indicated that the fluorescence intensity of BSA was decreased considerably upon the addition of glutathione through a static quenching mechanism. The fluorescence quenching obtained was related to the formation of BSA-glutathione complex. The values of KSV, Ka and Kb for the glutathione and BSA interaction were in the order of 10(5). The thermodynamic parameters including enthalpy change (ΔH), entropy change (ΔS) and also Gibb's free energy (ΔG) were determined using Van't Hoff equation. These values showed that hydrogen bonding and van der Waals forces were the main interactions in the binding of glutathione to BSA and the stabilization of the complex. Also, the interaction of glutathione and BSA was spontaneous. The effects of glutathione on the BSA conformation were determined using UV-vis spectroscopy. Moreover, glutathione was docked in BSA using ArgusLab as a molecular docking program. It was recognized that glutathione binds within the sub-domain IIA pocket in domain II of BSA. PMID:26920314

  14. Decoration of heparin and bovine serum albumin on polysulfone membrane assisted via polydopamine strategy for hemodialysis.

    PubMed

    Xie, Bingwu; Zhang, Ranran; Zhang, Huan; Xu, Anxiu; Deng, Yi; Lv, Yalin; Deng, Feng; Wei, Shicheng

    2016-06-01

    Renal failure brings about abnormality of waste and toxins and deposition in the body. In clinic, the waste and toxins in vitro are eliminated by hemodialysis device with polysulfone (PSF) porous membranes. In the work, decoration of heparin (Hep) and bovine serum albumin (BSA) on PSF membranes would be beneficial to improve the hemocompatibility and reduce the anaphylatoxin formation during hemodialysis. The PSF porous membranes are surface-modified by simply dipping them into dopamine aqueous solution for 8 h. Then, Hep and BSA are immobilized covalently onto the resultant membrane. Attenuated total reflectance Fourier transform infrared spectra (ATR-FTIR) confirms that Hep and BSA are successfully introduced onto the surface of PSF membranes. Scanning electronic microscopy (SEM) and atomic force microscopy (AFM) display the changes of surface morphologies after modification. The result of water contact angle measurement shows that the hydrophilicity of PSF membranes is remarkably improved after coating polydopamine (pDA) and binding Hep and BSA. The experiments of hemocompatibility indicate that Hep and BSA grafted onto membranes suppress the adhesion of platelet and enhance the anticoagulation ability of PSF membranes. Furthermore, the protein adsorption tests reveal that Hep and BSA immobilized onto membranes depress the protein absorption and develop antifouling-protein ability of pristine membrane. This study proves a convenient and simple approach to graft two functional organic polymers which, respectively, play a vital role and then improve the hemocompatibility and biocompatibility of PSF membranes for their biomedical and blood-contacting applications. PMID:27018964

  15. Binding of ascorbic acid and α-tocopherol to bovine serum albumin: a comparative study.

    PubMed

    Li, Xiangrong; Wang, Gongke; Chen, Dejun; Lu, Yan

    2014-02-01

    Binding of ascorbic acid (water-soluble antioxidant) and α-tocopherol (lipid-soluble antioxidant) to bovine serum albumin (BSA) has been studied using isothermal titration calorimetry (ITC), in combination with fluorescence spectroscopy, UV-vis absorption spectroscopy and Fourier transform infrared (FT-IR) spectroscopy. Thermodynamic investigations reveal that ascorbic acid/α-tocopherol binding to BSA is driven by favorable enthalpy and unfavorable entropy, and the major driving forces are hydrogen bonding and van der Waals forces. For ascorbic acid, the interaction is characterized by a high number of binding sites, which suggests that binding occurs by a surface adsorption mechanism that leads to coating of the protein surface. For α-tocopherol, one molecule of α-tocopherol combines with one molecule of BSA and no more α-tocopherol binding to BSA occurs at concentration ranges used in this study. Fluorescence experiments suggest that ascorbic acid has predominantly a "sphere of action" quenching mechanism, whereas, for α-tocopherol, the quenching mechanism is "static quenching" and due to the formation of a ground state complex. Additionally, as shown by the UV-vis absorption, synchronous fluorescence spectroscopy, and FT-IR, ascorbic acid and α-tocopherol may induce conformational and microenvironmental changes of BSA. PMID:24310979

  16. Interaction of oridonin with human serum albumin by isothermal titration calorimetry and spectroscopic techniques.

    PubMed

    Li, Xiangrong; Yang, Zhenhua

    2015-05-01

    Oridonin has been traditionally and widely used for treatment of various human diseases due to its uniquely biological, pharmacological and physiological functions. In this study, the interaction between oridonin and human serum albumin (HSA) was investigated using isothermal titration calorimetry (ITC), in combination with fluorescence spectroscopy and UV-vis absorption spectroscopy. We found that the hydrogen bond and van der Waals force are the major binding forces in the binding of oridonin to HSA. The binding of oridonin to HSA is driven by favorable enthalpy and unfavorable entropy. Oridonin can quench the fluorescence of HSA through a static quenching mechanism. The binding constant between oridonin and HSA is moderate and the equilibrium fraction of unbound oridonin f(u) > 60%. Binding site I is found to be the primary binding site for oridonin. Additionally, oridonin may induce conformational changes of HSA and affect its biological function as the carrier protein. The results of the current study suggest that oridonin can be stored and transported from the circulatory system to reach its target organ to provide its therapeutic effects. But its side-effect in the clinics cannot be overlook. The study provides an accurate and full basic data for clarifying the binding mechanism of oridonin with HSA and is helpful for understanding its effect on protein function during the blood transportation process and its biological activity in vivo. PMID:25816984

  17. Oxidation Enhances Human Serum Albumin Thermal Stability and Changes the Routes of Amyloid Fibril Formation

    PubMed Central

    Sancataldo, Giuseppe; Vetri, Valeria; Foderà, Vito; Di Cara, Gianluca; Militello, Valeria; Leone, Maurizio

    2014-01-01

    Oxidative damages are linked to several aging-related diseases and are among the chemical pathways determining protein degradation. Specifically, interplay of oxidative stress and protein aggregation is recognized to have a link to the loss of cellular function in pathologies like Alzheimer's and Parkinson's diseases. Interaction between protein and reactive oxygen species may indeed induce small changes in protein structure and lead to the inhibition/modification of protein aggregation process, potentially determining the formation of species with different inherent toxicity. Understanding the temperate relationship between these events can be of utmost importance in unraveling the molecular basis of neurodegeneration. In this work, we investigated the effect of hydrogen peroxide oxidation on Human Serum Albumin (HSA) structure, thermal stability and aggregation properties. In the selected conditions, HSA forms fibrillar aggregates, while the oxidized protein undergoes aggregation via new routes involving, in different extents, specific domains of the molecule. Minute variations due to oxidation of single residues affect HSA tertiary structure leading to protein compaction, increased thermal stability, and reduced association propensity. PMID:24416244

  18. Spectroscopic studies on the interaction of fluorine containing triazole with bovine serum albumin.

    PubMed

    Liu, Yang; Mei, Ping; Zhang, Ye-Zhong; Sun, Xiao-Hong; Liu, Yi

    2010-12-01

    The binding of one fluorine including triazole (C(10)H(9)FN(4)S, FTZ) to bovine serum albumin (BSA) was studied by spectroscopic techniques including fluorescence spectroscopy, UV-Vis absorption, and circular dichroism (CD) spectroscopy under simulative physiological conditions. Fluorescence data revealed that the fluorescence quenching of BSA by FTZ was the result of forming a complex of BSA-FTZ, and the binding constants (K (a)) at three different temperatures (298, 304, and 310 K) were 1.516 × 10(4), 1.627 × 10(4), and 1.711 × 10(4) mol L(-1), respectively, according to the modified Stern-Volmer equation. The thermodynamic parameters ΔH and ΔS were estimated to be 7.752 kJ mol(-1) and 125.217 J mol(-1) K(-1), respectively, indicating that hydrophobic interaction played a major role in stabilizing the BSA-FTZ complex. It was observed that site I was the main binding site for FTZ to BSA from the competitive experiments. The distance r between donor (BSA) and acceptor (FTZ) was calculated to be 7.42 nm based on the Förster theory of non-radioactive energy transfer. Furthermore, the analysis of fluorescence data and CD data revealed that the conformation of BSA changed upon the interaction with FTZ. PMID:20195922

  19. Binding of the bioactive component Aloe dihydroisocoumarin with human serum albumin

    NASA Astrophysics Data System (ADS)

    Zhang, Xiu-Feng; Xie, Ling; Liu, Yang; Xiang, Jun-Feng; Tang, Ya-Lin

    2008-11-01

    Aloe dihydroisocoumarin, one of new components isolated from Aloe vera, can scavenge reactive oxygen species. In order to explore the mechanism of drug action at a molecular level, the binding of Aloe dihydroisocoumarin with human serum albumin (HSA) has been investigated by using fluorescence, ultraviolet (UV), circular dichroism (CD) and Fourier transform infrared (FT-IR) spectroscopy, fluorescence dynamics, and molecular dynamic docking for the first time. We observed a quenching of fluorescence of HSA in the presence of Aloe dihydroisocoumarin and also analyzed the quenching results using the Stern-Volmer equation and obtained high affinity binding to HSA. An isoemissive point at 414 nm is seen, indicating that the quenching of HSA fluorescence depends on the formation of Aloe dihydroisocoumarin-HSA complex, which is further confirmed by fluorescence dynamic result. From the CD and FT-IR results, it is apparent that the interaction of Aloe dihydroisocoumarin with HSA causes a conformational change of the protein, with the gain of α-helix, β-sheet and random coil stability and the loss of β-turn content. Data obtained by fluorescence spectroscopy, fluorescence dynamics, CD, and FTIR experiments along with the docking studies suggest that Aloe dihydroisocoumarin binds to residues located in subdomain IIA of HSA.

  20. Inhibitory effect of gold nanoparticles on the D-ribose glycation of bovine serum albumin

    PubMed Central

    Liu, Weixi; Cohenford, Menashi A; Frost, Leslie; Seneviratne, Champika; Dain, Joel A

    2014-01-01

    Formation of advanced glycation end products (AGEs) by nonenzymatic glycation of proteins is a major contributory factor to the pathophysiology of diabetic conditions including senile dementia and atherosclerosis. This study describes the inhibitory effect of gold nanoparticles (GNPs) on the D-ribose glycation of bovine serum albumin (BSA). A combination of analytical methods including ultraviolet–visible spectrometry, high performance liquid chromatography, circular dichroism, and matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry were used to determine the extent of BSA glycation in the presence of citrate reduced spherical GNPs of various sizes and concentrations. GNPs of particle diameters ranging from 2 nm to 20 nm inhibited BSA’s AGE formation. The extent of inhibition correlated with the total surface area of the nanoparticles. GNPs of highest total surface area yielded the most inhibition whereas those with the lowest total surface area inhibited the formation of AGEs the least. Additionally, when GNPs’ total surface areas were set the same, their antiglycation activities were similar. This inhibitory effect of GNPs on BSA’s glycation by D-ribose suggests that colloidal particles may have a therapeutic application for the treatment of diabetes and conditions that promote hyperglycemia. PMID:25473284

  1. Cys34-PEGylated Human Serum Albumin for Drug Binding and Delivery

    PubMed Central

    Mehtala, Jonathan G.; Kulczar, Chris; Lavan, Monika; Knipp, Gregory; Wei, Alexander

    2015-01-01

    Polyethylene glycol (PEG) derivatives were conjugated onto the Cys-34 residue of human serum albumin (HSA) to determine their effects on the solubilization, permeation, and cytotoxic activity of hydrophobic drugs such as paclitaxel (PTX). PEG(C34)HSA conjugates were prepared on a multigram scale by treating native HSA (n-HSA) with 5- or 20-kDa mPEG-maleimide, resulting in up to 77% conversion of the mono-PEGylated adduct. Nanoparticle tracking analysis of PEG(C34)HSA formulations in phosphate buffer revealed an increase in nanosized aggregates relative to n-HSA, both in the absence and presence of PTX. Cell viability studies conducted with MCF-7 breast cancer cells indicated that PTX cytotoxicity was enhanced by PEG(C34)HSA when mixed at 10:1 mole ratios, up to a two-fold increase in potency relative to n-HSA. The PEG(C34)HSA conjugates were also evaluated as PTX carriers across monolayers of HUVEC and hCMEC/D3 cells, and found to have nearly identical permeation profiles as n-HSA. PMID:25918947

  2. Adsorption of bovine serum albumin onto synthetic Fe-doped geomimetic chrysotile

    PubMed Central

    Adamiano, Alessio; Lesci, Isidoro Giorgio; Fabbri, Daniele; Roveri, Norberto

    2015-01-01

    Synthetic stoichiometric and Fe-doped geomimetic chrysotile nanocrystals represent a reference standard to investigate the health hazard associated with mineral asbestos fibres. Experimental evidence suggests that the generation of reactive oxygen species and other radicals, catalysed by iron ions at the fibre surface, plays an important role in asbestos-induced cytotoxicity and genotoxicity. In this study, structural modification of bovine serum albumin (BSA) adsorbed onto synthetic chrysotile doped with different amounts of Fe has been investigated by Fourier transform infrared spectroscopy (FT-IR), thermal gravimetric analysis (TGA) and analytical pyrolysis coupled with gas chromatography–mass spectrometry. FT-IR data evidenced a marked increase in disordered structures like random coil and β-turn of BSA–nanocrystal adduct with 0.52 wt% of Fe doped. The TGA profile of the BSA revealed that its interaction with the synthetic chrysotile surface was strongly affected by the substitution of Fe into the chrysotile structure. The 2,5-diketopiperazine yields, formed upon thermal degradation of the polypeptide chain (pyrolysis–gas chromatography), changed when the BSA was adsorbed on the nanofibres. In general, results suggested that minute amount (less than 1 wt%) of Fe doping in chrysotile affected the protein–nanofibre interactions, supporting the role that this element may play in asbestos toxicity. The catalytic role of iron and the consequent unfolding of protein due to the structural surface modification of nanofibres were also evaluated. PMID:26018963

  3. Molecular interaction and energy transfer between human serum albumin and bioactive component Aloe dihydrocoumarin

    NASA Astrophysics Data System (ADS)

    Zhang, Xiu-Feng; Xie, Ling; Liu, Yang; Xiang, Jun-Feng; Li, Lin; Tang, Ya-Lin

    2008-10-01

    Aloe dihydrocoumarin is an antioxidant and a candidate of immunomodulatory drug on the immune system and can balance physiological reactive oxygen species (ROS) levels which may be useful to maintain homeostasis. In order to explore the mechanism of drug action at a molecular level, the binding of Aloe dihydrocoumarin with human serum albumin (HSA) has been investigated by fluorescence, ultraviolet (UV), circular dichroism (CD) and Fourier transform infrared (FT-IR) spectroscopy, fluorescence dynamics, and molecular dynamic docking for the first time. We observed a quenching of fluorescence of HSA in the presence of Aloe dihydrocoumarin and also analyzed the quenching results using the Stern-Volmer equation and obtained high affinity binding to HSA. A Förster type fluorescence resonance energy transfer mechanism is involved in this quenching of Trp fluorescence by Aloe dihydrocoumarin. From the CD and FT-IR results, it is apparent that the interaction of Aloe dihydrocoumarin with HSA causes a conformational change of the protein, with the loss of α-helix stability and the gain of β-sheet and β-turn content. Data obtained by fluorescence spectroscopy, fluorescence dynamics, CD, and FT-IR experiments along with the docking studies suggest that Aloe dihydrocoumarin binds to residues located in subdomain IIA of HSA.

  4. Potentiometric responses of ion-selective microelectrode with bovine serum albumin adsorption.

    PubMed

    Goda, Tatsuro; Yamada, Eriko; Katayama, Yurika; Tabata, Miyuki; Matsumoto, Akira; Miyahara, Yuji

    2016-03-15

    There is a growing demand for an in situ measurement of local pH and ion concentrations in biological milieu to monitor ongoing process of bioreaction and bioresponse in real time. An ion-selective microelectrode can meet the requirements. However, the contact of the electrode with biological fluids induces biofouling by protein adsorption to result in a noise signal. Therefore, we investigated the relationship between the amount of nonspecific protein adsorption and the electrical signals in potentiometry by using ion-selective microelectrodes, namely silver/silver chloride (Ag/AgCl), iridium/iridium oxides (Ir/IrOx), and platinum/iridium oxides (Pt/IrOx). The microelectrodes reduced a potential change following the adsorption of bovine serum albumin (BSA) by comparison with the original metal microelectrodes without oxide layers. Suppression in the noise signal was attributed to the increased capacitance at the electrode/solution interface due to the formation of granulated metal oxide layer rather than a decrease in the amount of protein adsorbed. Ion sensitivity was maintained for Ir/IrOx against proton, but it was not for Ag/AgCl against chloride ion (Cl(-)), because of the interference of the equilibrium reaction by adsorbed BSA molecules on the electrode surface at<10(-2)M [Cl(-)] in the solution. The results open up the application of the Ir/IrOx microelectrode for measuring local pH in realistic dirty samples with a limited influence of electrode pollution by protein adsorption. PMID:26409020

  5. Spectroscopic investigation of the interaction of water-soluble azocalix[4]arenes with bovine serum albumin.

    PubMed

    Fan, Ping; Wan, Lu; Shang, Yunshan; Wang, Jun; Liu, Yulong; Sun, Xiaoyu; Chen, Chen

    2015-02-01

    In this work, three hydrosoluble azocalix[4]arene derivatives, 5-(o-methylphenylazo)-25,26,27-tris(carboxymethoxy)-28-hydroxycalix[4]arene (o-MAC-Calix), 5-(m-methylphenylazo)-25,26,27-tris(carboxymethoxy)-28-hydroxycalix[4]arene (m-MAC-Calix) and 5-(p-methylphenylazo)-25,26,27-tris(carboxymethoxy)-28-hydroxycalix[4]arene (p-MAC-Calix) were synthesized. Their structures were characterized by infrared spectrum (IR), nuclear magnetic resonance spectrum (1H NMR and 13C NMR) and mass spectrum (MS). The interactions between these compounds and bovine serum albumin (BSA) were studied by fluorescence spectroscopy, UV-vis spectrophotometry and circular dichroic spectroscopy. According to experimental results, three azocalix[4]arene derivatives can efficiently bind to BSA molecules and the o-MAC-Calix displays more efficient interactions with BSA molecules than m-MAC-Calix and p-MAC-Calix. Molecular docking showed that the o-MAC-Calix was embedded in the hydrophobic cavity of helical structure of BSA molecular and the tryptophan (Trp) residue of BSA molecular had strong interaction with o-MAC-Calix. The fluorescence quenching of BSA caused by azocalix[4]arene derivatives is attributed to the static quenching process. In addition, the synchronous fluorescence spectroscopy indicates that these azocalix[4]arene derivatives are more accessible to Trp residues of BSA molecules than the tyrosine (Tyr) residues. The circular dichroic spectroscopy further verified the binding of azocalix[4]arene derivatives and BSA. PMID:25549320

  6. Human islet purification: a prospective comparison of Euro-Ficoll and bovine serum albumin density gradients.

    PubMed

    Chadwick, D R; Robertson, G S; Contractor, H; Swift, S; Rose, S; Thirdborough, S T; Chamberlain, R; James, R F; Bell, P R; London, N J

    1993-01-01

    Euro-Ficoll (EF) and bovine serum albumin (BSA) are the two most commonly used media for the density gradient purification of human pancreatic islets. The aim of this study was to compare these two media with respect to the efficiency of human islet isolation. Ten human pancreata were collagenase-digested, and samples of digest were separated on either a continuous linear density gradient of BSA or a discontinuous gradient of EF (1.108/1.096/1.037/Euro-Collins). Efficiency of islet purification was assessed by insulin and amylase assay of aliquots aspirated from the BSA gradients, and from the interfaces of the EF gradients. Islets were obtained from two interfaces in the EF gradients. Islet yield from the upper interface was generally poor (median 28% of total insulin; range 2-71%), but purity was better than for an equivalent yield using BSA [1% (0-3%) amylase contamination for EF versus 6% (0-37%) for BSA; P = 0.013]. Pooling both EF interfaces increased yield to 66% (17-81%) but markedly reduced purity [46% (0-50%) amylase for EF versus 31% (0-52%) for BSA]. In conclusion, the efficiency of human islet purification is similar, though disappointingly low, with BSA and with EF. Considerable scope exists, therefore, for improvement in the density gradient purification of human islets. PMID:8329732

  7. Comprehensive spectroscopic probing the interaction and conformation impairment of bovine serum albumin (BSA) by herbicide butachlor.

    PubMed

    Liu, Xiaoyi; Ling, Zhaoxing; Zhou, Xing; Ahmad, Farooq; Zhou, Ying

    2016-09-01

    Butachlor is an effective herbicide to deal with undesired weeds selectively and is used at high levels in Asian countries. However, its interaction and impairment effect on BSA was still not clear. In this study, we investigated the interaction between butachlor and bovine serum albumin (BSA) by multi-spectroscopic methods including UV absorption, circular dichroism (CD) spectra, Fourier transform infrared (FTIR) spectra and fluorescence spectra under physiological conditions (pH=7.4). The results revealed that there was a static quenching of BSA induced by butachlor stemmed from the formation of complex. Based on thermodynamic data, the interaction of butachlor with BSA was due to happen, and van der Waals force as well as hydrogen bond were the major forces contributed to the interaction. The binding constant Kb and number of binding site of butachlor with BSA were 5.158×10(5) and 1.372 at 303K, respectively. The distance r between donor (BSA) and acceptor (butachlor) was 0.113nm, obtained according to the Förster theory. The results revealed that butachlor induced conformational changes in BSA but the secondary structure of BSA was still retained. In addition, the microenvironment around chromophore residues of BSA, for example, tryptophan, changed as well, resulting from the formation of more hydrogen bonds. PMID:27419617

  8. Rotational diffusion of bovine serum albumin denaturated by sodium dodecylsulfate, According to data from tryptophan fluorescence

    NASA Astrophysics Data System (ADS)

    Vlasova, I. M.; Zhuravleva, V. V.; Saletskii, A. M.

    2014-03-01

    The rotational diffusion of bovine serum albumin (BSA) molecules in solutions with different concentrations of the anionic detergent sodium dodecylsulfate (SDS) at different pH values is investigated, yielding information on the denaturation of BSA under the action of SDS. It is found from the increased degree of polarization in the tryptophan fluorescence of BSA and the registered parameters for the rotational diffusion of BSA molecules that the denaturation of BSA under the action of SDS at pH values less than the isoelectric point (pI) of BSA (4-9) is a two-stage process. It is shown that the first stage of BSA denaturation common for all pH values is the decondensation of BSA globules, while the second stage of BSA denaturation at pH greater than the pI of BSA is the unfolding of the protein's amino acid chain. It is concluded that the denaturation of BSA under the action of SDS proceeds more deeply at pH values greater than the pI of BSA.

  9. Peroxidase-mediated conjugation of corn fiber gum and bovine serum albumin to improve emulsifying properties.

    PubMed

    Liu, Yan; Qiu, Shuang; Li, Jinlong; Chen, Hao; Tatsumi, Eizo; Yadav, Madhav; Yin, Lijun

    2015-03-15

    The emulsifying properties of corn fiber gum (CFG), a naturally occurring polysaccharide-protein complex, was improved by kinetically controlled formation of hetero-covalent linkages with bovine serum albumin (BSA), using horseradish peroxidase (HRP). The formation of hetero-crosslinked CFG-BSA conjugates was confirmed using ultraviolet-visible and Fourier-transform infrared analyses. The optimum CFG-BSA conjugates were prepared at a CFG:BSA weight ratio of 10:1, and peroxidase:BSA weight ratio of 1:4000. Selected CFG-BSA conjugates were used to prepare oil-in-water emulsions; the emulsifying properties were better than those of emulsions stabilized with only CFG or BSA. Measurements of mean droplet sizes and zeta potentials showed that CFG-BSA-conjugate-stabilized emulsions were less susceptible to environmental stresses, such as pH changes, high K ionic strengths, and freeze-thaw treatments than CFG- or BSA-stabilized emulsions. These conjugates have potential applications as novel emulsifiers in food industry. PMID:25542109

  10. Adsorption of bovine serum albumin on nano and bulk oxide particles in deionized water.

    PubMed

    Song, Lei; Yang, Kun; Jiang, Wei; Du, Peng; Xing, Baoshan

    2012-06-01

    In this work, the influence of particle size and surface functional groups on the adsorption behavior of bovine serum albumin (BSA) by three types of oxide nanoparticles (NPs), TiO(2) (50±5 nm), SiO(2) (30±5 nm), and Al(2)O(3) (150±5 nm for α type and 60±5 nm for γ type) was investigated in deionized water, in order to explore their interaction mechanisms without competitive influence of other ions. Bulkparticles (BPs) were also used for comparison with NPs. BSA adsorption maxima on oxide particles were controlled by the surface area and hydrogen content, while adsorption process was primarily induced by electrostatic interaction, hydrophobic interaction and ligand exchange between BSA and oxide surfaces. With the increase of hydrogen content, the BSA adsorption mechanism switched from mainly hydrophobic interaction to hydrogen bonding and ligand exchange. Calculations, based on surface area and BSA size, suggested that a multilayer of BSA covered on α-Al(2)O(3), and single layer on the other oxide particle surfaces. BPs led to greater conformational change of BSA molecules after the adsorption on the surfaces of oxide particles though NPs adsorbed more BSA than BPs. PMID:22405471

  11. Spectroscopic studies on the interaction of cinnamic acid and its hydroxyl derivatives with human serum albumin

    NASA Astrophysics Data System (ADS)

    Min, Jiang; Meng-Xia, Xie; Dong, Zheng; Yuan, Liu; Xiao-Yu, Li; Xing, Chen

    2004-04-01

    Cinnamic acid and its derivatives possess various biological effects in remedy of many diseases. Interaction of cinnamic acid and its hydroxyl derivatives, p-coumaric acid and caffeic acid, with human serum albumin (HSA), and concomitant changes in its conformation were studied using fluorescence and Fourier transform infrared spectroscopic methods. Fluorescence data revealed the presence of one binding site on HSA for cinnamic acid and its hydroxyl derivatives, and their binding constants ( KA) are caffeic acid> p-coumaric acid> cinnamic acid when Cdrug/ CHSA ranging from 1 to 10. The changes of the secondary structure of HSA after interacting with the three drugs are estimated, respectively by combining the curve-fitting results of amid I and amid III bands. The α-helix structure has a decrease of ≈9, 5 and 3% after HSA interacted with caffeic acid, p-coumaric acid and cinnamic acid, respectively. It was found that the hydroxyls substituted on aromatic ring of the drugs play an important role in the changes of protein's secondary structure. Combining the result of fluorescence quenching and the changes of secondary structure of HSA after interaction with the three drugs, the drug-HSA interaction mode was discussed.

  12. Bovine serum albumin interacts with silver nanoparticles with a "side-on" or "end on" conformation.

    PubMed

    Dasgupta, Nandita; Ranjan, Shivendu; Patra, Dhabaleswar; Srivastava, Priyanka; Kumar, Ashutosh; Ramalingam, Chidambaram

    2016-06-25

    As the nanoparticles (NPs) enter into the biological interface, they have to encounter immediate and first exposure to many proteins of different concentrations. The physicochemical interaction of NPs and proteins is greatly influenced not only by the number and type of proteins; but also the surface chemistry of NPs. To analyze the effects of NPs on proteins, the interaction between bovine serum albumin (BSA) and silver nanoparticles (AgNPs) at different concentrations were investigated. The interaction, BSA conformations, kinetics and adsorption were analyzed by UV-Visible spectrophotometer, dynamic light scattering (DLS), FT-IR spectroscopy and fluorescence quenching. DLS, FTIR and UV-visible spectrophotometric analysis confirms the interaction with minor alterations in size of the protein. Fluorescence quenching analysis confirms the side-on or end-on interaction of 1.5 molecules of BSA to AgNP. Further, pseudo-second order kinetics was determined with equilibrium contact-time of 30 min. The data of the present study determines the detailed evaluation of BSA adsorption on AgNP along with mechanism, kinetics and isotherm of the adsorption. PMID:27180205

  13. Influence of post-emulsification drying processes on the microencapsulation of human serum albumin.

    PubMed

    Lane, Majella E; Brennan, Fiona S; Corrigan, Owen I

    2006-01-01

    In the present work, methods used to microencapsulate Human Serum Albumin (HSA) in a biodegradable polymer were compared for their effects on the physicochemical characteristics of HSA-loaded microparticles and on the release and integrity of encapsulated HSA. The polymer used was poly(D,L-lactide-co-glycolide) (75:25) (PLGA) (Boehringer Ingelheim, Resomer RG 752, MW 20,900). Microparticles were formulated by (i) w/o/w emulsification and freeze-drying (EFD) or (ii) w/o/w emulsification and spray-drying (ESD). Particle morphology and size were evaluated by scanning electron microscopy and by laser diffraction analysis. Loading, encapsulation efficiency and protein release were determined using a commercial protein assay kit. Protein integrity was evaluated by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis. Particles produced by emulsification/spray-drying exhibited greater diversity in shape than those produced by emulsification/freeze-drying. Additionally, protein loading values were significantly higher for particles produced by emulsification/spray-drying rather than particles produced by emulsification/freeze-drying. The structural integrity of encapsulated protein was confirmed for particles produced by both processes. The fraction of HSA released was similar for both formulations. The emulsification/spray-drying technique described appears to be a rapid and efficient method for the preparation of PLGA microparticles loaded with a model protein. PMID:16274944

  14. Potential-Assisted Adsorption of Bovine Serum Albumin onto Optically-Transparent Carbon Electrodes

    PubMed Central

    Benavidez, Tomás E.; Garcia, Carlos D.

    2013-01-01

    This manuscript describes the effect of the applied potential on the adsorption of bovine serum albumin (BSA) to optically transparent carbon electrodes (OTCE). To decouple the effect of the applied potential from the high affinity of the protein for the bare surface, the surface of the OTCE was initially saturated with a layer of BSA. Experiments described in the manuscript show that potential values higher than +500 mV induced a secondary adsorption process (not observed at open-circuit potentials), yielding significant changes in the thickness (and adsorbed amount) of the BSA layer obtained. Although the process showed a significant dependence on the experimental conditions selected, the application of higher potentials, selection of pH values around the isoelectric point (IEP) of the protein, high concentrations of protein, and low ionic strengths yielded faster kinetics and the accumulation of larger amounts of protein on the substrate. These experiments, obtained around the IEP of the protein, contrast with the traditional hypothesis that enhanced electrostatic interactions between the polarized substrate and the (oppositely charged) protein are solely responsible for the enhanced adsorption. These results suggest that the potential applied to the electrode is able to polarize the adsorbed layer and induce dipole-dipole interactions between the adsorbed and the incoming protein. This mechanism could be responsible for the potential-dependent oversaturation of the surface and could bolster to the development of surfaces with enhanced catalytic activity and implants with improved biocompatibility. PMID:24156567

  15. Detecting trypsin at liquid crystal/aqueous interface by using surface-immobilized bovine serum albumin.

    PubMed

    Chuang, Cheng-Hao; Lin, Yi-Cheng; Chen, Wei-Long; Chen, Yu-Hsuan; Chen, Yu-Xun; Chen, Chieh-Ming; Shiu, Hung Wei; Chang, Lo-Yueh; Chen, Chia-Hao; Chen, Chih-Hsin

    2016-04-15

    We report a new mechanism for liquid crystal (LC)-based sensor system for trypsin detection. In this system, bovine serum albumin (BSA) was immobilized on gold grids as the enzymatic substrate. When the BSA-modified grid was filled with LC and immersed in the solution containing trypsin, the peptide bonds of BSA were hydrolyzed and peptide fragments were desorbed from the surface of gold grid, which disrupted the orientation of LC at the vicinity and resulted in a dark-to-bright transition of optical image of LCs. By using this mechanism, the limit of detection (LOD) of trypsin is 10 ng/mL, and it does not respond to thrombin and pepsin. Besides, the cleavage behavior on gold surfaces was directly visualized by the scanning photoelectron microscopy (SPEM), in particular for the chemical composition identification and element-resolved image. The loss of BSA fragments and the enhancement of Au photoelectron signal after trypsin cleavage were corresponding to the proposed mechanism of the LC-based sensor system. Because the signals reported by LC can be simply interpreted through the human naked-eye, it provides a simple method for fast-screening trypsin activity in aqueous solution. PMID:26613511

  16. Green synthesis and physical characterization of Au nanoparticles and their interaction with bovine serum albumin.

    PubMed

    Yue, Hua-Li; Hu, Yan-Jun; Chen, Jun; Bai, Ai-Min; Ouyang, Yu

    2014-10-01

    In this study, we used morin as a reducing agent for the synthesis of stable and nearly spherical Au nanoparticles (M-AuNPs), which were characterized by UV-vis, transmission electron microscopy (TEM) and X-ray diffraction (XRD). The binding characteristics and molecular mechanism of the interaction between the M-AuNPs and bovine serum albumin (BSA) were explored by UV-vis absorbance, fluorescence spectroscopy, and circular dichroism spectra (CD). The results showed that the quenching mechanisms were based on static quenching. The thermodynamic parameters ΔG, ΔH and ΔS, suggested that the reaction was spontaneous, and mainly driven by electrostatic interactions. Site marker competitive displacement experiments indicated that MAuNPs bound with high affinity to site I (subdomain IIA) of BSA. Synchronous fluorescence and CD spectra demonstrated that BSA conformation was slightly altered in the presence of M-AuNPs. In addition, the effect of pH, temperature, morin quantity, and reaction time were investigated. PMID:25033430

  17. Urea-induced binding between diclofenac sodium and bovine serum albumin: a spectroscopic insight.

    PubMed

    Dohare, Neeraj; Khan, Abbul Bashar; Athar, Fareeda; Thakur, Sonu Chand; Patel, Rajan

    2016-06-01

    We investigated the interaction of diclofenac sodium (Dic.Na) with bovine serum albumin (BSA) in the absence and presence of urea using different spectroscopic techniques. A fluorescence quenching study revealed that the Stern-Volmer quenching constant decreases in the presence of urea, decreasing further at higher urea concentrations. The binding constant and number of binding sites were also evaluated for the BSA-Dic.Na interaction system in the absence and presence of urea using a modified Stern-Volmer equation. The binding constant is greater at high urea concentrations, as shown by the fluorescence results. In addition, for the BSA-Dic.Na interaction system, a static quenching mechanism was observed, which was further confirmed using time-resolved fluorescence spectroscopy. UV-vis spectroscopy provided information about the formation of a complex between BSA and Dic.Na. Circular dichroism was carried out to explain the conformational changes in BSA induced by Dic.Na in the absence and presence of urea. The presence of urea reduced the α-helical content of BSA as the Dic.Na concentration varied. The distance r between the donor (BSA) and acceptor (Dic.Na) was also obtained in the absence and presence of urea, using fluorescence resonance energy transfer. Copyright © 2015 John Wiley & Sons, Ltd. PMID:26564279

  18. Functional improvements in bovine serum albumin-fucoidan conjugate through the Maillard reaction.

    PubMed

    Kim, Do-Yeong; Shin, Weon-Sun

    2016-01-01

    The solubility, thermal stability, surface activity and emulsifying properties of native bovine serum albumin (BSA), heat-treated BSA, a BSA-fucoidan mixture, and a BSA-fucoidan conjugate were assessed. Covalent linkage of BSA with fucoidan resulted in significantly (p < 0.05) high solubility after heating at 90 °C for 15 min, particularly at pH 5. The BSA-fucoidan conjugate had a high melting temperature (97.09 ± 1.45 °C), as found by differential scanning calorimetry, indicating strong heat stability and high resistance to denaturation. Although the attachment of fucoidan, a non-surface-active hydrophilic polysaccharide, gave no change in the surface activity, the emulsifying activity and the emulsion stability of the conjugate at pH 5 were superior to those of native BSA, heat-treated BSA, and the BSA-fucoidan mixture. Conclusively, fucoidan attachment enhanced the solubility, thermal stability and emulsifying properties of the protein molecules with negative charge distribution and steric stabilization. PMID:26213064

  19. Spectroscopic studies of interaction between CuO nanoparticles and bovine serum albumin.

    PubMed

    Esfandfar, Paniz; Falahati, Mojtaba; Saboury, AliAkbar

    2016-09-01

    Recently, the great interests in manufacturing and application of metal oxide nanoparticles in commercial and industrial products have led to focus on the potential impact of these particles on biomacromolecules. In the present study, the interaction of copper oxide (CuO) nanoparticles with bovine serum albumin (BSA) was studied by spectroscopic techniques. The zeta potential value for BSA and CuO nanoparticles with average diameter of around 50 nm at concentration of 10 μM in the deionized (DI) water were -5.8 and -22.5 mV, respectively. Circular dichroism studies did not show any changes in the content of secondary structure of the protein after CuO nanoparticles interaction. Fluorescence data revealed that the fluorescence quenching of BSA by CuO nanoparticles was the result of the formed complex of CuO nanoparticles - BSA. Binding constants and other thermodynamic parameters were determined at three different temperatures. The hydrogen bond interactions are the predominant intermolecular forces to stabilize the CuO nanoparticle - BSA complex. This study provides important insight into the interaction of CuO nanoparticles with proteins, which may be of importance for further application of these nanoparticles in biomedical applications. PMID:26555383

  20. On the possible involvement of bovine serum albumin precursor in lipofection pathway.

    PubMed

    Mukherjee, Anubhab; Bhattacharyya, Jayanta; Chaudhuri, Arabinda

    2014-03-01

    Protein factors involved in lipofection pathways remain elusive. Using avidin-biotin affinity chromatography and mass finger printing analysis technique, herein we report the identification of a 70 kDa size protein (bovine serum albumin precursor, BSAP) which binds strongly with lipoplexes and may play role in lipofection pathway. Using multiple cultured animal cells and three structurally different cationic transfection lipids, we show that the efficiencies of liposomal transfection vectors get significantly enhanced (by ~2.5- to 5.0-fold) in cells pre-transfected with lipoplexes of reporter plasmid construct encoding BSAP. Findings in the cellular uptake experiments in A549 cells cultured in DMEM supplemented with 10 percent (w/w) BODIPY-labelled BSAP are consistent with the supposition that BSAP enters cell cytoplasm from the cell culture medium (DMEM supplemented with 10 percent FBS) used in lipofection. Cellular uptake studies by confocal microscopy using BODIPY-labelled BSAP and FITC-labelled plasmid DNA revealed co-localization of plasmid DNA and BSAP within the cell cytoplasm and nucleus. In summary, the present findings hint at the possible involvement of BSAP in lipofection pathway. PMID:24499789

  1. Influence of Aggregation and Route of Injection on the Biodistribution of Mouse Serum Albumin

    PubMed Central

    Kijanka, Grzegorz; Prokopowicz, Malgorzata; Schellekens, Huub; Brinks, Vera

    2014-01-01

    Protein aggregates are a major risk factor for immunogenicity. Until now most studies on aggregate-driven immunogenicity have focused on linking physicochemical features of the aggregates to the formation of anti-drug antibodies. Lacking is however, basic knowledge on the effect of aggregation on the biodistribution and clearance of therapeutic proteins in vivo. The aim of current study was to get insight into the effect of aggregation on biodistribution in mice using different routes of administration. Fluorescently labeled stressed and unstressed mouse serum albumin was injected via different routes in mice and detected via in vivo fluorescence imaging up to 48 hrs post-injection. We found that biodistribution of stressed MSA significantly differed from its unstressed counterpart. Subcutaneous and intramuscular administration resulted in accumulation of protein at the site of injection, from which clearance of stressed MSA was considerably slower than clearance of unstressed MSA. Upon intravenous and intraperitoneal injection of stressed MSA, fluorescent “hotspots” were observed in the spleens, livers and lungs. Further and more detailed examination of biodistribution after intraperitoneal injection showed higher fluorescence in most of tested organs suggesting more efficient diffusion and/or lymphatic uptake from peritoneum of unstressed MSA than the stressed formulation. PMID:24465523

  2. Influence of aggregation and route of injection on the biodistribution of mouse serum albumin.

    PubMed

    Kijanka, Grzegorz; Prokopowicz, Malgorzata; Schellekens, Huub; Brinks, Vera

    2014-01-01

    Protein aggregates are a major risk factor for immunogenicity. Until now most studies on aggregate-driven immunogenicity have focused on linking physicochemical features of the aggregates to the formation of anti-drug antibodies. Lacking is however, basic knowledge on the effect of aggregation on the biodistribution and clearance of therapeutic proteins in vivo. The aim of current study was to get insight into the effect of aggregation on biodistribution in mice using different routes of administration. Fluorescently labeled stressed and unstressed mouse serum albumin was injected via different routes in mice and detected via in vivo fluorescence imaging up to 48 hrs post-injection. We found that biodistribution of stressed MSA significantly differed from its unstressed counterpart. Subcutaneous and intramuscular administration resulted in accumulation of protein at the site of injection, from which clearance of stressed MSA was considerably slower than clearance of unstressed MSA. Upon intravenous and intraperitoneal injection of stressed MSA, fluorescent "hotspots" were observed in the spleens, livers and lungs. Further and more detailed examination of biodistribution after intraperitoneal injection showed higher fluorescence in most of tested organs suggesting more efficient diffusion and/or lymphatic uptake from peritoneum of unstressed MSA than the stressed formulation. PMID:24465523

  3. Effect of (-)-epigallocatechin-3-gallate on glucose-induced human serum albumin glycation.

    PubMed

    Li, M; Hagerman, A E

    2015-01-01

    (-)-Epigallocatechin-3-gallate (EGCg) is a naturally occurring polyphenol found in plant-based foods and beverages such as green tea. Although EGCg can eliminate carbonyl species produced by glucose autoxidation and thus can inhibit protein glycation, it is also reported to be a pro-oxidant that stimulates protein glycation in vitro. To better understand the balance between antioxidant and pro-oxidant features of EGCg, we evaluated EGCg-mediated bioactivities in a human serum albumin (HSA)/glucose model by varying three different parameters (glucose level, EGCg concentration, and time of exposure to EGCg). Measurements of glycation-induced fluorescence, protein carbonyls, and electrophoretic mobility showed that the level of HSA glycation was positively related to the glucose level over the range 10-100 mM during a 21-day incubation at 37°C and pH: 7.4. Under mild glycemic pressure (10 mM), long exposure to EGCg enhanced HSA glycation, while brief exposure to low concentrations of EGCg did not. Under high glycemic pressure (100 mM glucose), long exposure to EGCg inhibited glycation. For the first time we showed that brief exposure to EGCg reversed glycation-induced fluorescence, indicating a restorative effect. In conclusion, our research identified glucose level, EGCg concentration, and time of exposure as critical factors dictating EGCg bioactivities in HSA glycation. EGCg did not affect HSA glycation under normal physiological conditions but had a potential therapeutic effect on HSA severely damaged by glycation. PMID:25794449

  4. Glycation of human serum albumin in diabetes: impacts on the structure and function.

    PubMed

    Cao, Hui; Chen, Tingting; Shi, Yujun

    2015-01-01

    Diabetes mellitus is one of the most serious diseases in the world. The levels of glycated proteins in the blood of diabetics are higher than that of non-diabetic subjects. The glycation of proteins is believed to link to the occurrence of diabetic complications and related diseases. This review focuses on the influence of glycation of human serum albumin (HSA) on its structure and function. The glycation leads to change the HSA conformation, which will further influence its ligand binding properties. The levels of glycated HSA in hyperglycemic conditions showed a significant relationship to the germination of serious complications for diabetics, especially by affecting various cells functions. The conclusion from individual report is contradictory to each other; therefore, it is very difficult to give an univocal comment on the impact of glycation on the binding behaviors of HSA for small molecules. The influence of glycation of HSA on the binding affinities for small molecules is decided by the assay, the structures of small molecules, as well as the degree of glycation. However, the glycation of HSA is believed to reduce the binding affinities for acidic drugs such as polyphenols and phenolic acids. PMID:25245514

  5. Evidence that L-Arginine inhibits glycation of human serum albumin (HSA) in vitro

    SciTech Connect

    Servetnick, D.A.; Wiesenfeld, P.L.; Szepesi, B. )

    1990-02-26

    Previous work by Brownlee has shown that glycation of bovine serum albumin can be reduced in the presence of aminoguanidine (AG). Presumably, the guanidinium group on AG interferes with further rearrangement of amadori products to advanced glycosylated end products (AGE). Since L-arginine (ARG) also contains a guanidinium group, its ability to inhibit the formation of AGE products was investigated. HSA was incubated at 37{degrees}C in the presence or absence of glucose; with glucose and fructose; or with sugars in the presence or absence of ARG or AG. A tracer amount of U-{sup 14}C-glucose was added to each tube containing sugars. Protein bound glucose was separated from unreacted glucose by gel filtration. Radioactivity, total protein, fluorescence, and glucose concentration were measured. Preliminary data show enhanced binding of {sup 14}C-glucose to HSA with fructose at all time points. A 30-40% decrease in {sup 14}C-glucose incorporation was observed when ARG or AG as present. ARG and AG were equally effective in inhibiting incorporation of {sup 14}C-glucose. FPLC analysis is in progress to determine the type and degree of HSA crosslinking during the 2 week incubation period.

  6. Bovine serum albumin with glycated carboxyl groups shows membrane-perturbing activities.

    PubMed

    Yang, Shin-Yi; Chen, Ying-Jung; Kao, Pei-Hsiu; Chang, Long-Sen

    2014-12-15

    The aim of the present study aimed to investigate whether glycated bovine serum albumin (BSA) showed novel activities on the lipid-water interface. Mannosylated BSA (Man-BSA) was prepared by modification of the carboxyl groups with p-aminophenyl α-d-mannopyranoside. In contrast to BSA, Man-BSA notably induced membrane permeability of egg yolk phosphatidylcholine (EYPC)/egg yolk sphingomyelin (EYSM)/cholesterol (Chol) and EYPC/EYSM vesicles. Noticeably, Man-BSA induced the fusion of EYPC/EYSM/Chol vesicles, but not of EYPC/EYSM vesicles. Although BSA and Man-BSA showed similar binding affinity for lipid vesicles, the lipid-bound conformation of Man-BSA was distinct from that of BSA. Moreover, Man-BSA adopted distinct structure upon binding with the EYPC/EYSM/Chol and EYPC/EYSM vesicles. Man-BSA could induce the fusion of EYPC/EYSM/Chol vesicles with K562 and MCF-7 cells, while Man-BSA greatly induced the leakage of Chol-depleted K562 and MCF-7 cells. The modified BSA prepared by conjugating carboxyl groups with p-aminophenyl α-d-glucopyranoside also showed membrane-perturbing activities. Collectively, our data indicate that conjugation of carboxyl groups with monosaccharide generates functional BSA with membrane-perturbing activities on the lipid-water interface. PMID:25449061

  7. Kinetic regime of dithiothreitol-induced aggregation of bovine serum albumin.

    PubMed

    Borzova, Vera A; Markossian, Kira A; Kara, Dmitriy A; Kurganov, Boris

    2015-09-01

    A search for agents, which are capable of effectively suppressing protein aggregation, and elaboration of the appropriate test systems, are among important problems of modern biochemistry and biotechnology. One such test system is based on dithiothreitol (DTT)-induced aggregation of bovine serum albumin (BSA). Study of the kinetics of DTT-induced aggregation of BSA by asymmetric flow field flow fractionation showed that a decrease in the portion of the non-aggregated protein in time followed the exponential law, the rate constant of the first order remaining unchanged at varying protein concentration (0.1M Na-phosphate buffer, pH 7.0; 45 °C). The obtained results indicate that the rate-limiting stage of the general aggregation process is that of unfolding of the protein molecule. When studying the kinetics of DTT-induced aggregation of BSA by dynamic light scattering, we proposed to use parameter K(LS) as a measure of the initial rate of aggregation. Parameter K(LS) corresponds to the initial slope of the dependence of (I-I0)(0.5) on time (I0 and I are the initial and current values of the light scattering intensity, respectively). The K(LS) value has been applied to estimate anti-aggregation activity of chemical chaperones (arginine, its derivatives and proline). PMID:26116389

  8. HPLC separation of human serum albumin isoforms based on their isoelectric points.

    PubMed

    Turell, Lucía; Botti, Horacio; Bonilla, Lucía; Torres, María José; Schopfer, Francisco; Freeman, Bruce A; Armas, Larissa; Ricciardi, Alejandro; Alvarez, Beatriz; Radi, Rafael

    2014-01-01

    Human serum albumin (HSA) is the most abundant protein in plasma. Cys34, the only free Cys residue, is the predominant plasma thiol and a relevant sacrificial antioxidant. Both in vivo circulating HSA and pharmaceutical preparations are heterogeneous with respect to the oxidation state of Cys34. In this work, we developed an external pH gradient chromatofocusing procedure that allows the analysis of the oxidation status of HSA in human plasma and biopharmaceutical products based on the different apparent isoelectric points and chemical properties of the redox isoforms. Specifically, reduced-mercury blocked HSA (HSA-SHg(+)), HSA with Cys34 oxidized to sulfenic acid (HSA-SOH) and HSA oxidized to sulfinate anion (HSA-SO2(-)) can be separated with resolutions of 1.4 and 3.1 (first and last pair) and hence quantified and purified. In addition, an N-terminally degraded isoform (HSA3-585) in different redox states can be resolved as well. Confirmation of the identity of the chromatofocusing isolated isoforms was achieved by high resolution whole protein MS. It is proposed that the chromatofocusing procedure can be used to produce more exact and complete descriptions of the redox status of HSA in vivo and in vitro. Finally, the scalability capabilities of the chromatofocusing procedure allow for the preparation of highly pure standards of several redox isoforms of HSA. PMID:24316526

  9. (99m)Tc-human serum albumin nanocolloids: particle sizing and radioactivity distribution.

    PubMed

    Persico, Marco G; Lodola, Lorenzo; Buroni, Federica E; Morandotti, Marco; Pallavicini, Piersandro; Aprile, Carlo

    2015-07-01

    Several parameters affect the biodistribution of administered nanocolloids (NC) for Sentinel Lymph Node (SLN) detection: particle size distribution, number of Tc atoms per particle and specific activity (SA). Relatively few data are available with frequently conflicting results. (99m)Tc-NC-human serum albumin (HSA) Nanocoll®, Nanoalbumon® and Nanotop® were analysed for particles' dimensional and radioactivity distribution, and a mathematical model was elaborated to estimate the number of particles involved. Commercially available kits were reconstituted at maximal SA of 11 MBq/µg HSA. Particles size distribution was evaluated by Dynamic Light Scattering. These data were related to the radioactivity distribution analysis passing labelled NC through three polycarbonate filters (15-30-50-nm pore size) under vacuum. Highest radioactivity was carried by 30-50 nm particles. The smallest ones, even though most numerous, carried only the 10% of (99m)Tc atoms. Nanocoll and Nanotop are not significantly different, while Nanoalbumon is characterized by largest particles (>30 nm) that carried the most of radioactivity (80%). Smallest particles could saturate the clearing capacity of macrophages; therefore, if the tracer is used for SLN detection, more node tiers could be visualized, reducing accuracy of SLN mapping. Manufacturers could implement technical leaflets with particle size distribution and could improve the labelling protocol to provide clinicians useful information. PMID:26198778

  10. Capturing Labile Sulfenamide and Sulfinamide Serum Albumin Adducts of Carcinogenic Arylamines by Chemical Oxidation

    PubMed Central

    Peng, Lijuan; Turesky, Robert J.

    2013-01-01

    Aromatic amines and heterocyclic aromatic amines (HAAs) are a class of structurally related carcinogens that are formed during the combustion of tobacco or during the high temperature cooking of meats. These procarcinogens undergo metabolic activation by N-oxidation of the exocyclic amine group to produce N-hydroxylated metabolites, which are critical intermediates implicated in toxicity and DNA damage. The arylhydroxylamines and their oxidized arylnitroso derivatives can also react with cysteine (Cys) residues of glutathione or proteins to form, respectively, sulfenamide and sulfinamide adducts. However, sulfur-nitrogen linked adducted proteins are often difficult to detect because they are unstable and undergo hydrolysis during proteolytic digestion. Synthetic N-oxidized intermediates of 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), a carcinogenic HAA produced in cooked meats, and 4-aminobiphenyl, a carcinogenic aromatic amine present in tobacco smoke were reacted with human serum albumin (SA) and formed labile sulfenamide or sulfinamide adducts at the Cys34 residue. Oxidation of the carcinogen-modified SA with m-chloroperoxybenzoic acid (m-CPBA) produced the arylsulfonamide adducts, which were stable to heat and the chemical reduction conditions employed to denature SA. The sulfonamide adducts of PhIP and 4-ABP were identified, by liquid chromatography/mass spectrometry, in proteolytic digests of denatured SA. Thus, selective oxidation of arylamine-modified SA produces stable arylsulfonamide-SA adducts, which may serve as biomarkers of these tobacco and dietary carcinogens. PMID:23240913

  11. Insights into the binding of thiosemicarbazone derivatives with human serum albumin: spectroscopy and molecular modelling studies.

    PubMed

    Karthikeyan, Subramani; Bharanidharan, Ganesan; Kesherwani, Manish; Mani, Karthik Ananth; Srinivasan, Narasimhan; Velmurugan, Devadasan; Aruna, Prakasarao; Ganesan, Singaravelu

    2016-06-01

    4-[(1Z)-1-(2-carbamothioylhydrazinylidene)ethyl]phenyl acetate [Ace semi],4-[(1Z)-1-(2-carbamothioylhydrazinylidene)ethyl]phenyl propanoate [Pro semi] from the family of thiosemicarbazones derivative has been newly synthesized. It has good anticancer activity as well as antibacterial and it is also less toxic in nature, its binding characteristics are therefore of huge interest for understanding pharmacokinetic mechanism of the drug. The binding of thiosemicarbazone derivative to human serum albumin (HSA) has been investigated by studying its quenching mechanism, binding kinetics and the molecular distance (r) between donor (HSA) and acceptor (thiosemicarbazone derivative) was estimated according to Forster's theory of non-radiative energy transfer using fluorescence spectroscopy. The binding dynamics has been elaborated using synchronous fluorescence spectroscopy, and the feature of thiosemicarbazone derivative induced structural changes of HSA has been studied by circular dichorism, Fourier transform infrared spectroscopy. Molecular modelling simulations explore the hydrophobic interaction and hydrogen bonding which stabilizes the interaction. PMID:26368536

  12. Binding and relaxometric properties of heme complexes with cyanogen bromide fragments of human serum albumin.

    PubMed Central

    Monzani, Enrico; Curto, Maria; Galliano, Monica; Minchiotti, Lorenzo; Aime, Silvio; Baroni, Simona; Fasano, Mauro; Amoresano, Angela; Salzano, Anna Maria; Pucci, Piero; Casella, Luigi

    2002-01-01

    The spectroscopic and reactivity properties of hemin complexes formed with cyanogen bromide fragments B (residues 1-123), C (124-298), A (299-585), and D (1-298) of human serum albumin (HSA) have been investigated. The complex hemin-D exhibits binding, spectral, circular dichroism, and reactivity characteristics very similar to those of hemin-HSA, indicating that fragment D contains the entire HSA domain involved in heme binding. The characteristics of the other hemin complexes are different, and a detailed investigation of the properties of hemin-C has been carried out because this fragment contains the HSA binding region of several important drugs. Hemin-C contains a low-spin Fe(III) center, with two imidazole ligands, but the complex undergoes a reversible structural transition at basic pH leading to a high-spin, five-coordinated Fe(III) species. This change determines a marked increase in the relaxation rate of water protons. Limited proteolysis experiments and mass spectral analysis carried out on fragment C and hemin-C show that the region encompassing residues Glu-208 to Trp-214 is protected from activity of proteases in the complex and, therefore, is involved in the interaction with hemin. A structural model of fragment C enables us to propose that His-242 and His-288 are the axial ligands for the Fe(III) center. PMID:12324442

  13. A spectroscopic investigations of anticancer drugs binding to bovine serum albumin

    NASA Astrophysics Data System (ADS)

    Bakkialakshmi, S.; Chandrakala, D.

    2012-03-01

    The binding of anticancer drugs (i) Uracil (U), (ii) 5-Fluorouracil (5FU) and (iii) 5-Chlorouracil (5ClU), to bovine serum albumin (BSA) at two levels of temperature was studied by the fluorescence of quenching method. UV/Vis, time-resolved fluorescence, Fourier transform infrared spectroscopy (FTIR), proton nuclear magnetic resonance (1H NMR) and scanning electron microscope (SEM) analyses were also made. Binding constants (Ka) and binding sites (n) at various levels of temperature were calculated. The obtained binding sites were found to be equal to one for all the three quenchers (U, 5FU and 5ClU) at two different temperature levels. Thermodynamic parameters ΔH, ΔG and ΔS have been calculated and were presented in tables. Change in FTIR absorption intensity shows strong binding of anticancer drugs to BSA. Changes in chemical shifts of NMR and fluorescence lifetimes of the drugs indicate the presence of interaction and binding of BSA to anticancer drugs. 1H NMR spectra and SEM photographs also conform this binding.

  14. Fluorescence modulation and associative behavior of lumazine in hydrophobic domain of micelles and bovine serum albumin.

    PubMed

    Moyon, N Shaemningwar; Islam, Mullah Muhaiminul; Phukan, Smritakshi; Mitra, Sivaprasad

    2013-04-01

    The photophysical behavior of the deprotonated form of lumazine (Lum-anion) was studied in biologically relevant surfactant systems like sodium dodecyl sulfate (SDS), cetyltrimethylammonium bromide (CTAB) and TritonX-100 (TX-100) and also model water soluble protein, bovine serum albumin (BSA), using steady-state and time-resolved fluorescence spectroscopy in buffer solution of pH 12.0. The association constant values were calculated from modulated fluorescence intensity of Lum-anion in different medium. The interaction of non-ionic surfactant TX-100 was found to be about 10 times greater than SDS and CTAB. However, while the driving force of binding in SDS and/or TX-100 is mainly hydrophobic in nature, electrostatic interaction with the oppositely charged micellar head group is the predominant factor in CTAB. The thermodynamic parameters like enthalpy (ΔH) and entropy (ΔS) change, etc., corresponding to the binding of Lum-anion with BSA were estimated by performing the fluorescence titration experiment at different temperatures. Thermodynamically favorable and strong binding of Lum-anion (K~10(4) M(-1)) into BSA is due to hydrophobic interaction in the ligand binding domain II. However, the binding mechanism is entirely different in presence of protein denaturing agent like urea and electrostatic interaction plays a major role under this condition. PMID:23501728

  15. Interaction Studies of Greenly Synthesized Gold Nanoparticles with Bovine Serum Albumin (BSA) Using Fluorescence Spectroscopy.

    PubMed

    Ravikumar, Sambandam; Sreekanth, T V M; Eom, In-Yong

    2015-12-01

    In the present study, gold nanoparticles (AuNPs) with an average particle size of -41.23 nm were synthesized using eco-friendly reducing material (i.e., aqueous Nelumbo nucifera root extract). Rapid reduction results in the formation of polydispersed nanoparticles. The formation of AuNPs was characterized by surface plasmon resonance (SPR) which was determined by UV-Vis spectra (band at 544 nm), FTIR, SEM-EDX, TEM, HR-TEM, and XRD. This study aims to investigate the interaction between AuNPs and Bovine Serum Albumin (BSA) using fluorescence spectroscopy. The analysis of fluorescence spectra and intensity at physiological pH in an aqueous solution indicates that AuNPs have a potent ability to quench the BSA fluorescence by both quenching mechanisms. Resonance light scattering spectra indicated the formation of BSA-AuNPs complex. The number of binding sites and binding constants were determined based on fluorescence quenching at different temperatures. The thermodynamic parameters were also calculated at various temperatures that indicate that hydrophobic forces are abundant in the AuNPs-BSA complex. Negative ΔG degrees values suggest that the binding process is spontaneous. Synchronous fluorescence spectra showed a blue shift and CD spectra showed an increase in a-helicity content which is an indication of increasing hydrophobicity. PMID:26682387

  16. Mechanistic investigation of domain specific unfolding of human serum albumin and the effect of sucrose

    PubMed Central

    Yadav, Rajeev; Sen, Pratik

    2013-01-01

    This study is devoted to understand the unfolding mechanism of a multidomain protein, human serum albumin (HSA), in absence and presence of the sucrose by steady-state and time-resolved fluorescence spectroscopy with domain specific marker molecules and is further being substantiated by molecular dynamics (MD) simulation. In water, the domain III of HSA found to unfold first followed by domains I and II as the concentration of GnHCl is increased in the medium. The sequential unfolding behavior of different domains of HSA remains same in presence of sucrose; however, a higher GnHCl concentration is required for unfolding, suggesting stabilizing effect of sucrose on HSA. Domain I is found to be most stabilized by sucrose. The stabilization of domain II is somewhat similar to domain I, but the effect of sucrose on domain III is found to be very small. MD simulation also predicted a similar behavior of sucrose on HSA. The stabilizing effect of sucrose is explained in terms of the entrapment of water molecules in between HSA surface and sucrose layer as well as direct interaction between HSA and sucrose. PMID:24038622

  17. Understanding the Robust Physisorption between Bovine Serum Albumin and Amphiphilic Polymer Coated Nanoparticles.

    PubMed

    Liu, Yushuang; Zhong, Ruibo; Zhang, Ping; Ma, Yuxing; Yun, Xiaoling; Gong, Pei; Wei, Jianmin; Zhao, Xinmin; Zhang, Feng

    2016-02-01

    The robust physisorption between nanoparticles (NPs) and proteins has attracted increasing attention due to the significance for both conjugation techniques and protein's corona formation at the bionano interface. In the present study, we first explored the possible binding sites of the bovine serum albumin (BSA) on amphiphilic polymer coated gold nanoparticles (AP-AuNPs). By using mass spectrometry, a 105-amino-acid peptide (12.2 kDa) is discovered as the possible "epitope" responsible for the robust physisorption between BSA and AP-AuNPs. Second, with the help of nanometal surface energy transfer (NSET) theory, we further found that the epitope peptide could insert at least 2.9 nm into the organic molecular layers of AP-AuNPs when the robust conjugates formed, which indicates how such a long epitope peptide can be accommodated by AP-AuNPs and resist protease's digestion. These findings might shed light on a new strategy for studying interactions between proteins and NPs, and further guide the rational design of NPs for safe and effective biomedical applications. PMID:26718324

  18. Temperature induced morphological transitions from native to unfolded aggregated States of human serum albumin.

    PubMed

    Das, Nirmal Kumar; Ghosh, Narayani; Kale, Ajit Prabhakar; Mondal, Ramakanta; Anand, Uttam; Ghosh, Subhadip; Tiwari, Virendra Kumar; Kapur, Manmohan; Mukherjee, Saptarshi

    2014-07-01

    The circulatory protein, human serum albumin (HSA), is known to have two melting point temperatures, 56 and 62 °C. In this present manuscript, we investigate the interaction of HSA with a synthesized bioactive molecule 3-pyrazolyl 2-pyrazoline (PZ). The sole tryptophan amino acid residue (Trp214) of HSA and PZ forms an excellent FRET pair and has been used to monitor the conformational dynamics in HSA as a function of temperature. Molecular docking studies reveal that the PZ binds to a site which is in the immediate vicinity of Trp214, and such data are also supported by time-resolved FRET studies. Steady-state and time-resolved anisotropy of PZ conclusively proved that the structural and morphological changes in HSA mainly occur beyond its first melting temperature. Although the protein undergoes thermal denaturation at elevated temperatures, the Trp214 gets buried inside the protein scaffolds; this fact has been substantiated by acrylamide quenching studies. Finally, we have used atomic force microscopy to establish that at around 70 °C, HSA undergoes self-assembly to form fibrillar structures. Such an observation may be attributed to the loss of α-helical content of the protein and a subsequent rise in β-sheet structure. PMID:24915234

  19. Interaction between Z-ligustilide from Radix Angelica sinensis and human serum albumin.

    PubMed

    Chen, Tingting; Zhu, Xiting; Chen, Qi; Ge, Ming; Jia, Xueping; Wang, Xiang; Ge, Cunwang

    2015-11-01

    Z-ligustilide (LIG), an essential oil extract from Radix Angelica sinensis, has broad pharmaceutical applications in treating cardiovascular and cerebrovascular diseases. Interaction of LIG with the major transport protein of human blood circulation, human serum albumin (HSA) has been investigated by steady-state, UV-vis and circular dichroism (CD) spectroscopic methods, as well as the effect of metal ions (e.g. Zn(2+), Cu(2+), Fe(3+), Co(2+), Ni(2+)) on the LIG-HSA system. Fluorescence results revealed that a moderate binding affinity (1.59 × 10(4) M(-1) at 298 K) between LIG and HSA with a 1:1 stoichiometry. Thermodynamic analysis of the binding data (ΔS = +12.96 J mol(-1) K(-1) and ΔH =- 20.11 kJ mol(-1)) suggested the involvement of hydrophobic and van der Waals forces, as well as hydrogen bonding in the complex formation. The specific binding distance r (3.75 nm) between donor (Trp-214) and acceptor (LIG) was obtained according to fluorescence resonance energy transfer. CD results showed that slight conformational changes occurred in the protein upon complexation with LIG. PMID:25976824

  20. Effect of cationic grafted copolymer structure on the encapsulation of bovine serum albumin.

    PubMed

    Flynn, Nicholas; Topal, Ç Özge; Hikkaduwa Koralege, Rangika S; Hartson, Steve; Ranjan, Ashish; Liu, Jing; Pope, Carey; Ramsey, Joshua D

    2016-05-01

    The aim of the present study was to evaluate a library of poly-L-lysine (PLL)-graft (g)-polyethylene glycol (PEG) copolymers for the ability to encapsulate effectively a model protein, bovine serum albumin (BSA), and to characterize the stability and protein function of the resulting nanoparticle. A library of nine grafted copolymers was produced by varying PLL molecular weight and PEG grafting ratio. Electrostatic self-assembly of the protein and the grafted copolymer drove encapsulation. The formation of protein/polymer nanoparticles with a core/shell structure was confirmed using PAGE, dynamic light scattering, and electron microscopy. Encapsulation of the BSA into nanoparticles was strongly dependent on the copolymer-to-protein mass ratio, PEG grafting ratio, and PLL molecular weight. A copolymer-to-protein mass ratio of 7:1 and higher was generally required for high levels of encapsulation, and under these conditions, no loss of protein activity was observed. Copolymer characteristics also influenced nanoparticle resistance to polyanions and protease degradation. The results indicate that a copolymer of 15-30 kDa PLL, with a PEG grafting ratio of 10:1, is most promising for protein delivery. PMID:26952455

  1. Interaction of the Anticancer Plant Alkaloid Sanguinarine with Bovine Serum Albumin

    PubMed Central

    Suresh Kumar, Gopinatha

    2011-01-01

    Background Interaction of the iminium and alkanolamine forms of sanguinarine with bovine serum albumin (BSA) was characterized by spectroscopic and calorimetric techniques. Methodology/Principal Findings Formation of strong complexes of BSA with both iminium and alkanolamine forms was revealed from fluorescence quenching of sanguinarine. Binding parameters calculated from Stern-Volmer quenching method revealed that the neutral alkanolamine had higher affinity to BSA compared to the charged iminium form. Specific binding distances of 3.37 and 2.38 nm between Trp 212 (donor) and iminium and alkanolamine forms (acceptor), respectively, were obtained from Forster resonance energy transfer studies. Competitive binding using the site markers warfarin and ibuprofen, having definite binding sites, demonstrated that both forms of sanguinarine bind to site I (subdomain IIA) on BSA. Sanguinarine binding alters protein conformation by reducing the α-helical organization and increasing the coiled structure, indicating a small but definitive partial unfolding of the protein. Thermodynamic parameters evaluated from isothermal titration calorimetry suggested that the binding was enthalpy driven for the iminium form but favoured by negative enthalpy and strong favourable entropy contributions for the alkanolamine form, revealing the involvement of different molecular forces in the complexation. Conclusions/Significance The results suggest that the neutral alkanolamine form binds to the protein more favourably compared to the charged iminium, in stark contrast to the reported DNA binding preference of sanguinarine. PMID:21494677

  2. Binding interaction of quinclorac with bovine serum albumin: A biophysical study

    NASA Astrophysics Data System (ADS)

    Han, Xiao-Le; Mei, Ping; Liu, Yi; Xiao, Qi; Jiang, Feng-Lei; Li, Ran

    2009-10-01

    Quinclorac (QUC) is a new class of highly selective auxin herbicides. The interaction between QUC and bovine serum albumin (BSA) was investigated by fluorescence spectroscopy, synchronous fluorescence, three-dimensional fluorescence, CD spectroscopy and UV-vis absorption spectroscopy under simulative physiological condition. It was proved that the probable quenching mechanism of BSA by quinclorac was dynamic quenching. The Stern-Volmer quenching model has been successfully applied and the activation energy of the interaction as much as 8.03 kJ mol -1, corresponding thermodynamic parameters Δ Hθ, Δ Sθ and Δ Gθ were calculated. The results indicated that the acting forces between QUC and BSA were mainly hydrogen bonding and van der Waals forces. According to the Förster non-radiation energy transfer theory, the average binding distance between donor (BSA) and acceptor (QUC) was obtained ( r = 3.12 nm). The alterations of protein secondary structure in the presence of QUC were confirmed by the evidences from three-dimensional fluorescence, synchronous fluorescence and CD spectroscopy. Furthermore, the site marker competitive experiments indicated that the binding of QUC to BSA primarily took place in Sudlow site I.

  3. Caffeine and sulfadiazine interact differently with human serum albumin: A combined fluorescence and molecular docking study.

    PubMed

    Islam, Mullah Muhaiminul; Sonu, Vikash K; Gashnga, Pynsakhiat Miki; Moyon, N Shaemningwar; Mitra, Sivaprasad

    2016-01-01

    The interaction and binding behavior of the well-known drug sulfadiazine (SDZ) and psychoactive stimulant caffeine (CAF) with human serum albumin (HSA) was monitored by in vitro fluorescence titration and molecular docking calculations under physiological condition. The quenching of protein fluorescence on addition of CAF is due to the formation of protein-drug complex in the ground state; whereas in case of SDZ, the experimental results were explained on the basis of sphere of action model. Although both these compounds bind preferentially in Sudlow's site 1 of the protein, the association constant is approximately two fold higher in case of SDZ (∼4.0×10(4)M(-1)) in comparison with CAF (∼9.3×10(2)M(-1)) and correlates well with physico-chemical properties like pKa and lipophilicity of the drugs. Temperature dependent fluorescence study reveals that both SDZ and CAF bind spontaneously with HSA. However, the binding of SDZ with the protein is mainly governed by the hydrophobic forces in contrast with that of CAF; where, the interaction is best explained in terms of electrostatic mechanism. Molecular docking calculation predicts the binding of these drugs in different location of sub-domain IIA in the protein structure. PMID:26186394

  4. A Comprehensive Computational Study of the Interaction between Human Serum Albumin and Fullerenes.

    PubMed

    Leonis, Georgios; Avramopoulos, Aggelos; Papavasileiou, Konstantinos D; Reis, Heribert; Steinbrecher, Thomas; Papadopoulos, Manthos G

    2015-12-01

    Human serum albumin (HSA) is the most abundant blood plasma protein, which transports fatty acids, hormones, and drugs. We consider nanoparticle-HSA interactions by investigating the binding of HSA with three fullerene analogs. Long MD simulations, quantum mechanical (fragment molecular orbital, energy decomposition analysis, atoms-in-molecules), and free energy methods elucidated the binding mechanism in these complexes. Such a systematic study is valuable due to the lack of comprehensive theoretical approaches to date. The main elements of the mechanism include the following: binding to IIA site results in allosteric modulation of the IIIA and heme binding sites with an increase in α-helical structure of IIIA. Fullerenes displayed high binding affinities for HSA; therefore, HSA can be used as a fullerene carrier, facilitating any toxic function the fullerene may exert. Complex formation is driven by hydrogen bonding, van der Waals, nonpolar, charge transfer, and dispersion energy contributions. Proper functionalization of C60 has enhanced its binding to HSA by more than an order of magnitude. This feature may be important for biological applications (e.g., photodynamic therapy of cancer). Satisfactory agreement with relevant experimental and theoretical data has been obtained. PMID:26523956

  5. Structural aspects of a protein-surfactant assembly: native and reduced States of human serum albumin.

    PubMed

    Anand, Uttam; Ray, Sutapa; Ghosh, Subhadip; Banerjee, Rajat; Mukherjee, Saptarshi

    2015-04-01

    The inherently present seventeen disulfide bonds of the circulatory protein, human serum albumin (HSA) provide the necessary structural stability. Various spectroscopic approaches were used to investigate the effect of reduction of these disulfide bonds and its binding with the anionic surfactant, sodium dodecyl sulfate (SDS). Based on several spectroscopic analyses, our investigations highlight the following interesting aspects: (1) HSA on reduction loses not only its tertiary structure but also a significant amount of secondary structure as well. However, the reduced state of the protein is not like the molten-globule, (2) this structural loss of the protein due to reduction is more prominent than that caused by higher SDS concentrations alone and can certainly be attributed to the role of disulfide bonds, (3) lower surfactant concentrations provide marginal structural rigidity to the native state of the protein, whereas, higher concentrations of SDS induces secondary structure to the reduced state of HSA, (4) the binding of SDS with both the native and reduced states of HSA, occurred in three distinct stages which was followed by a saturation stage. However, the nature of such binding is different for both the states as investigated by using the Stern-Volmer equations and estimating the thermodynamic parameters. Besides, in contrast to the native state, the reduced state of HSA shows that the lone tryptophan residue gets more buried. However, there occurs a sudden decrement in the lifetime of the tryptophan and the hydrodynamic diameter increases by twofold. PMID:25821118

  6. Comparative binding character of two general anaesthetics for sites on human serum albumin.

    PubMed Central

    Liu, Renyu; Meng, Qingcheng; Xi, Jin; Yang, Jinsheng; Ha, Chung-Eun; Bhagavan, Nadhipuram V; Eckenhoff, Roderic G

    2004-01-01

    Propofol and halothane are clinically used general anaesthetics, which are transported primarily by HSA (human serum albumin) in the blood. Binding characteristics are therefore of interest for both the pharmacokinetics and pharmacodynamics of these drugs. We characterized anaesthetic-HSA interactions in solution using elution chromatography, ITC (isothermal titration calorimetry), hydrogen-exchange experiments and geometric analyses of high-resolution structures. Binding affinity of propofol to HSA was determined to have a K(d) of 65 microM and a stoichiometry of approx. 2, whereas the binding of halothane to HSA showed a K(d) of 1.6 mM and a stoichiometry of approx. 7. Anaesthetic-HSA interactions are exothermic, with propofol having a larger negative enthalpy change relative to halothane. Hydrogen-exchange studies in isolated recombinant domains of HSA showed that propofol-binding sites are primarily found in domain III, whereas halothane sites are more widely distributed. Both location and stoichiometry from these solution studies agree with data derived from X-ray crystal-structure studies, and further analyses of the architecture of sites from these structures suggested that greater hydrophobic contacts, van der Waals interactions and hydrogen-bond formation account for the stronger binding of propofol as compared with the less potent anaesthetic, halothane. PMID:14759223

  7. Conformational stability and warfarin-binding properties of human serum albumin studied by recombinant mutants.

    PubMed Central

    Watanabe, H; Kragh-Hansen, U; Tanase, S; Nakajou, K; Mitarai, M; Iwao, Y; Maruyama, T; Otagiri, M

    2001-01-01

    Correctly folded recombinant wild-type human serum albumin and the single-residue mutants K199A, W214A, R218H and H242Q were produced with the use of a yeast expression system. The changes in R218H resulted in a pronounced decrease in intrinsic fluorescence. Thermodynamic parameters for thermal denaturation of the present mutants and of five additional mutants have been determined, showing small increases in stability for two mutants (R218H and H242Q) and a larger decrease in stability for one (W214A). In the last of these, denaturation was a heterogeneous process starting at physiological temperature. The high-affinity binding constant for warfarin at pH 7.4 was determined by fluorescence spectroscopy: there was a significant increase in affinity for binding of warfarin to H242Q and K199A and a smaller decrease in affinity for W214A and R218H. The findings show that Trp-214 is not as essential for the high-affinity binding of warfarin as has previously been thought. PMID:11415459

  8. Replica exchange Monte Carlo simulation of human serum albumin-catechin complexes.

    PubMed

    Li, Yunqi; An, Lijia; Huang, Qingrong

    2014-09-01

    Replica exchange Monte Carlo simulation equipped with an orientation-enhanced hydrophobic interaction was utilized to study the impacts of molar ratio and ionic strength on the complex formation of human serum albumin (HSA) and catechin. Only a small amount of catechins was found to act as bridges in the formation of HSA-catechin complexes. Selective binding behavior was observed at low catechin to HSA molar ratio (R). Increase of catechin amount can suppress HSA self-aggregation and diminish the selectivity of protein binding sites. Strong saturation binding with short-range interactions was found to level off at around 4.6 catechins per HSA on average, while this number slowly increased with R when long-range interactions were taken into account. Meanwhile, among the three rings of catechin, the 3,4-dihydroxyphenyl (B-ring) shows the strongest preference to bind HSA. Neither the aggregation nor the binding sites of the HSA-catechin complex was sensitive to ionic strength, suggesting that the electrostatic interaction is not a dominant force in such complexes. These results provide a further molecular level understanding of protein-polyphenol binding, and the strategy employed in this work shows a way to bridge phase behaviors at macroscale and the distribution of binding sites at residue level. PMID:25111890

  9. Probing the binding of procyanidin B3 to human serum albumin by isothermal titration calorimetry

    NASA Astrophysics Data System (ADS)

    Li, Xiangrong; Yan, Yunhui

    2015-02-01

    Proanthocyanidins are a mixture of monomers, oligomers, and polymers of flavan-3-ols that are widely distributed in the plant kingdom. One of the most widely studied proanthocyanidins is procyanidin B3. In this study, the interaction between procyanidin B3 and human serum albumin (HSA) was investigated using isothermal titration calorimetry (ITC). Thermodynamic investigations reveal that the hydrogen bond and van der Waals force are the major binding forces in the binding of procyanidin B3 to HSA. The binding of procyanidin B3 to HSA is driven by favorable enthalpy and unfavorable entropy. The obtained binding constant for procyanidin B3 with HSA is in the intermediate range and the equilibrium fraction of unbound procyanidin B3 fu > 90% at the physiological concentration of HSA shows that procyanidin B3 can be stored and transported from the circulatory system to reach its target site. The stoichiometric binding number n approximately equals to 1, suggesting that one molecule of procyanidin B3 combines with one molecule of HSA and no more procyanidin B3 binding to HSA occurs at the concentration used in this study.

  10. Effects of titania nanotubes with or without bovine serum albumin loaded on human gingival fibroblasts

    PubMed Central

    Liu, Xiangning; Zhou, Xiaosong; Li, Shaobing; Lai, Renfa; Zhou, Zhiying; Zhang, Ye; Zhou, Lei

    2014-01-01

    Modifying the surface of the transmucosal area is a key research area because this process positively affects the three functions of implants: attachment to soft tissue, inhibiting bacterial biofilm adhesion, and the preservation of the crestal bone. To exploit the potential of titania nanotube arrays (TNTs) with or without using bovine serum albumin (BSA) to modify the surface of a dental implant in contact with the transmucosal area, BSA was loaded into TNTs that were fabricated by anodizing Ti sheets; the physical characteristics of these arrays, including their morphology, chemical composition, surface roughness, contact angle, and surface free energy (SFE), were assessed. The effect of Ti surfaces with TNTs or TNTs-BSA on human gingival fibroblasts (HGFs) was determined by analyzing cell morphology, early adhesion, proliferation, type I collagen (COL-1) gene expression, and the extracellular secretion of COL-1. The results indicate that early HGF adhesion and spreading behavior is positively correlated with surface characteristics, including hydrophilicity, SFE, and surface roughness. Additionally, TNT surfaces not only promoted early HGF adhesion, but also promoted COL-1 secretion. BSA-loaded TNT surfaces promoted early HGF adhesion, while suppressing late proliferation and COL-1 secretion. Therefore, TNT-modified smooth surfaces are expected to be applicable for uses involving the transmucosal area. Further study is required to determine whether BSA-loaded TNT surfaces actually affect closed loop formation of connective tissue because BSA coating actions in vivo are very rapid. PMID:24623977

  11. Biomimetic synthesis of hybrid hydroxyapatite nanoparticles using nanogel template for controlled release of bovine serum albumin.

    PubMed

    Qin, Jinli; Zhong, Zhenyu; Ma, Jun

    2016-05-01

    A biomimetic method was used to prepare hybrid hydroxyapatite (HAP) nanoparticles with chitosan/polyacrylic acid (CS-PAA) nanogel. The morphology, structure, crystallinity, thermal properties and biocompatibility of the obtained hybrid nanogel-HAP nanoparticles have been characterized. In addition, bovine serum albumin (BSA) was used as a model protein to study the loading and release behaviors of the hybrid nanogel-HAP nanoparticles. The results indicated that the obtained HAP nanoparticles were agglomerated and the nanogel could regulate the formation of HAP. When the nanogel concentration decreased, different HAP crystal shapes and agglomerate structures were obtained. The loading amount of BSA reached 67.6 mg/g for the hybrid nanoparticles when the mineral content was 90.4%, which decreased when the nanogel concentration increased. The release profile of BSA was sustained in neutral buffer. Meanwhile, an initial burst release was found at pH 4.5 due to the desorption of BSA from the surface, followed by a slow release. The hemolysis percentage of the hybrid nanoparticles was close to the negative control, and these particles were non-toxic to bone marrow stromal stem cells. The results suggest that these hybrid nanogel-HAP nanoparticles are promising candidate materials for biocompatible drug delivery systems. PMID:26952436

  12. Controlling the taste receptor accessible structure of rebaudioside A via binding to bovine serum albumin.

    PubMed

    Mudgal, Samriddh; Keresztes, Ivan; Feigenson, Gerald W; Rizvi, S S H

    2016-04-15

    We illustrate a method that uses bovine serum albumin (BSA) to control the receptor-accessible part of rebaudioside A (Reb A). The critical micelle concentration (CMC) of Reb A was found to be 4.5 mM and 5 mM at pH 3 and 6.7 respectively. NMR studies show that below its CMC, Reb A binds weakly to BSA to generate a Reb A-protein complex ("RPC"), which is only modestly stable under varying conditions of pH (3.0-6.7) and temperature (4-40°C) with its binding affinities determined to be in the range of 5-280 mM. Furthermore, saturation transfer difference (STD) NMR experiments confirm that the RPC has fast exchange of the bitterness-instigating diterpene of Reb A into the binding sites of BSA. Our method can be used to alter the strength of Reb A-receptor interaction, as a result of binding of Reb A to BSA, which may ultimately lead to moderation of its taste. PMID:26616927

  13. Exploring binding properties of sertraline with human serum albumin: Combination of spectroscopic and molecular modeling studies.

    PubMed

    Shahlaei, Mohsen; Rahimi, Behnoosh; Nowroozi, Amin; Ashrafi-Kooshk, Mohammad Reza; Sadrjavadi, Komail; Khodarahmi, Reza

    2015-12-01

    Human serum albumin (HSA)-drug binding is an important factor to determine half life and bioavailability of drugs. In the present research, the interaction of sertraline (SER) to HSA was investigated using combination of spectroscopic and molecular modeling techniques. Changes in the UV-Vis, CD and FT-IR spectra as well as a significant degree of tryptophan fluorescence quenching were observed upon SER-HSA interaction. Data obtained by spectroscopic methods along with the computational studies suggest that SER binds to residues located in subdomain IIA of HSA. Analysis of spectroscopic data represented the formation of 1:1 complex, significant binding affinity, negative values of entropy and enthalpy changes and the essential role of hydrophobic interactions in binding of SER to HSA. The binding models were demonstrated in the aspects of SER's conformation, active site interactions, important amino acids and hydrogen bonding. Computational mapping of the possible binding site of SER confirmed that the ligand to be bound in a large hydrophobic cavity of HSA. In accordance with experimental data, computational analyses indicated that SER binding does not alter the secondary structure of the protein. The results not only lead to a better understanding of interaction between SER and HSA but also provide useful data about the influence of SER on the protein conformation. PMID:26471709

  14. Interaction of carboxylated single-walled carbon nanotubes with bovine serum albumin

    NASA Astrophysics Data System (ADS)

    Li, Lili; Lin, Rui; He, Hua; Jiang, Li; Gao, Mengmeng

    2013-03-01

    Carboxylated single-walled carbon nanotubes (c-SWNTs) were synthesized prosperously in order to improve dispersion of raw carbon nanotubes. Then, bovine serum albumin (BSA) was used as the template protein to study the biocompatibility of c-SWNTs by UV-Vis, fluorescence and circular dichroism (CD) spectroscopic methods at the molecular level. Results from fluorescence spectrum showed obvious decreases in fluorescence intensity of BSA induced by c-SWNTs, indicating the occurrence of interaction between BSA and c-SWNTs. Static quenching effect of c-SWNTs was verified by linear Stern-Volmer plots and KSV values. Thermodynamic parameters at different temperatures demonstrated that the interaction between c-SWNTs and BSA was mainly favored by hydrophobic force. In addition, Na+ interfered with the quenching effect of c-SWNTs, which revealed that electrostatic force played a role in binding roles of BSA to c-SWNTs simultaneously. The results of UV and synchronous fluorescence spectrum validated that hydrophobicity of amino acid residues expressly increased with the addition of c-SWNTs. The content of α-helix structure in BSA decreased by 14.06% with c-SWNTs viewed from CD spectrum. Effect of SWNTs on the conformation of BSA could be controlled by the surface chemistry of SWNTs.

  15. Intermolecular interaction of prednisolone with bovine serum albumin: Spectroscopic and molecular docking methods

    NASA Astrophysics Data System (ADS)

    Shi, Jie-hua; Zhu, Ying-Yao; Wang, Jing; Chen, Jun; Shen, Ya-Jing

    2013-02-01

    The intermolecular interaction of prednisolone with bovine serum albumin (BSA) was studied using fluorescence, circular dichroism (CD) and molecular docking methods. The experimental results showed that the fluorescence quenching of the BSA at 338 nm by prednisolone resulted from the formation of prednisolone-BSA complex. The number of binding sites (n) for prednisolone binding on BSA was approximately equal to 1. Base on the sign and magnitude of the enthalpy and entropy changes (ΔH0 = -149.6 kJ mol-1 and ΔS0 = -370.7 J mol-1 K-1) and the results of molecular docking, it could be suggested that the interaction forces were mainly Van der Waals and hydrogen bonding interactions. Moreover, in the binding process of BSA with prednisolone, prednisolone molecule can be inserted into the hydrophobic cavity of subdomain IIIA (site II) of BSA. The distance between prednisolone and Trp residue of BSA was calculated as 2.264 nm according to Forster's non-radiative energy transfer theory.

  16. Studies on the interaction between vincamine and human serum albumin: a spectroscopic approach.

    PubMed

    Pu, Hanlin; Jiang, Hua; Chen, Rongrong; Wang, Hongcui

    2014-08-01

    The interaction between vincamine (VCM) and human serum albumin (HSA) has been studied using a fluorescence quenching technique in combination with UV/vis absorption spectroscopy, Fourier transform infrared (FT-IR) spectroscopy, circular dichroism (CD) spectroscopy and molecular modeling under conditions similar to human physiological conditions. VCM effectively quenched the intrinsic fluorescence of HSA via static quenching. The binding constants were calculated from the fluorescence data. Thermodynamic analysis by Van't Hoff equation revealed enthalpy change (ΔH) and entropy change (ΔS) were -4.57 kJ/mol and 76.26 J/mol/K, respectively, which indicated that the binding process was spontaneous and the hydrophobic interaction was the predominant force. The distance r between the donor (HSA) and acceptor (VCM) was obtained according to the Förster's theory of non-radiative energy transfer and found to be 4.41 nm. Metal ions, viz., Na(+), K(+), Li(+), Ni(2+), Ca(2+), Zn(2+) and Al(3+) were found to influence binding of the drug to protein. The 3D fluorescence, FT-IR and CD spectral results revealed changes in the secondary structure of the protein upon interaction with VCM. Furthermore, molecular modeling indicated that VCM could bind to the subdomain IIA (site I) of HSA. PMID:24039032

  17. Binding interaction of atorvastatin with bovine serum albumin: Spectroscopic methods and molecular docking.

    PubMed

    Wang, Qi; Huang, Chuan-ren; Jiang, Min; Zhu, Ying-yao; Wang, Jing; Chen, Jun; Shi, Jie-hua

    2016-03-01

    The interaction of atorvastatin with bovine serum albumin (BSA) was investigated using multi-spectroscopic methods and molecular docking technique for providing important insight into further elucidating the store and transport process of atorvastatin in the body and the mechanism of action and pharmacokinetics. The experimental results revealed that the fluorescence quenching mechanism of BSA induced atorvastatin was a combined dynamic and static quenching. The binding constant and number of binding site of atorvastatin with BSA under simulated physiological conditions (pH=7.4) were 1.41 × 10(5) M(-1) and about 1 at 310K, respectively. The values of the enthalpic change (ΔH(0)), entropic change (ΔS(0)) and Gibbs free energy (ΔG(0)) in the binding process of atorvastatin with BSA at 310K were negative, suggesting that the binding process of atorvastatin and BSA was spontaneous and the main interaction forces were van der Waals force and hydrogen bonding interaction. Moreover, atorvastatin was bound into the subdomain IIA (site I) of BSA, resulting in a slight change of the conformation of BSA. PMID:26688207

  18. Elucidating the interaction of limonene with bovine serum albumin: a multi-technique approach.

    PubMed

    Chaturvedi, Sumit Kumar; Ahmad, Ejaz; Khan, Javed Masood; Alam, Parvez; Ishtikhar, Mohd; Khan, Rizwan Hasan

    2015-01-01

    The interaction of Bovine Serum Albumin (BSA) with limonene has been studied by UV-visible spectroscopy, fluorescence spectroscopy and molecular docking, and its effects on protein conformation, topology and stability were determined by Circular Dichroism (CD), Dynamic Light Scattering (DLS) and Differential Scanning Calorimetry (DSC). A gradual decrease in Stern-Volmer quenching constants with the increase in temperature showed the static mode of fluorescence quenching. The obtained binding constant (Kb) was ∼10(4) M(-1). The temperature dependent Kb, Gibbs free energy (ΔG), enthalpy (ΔH) and entropy (ΔS) changes were calculated, which revealed that the reaction is spontaneous and exothermic. The UV-visible spectra showed a change in the peaks within the aromatic region indicating hydrophobic interactions with Trp, Tyr and Phe in the protein. Moreover, limonene induced an increase in α-helical contents probably on the cost of random coils or/and β-sheets of BSA, as observed from the far-UV CD spectra. The topology of BSA in the presence of limonene was slightly altered, as obtained from DLS results. The stability was also enhanced as revealed through thermal denaturation study by DSC and CD. Molecular docking study depicted that limonene fits into the hydrophobic pocket close to Sudlow site I in domain IIA of BSA. The present study will be helpful in understanding the binding mechanism of limonene and associated stability and conformational changes. PMID:25382435

  19. Spread Films of Human Serum Albumin at the Air-Water Interface: Optimization, Morphology, and Durability.

    PubMed

    Campbell, Richard A; Ang, Joo Chuan; Sebastiani, Federica; Tummino, Andrea; White, John W

    2015-12-22

    It has been known for almost one hundred years that a lower surface tension can be achieved at the air-water interface by spreading protein from a concentrated solution than by adsorption from an equivalent total bulk concentration. Nevertheless, the factors that control this nonequilibrium process have not been fully understood. In the present work, we apply ellipsometry, neutron reflectometry, X-ray reflectometry, and Brewster angle microscopy to elaborate the surface loading of human serum albumin in terms of both the macroscopic film morphology and the spreading dynamics. We show that the dominant contribution to the surface loading mechanism is the Marangoni spreading of protein from the bulk of the droplets rather than the direct transfer of their surface films. The films can be spread on a dilute subphase if the concentration of the spreading solution is sufficient; if not, dissolution of the protein occurs, and only a textured adsorbed layer slowly forms. The morphology of the spread protein films comprises an extended network with regions of less textured material or gaps. Further, mechanical cycling of the surface area of the spread films anneals the network into a membrane that approach constant compressibility and has increased durability. Our work provides a new perspective on an old problem in colloid and interface science. The scope for optimization of the surface loading mechanism in a range of systems leading to its exploitation in deposition-based technologies in the future is discussed. PMID:26607026

  20. Binding interactions of water-soluble camptothecin derivatives with bovine serum albumin

    NASA Astrophysics Data System (ADS)

    Li, Qingyong; Zhu, Qiaochu; Deng, Xiaoqiu; He, Wuna; Zhao, Tengfei; Zhang, Baoyou

    2012-02-01

    In this study, the binding interactions of the water-soluble camptothecin derivatives hydroxycamptothecin (10-HCPT), topotecan (TPT), and camptothecin quaternary salt (CPT8), to bovine serum albumin (BSA) were determined using fluorescence spectra and UV-vis spectra. The results revealed that the fluorescence of BSA was strongly quenched by the binding of camptothecin derivatives to BSA. The quenching mechanism of the camptothecin derivatives was found to be static according to the Stern-Volmer equation. The binding constant and binding sites were confirmed by fluorescence quenching spectra. The thermodynamic parameters Gibbs free energy change (Δ G < 0), enthalpy change (Δ H > 0), and entropy change (Δ S > 0) implied that the interaction process was spontaneous and endothermic, and the interaction forces between camptothecin compounds and BSA were found to be hydrophobic. According to Föster non-radioactive energy transfer, the binding distances between 10-HCPT, TPT, and CPT8, and BSA were determined to be 1.73 nm, 1.63 nm, and 1.61 nm, respectively. The synchronous fluorescence spectra confirmed that the camptothecin compounds cannot cause conformational changes in BSA. A rapid and sensitive method for determining the binding interaction between water-soluble camptothecin derivatives and BSA was established based on these principles of fluorescence quenching.

  1. The interaction between 4-aminoantipyrine and bovine serum albumin: multiple spectroscopic and molecular docking investigations.

    PubMed

    Teng, Yue; Liu, Rutao; Li, Chao; Xia, Qing; Zhang, Pengjun

    2011-06-15

    4-Aminoantipyrine (AAP) is widely used in the pharmaceutical industry, in biochemical experiments and in environmental monitoring. AAP as an aromatic pollutant in the environment poses a great threat to human health. To evaluate the toxicity of AAP at the protein level, the effects of AAP on bovine serum albumin (BSA) were investigated by multiple spectroscopic techniques and molecular modeling. After the inner filter effect was eliminated, the experimental results showed that AAP effectively quenched the intrinsic fluorescence of BSA via static quenching. The number of binding sites, the binding constant, the thermodynamic parameters and binding subdomain were measured, and indicated that AAP could spontaneously bind with BSA on subdomain IIIA through electrostatic forces. Molecular docking results revealed that AAP interacted with the Glu 488 and Glu 502 residues of BSA. Furthermore, the conformation of BSA was demonstrably changed in the presence of AAP. The skeletal structure of BSA loosened, exposing internal hydrophobic aromatic ring amino acids and peptide strands to the solution. PMID:21497437

  2. The competition of drugs to serum albumin in combination chemotherapy: NMR study

    NASA Astrophysics Data System (ADS)

    Sułkowska, A.; Bojko, B.; Równicka, J.; Rezner, P.; Sułkowski, W. W.

    2005-06-01

    Combination chemotherapy with cyclophosphamide (CM), metotrexate and 5-fluorouracil (FU) is used in treatment of patients with breast carcinoma. Although clinical toxicity of CM combinated with FU is greater than that of CM, the levels were clinically acceptable. The mechanism of competition of CM and FU to bovine serum albumin (BSA) was examined with the use of 1H and 13C NMR spectroscopy. The chemical shifts and the linewidth of individual proton and carbon resonances of each drug were measured as a function of the drug/BSA molar ratio in order to analyse the drug-protein interaction and the molecular motion of the drug. The effect of the second drug used in the combination chemotherapy on the analysed NMR parameters is discussed. It was found that FU and CM bind to BSA at molar ratio drug/BSA 160 and 330, respectively. The formation of lev-BSA complex was not confirmed. Whereas it was proved that in the presence of both lev and CM the number of FU molecules bound with BSA increases. It was also observed that FU induces the rising of the affinity between lev and BSA.

  3. Caffeine and sulfadiazine interact differently with human serum albumin: A combined fluorescence and molecular docking study

    NASA Astrophysics Data System (ADS)

    Islam, Mullah Muhaiminul; Sonu, Vikash K.; Gashnga, Pynsakhiat Miki; Moyon, N. Shaemningwar; Mitra, Sivaprasad

    2016-01-01

    The interaction and binding behavior of the well-known drug sulfadiazine (SDZ) and psychoactive stimulant caffeine (CAF) with human serum albumin (HSA) was monitored by in vitro fluorescence titration and molecular docking calculations under physiological condition. The quenching of protein fluorescence on addition of CAF is due to the formation of protein-drug complex in the ground state; whereas in case of SDZ, the experimental results were explained on the basis of sphere of action model. Although both these compounds bind preferentially in Sudlow's site 1 of the protein, the association constant is approximately two fold higher in case of SDZ (∼4.0 × 104 M-1) in comparison with CAF (∼9.3 × 102 M-1) and correlates well with physico-chemical properties like pKa and lipophilicity of the drugs. Temperature dependent fluorescence study reveals that both SDZ and CAF bind spontaneously with HSA. However, the binding of SDZ with the protein is mainly governed by the hydrophobic forces in contrast with that of CAF; where, the interaction is best explained in terms of electrostatic mechanism. Molecular docking calculation predicts the binding of these drugs in different location of sub-domain IIA in the protein structure.

  4. Size and molecular flexibility affect the binding of ellagitannins to bovine serum albumin.

    PubMed

    Dobreva, Marina A; Green, Rebecca J; Mueller-Harvey, Irene; Salminen, Juha-Pekka; Howlin, Brendan J; Frazier, Richard A

    2014-09-17

    Binding to bovine serum albumin of monomeric (vescalagin and pedunculagin) and dimeric ellagitannins (roburin A, oenothein B, and gemin A) was investigated by isothermal titration calorimetry and fluorescence spectroscopy, which indicated two types of binding sites. Stronger and more specific sites exhibited affinity constants, K1, of 10(4)-10(6) M(-1) and stoichiometries, n1, of 2-13 and dominated at low tannin concentrations. Weaker and less-specific binding sites had K2 constants of 10(3)-10(5) M(-1) and stoichiometries, n2, of 16-30 and dominated at higher tannin concentrations. Binding to stronger sites appeared to be dependent on tannin flexibility and the presence of free galloyl groups. Positive entropies for all but gemin A indicated that hydrophobic interactions dominated during complexation. This was supported by an exponential relationship between the affinity, K1, and the modeled hydrophobic accessible surface area and by a linear relationship between K1 and the Stern-Volmer quenching constant, K(SV). PMID:25162485

  5. Spectroscopic Investigation on the Interaction of Titanate Nanotubes with Bovine Serum Albumin

    NASA Astrophysics Data System (ADS)

    Zhao, L. Z.; Zhao, Y. S.; Teng, H. H.; Shi, S. Y.; Ren, B. X.

    2014-09-01

    In order to understand the transport mechanism and evaluate the biological safety of titanate nanotubes, the interactions of titanate nanotubes (TNTs) with bovine serum albumin (BSA) were investigated by applying spectroscopic methods under simulated physiological conditions. After taking into account the inner filter effect, the fluorescence intensity of BSA was found to be significantly enhanced by the presence of TNTs, indicating that the microenvironment of tryptophan and tyrosine residues in BSA became more hydrophobic. In addition, the absorption spectra of BSA showed a hyperchromic effect around 280 nm as the concentration of TNTs increased, suggesting that TNTs changed the microenvironment of the tryptophan and tyrosine residues. This is consistent with the results from fl uorescence spectroscopy studies. However, circular dichroism spectroscopy revealed that no signifi cant conformational change in BSA occurred during the interaction. We believe that Trp-213 was buried more compactly in the internal hydrophobic region, and hydrophobicity increased around Trp-134 with increasing TNTs concentration. From a spectroscopic point of view, this work elucidates the interaction mechanism of titanate nanotubes with BSA, and the methods used in this paper can also be applied to explore the molecular mechanism underlying toxicity of other nanomaterials.

  6. Spectroscopy and Molecular Modeling Study on Binding of Nickel Phthalocyanine to Human Serum Albumin.

    PubMed

    Dezhampanah, Hamid; Firouzi, Roghaye; Hasani, Leila

    2016-01-01

    The interaction of nickel tetra sulfunated phthalocyanine( NiTSPc) with human serum albumin (HSA), in 20 mM phosphate buffer pH 7.4 was investigated using advanced techniques including fluorescence, synchronous fluorescence, Fourier transform infrared (FT-IR), circular dichroism (CD) spectroscopy and molecular docking. The fluorescence quenching measurements showed a single binding site on HSA for NiTSPc with the binding constant (Kb) value equals to 1.26×106 at 25°C. The results showed that quenching mechanism of HSA by NiTSPc was of dynamic type. The results from FTIR and CD spectroscopies demonstrated that NiTSPc binds to amino acid residues of the main polypeptide chain in protein destroying the hydrogen bonding network. The corresponding thermodynamic parameters were then calculated by analysis of fluorescence data using van't Hoff plot. These data indicated that driving force for interaction was mainly hydrophobic in nature and the process was entropy driven. The information obtained from CD, FT-IR and synchronous fluorescence spectroscopies revealed that both microenvironment and conformation of HSA was changed. Molecular docking study confirmed the binding mode obtained by experimental data. PMID:27449940

  7. The effect of Berberine on the secondary structure of human serum albumin

    NASA Astrophysics Data System (ADS)

    Li, Ying; He, WenYing; Tian, Jianniao; Tang, Jianghong; Hu, Zhide; Chen, Xingguo

    2005-05-01

    The presence of several high affinity binding sites on human serum albumin (HSA) makes it a possible target for many drugs. This study is designed to examine the effect of Berberine (an ancient Chinese drug used for antimicrobial, antiplasmodial, antidiarrheal and cardiovascular) on the solution structure of HSA using fluorescence, Fourier transform infrared (FT-IR), circular dichroism (CD) spectroscopic methods. The fluorescence spectroscopic results show that the fluorescence intensity of HSA was significantly decreased in the presence of Berberine. The Scatchard's plots indicated that the binding of Berberine to HSA at 296, 303, 318 K is characterized by one binding site with the binding constant is 4.071(±0.128)×10 4, 3.741(±0.089)×10 4, 3.454(±0.110)×10 4 M -1, respectively. The protein conformation is altered (FT-IR and CD data) with reductions of α-helices from 54 to 47% for free HSA to 45-32% and with increases of turn structure5% for free HSA to 18% in the presence of Berberine. The binding process was exothermic, enthalpy driven and spontaneous, as indicated by the thermodynamic analyses, Berberine bound to HSA was mainly based on hydrophobic interaction and electrostatic interaction cannot be excluded from the binding. Furthermore, the displace experiments indicate that Berberine can bind to the subdomain IIA, that is, high affinity site (site II).

  8. Structural Insights into the Competitive Binding of Diclofenac and Naproxen by Equine Serum Albumin.

    PubMed

    Sekula, Bartosz; Bujacz, Anna

    2016-01-14

    The binding modes to equine serum albumin (ESA) of two nonsteroidal anti-inflammatory drugs (NSAIDs), diclofenac (Dic) and naproxen (Nps), were studied by X-ray crystallography and isothermal titration calorimetry. On the basis of the crystal structure of ESA/Dic determined to a resolution of 1.92 Å and the structure of the previously described ESA/Nps complex (2.42 Å), it was found that both NSAIDs bind within drug site 2 (DS2) of ESA and both occupy secondary binding sites in separate cavities of domain II (Nps) and domain III (Dic). The two structures of the ternary complex ESA/Dic/Nps, obtained by competitive cocrystallization (2.19 Å) and through a displacement experiment (2.35 Å), were determined to investigate possible competition of these widely used pharmaceutical drugs in binding to ESA. In these complexes Nps occupies the DS2 pocket common for both drugs, whereas the other distinct binding sites of Dic and Nps remain unaffected. These results suggest that combined application of both drugs may result in increased concentration of free diclofenac in plasma. PMID:26652101

  9. Investigation of interaction of nuclear fast red with human serum albumin by experimental and computational approaches.

    PubMed

    Gholivand, Mohammad-Bagher; Jalalvand, Ali R; Goicoechea, Hector C; Omidi, Mehdi

    2013-11-01

    For the first time, interaction of nuclear fast red (NFR) with human serum albumin (HSA) was studied by experimental and computational approaches. Firstly, experimental measurements including fluorescence spectroscopy (F), UVvis spectrophotometry (UVvis), cyclic voltammetry (CV), differential pulse voltammetry (DPV) and linear sweep voltammetry (LSV) were separately used to investigate the interaction of NFR with HSA and interesting thermodynamics information was obtained from these studies. Secondly, new information including electrochemical behavior of NFR-HSA complex species, relative concentrations of the various reacting species and effects of NFR on the sub-structure of HSA was obtained by applying multivariate curve resolution-alternating least squares (MCR-ALS). In this case, a row- and column-wise augmented matrix was built with DPV, LSV, F and UVvis sub-matrices and resolved by MCR-ALS. Surprisingly, by this method two NFR-HSA complex species with different stoichiometries and different electrochemical behaviors were found. Furthermore, by the use of the recorded voltammetric and spectroscopic data the binding constants of complex species were computed by EQUISPEC (a hard-modeling algorithm). Finally, the binding of NFR to HSA was modeled by molecular modeling and molecular dynamics (MD) simulations methods. Excellent agreement was found between experimental and computational results. Both experimental and computational results suggested that the NFR binds mainly to the sub-domain IIA of HSA. PMID:23871980

  10. The Reactivity of Human Serum Albumin towards trans-4-Hydroxy-2-nonenal

    PubMed Central

    Liu, Qingyuan; Simpson, David C.; Gronert, Scott

    2012-01-01

    Mass spectrometry was used to probe the preferred locations of trans-4-hydroxy-2-nonenal (HNE) addition to the cysteine, histidine, and lysine residues of human serum albumin (HSA). Considering only those modified peptides supported by high mass accuracy Orbitrap precursor ion measurements (high confidence hits), with HNE:HSA ratios of 1:1 and 10:1, 3 and 15 addition sites, respectively, were identified. Using less stringent criteria, a total of 34 modifications were identified at the higher concentration. To gain quantitative data, iTRAQ labeling studies were completed. Previous work had identified Cys34, the only free cysteine, as the most reactive residue in HSA and we have found that Lys199, His242/7, and His288 are the next most reactive residues. Although the kinetic data indicate the lysines and histidines can react at relatively similar rates, the results show that lysine addition is much less favorable thermodynamically; under our reaction conditions, lysine addition generally does not go to completion. This suggests that under physiological conditions, HNE addition to lysine is only relevant in situations where unusually high HNE concentrations or access to irreversible secondary reactions are found. PMID:22689617

  11. Fabrication and characterization of SPR chips with the modified bovine serum albumin

    NASA Astrophysics Data System (ADS)

    Chen, Xing; Zhang, Lu-lu; Cui, Da-fu

    2016-03-01

    A facile surface plasmon resonance (SPR) chip is developed for small molecule determination and analysis. The SPR chip was prepared based on a self assembling principle, in which the modified bovine serum albumin (BSA) was directly self-assembled onto the bare gold surface. The surface morphology of the chip with the modified BSA was investigated by atomic force microscopy (AFM) and its optical properties were characterized. The surface binding capacity of the bare facile SPR chip with a uniform morphology is 8 times of that of the bare control SPR chip. Based on the experiments of immune reaction between cortisol antibody and cortisol derivative, the sensitivity of the facile SPR chip with the modified BSA is much higher than that of the control SPR chip with the un-modified BSA. The facile SPR chip has been successfully used to detect small molecules. The lowest detection limit is 5 ng/mL with a linear range of 5—100 ng/mL for cortisol analysis. The novel facile SPR chip can also be applied to detect other small molecules.

  12. Nucleolin is a receptor for maleylated-bovine serum albumin on macrophages.

    PubMed

    Miki, Yuichi; Koyama, Keisuke; Kurusu, Haruna; Hirano, Kazuya; Beppu, Masatoshi; Fujiwara, Yasuyuki

    2015-01-01

    Scavenger receptors have a broad range of functions that include pathogen clearance, and identification of the scavenger receptor family has been of great benefit to the field of physiology. The shuttling-protein nucleolin has recently been shown to possess scavenger receptor-like activity. We therefore investigated whether or not nucleolin is a receptor for maleylated-bovine serum albumin (maleylated-BSA), which is a common ligand for scavenger receptors. Binding and phagocytosis of native control-BSA by thioglycollate-elicited mouse peritoneal macrophages was weak, but that of maleylated-BSA was strong. Surface plasmon-resonance analysis revealed that nucleolin strongly associated with maleylated-BSA but not control-BSA or maleic anhydride. Further, co-treatment of macrophages with anti-nucleolin antibody, but not control-immunoglobulin G, inhibited binding of maleylated-BSA. In addition, antineoplastic guanine rich oligonucleotide (AGRO), a nucleolin-specific oligonucleotide aptamer, inhibited binding of maleylated-BSA. Further, binding of maleylated-BSA to nucleolin-transfected HEK293 cells was higher than that by control HEK cells. These results indicate that nucleolin is a receptor that enables macrophages to recognize maleylated-BSA. PMID:25744467

  13. The investigation of the interaction between Tropicamide and bovine serum albumin by spectroscopic methods

    NASA Astrophysics Data System (ADS)

    Yu, Xianyong; Liao, Zhixi; Yao, Qing; Liu, Heting; Li, Xiaofang; Yi, Pinggui

    2014-01-01

    The fluorescence and ultraviolet-visible (UV-Vis) spectroscopy were explored to study the interaction between Tropicamide (TA) and bovine serum albumin (BSA) at three different temperatures (292, 301 and 310 K) under imitated physiological conditions. The experimental results showed that the fluorescence quenching mechanism between TA and BSA was static quenching procedure. The binding constant (Ka), binding sites (n) were obtained. The corresponding thermodynamic parameters (ΔH, ΔS and ΔG) of the interaction system were calculated at different temperatures. The results revealed that the binding process is spontaneous, hydrogen binds and vander Waals were the main force to stabilize the complex. According to Förster non-radiation energy transfer theory, the binding distance between TA and BSA was calculated to be 4.90 nm. Synchronous fluorescence spectroscopy indicated the conformation of BSA changed in the presence of TA. Furthermore, the effect of some common metal ions (Mg2+, Ca2+, Cu2+, and Ni2+) on the binding constants between TA and BSA were examined.

  14. Differences in Esterase Activity to Aspirin and p-Nitrophenyl Acetate among Human Serum Albumin Preparations.

    PubMed

    Tatsumi, Akitoshi; Okada, Masaya; Inagaki, Yoshihiro; Inoue, Sachiyo; Hamaguchi, Tsuneo; Iwakawa, Seigo

    2016-01-01

    Human serum albumin (HSA) has two major ligand-binding sites, sites I and II, and also hydrolyzes some compounds at both sites. In the present study, we investigated differences in esterase activity among HSA preparations, and also the effects of warfarin, indomethacin, and naproxen on the hydrolytic activities of HSA to aspirin and p-nitrophenyl acetate. The esterase activities of HSA to aspirin or p-nitrophenyl acetate were measured from the pseudo-first-order formation rate constant (kobs) of salicylic acid or p-nitrophenol by HSA. Inter-lot variations were observed in the esterase activities of HSA to aspirin and p-nitrophenyl acetate; however, the esterase activity of HSA to aspirin did not correlate with that to p-nitrophenyl acetate. The inhibitory effects of warfarin and indomethacin on the esterase activity of HSA to aspirin were stronger than that of naproxen. In contrast, the inhibitory effect of naproxen on the esterase activity of HSA to p-nitrophenyl acetate was stronger than those of warfarin and indomethacin. These results suggest that the administration of different commercial HSA preparations and the co-administration with site I or II high-affinity binding drugs may change the pharmacokinetic profiles of drugs that are hydrolyzed by HSA. PMID:27476944

  15. Probing the Sudlow binding site with warfarin: how does gold nanocluster growth alter human serum albumin?

    PubMed

    Russell, B A; Mulheran, P A; Birch, D J S; Chen, Y

    2016-08-17

    The search for new fluorescent molecules is vital to the advancement of molecular imaging and sensing for the benefit of medical and biological studies. One such class of new fluorescent molecule is fluorescent gold nanoclusters encapsulated in Human Serum Albumin (HSA-AuNC). In order to use this new fluorescent molecule as a sensor or fluorescent marker in biological imaging both in vitro and in vivo it is important to understand whether/how the proteins function is changed by the synthesis and presence of the gold nanoclusters inside the protein. Natural HSA acts as the main drug carrier in the blood stream, carrying a multitude of molecules in two major binding sites (Sudlow I and II). To test the effects of gold on the ability of HSA to act as a drug carrier we employed warfarin, an anticoagulant drug, as a fluorescent probe to detect changes between natural HSA and HSA-AuNCs. AuNCs are found to inhibit the take up of warfarin by HSA. Evidence for this is found from fluorescence spectral and lifetime measurements. Interestingly, the presence of warfarin bound to HSA also inhibits the formation of gold nanoclusters within protein. This research provides valuable insight into how protein function can change upon synthesis of AuNCs and how that will affect their use as a fluorescent probe. PMID:27480626

  16. Enhancement of recombinant human serum albumin in transgenic rice cell culture system by cultivation strategy.

    PubMed

    Liu, Yu-Kuo; Li, Yu-Teng; Lu, Ching-Fan; Huang, Li-Fen

    2015-05-25

    Fusion of the sugar-starvation-induced αAmy3 promoter with its signal peptide has enabled secretion of recombinant human serum albumin (rHSA) into the culture medium. To simplify the production process and increase the rHSA yield in rice suspension cells, a one-step strategem without medium change was adopted. The yield of rHSA was increased sixfold by this one-step approach compared with the two-step recombinant protein process, in which a change of the culture medium to sugar-free medium is required. The one-step strategem was applied to check repeated cycle of rHSA production, and the production of rHSA was also higher in each cycle in the one-step, as opposed to the two-step, production process. The use of the one-step process resulted in fewer damaged cells during the cell sugar starvation phase for recombinant protein production. Furthermore, we scaled up the rHSA production in a 2-L airlift and a 2-L stirred tank bioreactor by the one-step approach, and concluded that rHSA can be enriched to 45 mg L(-1) in plant culture commonly used MS medium by the airlift-type bioreactor. Our results suggest that rHSA production can be enriched by this optimized cultivation strategem. PMID:25765580

  17. ANALYSIS OF DRUG-PROTEIN BINDING BY ULTRAFAST AFFINITY CHROMATOGRAPHY USING IMMOBILIZED HUMAN SERUM ALBUMIN

    PubMed Central

    Mallik, Rangan; Yoo, Michelle J.; Briscoe, Chad J.; Hage, David S.

    2010-01-01

    Human serum albumin (HSA) was explored for use as a stationary phase and ligand in affinity microcolumns for the ultrafast extraction of free drug fractions and the use of this information for the analysis of drug-protein binding. Warfarin, imipramine, and ibuprofen were used as model analytes in this study. It was found that greater than 95% extraction of all these drugs could be achieved in as little as 250 ms on HSA microcolumns. The retained drug fraction was then eluted from the same column under isocratic conditions, giving elution in less than 40 s when working at 4.5 mL/min. The chromatographic behavior of this system gave a good fit with that predicted by computer simulations based on a reversible, saturable model for the binding of an injected drug with immobilized HSA. The free fractions measured by this method were found to be comparable to those determined by ultrafiltration, and equilibrium constants estimated by this approach gave good agreement with literature values. Advantages of this method include its speed and the relatively low cost of microcolumns that contain HSA. The ability of HSA to bind many types of drugs also creates the possibility of using the same affinity microcolumn to study and measure the free fractions for a variety of pharmaceutical agents. These properties make this technique appealing for use in drug binding studies and in the high-throughput screening of new drug candidates. PMID:20227701

  18. Studies of drug interactions with glycated human serum albumin by high-performance affinity chromatography

    PubMed Central

    Matsuda, Ryan; Kye, So-Hwang; Anguizola, Jeanethe; Hage, David S.

    2015-01-01

    Diabetes is a health condition associated with elevated levels of glucose in the bloodstream and affects 366 million people worldwide. Type II diabetes is often treated with sulfonylurea drugs, which are known to bind tightly in blood to the transport protein human serum albumin (HSA). One consequence of the elevated levels of glucose in diabetes is the non-enzymatic glycation of proteins such as HSA. Several areas of HSA are now known to be affected by glycation-related modifications, which may in turn affect the binding of sulfonylurea drugs and other solutes to this protein. This review discusses some recent studies that have examined these changes in drug-protein binding by employing high-performance affinity chromatography (HPAC). A description of the theoretical and experimental techniques that were used in these studies is given. The information on drug interactions with glycated HSA, as obtained through this method, is also summarized. In addition, the potential advantages of this approach in the areas of biointeraction analysis and personalized medicine are considered. PMID:26526139

  19. Studies of drug interactions with glycated human serum albumin by high-performance affinity chromatography.

    PubMed

    Matsuda, Ryan; Kye, So-Hwang; Anguizola, Jeanethe; Hage, David S

    2014-08-01

    Diabetes is a health condition associated with elevated levels of glucose in the bloodstream and affects 366 million people worldwide. Type II diabetes is often treated with sulfonylurea drugs, which are known to bind tightly in blood to the transport protein human serum albumin (HSA). One consequence of the elevated levels of glucose in diabetes is the non-enzymatic glycation of proteins such as HSA. Several areas of HSA are now known to be affected by glycation-related modifications, which may in turn affect the binding of sulfonylurea drugs and other solutes to this protein. This review discusses some recent studies that have examined these changes in drug-protein binding by employing high-performance affinity chromatography (HPAC). A description of the theoretical and experimental techniques that were used in these studies is given. The information on drug interactions with glycated HSA, as obtained through this method, is also summarized. In addition, the potential advantages of this approach in the areas of biointeraction analysis and personalized medicine are considered. PMID:26526139

  20. Forced Desorption of Bovine Serum Albumin and Lysozyme from Graphite: Insights from Molecular Dynamics Simulation.

    PubMed

    Mücksch, Christian; Urbassek, Herbert M

    2016-08-18

    We use molecular dynamics (MD) simulation to study the adsorption and desorption of two widely different proteins, bovine serum albumin (BSA) and lysozyme, on a graphite surface. The adsorption is modeled using accelerated MD to allow the proteins to find optimum conformations on the surface. Our results demonstrate that the "hard protein" lysozyme retains much of its secondary structure during adsorption, whereas BSA loses it almost completely. BSA has a considerably larger adsorption energy compared to that of lysozyme, which does not scale with chain length. Desorption simulations are carried out using classical steered MD. The BSA molecule becomes fully unzipped during pull-off, whereas several helices survive this process in lysozyme. The unzipping process shows up in the force-distance curve of BSA as a series of peaks, whereas only a single or few, depending on protein orientation, force peaks occur for lysozyme. The maximum desorption force is larger for BSA than for lysozyme, but only by a factor of about 2.3. PMID:27421144

  1. DNP-Enhanced MAS NMR of Bovine Serum Albumin Sediments and Solutions

    PubMed Central

    2015-01-01

    Protein sedimentation sans cryoprotection is a new approach to magic angle spinning (MAS) and dynamic nuclear polarization (DNP) nuclear magnetic resonance (NMR) spectroscopy of proteins. It increases the sensitivity of the experiments by a factor of ∼4.5 in comparison to the conventional DNP sample preparation and circumvents intense background signals from the cryoprotectant. In this paper, we investigate sedimented samples and concentrated frozen solutions of natural abundance bovine serum albumin (BSA) in the absence of a glycerol-based cryoprotectant. We observe DNP signal enhancements of ε ∼ 66 at 140 GHz in a BSA pellet sedimented from an aqueous solution containing the biradical polarizing agent TOTAPOL and compare this with samples prepared using the conventional protocol (i.e., dissolution of BSA in a glycerol/water cryoprotecting mixture). The dependence of DNP parameters on the radical concentration points to the presence of an interaction between TOTAPOL and BSA, so much so that a frozen solution sans cryoprotectant still gives ε ∼ 50. We have studied the interaction of BSA with another biradical, SPIROPOL, that is more rigid than TOTAPOL and has been reported to give higher enhancements. SPIROPOL was also found to interact with BSA, and to give ε ∼ 26 close to its maximum achievable concentration. Under the same conditions, TOTAPOL gives ε ∼ 31, suggesting a lesser affinity of BSA for SPIROPOL with respect to TOTAPOL. Altogether, these results demonstrate that DNP is feasible in self-cryoprotecting samples. PMID:24460530

  2. Serum albumin 'camouflage' of plant virus based nanoparticles prevents their antibody recognition and enhances pharmacokinetics.

    PubMed

    Pitek, Andrzej S; Jameson, Slater A; Veliz, Frank A; Shukla, Sourabh; Steinmetz, Nicole F

    2016-05-01

    Plant virus-based nanoparticles (VNPs) are a novel class of nanocarriers with unique potential for biomedical applications. VNPs have many advantageous properties such as ease of manufacture and high degree of quality control. Their biocompatibility and biodegradability make them an attractive alternative to synthetic nanoparticles (NPs). Nevertheless, as with synthetic NPs, to be successful in drug delivery or imaging, the carriers need to overcome several biological barriers including innate immune recognition. Plasma opsonization can tag (V)NPs for clearance by the mononuclear phagocyte system (MPS), resulting in shortened circulation half lives and non-specific sequestration in non-targeted organs. PEG coatings have been traditionally used to 'shield' nanocarriers from immune surveillance. However, due to broad use of PEG in cosmetics and other industries, the prevalence of anti-PEG antibodies has been reported, which may limit the utility of PEGylation in nanomedicine. Alternative strategies are needed to tailor the in vivo properties of (plant virus-based) nanocarriers. We demonstrate the use of serum albumin (SA) as a viable alternative. SA conjugation to tobacco mosaic virus (TMV)-based nanocarriers results in a 'camouflage' effect more effective than PEG coatings. SA-'camouflaged' TMV particles exhibit decreased antibody recognition, as well as enhanced pharmacokinetics in a Balb/C mouse model. Therefore, SA-coatings may provide an alternative and improved coating technique to yield (plant virus-based) NPs with improved in vivo properties enhancing drug delivery and molecular imaging. PMID:26950168

  3. Diosmin binding to human serum albumin and its preventive action against degradation due to oxidative injuries.

    PubMed

    Barreca, Davide; Laganà, Giuseppina; Bruno, Giuseppe; Magazù, Salvatore; Bellocco, Ersilia

    2013-11-01

    Diosmin is a glycosylated polyphenolic compound, commonly found in fruits and vegetables, which is utilized for the pharmacological formulation of some drugs. The interactions of diosmin to human serum albumin have been investigated by fluorescence, UV-visible, FTIR spectroscopy, native electrophoresis and protein-ligand docking studies. The fluorescence studies indicate that the binding site of the additive involves modifications of environment around Trp214 at the level of subdomain IIA. Combining the curve-fitting results of infrared Amide I' band, the modifications of protein secondary structure have been estimated, indicating a decrease in α-helix structure following flavonoid binding. Data obtained by fluorescence and UV-visible spectroscopy, FTIR experiments and molecular modeling afforded a clear picture of the association mode of diosmin to HSA, suggesting that the primary binding site of diosmin is located in Sudlow's site I. Computational mapping confirms this observation suggesting that the possible binding site of diosmin is located in the hydrophobic cavity of subdomain IIA, whose microenvironment is able to help and stabilize the binding of the ligand in non-planar conformation. Moreover the binding of diosmin to HSA significantly contributes to protect the protein against degradation due to HCLO and Fenton reaction. PMID:23886889

  4. Revealing deposition mechanism of colloid particles on human serum albumin monolayers.

    PubMed

    Nattich-Rak, Małgorzata; Adamczyk, Zbigniew; Kujda, Marta

    2016-01-01

    Colloid particle deposition was applied in order to characterize human serum albumin (HSA) monolayers on mica adsorbed under diffusion transport at pH 3.5. The surface concentration of HSA was determined by a direct AFM imaging of single molecules. The electrokinetic characteristics of the monolayers for various ionic strength were done by in situ streaming potential measurements. In this way the mean-field zeta potential of monolayers was determined. It was shown that the initially negative potential changed its sign for HSA surface concentrations above 2800μm(-2) that was interpreted as overcharging effect. The monolayers were also characterized by the colloid deposition method where negatively charged polystyrene particles, 810nm in diameter were used. The kinetics of particle deposition and their maximum coverage were determined as a function of the HSA monolayer surface concentration. An anomalous deposition of particles on substrates exhibiting a negative zeta potential was observed, which contradicts the mean-field theoretical predictions. This effect was quantitatively interpreted in terms of the random site sequential adsorption model. It was shown that efficient immobilization of particles only occurs at adsorption sites formed by three and more closely adsorbed HSA molecules. These results can be exploited as useful reference data for the analysis of deposition phenomena of bioparticles at protein monolayers that has practical significance for the regulation of the bioadhesive properties of surfaces. PMID:26272241

  5. A comparative study of the interaction of Tamiflu and Oseltamivir carboxylate with bovine serum albumin.

    PubMed

    Vishkaee, Tahereh Sadigh; Mohajerani, Niloufar; Nafisi, Shohreh

    2013-02-01

    Oseltamivir phosphate (Tamiflu) is a pro-drug that is metabolized to its active form (Oseltamivir carboxylate), after oral administration. OC inhibits influenza A and B neuraminidases in vitro and OP inhibits influenza virus infection and replication in vitro. Serum albumin is the most abundant of the proteins in the circulatory system of a wide variety of organisms and plays an important role in the transport and deposition of many drugs. The aim of this study was to examine the interaction of BSA with Tamiflu and Oseltamivir carboxylate in aqueous solution at physiological conditions, using a constant protein concentration and various drug contents. FTIR, UV-Vis spectroscopic methods were used to determine the drugs binding mode, the binding constant and the effects of drug complexation on protein secondary structure. Structural analysis showed that OP and OC bind BSA with overall binding constants of K(OP-BSA)=1.88 (±0.16)×10(4)M(-1) and K(OC-BSA)=5.7 (±0.09)×10(2)M(-1). Drug complexation alters protein conformation by major reduction of α-helix and random coil and increase of β-sheet and turn structures that indicate a partial protein destabilization. The results suggest that BSA might act as carrier proteins for OP in delivering it to target molecules. PMID:23353784

  6. Interactions of acidic pharmaceuticals with human serum albumin: insights into the molecular toxicity of emerging pollutants.

    PubMed

    Chen, Jiabin; Zhou, Xuefei; Zhang, Yalei; Qian, Yajie; Gao, Haiping

    2012-10-01

    Acidic pharmaceuticals such as diclofenac (DCF), clofibric acid (CA) and ketoprofen (KTP) have been detected frequently in environmental media. In order to reveal the toxicity of such emerging pollutants, their interactions with human serum albumin (HSA) were investigated by capillary electrophoresis, molecular spectrometry, and equilibrium dialysis. The binding constants and sites of these acidic pharmaceuticals with HSA were obtained. The thermodynamic parameters, e.g. enthalpy change and entropy change of these interactions were calculated to characterize that all the reactions resulted from hydrophobic and electrostatic interactions. The static quenching of the fluorescence of HSA was observed when interacted with acidic pharmaceuticals, indicating acidic pharmaceuticals bound to Tryptophan residue of HSA. The 3D fluorescence and circular dichroism confirmed that the secondary conformation of HSA changed after the interactions with the pharmaceuticals. At physiological condition, only 0.12 mM acidic pharmaceuticals reduced the binding of vitamin B(2) to HSA by 37, 30 and 21% for DCF, KTP and CA, respectively. This work provides an insight into non-covalent interactions between emerging contaminants and biomolecule, and is helpful for clarifying the toxic mechanism of such emerging contaminants. PMID:22307229

  7. Binding interaction of atorvastatin with bovine serum albumin: Spectroscopic methods and molecular docking

    NASA Astrophysics Data System (ADS)

    Wang, Qi; Huang, Chuan-ren; Jiang, Min; Zhu, Ying-yao; Wang, Jing; Chen, Jun; Shi, Jie-hua

    2016-03-01

    The interaction of atorvastatin with bovine serum albumin (BSA) was investigated using multi-spectroscopic methods and molecular docking technique for providing important insight into further elucidating the store and transport process of atorvastatin in the body and the mechanism of action and pharmacokinetics. The experimental results revealed that the fluorescence quenching mechanism of BSA induced atorvastatin was a combined dynamic and static quenching. The binding constant and number of binding site of atorvastatin with BSA under simulated physiological conditions (pH = 7.4) were 1.41 × 105 M- 1 and about 1 at 310 K, respectively. The values of the enthalpic change (ΔH0), entropic change (ΔS0) and Gibbs free energy (ΔG0) in the binding process of atorvastatin with BSA at 310 K were negative, suggesting that the binding process of atorvastatin and BSA was spontaneous and the main interaction forces were van der Waals force and hydrogen bonding interaction. Moreover, atorvastatin was bound into the subdomain IIA (site I) of BSA, resulting in a slight change of the conformation of BSA.

  8. nanoparticles via a facile one-step solvothermal process for adsorption of bovine serum albumin

    NASA Astrophysics Data System (ADS)

    Shen, Mao; Yu, Yujing; Fan, Guodong; Chen, Guang; Jin, Ying min; Tang, Wenyuan; Jia, Wenping

    2014-06-01

    Preparation of magnetic nanoparticles coated with chitosan (CS-coated Fe3O4 NPs) in one step by the solvothermal method in the presence of different amounts of added chitosan is reported here. The magnetic property of the obtained magnetic composite nanoparticles was confirmed by X-ray diffraction (XRD) and magnetic measurements (VSM). Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) allowed the identification of spherical nanoparticles with about 150 nm in average diameter. Characterization of the products by Fourier transform infrared spectroscopy (FTIR) demonstrated that CS-coated Fe3O4 NPs were obtained. Chitosan content in the obtained nanocomposites was estimated by thermogravimetric analysis (TGA). The adsorption properties of the CS-coated Fe3O4 NPs for bovine serum albumin (BSA) were investigated under different concentrations of BSA. Compared with naked Fe3O4 nanoparticles, the CS-coated Fe3O4 NPs showed a higher BSA adsorption capacity (96.5 mg/g) and a fast adsorption rate (45 min) in aqueous solutions. This work demonstrates that the prepared magnetic nanoparticles have promising applications in enzyme and protein immobilization.

  9. Binding of dihydromyricetin and its metal ion complexes with bovine serum albumin

    PubMed Central

    Guo, Qingquan; Yuan, Juan; Zeng, Jinhua

    2014-01-01

    The binding mechanisms of the interaction of three dihydromyricetin (DMY)–metal complexes (DMY–Cu (II) complex, DMY–Mn (II) complex, DMY–Zn (II) complex) and DMY with bovine serum albumin (BSA) were investigated using fluorescence and ultraviolet spectroscopy at different temperatures. The results indicated some differences in the binding process between different DMY–metal complexes and BSA compared with that of free DMY. All of the complexes and DMY quenched the fluorescence of BSA based on static mode combined with radiationless energy transfer, yet having different binding distance based on the Förster theory. Different DMY–metal complexes can change the binding constants. The binding constants increase for DMY–Cu (II) and DMY–Mn (II) complexes, whereas the opposite is true for the DMY–Zn (II) complex compared to the one with free DMY. The DMY–metal complexes can also affect the types of the interaction. The van der Waals forces and hydrogen bonding may play a major role in the interaction of free DMY with BSA, while for the three complexes, the nature of the binding forces lies in hydrophobic forces and hydrogen bonding based on the thermodynamic parameters. PMID:26019518

  10. Effect of (−)-Epigallocatechin-3-Gallate on Glucose-Induced Human Serum Albumin Glycation

    PubMed Central

    Li, Min; Hagerman, Ann E.

    2016-01-01

    (−)-Epigallocatechin-3-gallate (EGCg) is a naturally occurring polyphenol found in plant-based foods and beverages such as green tea. Although EGCg can eliminate carbonyl species produced by glucose autoxidation and thus can inhibit protein glycation, it is also reported to be a pro-oxidant that stimulates protein glycation in vitro. To better understand the balance between antioxidant and pro-oxidant features of EGCg, we evaluated EGCg-mediated bioactivities in a human serum albumin (HSA)/glucose model by varying three different parameters (glucose level, EGCg concentration, and time of exposure to EGCg). Measurements of glycation-induced fluorescence, protein carbonyls, and electrophoretic mobility showed that the level of HSA glycation was positively related to the glucose level over the range 10 to 100 mM during a 21-day incubation at 37 °C and pH 7.4. Under mild glycemic pressure (10 mM), long exposure to EGCg enhanced HSA glycation, while brief exposure to low concentrations of EGCg did not. Under high glycemic pressure (100 mM glucose), long exposure to EGCg inhibited glycation. For the first time we showed that brief exposure to EGCg reversed glycation-induced fluorescence, indicating a restorative effect. In conclusion, our research identified glucose level, EGCg concentration, and time of exposure as critical factors dictating EGCg bioactivities in HSA glycation. EGCg did not affect HSA glycation under normal physiological conditions but had a potential therapeutic effect on HSA severely damaged by glycation. PMID:25794449

  11. Fatty acid-binding site environments of serum vitamin D-binding protein and albumin are different

    PubMed Central

    Swamy, Narasimha; Ray, Rahul

    2008-01-01

    Vitamin D-binding protein (DBP) and albumin (ALB) are abundant serum proteins and both possess high-affinity binding for saturated and unsaturated fatty acids. However, certain differences exist. We surmised that in cases where serum albumin level is low, DBP presumably can act as a transporter of fatty acids. To explore this possibility we synthesized several alkylating derivatives of 14C-palmitic acid to probe the fatty acid binding pockets of DBP and ALB. We observed that N-ethyl-5-phenylisooxazolium-3′-sulfonate-ester (WRK ester) of 14C-palmitic acid specifically labeled DBP; but p-nitrophenyl- and N-hydroxysuccinimidyl-esters failed to do so. However, p-nitrophenyl ester of 14C-palmitic acid specifically labeled bovine ALB, indicating that the micro-environment of the fatty acid-binding domains of DBP and ALB may be different; and DBP may not replace ALB as a transporter of fatty acids. PMID:18374965

  12. Grafting of bovine serum albumin proteins on plasma-modified polymers for potential application in tissue engineering

    NASA Astrophysics Data System (ADS)

    Kasálková, Nikola Slepičková; Slepička, Petr; Kolská, Zdeňka; Hodačová, Petra; Kučková, Štěpánka; Švorčík, Václav

    2014-04-01

    In this work, an influence of bovine serum albumin proteins grafting on the surface properties of plasma-treated polyethylene and poly- l-lactic acid was studied. The interaction of the vascular smooth muscle cells with the modified polymer surface was determined. The surface properties were characterized by X-ray photoelectron spectroscopy, atomic force microscopy, nano-LC-ESI-Q-TOF mass spectrometry, electrokinetic analysis, and goniometry. One of the motivations for this work is the idea that by the interaction of the cell with substrate surface, the proteins will form an interlayer between the cell and the substrate. It was proven that when interacting with the plasma-treated high-density polyethylene and poly- l-lactic acid, the bovine serum albumin protein is grafted on the polymer surface. Since the proteins are bonded to the substrate surface, they can stimulate cell adhesion and proliferation.

  13. Human Serum Versus Human Serum Albumin Supplementation in Human Islet Pretransplantation Culture: In Vitro and In Vivo Assessment.

    PubMed

    Nacher, Montserrat; Estil Les, Elisabet; Garcia, Ainhoa; Nadal, Belen; Pairó, Mar; Garcia, Cristofer; Secanella, Lluís; Novials, Anna; Montanya, Eduard

    2016-01-01

    There is conflicting evidence favoring both the use of human serum (HS) and of human serum albumin (HSA) in human islet culture. We evaluated the effects of HS versus HSA supplementation on 1) in vitro β-cell viability and function and 2) in vivo islet graft revascularization, islet viability, β-cell death, and metabolic outcome after transplantation. Islets isolated from 14 cadaveric organ donors were cultured for 3 days in CMRL 1066 medium supplemented with HS or HSA. After 3 days in culture, β-cell apoptosis was lower in HS group (1.41 ± 0.27 vs. 2.38 ± 0.39%, p = 0.029), and the recovery of islets was 77 ± 11% and 54 ± 1% in HS- and HSA-cultured groups, respectively. Glucose-stimulated insulin secretion (GSIS) was higher in HS group (29.4, range 10.4-99.9, vs. 22.3, range 8.7-70.6, p = 0.031). In vivo viability and revascularization was determined in HS- and HSA-cultured islets transplanted into the anterior chamber of the eye of Balb/c mice (n = 14), and β-cell apoptosis in paraffin-embedded mouse eyes. Islet viability and β-cell apoptosis were similar in both groups. Revascularization was observed in one graft (HS group) on day 10 after transplantation. Islet function was determined in streptozotocin (STZ)-diabetic nude mice (n = 33) transplanted with 2,000 IEQs cultured with HS or HSA that showed similar blood glucose levels and percentage of normoglycemic animals over time. In conclusion, human islets cultured in medium supplemented with HS showed higher survival in vitro, as well as islet viability and function. The higher in vitro survival increased the number of islets available for transplantation. However, the beneficial effect on viability and function did not translate into an improved metabolic evolution when a similar number of HSA- and HS-cultured islets was transplanted. PMID:25955150

  14. Surface plasmon resonance and circular dichroism characterization of cucurbitacins binding to serum albumins for early pharmacokinetic profiling.

    PubMed

    Fabini, Edoardo; Fiori, Giovana Maria Lanchoti; Tedesco, Daniele; Lopes, Norberto Peporine; Bertucci, Carlo

    2016-04-15

    Cucurbitacins are a group of tetracyclic triterpenoids, known for centuries for their anti-cancer and anti-inflammatory properties, which are being actively investigated over the past decades in order to elucidate their mechanism of action. In perspective of being used as therapeutic molecules, a pharmacokinetic characterization is crucial to assess the affinity toward blood carrier proteins and extrapolate distribution volumes. Usually, pharmacokinetic data are first collected on animal models and later translated to humans; therefore, an early characterization of the interaction with carrier proteins from different species is highly desirable. In the present study, the interactions of cucurbitacins E and I with human and rat serum albumins (HSA and RSA) were investigated by means of surface plasmon resonance (SPR)-based optical biosensing and circular dichroism (CD) spectroscopy. Active HSA and RSA sensor chip surfaces were prepared through an amine coupling reaction protocol, and the equilibrium dissociation constants (Kd) for the different cucurbitacins-serum albumins complexes were then determined by SPR analysis. Further information on the binding of cucurbitacins to serum albumins was obtained by CD competition experiments with biliverdin, a specific marker binding to subdomain IB of HSA. SPR data unveiled a previously unreported binding event between CucI and HSA; the determined binding affinities of both compounds were slightly higher for RSA with respect to HSA, even though all the compounds can be ranked as high-affinity binders for both carriers. CD analysis showed that the two cucurbitacins modify the binding of biliverdin to serum albumins through opposite allosteric modulation (positive for HSA, negative for RSA), confirming the need for caution in the translation of pharmacokinetic data across species. PMID:26856457

  15. Serum albumin attenuates the open-channel blocking effects of propofol on the human Kv1.5 channel.

    PubMed

    Kojima, Akiko; Bai, Jia-Yu; Ito, Yuki; Ding, Wei-Guang; Kitagawa, Hirotoshi; Matsuura, Hiroshi

    2016-07-15

    The intravenous anesthetic propofol modulates various ion channel functions. It is generally accepted that approximately 98% of propofol binds to blood constituents and that the free (unbound) drug preferentially affects target proteins including ion channels. However, modulatory effects of propofol on ion channels have not been previously explored in the presence of serum albumin. This study was designed to investigate the effects of serum albumin on the blocking action of propofol on the human Kv1.5 (hKv1.5) current. Whole-cell patch-clamp method was used to record the hKv1.5 channel current, heterologously expressed in Chinese hamster ovary cells, in the absence and presence of bovine serum albumin (BSA). Propofol induced a time-dependent decline of the hKv1.5 current during depolarizing steps and slowed the time course of tail current decay upon repolarization, supporting that propofol acts as an open-channel blocker. This blocking effect was reversible and concentration-dependent with an IC50 of 62.9±3.1μM (n = 6). Bath application of 1% BSA markedly reduced the blocking potency of propofol on hKv1.5 current (IC50 of 1116.0±491.4μM; n = 6). However, in the presence of BSA, the propofol-induced inhibition of hKv1.5 current was also accompanied by a gradual decline of activated current during depolarization and deceleration of deactivating tail current upon repolarization. The presence of BSA greatly attenuated the blocking potency of propofol on hKv1.5 channel without affecting the mode of action of propofol on the channel. Serum albumin thus appears to bind to propofol and thereby reducing effective concentrations of the drug for inhibition of hKv1.5 channel. PMID:27164421

  16. Quantitation of 4,4′-methylene diphenyl diisocyanate human serum albumin adducts

    PubMed Central

    Luna, Leah G.; Green, Brett J.; Zhang, Fagen; Arnold, Scott M.; Siegel, Paul D.; Bartels, Michael J.

    2016-01-01

    4,4′-Methylene diphenyl diisocyanate (herein 4,4′-MDI) is used in the production of polyurethane foams, elastomers, coatings, adhesives and the like for a wide range of commercial products. Occupational exposure to MDI levels above current airborne exposure limits can elicit immune mediated hypersensitivity reactions such as occupational asthma in sensitive individuals. To accurately determine exposure, there has been increasing interest in developing analytical methods to measure internal biomarkers of exposure to MDI. Previous investigators have reported methodologies for measuring MDI diamine metabolites and MDI-Lysine (4,4′-MDI-Lys) adducts. The purpose of this study was to develop and validate an ultra performance liquid chromatography isotope dilution tandem mass spectrometry (UPLC-ID/MS/MS) quantitation method via a signature peptide approach to enable biomonitoring of 4,4′-MDI adducted to human serum albumin (HSA) in plasma. A murine, anti-4,4′-MDI monoclonal IgM antibody was bound to magnetic beads and utilized for enrichment of the MDI adducted HSA. Following enrichment, trypsin digestion was performed to generate the expected 414 site (primary site of adduction) 4,4′-MDI-adducted HSA signature peptide that was quantified by UPLC-ID/MS/MS. An Agilent 6530 UPLC/quadrupole time of flight MS (QTOF) system was utilized for intact adducted protein analysis and an Agilent 6490 UPLC/MS/MS system operated in multiple reaction monitoring (MRM) mode was utilized for quantification of the adducted signature peptide biomarker both for in chemico and worker serum samples. Worker serum samples were initially screened utilizing the previously developed 4,4′-MDI-Lys amino acid method and results showed that 12 samples were identified as quantifiable for 4,4′-MDI-Lys adducts. The signature peptide adduct approach was applied to the 12 worker samples identified as quantifiable for 4,4′-MDI-Lys adducts. Results indicated no positive results were obtained

  17. Spectral characterization of the binding and conformational changes of serum albumins upon interaction with an anticancer drug, anastrozole

    NASA Astrophysics Data System (ADS)

    Punith, Reeta; Seetharamappa, J.

    2012-06-01

    The present study employed different optical spectroscopic techniques viz., fluorescence, FTIR, circular dichroism (CD) and UV-vis absorption spectroscopy to investigate the mechanism of interaction of an anticancer drug, anastrozole (AZ) with transport proteins viz., bovine serum albumin (BSA) and human serum albumin (HSA). The drug, AZ quenched the intrinsic fluorescence of protein and the analysis of results revealed the presence of dynamic quenching mechanism. The binding characteristics of drug-protein were computed. The thermodynamic parameters, enthalpy change (ΔH°) and entropy change (ΔS°) were calculated to be +92.99 kJ/mol and +159.18 J/mol/K for AZ-BSA and, +99.43 kJ/mol and +159.19 J/mol/K for AZ-HSA, respectively. These results indicated that the hydrophobic forces stabilized the interaction between the drug and protein. CD, FTIR, absorption, synchronous and 3D fluorescence results indicated that the binding of AZ to protein induced structural perturbation in both serum albumins. The distance, r between the drug and protein was calculated based on the theory of Förster's resonance energy transfer and found to be 5.9 and 6.24 nm, respectively for AZ-BSA and AZ-HSA.

  18. Novel curcumin-loaded human serum albumin nanoparticles surface functionalized with folate: characterization and in vitro/vivo evaluation.

    PubMed

    Song, Zhiwang; Lu, Yonglin; Zhang, Xia; Wang, Haiping; Han, Junyi; Dong, Chunyan

    2016-01-01

    Folate-conjugated, curcumin-loaded human serum albumin nanoparticles (F-CM-HSANPs) were obtained by the chemical conjugation of folate to the surface of the curcumin (CM)-loaded human serum albumin nanoparticles (NPs). The NPs were characterized by various parameters, including size, polydispersity, zeta potential, morphology, encapsulation efficiency, and drug release profile. The mean particle size of F-CM-HSANPs was 165.6±15.7 nm (polydispersity index <0.28), and the average encapsulation efficiency percentage and drug loading percentage of the F-CM-HSANPs were 88.7%±4.8% and 7.9%±0.4%, respectively. Applied in vitro, the CM NPs, after conjugation with folate, maintained sustained release, and a faster release of CM was more visibly observed than the unconjugated NPs. F-CM-HSANPs can prolong the retention time of CM significantly in vivo. However, after intravenous injection of F-CM-HSANPs, the pharmacokinetic parameters of CM were not significantly different from those of CM-loaded human serum albumin NPs. The improved antitumor activity of F-CM-HSANPs may be attributable to the protection of drug from enzymatic deactivation followed by the selective localization at the desired site. These results suggest that the intravenous injection of F-CM-HSANPs is likely to have an advantage in the current clinical CM formulation, because it does not require the use of a solubilization agent and it is better able to target the tumor tissue. PMID:27574403

  19. Novel curcumin-loaded human serum albumin nanoparticles surface functionalized with folate: characterization and in vitro/vivo evaluation

    PubMed Central

    Song, Zhiwang; Lu, Yonglin; Zhang, Xia; Wang, Haiping; Han, Junyi; Dong, Chunyan

    2016-01-01

    Folate-conjugated, curcumin-loaded human serum albumin nanoparticles (F-CM-HSANPs) were obtained by the chemical conjugation of folate to the surface of the curcumin (CM)-loaded human serum albumin nanoparticles (NPs). The NPs were characterized by various parameters, including size, polydispersity, zeta potential, morphology, encapsulation efficiency, and drug release profile. The mean particle size of F-CM-HSANPs was 165.6±15.7 nm (polydispersity index <0.28), and the average encapsulation efficiency percentage and drug loading percentage of the F-CM-HSANPs were 88.7%±4.8% and 7.9%±0.4%, respectively. Applied in vitro, the CM NPs, after conjugation with folate, maintained sustained release, and a faster release of CM was more visibly observed than the unconjugated NPs. F-CM-HSANPs can prolong the retention time of CM significantly in vivo. However, after intravenous injection of F-CM-HSANPs, the pharmacokinetic parameters of CM were not significantly different from those of CM-loaded human serum albumin NPs. The improved antitumor activity of F-CM-HSANPs may be attributable to the protection of drug from enzymatic deactivation followed by the selective localization at the desired site. These results suggest that the intravenous injection of F-CM-HSANPs is likely to have an advantage in the current clinical CM formulation, because it does not require the use of a solubilization agent and it is better able to target the tumor tissue. PMID:27574403

  20. Subnanosecond fluorescence spectroscopy of human serum albumin as a method to estimate the efficiency of the depression therapy

    NASA Astrophysics Data System (ADS)

    Syrejshchikova, T. I.; Gryzunov, Yu. A.; Smolina, N. V.; Komar, A. A.; Uzbekov, M. G.; Misionzhnik, E. J.; Maksimova, N. M.

    2010-05-01

    The efficiency of the therapy of psychiatric diseases is estimated using the fluorescence measurements of the conformational changes of human serum albumin in the course of medical treatment. The fluorescence decay curves of the CAPIDAN probe (N-carboxyphenylimide of the dimethylaminonaphthalic acid) in the blood serum are measured. The probe is specifically bound to the albumin drug binding sites and exhibits fluorescence as a reporter ligand. A variation in the conformation of the albumin molecule substantially affects the CAPIDAN fluorescence decay curve on the subnanosecond time scale. A subnanosecond pulsed laser or a Pico-Quant LED excitation source and a fast photon detector with a time resolution of about 50 ps are used for the kinetic measurements. The blood sera of ten patients suffering from depression and treated at the Institute of Psychiatry were preliminary clinically tested. Blood for analysis was taken from each patient prior to the treatment and on the third week of treatment. For ten patients, the analysis of the fluorescence decay curves of the probe in the blood serum using the three-exponential fitting shows that the difference between the amplitudes of the decay function corresponding to the long-lived (9 ns) fluorescence of the probe prior to and after the therapeutic procedure reliably differs from zero at a significance level of 1% ( p < 0.01).

  1. Serum enhanced cytokine responses of macrophages to silica and iron oxide particles and nanomaterials: a comparison of serum to lung lining fluid and albumin dispersions.

    PubMed

    Brown, David M; Johnston, Helinor; Gubbins, Eva; Stone, Vicki

    2014-11-01

    The potential hazard to humans exposed to nanomaterials such as silica and iron oxide was investigated using an in vitro macrophage cell culture system. Amorphous silica and iron oxide particles and nanomaterials (NMs) were dispersed in cell culture medium supplemented with either bovine serum albumin (BSA), lung lining fluid (LLF) or serum, in order to mimic the body fluids encountered during different routes of exposure in the body. End points investigated included macrophage viability and cytokine production. Silica NMs and particles (50 and 200 nm, respectively) were unmodified (plain) or aminated (NH2 ). Iron oxide NMs and particles, Fe3 O4 45 nm and Fe2 O3 280 nm were also used in this study. Silica particles and NMs induced a dose-dependent increase in cytotoxicity as measured by lactate dehydrogenase (LDH) release. Serum enhanced silica-induced interleukin (IL)-6, IL-10, IL-1β and MCP-1 release, whereas albumin partially inhibited MCP-1 release. Aminated silica, 50 nm was more potent than the 200-nm particles at inducing monocyte chemoattractant protein-1 (MCP-1) production when dispersed in medium or LLF, suggesting a size specific effect for these particles and this cytokine. Iron oxide particles were relatively inert compared with the silica particles and NMs; however, serum and albumin did affect cytokine release in some treatments. In conclusion, the data suggests that serum, compared with medium, BSA and LLF is very potent at enhancing macrophage responses to silica and iron oxide particles and NMs. Size was only influential in LLF for a limited number of parameters, whereas surface chemistry was not of consequence in this in vitro macrophage system. PMID:24737200

  2. Effect of serum albumin and low molecular weight ligands on Zn uptake by isolated rat hepatocytes

    SciTech Connect

    Flynn, A.; Loennerdal, B.

    1986-03-05

    Although the liver plays an important role in Zn metabolism, the mechanisms regulating hepatic Zn uptake are poorly understood. Hepatocytes were isolated from adult female rats, body weight 200-250 g, by the collagenase perfusion technique and purified by differential centrifugation. Uptake of Zn was studied by incubation of hepatocytes with /sup 65/Zn in 10 mM HEPES buffer, pH 7.4, containing 138 mM NaCl, 5.2 mM KCl, 0.9 mM MgCl/sub 2/ and 1.0 mM CaCl/sub 2/, followed by washing with ice-cold 10 mM EDTA, 0.9% NaCl, pH 7.3 on Whatman GF-C glass microfiber filters. Zn uptake of 37/sup 0/C from ZnSO/sub 4/ (10 ..mu..M) was linear up to approx. 5 min with an initial rate of uptake of 11-20 ng/min/10/sup 6/ viable cells. Initial rate of Zn uptake at 37/sup 0/C was over 10-fold greater than at 4/sup 0/C. At 37/sup 0/C initial rate of uptake increased as a function of Zn concentration in the range 2-20 ..mu..M, with K/sub m/ = 27 ..mu..M and V/sub max/ = 42 ng/min/10/sup 6/ viable cells. Inclusion of bovine serum albumin (2 mg/ml) with ZnSO/sub 4/ (10 ..mu..m) reduced the initial rate of uptake to approx. 25% of the rate with ZnSO/sub 4/ alone. The low molecular weight ligands, phosphate, citrate and histidine at equimolar concentrations with Zn had little effect on Zn uptake by hepatocytes.

  3. Probing the binding of morin to human serum albumin by optical spectroscopy.

    PubMed

    Qi, Zu-de; Zhang, Yue; Liao, Feng-Lin; Ou-Yang, Yi-Wen; Liu, Yi; Yang, Xi

    2008-03-13

    Morin [2-(2,4-dihydroxyphenyl)-3,5,7-trihydroxy-4H-1-benzopyran-4-one], a member of flavonols, is an important bioactive compound by interacting with nucleic acids, enzymes and protein. Its binding to human serum albumin was investigated by fluorescence quenching, fluorescence anisotropy, and UV-vis absorbance under the simulative physiological condition. Fluorescence quenching data show that the interaction of morin with HSA forms a non-fluorescent complex with the binding constants of 1.394 x 10(5), 1.489 x 10(5), 1.609 x 10(5) and 1.717 x 10(5)M(-1) at 292, 298, 303 and 310 K, respectively. The thermodynamics parameters, enthalpy change (DeltaH) and entropy change (DeltaS) were calculated to be 8.97 kJ mol(-1) and 129.15 J mol(-1)K(-1) via van't Hoff equation. From the spectroscopic results and thermodynamics parameters, it is observed that van der Waals and hydrogen bonds are predominant intermolecular forces when forming the complex. The distance r=4.25 nm between donor (Trp214) and accepter (morin) was estimated based on the Förster theory of non-radiative energy transfer. The red shift of UV-vis absorbance shows that morin is bound to several amino acids on the hydrophobic pocket of HSA. Moreover, the competitive probes, such as warfarin and ibuprofen (site I and II probes, respectively), reveal that the binding location of morin to HSA in the site I of the hydrophobic pocket, which corresponds to the results of UV-vis absorbance, while morin also binds other lower affinity binding sites on HSA from the fluorescence anisotropy spectroscopy. PMID:18178358

  4. Novel 7-(dimethylamino)fluorene-based fluorescent probes and their binding to human serum albumin.

    PubMed

    Park, Kwanghee Koh; Park, Joon Woo; Hamilton, Andrew D

    2009-10-21

    A novel solvatochromic fluorescent molecule, 9,9-dibutyl-7-(dimethylamino)-2-fluorenesulfonate 2 was synthesized from 2-nitrofluorene in moderate yield. The fluorescence spectra of 2 and 7-(dimethylamino)-2-fluorenesulfonate 1 shift to shorter wavelengths as the polarity of the medium decreases. Both 1 and 2 bind to hydrophobic sites of human serum albumin (HSA). The apparent binding constants were determined by fluorescence titration to be 0.37 x 10(6) M(-1) for 1 and 2.2 x 10(6) M(-1) for 2. The energy of the Trp-214 fluorescence of HSA is transferred to the HSA-bound fluorophores with near 100% efficiency. The covalent bonding of acrylodan (AC) to Cys-34 has little effect on the binding affinity of 2 to HSA or fluorescent behavior of HSA-bound 2. Bound 2 also has little effect on the fluorescence of AC, but 2-->AC and Trp-214-->2-->AC resonance energy transfers were observed. Competitive binding between the fluorene compounds and other ligands such as 1-anilino-8-naphthalenesulfonate, aspirin, S-(+)-ibuprofen and phenylbutazone were also studied fluorometrically. The results indicated that the primary binding site of 2 to HSA is site II in domain IIIA, whereas 1 binds to site I in domain IIA, but a different region from the phenylbutazone binding site. Because of its large molar absorptivity, strong fluorescence, sensitivity to its environment, and high binding constant to HSA, 2 can be used successfully in the study of proteins and their binding properties. PMID:19795061

  5. Thermodynamic characterization of drug binding to human serum albumin by isothermal titration microcalorimetry.

    PubMed

    Aki, H; Yamamoto, M

    1994-12-01

    Binding sites on human serum albumin (HSA) for anionic drugs and fatty acids have been thermodynamically characterized by microcalorimetry. The binding and the thermodynamic parameters were directly computed from the calorimetric titration data at 37 degrees C in a phosphate buffer (pH 7.4) using one- and two-class binding models. From compensation analyses plotting the molar enthalpy change (delta Hm,i) versus those of the molar free energy (delta Gm,i) and molar entropy (delta Sm,i) for each class of binding sites, HSA binding sites were classified into groups S1, S2, and S3. Group S1 included high-affinity binding sites for site II-bound drugs, such as ibuprofen, flufenamic acid, and ethacrynic acid, and short- or medium-length alkyl-chain fatty acids; group S2 included low-affinity binding sites of site II-bound drugs and long-length alkyl-chain fatty acids; and group S3 contained the high-affinity binding sites for site I-bound drugs, such as phenylbutazone, oxphenbutazone, and warfarin, and long-length alkyl-chain fatty acids. High- and low-affinity bindings sites for salicylic acid and acetylaslicylic acid agreed with the regions of groups S3 and S2, respectively. Groups S1 and S2 were characterized by large negative values of delta Hm,i and delta Sm,i, reflecting van der Waals interaction and hydrogen-bonding formation in low dielectric media, and the main force to stabilize the binding complex in group S3 was a hydrophobic interaction, characterized by a small negative delta Hm,i and minor or positive values of delta Sm,i (entropy-driven). PMID:7891299

  6. Binding of Fatty Acid Amide Amphiphiles to Bovine Serum Albumin: Role of Amide Hydrogen Bonding.

    PubMed

    Ghosh, Subhajit; Dey, Joykrishna

    2015-06-25

    The study of protein-surfactant interactions is important because of the widespread use of surfactants in industry, medicine, and pharmaceutical fields. Sodium N-lauroylsarcosinate (SL-Sar) is a widely used surfactant in cosmetics, shampoos. In this paper, we studied the interactions of bovine serum albumin (BSA) with SL-Sar and sodium N-lauroylglycinate (SL-Gly) by use of a number of techniques, including fluorescence and circular dichroism spectroscopy and isothermal titration calorimetry. The binding strength of SL-Sar is stronger than that of structurally similar SL-Gly, which differs only by the absence of a methyl group in the amide nitrogen atom. Also, these two surfactants exhibit different binding patterns with the BSA protein. The role of the amide bond and hence the surfactant headgroup in the binding mechanism is discussed in this paper. It was observed that while SL-Sar destabilized, SL-Gly stabilized the protein structure, even at concentrations less than the critical micelle concentration (cmc) value. The thermodynamics of surfactant binding to BSA was studied by use of ITC. From the ITC results, it is concluded that three molecules of SL-Sar in contrast to only one molecule of SL-Gly bind to BSA in one set of binding sites at room temperature. However, on increasing temperature four molecules of SL-Gly bind to the BSA through H-bonding and van der Waals interactions, due to loosening of the BSA structure. In contrast, with SL-Sar the binding process is enthalpy driven, and very little structural change of BSA was observed at higher temperature. PMID:26023820

  7. Pancreatic islet purification using bovine serum albumin: the importance of density gradient temperature and osmolality.

    PubMed

    Chadwick, D R; Robertson, G S; Toomey, P; Contractor, H; Rose, S; James, R F; Bell, P R; London, N J

    1993-01-01

    Euro-Ficoll and bovine serum albumin (BSA) are two of the most commonly used density gradient media for the purification of pancreatic islets. Euro-Ficoll is based upon Euro-Collins, a cold storage medium, and must, therefore, be used at 4 degrees C. The ionic composition of BSA, however, is likely to contribute to hypothermic cellular swelling, and this may influence the efficiency of islet purification using this medium at 4 degrees C. Experience in this laboratory also suggested that batch-to-batch variation in islet purity using BSA was related to differences in BSA osmolality. The aim of this study was to assess the effect of gradient medium temperature and osmolality on the purification of human and porcine islets using BSA. Pancreata were collagenase-digested, and islets were purified on continuous linear density gradients of BSA. The distribution of insulin and amylase in each gradient was assayed, and used to calculate the median density of islets and exocrine tissue, and the efficiency of islet purification (% amylase contamination at a fixed insulin yield), using: 1) gradient osmolalities of 300, 400, and 500 mOsm/kg H2O (seven porcine pancreata), and 2) gradients at 4 degrees C and at 22 degrees C (eight human and seven porcine pancreata). Increase in density gradient osmolality produced increases in porcine exocrine tissue density which exceeded changes in islet density, resulting in improved islet purity, maximal at a BSA osmolality of 400 mOsm/kg H2O. For human pancreata there was no significant change in pancreatic tissue densities nor islet purity with temperature.(ABSTRACT TRUNCATED AT 400 WORDS) PMID:7512874

  8. [Modification on the interaction of glipizide with bovine serum albumin by molecular spectroscopy].

    PubMed

    Liu, Bao-Sheng; Cao, Shi-Na; Li, Zhi-Yun; Chong, Bao-Hong

    2014-03-01

    In the Tris-HCl buffer solution with pH was 7.40, the interaction between glipizide (Gli) and bovine serum albumin (BSA) was investigated by classical fluorescence spectroscopy with the change of protein as investigation object and elastic scattering fluorescence spectrometry with the change of drugs as investigation object at 293 K and 303 K, the conclusions of the two methods were consistent. Results showed that Gli could quench the intrinsic fluorescence of BSA, and the quenching mechanism was a dynamic quenching process. The hydrophobic force played an important role in the conjugation reaction between BSA and Gli, the binding site mainly located in BSA hydrophobic region and the number of binding site (n) in the binary system was approximately to 1. The values of Hill's coefficients were less than 1, which indicated the weak negative cooperativity in BSA-Gli system. The binding constant (Ka) obtained by elastic scattering fluorescence spectrometric was much larger than the one obtained by classical fluorescence spectroscopy, indiciating that it was more accurate and reasonable when using the change of drug's fluorescence as the research object. At last, the scientificalness of the new method based on elastic scattering fluorescence spectrometric was verified by ultraviolet spectroscopy. The research results showed that there existed insufficiency in analysis of the interaction of drug with protein by classical fluorescence spectroscopy with the change of protein as investigation object, and the fluorescence spectrogram only reflected partial information of the interaction between drug and protein, while the interaction between drug and protein could be better expressed by elastic scattering fluorescence spectrometry with the change of drugs as investigation object. PMID:25208408

  9. Spectroscopic characterization of the binding mechanism of fluorescein and carboxyfluorescein in human serum albumin

    NASA Astrophysics Data System (ADS)

    Sulaiman, Saba A. J.; Kulathunga, H. Udani; Abou-Zied, Osama K.

    2015-03-01

    Fluorescein (FL) and some of its precursors have proven to be effective fluorescent tracers in pharmaceutical and medical applications owing to their high quantum yield of fluorescence in physiological conditions and their high membrane permeability. In order to protect FL from metabolic effects during the process of its delivery, human serum albumin (HSA) has been used as a carrier because of its compatibility with the human body. In the present work, we used spectroscopic methods to characterize the binding mechanisms of FL and one of its derivatives, 5(6)- carboxyfluorescein (CFL), in the HSA protein. The absorbance change of the two ligands (FL and CFL) was quantified as a function of the HSA concentration and the results indicate a moderate binding strength for the two ligands inside HSA (1.00 +/- 0.12 x 104 M-1). The quenching effect of FL(CFL) on the fluorescence intensity of W214 (the sole tryptophan in HSA) indicates that FL and CFL occupy Site I in the protein which is known to bind several hydrophobic drugs. By performing site-competitive experiments, the location of the ligands is determined to be similar to that of the anticoagulant drug warfarin. At higher ratios of [ligand]/[HSA], we observed an upward curvature in the Stern-Volmer plots which indicates that the ligands occupy more pockets in Site I, close to W214. Our results indicate that both ligands bind in HSA with a moderate strength that should not affect their release when used as fluorescent reporters. The chemical and physical identities of the two ligands are also preserved inside the HSA binding sites.

  10. A mixed-mode resin with tryptamine ligand for human serum albumin separation.

    PubMed

    Wu, Qi-Ci; Lin, Dong-Qiang; Shi, Wei; Zhang, Qi-Lei; Yao, Shan-Jing

    2016-01-29

    Mixed-mode chromatography (MMC) is a new technology that uses specially-designed ligands to improve the adsorption selectivity with multimodal protein-ligand interactions for protein separation. A new MMC resin TA-B-6FF with tryptamine as the functional ligand was prepared and used for human serum albumin (HSA) separation. Adsorption equilibria of plasma-derived HSA (pHSA) were investigated and compared with a commercial tryptophan-based resin (MX-Trp-650m), and the influence of pH and salt addition was studied. The results showed that weak acidic conditions (pH 5.0-7.0) were favorable for HSA adsorption. The maximum adsorption capacity of TA-B-6FF was 141.33mg/g at pH 5.0, which was two times higher than that of MX-Trp-650m. TA-B-6FF also showed better salt-tolerance than MX-Trp-650m. Moreover, TA-B-6FF was used to separate recombinant HSA (rHSA) from Pichia pastoris culture broth. The results indicated that rHSA could be directly captured by TA-B-6FF without dilution or pH adjustment. High purity (87.75%) of rHSA monomer could be obtained with a recovery of 98.53% through two-step elution process. Total content of rHSA monomer and degraded fragment was 99.75%, the removal of host cell proteins reached about 90%. The results demonstrate that new TA-B-6FF resin has a great potential for rHSA purification directly from the complex fermentation broth. PMID:26772961

  11. Study on the interaction of catechins with human serum albumin using spectroscopic and electrophoretic techniques

    NASA Astrophysics Data System (ADS)

    Trnková, Lucie; Boušová, Iva; Staňková, Veronika; Dršata, Jaroslav

    2011-01-01

    The interaction between eight naturally occurring flavanols (catechin, epicatechin, gallocatechin, epigallocatechin, catechin gallate, epicatechin gallate, gallocatechin gallate, and epigallocatechin gallate) and human serum albumin (HSA) has been investigated by spectroscopic (fluorescence quenching and UV-Vis absorption) and electrophoretic (native and SDS PAGE) techniques under simulated physiological conditions (pH 7.40, 37 °C). The spectroscopic results confirmed the complex formation for the tested systems. The binding constants and the number of binding sites were obtained by analysis of fluorescence data. The strongest binding affinity to HSA was found for epicatechin gallate and decreased in the order epicatechin gallate ⩾ catechin gallate > epigallocatechin gallate > gallocatechin gallate ≫ epicatechin ⩾ catechin > gallocatechin ⩾ epigallocatechin. All free energy changes possessed negative sign indicating the spontaneity of catechin-HSA systems formation. The binding distances between the donor (HSA) and the acceptors (catechins) estimated by the Förster theory revealed that non-radiation energy transfer from HSA to catechins occurred with high possibility. According to results obtained by native PAGE, the galloylated catechins increased the electrophoretic mobility of HSA, which indicated the change in the molecular charge of HSA, whilst the non-galloylated catechins caused no changes. The ability of aggregation and cross-linking of tested catechins with HSA was not proved by SDS-PAGE. The relationship between the structure characteristics of all tested catechins (e.g. presence of the galloyl moiety on the C-ring, the number of hydroxyl groups on the B-ring, and the spatial arrangement of the substituents on the C-ring) and their binding properties to HSA is discussed. The presented study contributes to the current knowledge in the area of protein-ligand binding, particularly catechin-HSA interactions.

  12. Adsorption of Bovine Serum Albumin (BSA) at the Oil/Water Interface: A Neutron Reflection Study.

    PubMed

    Campana, M; Hosking, S L; Petkov, J T; Tucker, I M; Webster, J R P; Zarbakhsh, A; Lu, J R

    2015-05-26

    The structure of the adsorbed protein layer at the oil/water interface is essential to the understanding of the role of proteins in emulsion stabilization, and it is important to glean the mechanistic events of protein adsorption at such buried interfaces. This article reports on a novel experimental methodology for probing protein adsorption at the buried oil/water interface. Neutron reflectivity was used with a carefully selected set of isotopic contrasts to study the adsorption of bovine serum albumin (BSA) at the hexadecane/water interface, and the results were compared to those for the air/water interface. The adsorption isotherm was determined at the isoelectric point, and the results showed that a higher degree of adsorption could be achieved at the more hydrophobic interface. The adsorbed BSA molecules formed a monolayer on the aqueous side of the interface. The molecules in this layer were partially denatured by the presence of oil, and once released from the spatial constraint by the globular framework they were free to establish more favorable interactions with the hydrophobic medium. Thus, a loose layer extending toward the oil phase was clearly observed, resulting in an overall broader interface. By analogy to the air/water interface, as the concentration of BSA increased to 1.0 mg mL(-1) a secondary layer extending toward the aqueous phase was observed, possibly resulting from the steric repulsion upon the saturation of the primary monolayer. Results clearly indicate a more compact arrangement of molecules at the oil/water interface: this must be caused by the loss of the globular structure as a consequence of the denaturing action of the hexadecane. PMID:25875917

  13. Disulfide-bond scrambling promotes amorphous aggregates in lysozyme and bovine serum albumin.

    PubMed

    Yang, Mu; Dutta, Colina; Tiwari, Ashutosh

    2015-03-12

    Disulfide bonds are naturally formed in more than 50% of amyloidogenic proteins, but the exact role of disulfide bonds in protein aggregation is still not well-understood. The intracellular reducing agents and/or improper use of antioxidants in extracellular environment can break proteins disulfide bonds, making them unstable and prone to misfolding and aggregation. In this study, we report the effect of disulfide-reducing agent dithiothreitol (DTT) on hen egg white lysozyme (lysozyme) and bovine serum albumin (BSA) aggregation at pH 7.2 and 37 °C. BSA and lysozyme proteins treated with disulfide-reducing agents form very distinct amorphous aggregates as observed by scanning electron microscope. However, proteins with intact disulfide bonds were stable and did not aggregate over time. BSA and lysozyme aggregates show unique but measurable differences in 8-anilino-1-naphthalenesulfonic acid (ANS) and 4,4'-dianilino-1,1'-binaphthyl-5,5'-disulfonic acid (bis-ANS) fluorescence, suggesting a loose and flexible aggregate structure for lysozyme but a more compact aggregate structure for BSA. Scrambled disulfide-bonded protein aggregates were observed by nonreducing sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) for both proteins. Similar amorphous aggregates were also generated using a nonthiol-based reducing agent, tris(2-carboxyethyl)phosphine (TCEP), at pH 7.2 and 37 °C. In summary, formation of distinct amorphous aggregates by disulfide-reduced BSA and lysozyme suggests an alternate pathway for protein aggregation that may be relevant to several proteins. PMID:25689578

  14. Identification of dityrosine cross-linked sites in oxidized human serum albumin.

    PubMed

    Annibal, Andrea; Colombo, Graziano; Milzani, Aldo; Dalle-Donne, Isabella; Fedorova, Maria; Hoffmann, Ralf

    2016-04-15

    Reactive oxygen species (ROS) can oxidize virtually all cellular components. In proteins cysteine, methionine, tryptophan, and tyrosine residues are most prone to oxidation and their oxidized forms are thus considered as biomarkers of oxidative protein damages. Ultraviolet radiation and some endogenous ROS can produce tyrosine radicals reacting with other tyrosine residues yielding intra- or intermolecular cross-links in proteins. These 3,3'-dityrosines can be quantified by their characteristic fluorescence, but analytical methods to identify the modification sites in proteins are still missing. Although mass spectrometry (MS) is routinely used to map other post-translational modifications, the analysis of dityrosines is challenged by simultaneous fragmentations of both cross-linked peptide chains producing complex tandem mass spectra. Additionally, the fragmentation patterns differ from linear peptides. Here, we studied the fragmentation behavior of dityrosine cross-linked peptides obtained by incubating three peptides (AAVYHHFISDGVR, TEVSSNHVLIYLDK, and LVAYYTLIGASGQR) with horseradish peroxidase in the presence of hydrogen peroxide. Homo- and hetero-dimerization via dityrosine was monitored by fluorescence spectroscopy and MS. The fragmentation characteristics of dityrosine-linked peptides were studied on an ESI-LTQ-Orbitrap-MS using collision induced dissociation, which allowed localizing the cross-linked positions and provided generic rules to identify this oxidative modification. When human serum albumin oxidized with 50-fold molar excess of HOCl in phosphate buffer saline was analyzed by nanoRPC-ESI-MS/MS, an automatic database search considering all possible (in-silico generated) tyrosine-containing peptides as dynamic modifications revealed four different types of oxidatively modified tyrosine residues including dityrosines linking ten different Tyr residues. The automatic database search was confirmed by manual interpretation of each tandem mass spectrum

  15. Deciphering the binding patterns and conformation changes upon the bovine serum albumin-rosmarinic acid complex.

    PubMed

    Peng, Xin; Wang, Xiangchao; Qi, Wei; Huang, Renliang; Su, Rongxin; He, Zhimin

    2015-08-01

    Rosmarinic acid (RA) is an importantly and naturally occurring polyphenol from plants of the mint family with potent biological activities. Here, the in vitro interaction of RA with bovine serum albumin (BSA) has been investigated using various biophysical approaches as well as molecular modeling methods, to ascertain its binding mechanism and conformational changes. The fluorescence results demonstrated that the fluorescence quenching of BSA by RA was mainly the result of the formation of a ground state BSA-RA complex, and BSA had one high affinity RA binding site with a binding constant of 4.18 × 10(4) mol L(-1) at 298 K. Analysis of thermodynamic parameters revealed that hydrophobic and hydrogen bond interactions were the dominant intermolecular force in the complex formation. The primary binding site of RA in BSA (site I) had been identified by site marker competitive experiments. The distance between RA and the tryptophan residue of BSA was evaluated at 3.12 nm based on Förster's theory of non-radiation energy transfer. The UV-vis absorption, synchronous fluorescence, three-dimensional fluorescence, 8-anilino-1-naphthalenesulfonic acid (ANS) fluorescence, circular dichroism (CD), and Fourier transform infrared (FT-IR) spectra confirmed that the conformation and structure of BSA were altered in the presence of RA. Moreover, the nuclear magnetic spectroscopy showed that the aromatic groups of RA took part in the binding reaction during the BSA-RA complexation. In addition, the molecular picture of the interaction mechanism between BSA and RA at the atomic level was well examined by molecular docking and dynamics studies. In brief, RA can bind to BSA with noncovalent bonds in a relatively stable way, and these findings will be beneficial to the functional food research of RA. PMID:26146359

  16. Hypohalous acid-modified human serum albumin induces neutrophil NADPH oxidase activation, degranulation, and shape change.

    PubMed

    Gorudko, Irina V; Grigorieva, Daria V; Shamova, Ekaterina V; Kostevich, Valeria A; Sokolov, Alexey V; Mikhalchik, Elena V; Cherenkevich, Sergey N; Arnhold, Jürgen; Panasenko, Oleg M

    2014-03-01

    Halogenated lipids, proteins, and lipoproteins formed in reactions with myeloperoxidase (MPO)-derived hypochlorous acid (HOCl) and hypobromous acid (HOBr) can contribute to the regulation of functional activity of cells and serve as mediators of inflammation. Human serum albumin (HSA) is the major plasma protein target of hypohalous acids. This study was performed to assess the potency of HSA modified by HOCl (HSA-Cl) and HOBr (HSA-Br) to elicit selected neutrophil responses. HSA-Cl/Br were found to induce neutrophil degranulation, generation of reactive oxygen intermediates, shape change, and actin cytoskeleton reorganization. Thus HSA-Cl/Br can initially act as a switch and then as a feeder of the "inflammatory loop" under oxidative stress. In HSA-Cl/Br-treated neutrophils, monoclonal antibodies against CD18, the β subunit of β2 integrins, reduced the production of superoxide anion radicals and hydrogen peroxide as well as MPO exocytosis, suggesting that CD18 contributed to neutrophil activation. HSA-Cl/Br-induced neutrophil responses were also inhibited by genistein, a broad-specificity tyrosine kinase inhibitor, and wortmannin, a phosphoinositide 3-kinase (PI3K) inhibitor, supporting the notion that activation of both tyrosine kinase and PI3K may play a role in neutrophil activation by HSA modified in MPO-dependent reactions. These results confirm the hypothesis that halogenated molecules formed in vivo via MPO-dependent reactions can be considered as a new class of biologically active substances potentially able to contribute to activation of myeloid cells in sites of inflammation and serve as inflammatory response modulators. PMID:24384524

  17. Bovine serum albumin-confined silver nanoclusters as fluorometric probe for detection of biothiols.

    PubMed

    Chen, Zhen; Lu, Dongtao; Cai, Zongwei; Dong, Chuan; Shuang, Shaomin

    2014-11-01

    Fluorescent bovine serum albumin-confined silver nanoclusters (BSA-AgNCs) were demonstrated to be a novel and environmentally friendly probe for the rapid detection of biothiols such as cysteine (Cys), homocysteine (Hcy) and glutathione (GSH). The sensing was ascribed to the strong affinity between the mercapto group of the biothiols and the silver nanoclusters. The fluorescence intensity of BSA-AgNCs was quenched efficiently on increasing the concentration of biothiol, corresponding with a red-shift in emission wavelength. However, the fluorescence of the silver nanoclusters was almost unchanged in the presence of other α-amino acids at 10-fold higher concentrations. By virtue of this specific response, a new, simple and rapid fluorescent method for detecting biothiols has been developed. The linear ranges for Cys, Hcy and GSH were 2.0 × 10(-6) to 9.0 × 10(-5) M (R(2) = 0.994), 2.0 × 10(-6) to 1.2 × 10(-4) M (R(2) = 0.996) and 1.0 × 10(-5) to 8.0 × 10(-5) M (R(2) = 0.980), respectively. The detection limits were 8.1 × 10(-7) M for Cys, 1.0 × 10(-6) M for Hcy and 1.1 × 10(-6) M for GSH. Our proposed method was successfully applied to the determination of thiols in human plasma and the recovery was 94.83-105.24%. It is potentially applicable to protein-stabilized silver nanoclusters in a chemical or biochemical sensing system. PMID:24403131

  18. Bovine Serum Albumin Adsorption in Mesoporous Titanium Dioxide: Pore Size and Pore Chemistry Effect.

    PubMed

    Liu, Chang; Guo, Yanhua; Hong, Qiliang; Rao, Chao; Zhang, Haijuan; Dong, Yihui; Huang, Liangliang; Lu, Xiaohua; Bao, Ningzhong

    2016-04-26

    Understanding the mechanism of protein adsorption and designing materials with high sensitivity, high specificity and fast response are critical to develop the next-generation biosensing and diagnostic platforms. Mesoporous materials with high surface area, tunable pores, and good thermal/hydrostatic stabilities are promising candidates in this field. Because of the excellent biocompatibility, titanium dioxide has received an increasing interest in the past decade for biomedical applications. In this work, we synthesized mesoporous titanium dioxide with controlled pore sizes (7.2-28.0 nm) and explored their application for bovine serum albumin (BSA) adsorption. Scanning electron microscopy (SEM), X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and nitrogen adsorption/desorption experiments were performed to characterize the mesoporous TiO2 samples before and after BSA adsorption. Isothermal microcalorimetry was applied to measure both the adsorption heat and conformation rearrangement heat of BSA in those mesopores. We also carried out thermogravimetry measurements to qualitatively estimate the concentration of hydroxyl groups, which plays an important role in stabilizing BSA in-pore adsorption. The adsorption stability was also examined by leaching experiments. The results showed that TiO2 mesopores can host BSA adsorption when their diameters are larger than the hydrodynamic size of BSA (∼9.5 nm). In larger mesopores studied, two BSA molecules were adsorbed in the same pores. In contrast to the general understanding that large mesopores demonstrate poor stabilities for protein adsorptions, the synthesized mesoporous TiO2 samples demonstrated good leaching stabilities for BSA adsorption. This is probably due to the combination of the mesoporous confinement and the in-pore hydroxyl groups. PMID:27048991

  19. Structural analysis of peptide fragments following the hydrolysis of bovine serum albumin by trypsin and chymotrypsin.

    PubMed

    Özyiğit, İbrahim Ethem; Akten, E Demet; Pekcan, Önder

    2016-05-01

    Peptide bond hydrolysis of bovine serum albumin (BSA) by chymotrypsin and trypsin was investigated by employing time-resolved fluorescence spectroscopy. As a fluorescent cross-linking reagent, N-(1-pyrenyl) maleimide (PM) was attached to BSA, through all free amine groups of arginine, lysine, and/or single free thiol (Cys34). Time-resolved fluorescence spectroscopy was used to monitor fluorescence decays analyzed by exponential series method to obtain the changes in lifetime distributions. After the exposure of synthesized protein substrate PM-BSA to chymotrypsin and trypsin, it is observed that each protease produced a distinct change in the lifetime distribution profile, which was attributed to distinct chemical environments created by short peptide fragments in each hydrolysate. The persistence of excimer emission at longer lifetime regions for chymotrypsin, as opposed to trypsin, suggested the presence of small-scale hydrophobic clusters that might prevent some excimers from being completely quenched. It is most likely that the formation of these clusters is due to hydrophobic end groups of peptide fragments in chymotrypsin hydrolysate. A similar hydrophobic shield was not suggested for trypsin hydrolysis, as the end groups of peptide fragments would be either arginine or lysine. Overall, in case the target protein's 3D structure is known, the structural analysis of possible excimer formation presented here can be used as a tool to explain the differences in activity between two proteases, i.e. the peak's intensity and location in the profile. Furthermore, this structural evaluation might be helpful in obtaining the optimum experimental conditions in order to generate the highest amount of PM-BSA complexes. PMID:26169062

  20. Optimization of human serum albumin monoliths for chiral separations and high-performance affinity chromatography.

    PubMed

    Pfaunmiller, Erika L; Hartmann, Mahli; Dupper, Courtney M; Soman, Sony; Hage, David S

    2012-12-21

    Various organic-based monoliths were prepared and optimized for immobilization of the protein human serum albumin (HSA) as a binding agent for chiral separations and high-performance affinity chromatography. These monoliths contained co-polymers based on glycidyl methacrylate (GMA) and ethylene glycol dimethacrylate (EDMA) or GMA and trimethylolpropane trimethacrylate (TRIM). A mixture of cyclohexanol and 1-dodecanol was used as the porogen, with the ratio of these solvents being varied along with the polymerization temperature to generate a library of monoliths. These monoliths were used with both the Schiff base and epoxy immobilization methods and measured for their final content of HSA. Monoliths showing the highest protein content were further evaluated in chromatographic studies using R/S-warfarin and d/l-tryptophan as model chiral solutes. A 2.6-2.7-fold increase in HSA content was obtained in the final monoliths when compared to similar HSA monoliths prepared according to the literature. The increased protein content made it possible for the new monoliths to provide higher retention and/or two-fold faster separations for the tested solutes when using 4.6mm i.d.× 50 mm columns. These monoliths were also used to create 4.6mm i.d.× 10 mm HSA microcolumns that could separate the same chiral solutes in only 1.5-6.0 min. The approaches used in this study could be extended to the separation of other chiral solutes and to the optimization of organic monoliths for use with additional proteins as binding agents. PMID:23010249

  1. Bovine Serum Albumin Glutaraldehyde for Completely Sutureless Laparoscopic Heminephrectomy in a Survival Porcine Model

    PubMed Central

    Gamboa, Aldrin Joseph R.; Kaplan, Adam G.; Khosravi, Amanda; Truong, Hung; Andrade, Lorena; Lin, Rachelle; Alipanah, Reza; Ortiz, Cervando; McCormick, David; Box, Geoffrey N.; Lee, Hak J.; Deane, Leslie A.; Edwards, Robert A.; McDougall, Elspeth M.; Clayman, Ralph V.

    2010-01-01

    Abstract Introduction Laparoscopic partial nephrectomy (LPN) has not received widespread clinical application because of its technical challenge. Bovine serum albumin glutaraldehyde (BSAG) is a hemostatic agent that is independent of the clotting cascade. We evaluated the use of BSAG as the sole agent for parenchymal and collecting system closure during LPN in a survival porcine model. Methods Eighteen pigs underwent hilar clamping and LPN by longitudinal excision of the lateral one-third of the right kidney. The opened collecting system was covered with oxidized cellulose to prevent BSAG seepage into the urinary tract. BSAG was allowed to set for 10 or 5 minutes. Twelve animals underwent survival LPN BSAG only closure; six control pigs were acutely studied using saline. Urinary extravasation was evaluated by injection of furosemide and indigo carmine, and then evaluating the renal surface and bladder catheter drainage for dye. A subjective bleeding score was assigned after hilum unclamping. At 6 weeks, BSAG kidneys were harvested for burst pressure testing and histopathological analysis. Results All 12 pigs survived for 6 weeks. No pigs had urinary extravasation. Mean percentage of kidney removed by weight was 19%. Mean warm ischemia time was 29 minutes. Five pigs required a second BSAG application to achieve a bleeding score of 0. Mean arterial and collecting system burst pressures were 301.8 and 322.4 mm Hg, respectively. Mean postoperative creatinine increase was 0.07 mg/dL. Conclusion BSAG for completely sutureless LPN in a survival porcine model was feasible. PMID:20059350

  2. Study of the interaction of C60 fullerene with human serum albumin in aqueous solution

    SciTech Connect

    Li, Song; Zhao, Xiongce; Mo, Yiming; Cummings, Peter T; Heller, William T

    2013-01-01

    Concern about the toxicity of engineered nanoparticles, such as the prototypical nanomaterial C60 fullerene, continues to grow. While evidence continues to mount that C60 and its derivatives may pose health hazards, the specific molecular interactions of these particles with biological macromolecules require further investigation. To better understand the interaction of C60 with proteins, the protein human serum albumin (HSA) was studied in solution with C60 at C60:HSA molar ratios ranging from 1:2 to 4:1. HSA is the major protein component of blood plasma and plays a role in a variety of functions, such as the maintenance of blood pH and pressure. The C60-HSA interaction was probed by a combination of circular dichroism (CD) spectroscopy, small-angle neutron scattering (SANS) and atomistic molecular dynamics (MD) simulations to understand C60-driven changes in the structure of HSA in solution. The CD spectroscopy demonstrates that the secondary structure of the protein decreases in -helical content in response to the presence of C60. Similarly, C60 produces subtle changes in the solution conformation of HSA, as evidenced by the SANS data and MD. The data do not indicate that C60 is causing a change in the oligomerization state of the protein. Taken together results demonstrate that C60 interacts with HSA, but it does not strongly perturb the structure of the protein by unfolding it or inducing aggregation, suggesting a mechanism for transporting C60 throughout the body to accumulate in various tissues.

  3. DNA damaging, cell cytotoxicity and serum albumin binding efficacy of the rutin-Cu(ii) complex.

    PubMed

    Roy, Atanu Singha; Tripathy, Debi Ranjan; Samanta, Sintu; Ghosh, Sudip K; Dasgupta, Swagata

    2016-04-26

    Flavonoids are widely used as anti-oxidants, anti-cancer agents and possess metal ion chelation properties. In this report we have investigated the DNA binding (and damaging), cell cytotoxicity and serum albumin (SA) binding efficacy of the rutin-Cu(ii) complex using differential spectroscopic methods. The rutin-Cu(ii) complex was able to intercalate into calf thymus DNA (ct-DNA) at lower concentrations and its DNA damaging properties were also confirmed from the agarose gel based assay, fluorescence and UV-vis studies. The copper complex was found to be effective against the growth of HeLa cells in vivo. The binding constants (Kb) of the rutin-Cu(ii) complex towards HSA and BSA were found to be (0.98 ± 0.03) and (1.05 ± 0.02) × 10(5) M(-1), respectively, at 299 K and observed to increase with the increase in temperature. Site selectivity studies revealed that the rutin-Cu(ii) complex binds near site 1 (subdomain IIA) of SAs. Thermodynamic parameters indicated that the mode of interaction of rutin and its copper complex with SAs are different from each other. Both ΔH° and ΔS° were observed to be positive for the interaction of the rutin-Cu(ii) complex with SAs, indicating the presence of hydrophobic association in binding. The values of ΔH° were estimated to be negative (-42.07 ± 2.92 and -23.29 ± 2.33 kJ mol(-1) for HSA and BSA respectively) in the binding of rutin with SAs. It implies that after chelation with Cu(ii) ion, rutin alters its binding mode which could have varying applications to its other physicochemical activities. PMID:27035097

  4. Characterization of the binding of an anticancer drug, lapatinib to human serum albumin.

    PubMed

    Kabir, Md Zahirul; Mukarram, Abdul Kadir; Mohamad, Saharuddin B; Alias, Zazali; Tayyab, Saad

    2016-07-01

    Interaction of a promising anticancer drug, lapatinib (LAP) with the major transport protein in human blood circulation, human serum albumin (HSA) was investigated using fluorescence and circular dichroism (CD) spectroscopy as well as molecular docking analysis. LAP-HSA complex formation was evident from the involvement of static quenching mechanism, as revealed by the fluorescence quenching data analysis. The binding constant, Ka value in the range of 1.49-1.01×10(5)M(-1), obtained at three different temperatures was suggestive of the intermediate binding affinity between LAP and HSA. Thermodynamic analysis of the binding data (∆H=-9.75kJmol(-1) and ∆S=+65.21Jmol(-1)K(-1)) suggested involvement of both hydrophobic interactions and hydrogen bonding in LAP-HSA interaction, which were in line with the molecular docking results. LAP binding to HSA led to the secondary and the tertiary structural alterations in the protein as evident from the far-UV and the near-UV CD spectral analysis, respectively. Microenvironmental perturbation around Trp and Tyr residues in HSA upon LAP binding was confirmed from the three-dimensional fluorescence spectral results. LAP binding to HSA improved the thermal stability of the protein. LAP was found to bind preferentially to the site III in subdomain IB on HSA, as probed by the competitive drug displacement results and supported by the molecular docking results. The effect of metal ions on the binding constant between LAP and HSA was also investigated and the results showed a decrease in the binding constant in the presence of these metal ions. PMID:27128364

  5. Exploring the interaction between picoplatin and human serum albumin: The effects on protein structure and activity.

    PubMed

    Wang, Yanqing; Wu, Peirong; Zhou, Xinchun; Zhang, Hongmei; Qiu, Ligan; Cao, Jian

    2016-09-01

    For the first time, the effects of picoplatin on the structure and esterase-like catalytic activity of human serum albumin (HSA) have been investigated by spectroscopic approaches and molecular modeling. The circular dichroism (CD) spectral examinations indicated that the binding of picoplatin with HSA induced a slight decrease of a-helix content of protein and unfolded the constituent polypeptides of the protein. The synchronous fluorescence and three-dimensional fluorescence spectral methods were used to estimate the effect of picoplatin on the micro-environmental changes of the Trp and Tyr residues of HSA, indicating that the micro-environment around the Tyr and Trp residue is partly disturbed by picoplatin. UV-vis absorption spectral result indicated the formation of the ground state complex between picoplatin with HSA. The ANS binding assay indicated the existence of competitive combination of picoplatin and ANS with HSA. The studies on the effects of picoplatin on the binding of HSA with bilirubin and heme showed that picoplatin binding caused a change of angle between two chromophores of bound bilirubin and the binding site of picoplatin does not locate in subdomain IB in HSA that bound with heme. The molecular modeling results showed that picoplatin binds to the connection between domain I and domain II by hydrophobic, hydrogen bonds, and van der Waals forces. In addition, HSA maintains most of its esterase activity in the presence of picoplatin. The investigations on how picoplatin interacts with HSA are important for the understanding of the anticancer mechanism and toxicity of platinum-based anticancer drug. PMID:27484966

  6. Binding of an anticancer drug, axitinib to human serum albumin: Fluorescence quenching and molecular docking study.

    PubMed

    Tayyab, Saad; Izzudin, Mohamad Mirza; Kabir, Md Zahirul; Feroz, Shevin R; Tee, Wei-Ven; Mohamad, Saharuddin B; Alias, Zazali

    2016-09-01

    Binding characteristics of a promising anticancer drug, axitinib (AXT) to human serum albumin (HSA), the major transport protein in human blood circulation, were studied using fluorescence, UV-vis absorption and circular dichroism (CD) spectroscopy as well as molecular docking analysis. A gradual decrease in the Stern-Volmer quenching constant with increasing temperature revealed the static mode of the protein fluorescence quenching upon AXT addition, thus confirmed AXT-HSA complex formation. This was also confirmed from alteration in the UV-vis spectrum of HSA upon AXT addition. Fluorescence quenching titration results demonstrated moderately strong binding affinity between AXT and HSA based on the binding constant value (1.08±0.06×10(5)M(-1)), obtained in 10mM sodium phosphate buffer, pH7.4 at 25°C. The sign and magnitude of the enthalpy change (∆H=-8.38kJmol(-1)) as well as the entropy change (∆S=+68.21Jmol(-1)K(-1)) clearly suggested involvement of both hydrophobic interactions and hydrogen bonding in AXT-HSA complex formation. These results were well supported by molecular docking results. Three-dimensional fluorescence spectral results indicated significant microenvironmental changes around Trp and Tyr residues of HSA upon complexation with AXT. AXT binding to the protein produced significant alterations in both secondary and tertiary structures of HSA, as revealed from the far-UV and the near-UV CD spectral results. Competitive drug displacement results obtained with phenylbutazone (site I marker), ketoprofen (site II marker) and hemin (site III marker) along with molecular docking results suggested Sudlow's site I, located in subdomain IIA of HSA, as the preferred binding site of AXT. PMID:27424099

  7. Binding of naproxen enantiomers to human serum albumin studied by fluorescence and room-temperature phosphorescence

    NASA Astrophysics Data System (ADS)

    Lammers, Ivonne; Lhiaubet-Vallet, Virginie; Ariese, Freek; Miranda, Miguel A.; Gooijer, Cees

    2013-03-01

    The interaction of the enantiomers of the non-steroidal anti-inflammatory drug naproxen (NPX) with human serum albumin (HSA) has been investigated using fluorescence and phosphorescence spectroscopy in the steady-state and time-resolved mode. The absorption, fluorescence excitation, and fluorescence emission spectra of (S)-NPX and (R)-NPX differ in shape in the presence of HSA, indicating that these enantiomers experience a different environment when bound. In solutions containing 0.2 M KI, complexation with HSA results in a strongly increased NPX fluorescence intensity and a decreased NPX phosphorescence intensity due to the inhibition of the collisional interaction with the heavy atom iodide. Fluorescence intensity curves obtained upon selective excitation of NPX show 8-fold different slopes for bound and free NPX. No significant difference in the binding constants of (3.8 ± 0.6) × 105 M-1 for (S)-NPX and (3.9 ± 0.6) × 105 M-1 for (R)-NPX was found. Furthermore, the addition of NPX quenches the phosphorescence of the single tryptophan in HSA (Trp-214) based on Dexter energy transfer. The short-range nature of this mechanism explains the upward curvature of the Stern-Volmer plot observed for HSA: At low concentrations NPX binds to HSA at a distance from Trp-214 and no quenching occurs, whereas at high NPX concentrations the phosphorescence intensity decreases due to dynamic quenching by NPX diffusing into site I from the bulk solution. The dynamic quenching observed in the Stern-Volmer plots based on the longest phosphorescence lifetime indicates an overall binding constant to HSA of about 3 × 105 M-1 for both enantiomers.

  8. Physiologically relevant plasma d,l-homocysteine concentrations mobilize Cd from human serum albumin.

    PubMed

    Sagmeister, Peter; Gibson, Matthew A; McDade, Kyle H; Gailer, Jürgen

    2016-08-01

    Although low-level chronic exposure of humans to cadmium (Cd(2+)) can result in a variety of adverse health effects, little is known about the role that its interactions with plasma proteins and small molecular weight (SMW) ligands in the bloodstream may play in delivering this metal to its target organs. To gain insight, a Cd-human serum albumin (HSA) 1:1 (molar ratio) complex was analyzed by size exclusion chromatography (SEC) coupled on-line to a flame atomic absorption spectrometer (FAAS). Using a phosphate buffered saline (PBS)-buffer mobile phase, the stability of the Cd-HSA complex was investigated in the presence of 2.0mM of SMW ligands, including taurine, acetaminophen, l-methionine, l-cysteine (Cys), d,l-homocysteine (hCys) or l-cysteine methyl-ester (Cys-Me). While taurine, acetaminophen and l-methionine did not affect its integrity, Cys, hCys and Cys-Me completely abstracted Cd from HSA. Subsequent investigations into the effect of 1.5, 1.0 and 0.5mM Cys and hCys on the integrity of the Cd-HSA complex revealed clear differences with regard to the nature of the eluting SMW-Cd species between these structurally related endogenous thiols. Interestingly, the Cd-specific chromatograms that were obtained for 0.5mM hCys revealed the elution of an apparent mixture of the parent Cd-HSA complex with a significant contribution of a structurally uncharacterized CdxhCysy species. Since this hCys concentration is encountered in blood plasma of hyperhomocysteinemia patients and since previous studies by others have revealed that a SH-containing carrier mediates the uptake of Cd into hepatocytes, our results suggest that plasma hCys may play a role in the toxicologically relevant translocation of Cd from the bloodstream to mammalian target organs. PMID:27294530

  9. Diagnostic Utility of Serum Glycated Albumin for Diabetes Mellitus and Its Correlation With Hyperlipidemia

    PubMed Central

    Park, Sholhui; Lee, Wookeun; Chung, Hae-Sun

    2016-01-01

    Background Glycated albumin (GA) is a better marker of short-term glycemic control than glycated hemoglobin (A1c). Dyslipidemia is the main cause of cardiovascular complications in diabetes mellitus (DM). Studies on the correlation of GA with lipid indices are sparse. We investigated the diagnostic utility of GA for DM and its relationship with serum lipid profiles compared with that of A1c. Methods The GA enzymatic method was used to determine the diagnostic utility of GA for DM by using samples from 163 normal subjects (group 1) and 102 patients newly diagnosed with type 2 DM (T2DM; group 2). To analyze the lipid profiles, 263 patients with T2DM receiving treatment (group 3) were recruited. Results GA correlated with A1c (r=0.934, P<0.0001). Linear regression analysis indicated that GA levels were about 2.48 folds those of A1c. In the ROC analysis for GA to diagnose DM, the areas under the curve (0.988, 95% confidence interval 0.972-1.004) was excellent. HDL levels were significantly lower in groups 2 and 3. In group 1, positive correlations were observed between A1c and triglyceride (TG), total cholesterol (TC), LDL, TG/HDL, TC/HDL, and LDL/HDL levels. A negative correlation was observed between HDL and A1c levels. In group 3, HDL levels (P=0.0124 and P=0.0141, respectively) were significantly higher and LDL levels tended to be lower, not statistically significant, in the well-controlled group categorized using the A1c and GA cut-off values. Conclusions GA is a potential diagnostic tool for DM. Compared with A1c, GA seems less relevant to dyslipidemia. PMID:27139602

  10. Protections of bovine serum albumin protein from damage on functionalized graphene-based electrodes by flavonoids.

    PubMed

    Sun, Bolu; Gou, Yuqiang; Xue, Zhiyuan; Zheng, Xiaoping; Ma, Yuling; Hu, Fangdi; Zhao, Wanghong

    2016-05-01

    A sensitive electrochemical sensor based on bovine serum albumin (BSA)/poly (diallyldimethylammonium chloride) (PDDA) functionalized graphene nanosheets (PDDA-G) composite film modified glassy carbon electrode (BSA/PDDA-G/GCE) had been developed to investigate the oxidative protein damage and protections of protein from damage by flavonoids. The performance of this sensor was remarkably improved due to excellent electrical conductivity, strong adsorptive ability, and large effective surface area of PDDA-G. The BSA/PDDA-G/GCE displayed the greatest degree of BSA oxidation damage at 40min incubation time and in the pH5.0 Fenton reagent system (12.5mM FeSO4, 50mM H2O2). The antioxidant activities of four flavonoids had been compared by fabricated sensor based on the relative peak current ratio of SWV, because flavonoids prevented BSA damage caused by Fenton reagent and affected the BSA signal in a solution containing Co(bpy)3(3+). The sensor was characterized by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and scanning electron microscopy (SEM). UV-vis spectrophotometry and FTIR were also used to investigate the generation of hydroxyl radical and BSA damage, respectively. On the basis of results from electrochemical methods, the order of the antioxidant activities of flavonoids is as follows: (+)-catechin>kaempferol>apigenin>naringenin. A novel, direct SWV analytical method for detection of BSA damage and assessment of the antioxidant activities of four flavonoids was developed and this electrochemical method provided a simple, inexpensive and rapid detection of BSA damage and evaluation of the antioxidant activities of samples. PMID:26952415

  11. Optimization of human serum albumin monoliths for chiral separations and high-performance affinity chromatography

    PubMed Central

    Pfaunmiller, Erika L.; Hartmann, Mahli; Dupper, Courtney M.; Soman, Sony; Hage, David S.

    2012-01-01

    Various organic-based monoliths were prepared and optimized for immobilization of the protein human serum albumin (HSA) as a binding agent for chiral separations and high-performance affinity chromatography. These monoliths contained co-polymers based on glycidyl methacrylate (GMA) and ethylene glycol dimethacrylate (EDMA) or GMA and trimethylolpropane trimethacrylate (TRIM). A mixture of cyclohexanol and 1-dodecanol was used as the porogen, with the ratio of these solvents being varied along with the polymerization temperature to generate a library of monoliths. These monoliths were used with both the Schiff base and epoxy immobilization methods and measured for their final content of HSA. Monoliths showing the highest protein content were further evaluated in chromatographic studies using R/S-warfarin and d/l-tryptophan as model chiral solutes. A 2.6–2.7-fold increase in HSA content was obtained in the final monoliths when compared to similar HSA monoliths prepared according to the literature. The increased protein content made it possible for the new monoliths to provide higher retention and/or two-fold faster separations for the tested solutes when using 4.6 mm i.d. × 50 mm columns. These monoliths were also used to create 4.6 mm i.d. × 10 mm HSA microcolumns that could separate the same chiral solutes in only 1.5–6.0 min. The approaches used in this study could be extended to the separation of other chiral solutes and to the optimization of organic monoliths for use with additional proteins as binding agents. PMID:23010249

  12. Nature of autofluorescence in human serum albumin under its native, unfolding and digested forms

    NASA Astrophysics Data System (ADS)

    Manjunath, S.; Rao, Bola Sadashiva Satish; Satyamoorthy, Kapaettu; Mahato, Krishna Kishore

    2014-02-01

    Autofluorescence characteristics of human serum albumin (HSA) are highly sensitive to its local environment. Identification and characterization of the proteins in normal and disease conditions may have great clinical implications. Aim of the present study was to understand how autofluorescence properties of HSA varies with denaturation under urea (3.0M, 6.0M, 9.0M) and guanidine hydrochloride (GnHCl) (2.0M, 4.0M, 6.0M) as well as digestion with trypsin. Towards this, we have recorded the corresponding autofluorescence spectra of HSA at 281nm laser excitation and compared the outcomes. Although, HSA contains 1 tryptophan and 17 tyrosine residues, it has shown intense autofluorescence due to tryptophan as compared to the tyrosine in native form, which may be due to the fluorescence resonance energy transfer (FRET) from tyrosine to tryptophan. As the unfolding progresses in denatured and digested forms of the protein, a clear increase in tyrosine fluorescence as compared to tryptophan was observed, which may be due to the increase of tryptophan - tyrosine separation disturbing the FRET between them resulting in differences in the overall autofluorescence properties. The decrease in tryptophan fluorescence of around 17% in urea denatured, 32% in GnHCl denatured and 96% in tryptic digested HSA was observed as compared to its native form. The obtained results show a clear decrease in FRET between tyrosine and tryptophan residues with the progression of unfolding and urea seems to be less efficient than GnHCl in unfolding of HSA. These results demonstrate the potential of autofluorescence in characterizing proteins in general and HSA in particular.

  13. Characterization of bovine serum albumin partitioning behaviors in polymer-salt aqueous two-phase systems.

    PubMed

    Chow, Yin Hui; Yap, Yee Jiun; Tan, Chin Ping; Anuar, Mohd Shamsul; Tejo, Bimo Ario; Show, Pau Loke; Ariff, Arbakariya Bin; Ng, Eng-Poh; Ling, Tau Chuan

    2015-07-01

    In this paper, a linear relationship is proposed relating the natural logarithm of partition coefficient, ln K for protein partitioning in poly (ethylene glycol) (PEG)-phosphate aqueous two-phase system (ATPS) to the square of tie-line length (TLL(2)). This relationship provides good fits (r(2) > 0.98) to the partition of bovine serum albumin (BSA) in PEG (1450 g/mol, 2000 g/mol, 3350 g/mol, and 4000 g/mol)-phosphate ATPS with TLL of 25.0-50.0% (w/w) at pH 7.0. Results also showed that the plot of ln K against pH for BSA partitioning in the ATPS containing 33.0% (w/w) PEG1450 and 8.0% (w/w) phosphate with varied working pH between 6.0 and 9.0 exhibited a linear relationship which is in good agreement (r(2) = 0.94) with the proposed relationship, ln K = α' pH + β'. These results suggested that both the relationships proposed could be applied to correlate and elucidate the partition behavior of biomolecules in the polymer-salt ATPS. The influence of other system parameters on the partition behavior of BSA was also investigated. An optimum BSA yield of 90.80% in the top phase and K of 2.40 was achieved in an ATPS constituted with 33.0% (w/w) PEG 1450 and 8.0% (w/w) phosphate in the presence of 8.5% (w/w) sodium chloride (NaCl) at pH 9.0 for 0.3% (w/w) BSA load. PMID:25553974

  14. Highly sensitive detection of bovine serum albumin based on the aggregation of triangular silver nanoplates

    NASA Astrophysics Data System (ADS)

    Zhang, Ling Ling; Ma, Fang Fang; Kuang, Yang Fang; Cheng, Shu; Long, Yun Fei; Xiao, Qiu Guo

    2016-02-01

    A simple, fast and highly sensitive spectrophotometric method for the determination of bovine serum albumin (BSA) has been developed based on the interactions between triangular silver nanoplates (TAgNPs) and BSA in the presence of Britton-Robison buffer solution (BR). Particularly, the wavelength of absorption maximum (λmax) of TAgNPs is red shifted in the presence of BSA together with Britton-Robinson buffer solution (BR, pH = 2.56), and the color of the solution changed from blue to light blue. This may be due to the interactions between BSA molecules on the surface of TAgNPs through electrostatic forces, hydrogen bonds, hydrophobic effects and van der Waals forces at pH 2.56, which leads to the aggregation of TAgNPs. The determination of BSA was achieved by measuring the change of λmax corresponding to localized surface plasmon resonance (LSPR) from UV-visible spectrophotometry. It was found that the shift value in the wavelength of absorption maximum (Δλ, the difference in absorption maxima of the TAgNPs/BSA/BR mixture and the TAgNPs/BR mixture) was proportionate to the concentration of BSA in the range of 1.0 ng mL- 1 to 100.0 ng mL- 1 with the correlation coefficient of r = 0.9969. The detection limit (3 σ/k) for BSA was found to be as low as 0.5 ng mL- 1.

  15. Viscous cosolvent effect on the ultrasonic absorption of bovine serum albumin.

    PubMed

    Almagor, A; Yedgar, S; Gavish, B

    1992-02-01

    Protein-ligand binding and enzyme activity have been shown to be regulated by solvent viscosity, induced by the addition of viscous cosolvents. This was indirectly interpreted as an effect on protein dynamics. However, viscous cosolvents might affect dynamic, e.g., viscosity, as well as thermodynamic properties of the solution, e.g., activity of solution components. This work was undertaken to examine the effect of viscous cosolvent on the structural dynamics of proteins and its correlation with dynamic and thermodynamic solution properties. For this purpose we studied the effect of viscous cosolvent on the specific ultrasonic absorption, delta mu, of bovine serum albumin, at pH = 7.0 and at 21 degrees C, and frequency range of 3-4 MHz. Ultrasonic absorption (UA) directly probes protein dynamics related to energy dissipation processes. It was found that the addition of sucrose, glycerol, or ethylene glycol increased the BSA delta mu. This increase correlates well with the solvent viscosity, but not with the cosolvent mass concentration, activity of the solvent components, dielectric constant, or the hydration of charged groups. On the grounds of these results and previously reported findings, as well as theoretical considerations, we propose the following mechanism for the solvent viscosity effect on the protein structural fluctuations, reflected in the UA: increased solvent viscosity alters the frequency spectrum of the polypeptide chain movements; attenuating the fast (small amplitude) movements, and enhancing the slow (large amplitude) ones. This modulates the interaction strength between the polypeptide and water species that "lubricates" the chain's movements, leading to larger protein-volume fluctuation and higher ultrasonic absorption. This study demonstrates that solvent viscosity is a regulator of protein structural fluctuations. PMID:1547333

  16. Characterisation of the de-agglomeration effects of bovine serum albumin on nanoparticles in aqueous suspension.

    PubMed

    Tantra, Ratna; Tompkins, Jordan; Quincey, Paul

    2010-01-01

    This paper describes the use of nanoparticle characterisation tools to evaluate the interaction between bovine serum albumin (BSA) and dispersed nanoparticles in aqueous media. Dynamic light scattering, zeta-potential measurements and scanning electron microscopy were used to probe the state of zinc oxide (ZnO) and titanium dioxide (TiO(2)) nanoparticles in the presence of various concentrations of BSA, throughout a three-day period. BSA was shown to adhere to ZnO but not to TiO(2). The adsorption of BSA led to subsequent de-agglomeration of the sub-micron ZnO clusters into smaller fragments, even breaking them up into individual isolated nanoparticles. We propose that certain factors, such as adsorption kinetics of BSA on to the surface of ZnO, as well as the initial agglomerated state of the ZnO, prior to BSA addition, are responsible for promoting the de-agglomeration process. Hence, in the case of TiO(2) we see no de-agglomeration because: (a) the nanoparticles are more highly agglomerated to begin with and (b) BSA does not adsorb effectively on the surface of the nanoparticles. The zeta-potential results show that, for either ZnO or TiO(2), the presence of BSA resulted in enhanced stability. In the case of ZnO, the enhanced stability is limited to BSA concentrations below 0.5 wt.%. Steric and electrostatic repulsion are thought to be responsible for improved stability of the dispersion. PMID:19775871

  17. Structural changes and metal binding by proalbumins and other amino-terminal genetic variants of human serum albumin.

    PubMed Central

    Takahashi, N; Takahashi, Y; Putnam, F W

    1987-01-01

    Proalbumins are rare genetic variants of human serum albumin containing a basic propeptide that is not removed during post-transcriptional processing because of a mutation in the site of excision, an Arg-Arg sequence. We have identified the amino acid substitutions in three different types of proalbumins designated Gainesville, Taipei, and Takefu. The first two proalbumins are identical to previously described proalbumins of the Christchurch and Lille types, respectively, and exhibit the characteristic properties of susceptibility to tryptic cleavage and of lower metal-binding affinity. Takefu is a third type of proalbumin and resists tryptic cleavage because of the substitution Arg-1----Pro. Each of the first two types of proalbumins has been identified in geographically separate, ethnically diverse populations and therefore must have arisen by independent mutations. There is some tendency for mutations in albumin to cluster in the propeptide sequence. Although the substitution His3----Gln in the genetic variant albumin Nagasaki-3 decreases metal-binding affinity, mutations further down the polypeptide chain have no such effect, nor is there any reduction of copper-binding affinity in albumin from patients with Wilson disease. Images PMID:3478700

  18. Chromatography of carbon nanotubes separated albumin from other serum proteins: a method for direct analysis of their interactions.

    PubMed

    Kuboki, Yoshinori; Koshikawa, Takamitu; Takita, Hiroko; Fujisawa, Ryuichi; Lee, Min-ho; Abe, Shigeaki; Akasaka, Tsukasa; Uo, Motohiro; Watari, Fumio; Sammons, Rachel

    2010-08-01

    Chromatography technology was employed to clarify the mechanism of interaction between multi-wall carbon nanotubes (MWCNT) and proteins. A column (16x100 mm) was packed with purified MWCNT, and various proteins were eluted with phosphate buffered saline (PBS) with and without gradient systems. It was found that albumin in bovine serum was eluted immediately from the column without any adsorption to MWCNT. Conversely, the non-albumin proteins, including a protein of 85 kDa molecular mass and a group of proteins with molecular masses higher than 115 kDa, exhibited considerably high affinity towards MWCNT. A sample of pure bovine serum albumin was also eluted immediately from the column, while lysozyme did not elute as a peak with PBS, but eluted with 0.6 M NaCl. Fundamentally, carbon nanotubes are devoid of any electrical charge. Therefore, other forces including the hydrogen bonds, hydrophilic interactions, and van der Waals forces were most probably responsible for the differential elution behaviors. In conclusion, this chromatographic method provided a simple and direct analysis of the interactions between carbon nanotubes and the various proteins. PMID:20610879

  19. Evidence for covalent binding of acyl glucuronides to serum albumin via an imine mechanism as revealed by tandem mass spectrometry.

    PubMed Central

    Ding, A; Ojingwa, J C; McDonagh, A F; Burlingame, A L; Benet, L Z

    1993-01-01

    Acyl glucuronide metabolites of bilirubin and many drugs can react with serum albumin in vivo to form covalent adducts. Such adducts may be responsible for some toxic effects of carboxylic nonsteroidal antiinflammatory agents. The mechanism of formation of the adducts and their chemical structures are unknown. In this paper we describe the use of tandem mass spectrometry to locate binding sites and elucidate the binding mechanism involved in the formation of covalent adducts from tolmetin glucuronide and albumin in vitro. Human serum albumin and excess tolmetin glucuronide were coincubated in the presence of sodium cyanoborohydride to trap imine intermediates. The total protein product was reduced, carboxymethylated, and digested with trypsin. Six tolmetin-containing peptides (indicated by absorbance at 313 nm) were isolated by high-pressure liquid chromatography and analyzed by liquid secondary-ion mass spectrometry and collision-induced dissociation, using a four-sector tandem mass spectrometer. All six peptides contained tolmetin linked covalently via a glucuronic acid to protein lysine groups. Major attachment sites on the protein were Lys-195, -199, and -525; minor sites were identified as Lys-137, -351, and -541. Our results show unambiguously that the glucuronic acid moiety of acyl glucuronides can be retained within the structure when these reactive metabolites bind covalently to proteins, and they suggest that acyl migration followed by Schiff base (imine) formation is a credible mechanism for the generation of covalent adducts in vivo. PMID:8483897

  20. Monitoring the Competence of a New Keto-tetrahydrocarbazole Based Fluorosensor Under Homogeneous, Micro-Heterogeneous and Serum Albumin Environments.

    PubMed

    Mitra, Amrit Krishna; Sau, Abhishek; Bera, Subhas Chandra; Chakraborty, Suchandra; Saha, Chandan; Basu, Samita

    2015-11-01

    We present here a detailed photophysical study of a recently synthesised fluorophore 8-methyl-8,9-dihydro-5H-[1,3]dioxolo[4,5-b]carbazol-6(7H)-one. This is a synthetic precursor of bio-active carbazole skeleton Clausenalene. Spectroscopic investigation of the fluorophore has been carried out in different protic and aprotic solvents, as well as in binary solvent mixtures, using absorption, steady-state and time-resolved fluorescence techniques. This fluorophore is particularly responsive to the hydrogen bonding nature as well as polarity of the solvent molecules. When considered in micelles and β-cyclodextrin, this behaves as a reporter of its immediate microenvironment. Steady state and time resolved fluorometric and circular dichroism techniques have been used to explore the binding interaction of the fluorophore with transport proteins, bovine serum albumin and human serum albumin. The probable binding sites of the fluorophore in the proteinous environments have been evaluated from fluorescence resonance energy transfer study. Laser flash photolysis experiments also have been performed to observe the triplet excited state interaction between the fluorophore and albumin proteins. PMID:26489935

  1. Lipid-rich bovine serum albumin improves the viability and hatching ability of porcine blastocysts produced in vitro

    PubMed Central

    SUZUKI, Chie; SAKAGUCHI, Yosuke; HOSHI, Hiroyoshi; YOSHIOKA, Koji

    2015-01-01

    The effects of lipid-rich bovine serum albumin (LR-BSA) on the development of porcine blastocysts produced in vitro were examined. Addition of 0.5 to 5 mg/ml LR-BSA to porcine blastocyst medium (PBM) from Day 5 (Day 0 = in vitro fertilization) significantly increased the hatching rates of blastocysts on Day 7 and the total cell numbers in Day-7 blastocysts. When Day-5 blastocysts were cultured with PBM alone, PBM containing LR-BSA, recombinant human serum albumin or fatty acid-free BSA, addition of LR-BSA significantly enhanced hatching rates and the cell number in blastocysts that survived compared with other treatments. The diameter, ATP content and numbers of both inner cell mass and total cells in Day-6 and Day-7 blastocysts cultured with PBM containing LR-BSA were significantly higher than in blastocysts cultured with PBM alone, whereas LR-BSA had no effect on mitochondrial membrane potential. The mRNA levels of enzymes involved in fatty acid metabolism and β-oxidation (ACSL1, ACSL3, CPT1, CPT2 and KAT) in Day-7 blastocysts were significantly upregulated by the addition of LR-BSA. The results indicated that LR-BSA enhanced hatching ability and quality of porcine blastocysts produced in vitro, as determined by ATP content, blastocyst diameter and expression levels of the specific genes, suggesting that the stimulatory effects of LR-BSA arise from lipids bound to albumin. PMID:26582048

  2. The impact of oxidized serum albumin on the oncotic pressure and hydration status of peritoneal dialysis patients

    PubMed Central

    Hassan, Kamal; Kristal, Batya; Hassan, Fadi; Abo Saleh, Saad; Michelis, Regina

    2016-01-01

    Objective Hypoalbuminemia, fluid overload (FO), and oxidative stress (OS) may be related to cardiovascular morbidity and mortality in peritoneal dialysis (PD) patients. OS produces molecular modifications of serum albumin that interfere with its quantification by the commonly used bromocresol green assay. This study evaluated the impact of oxidized serum albumin (OSA) on oncotic pressure (OP) and hydration status. Patients and methods Twenty-four stable hypoalbuminemic PD patients were enrolled in the study. After performing physical examination, assessment of the hydration status using a whole-body bioimpedance spectroscopy technique was performed, and blood samples were drawn for determination of OP, serum albumin levels, and OSA. Results Extracellular to total body water (E/TBW) ratio was higher in patients with FO ≥1.5 L with or without edema than in patients with FO <1.5 L (P≤0.043). E/TBW ratio was higher in patients with FO ≥1.5 L and edema compared to those with FO ≥1.5 L but without edema (P=0.004). OP was significantly higher in patients with FO ≥1.5 L and without edema compared to those with FO ≥1.5 L and with edema (P<0.001). Albumin-detection index (ADI) in patients with FO ≥1.5 L and without edema was similar to ADI in patients with FO <1.5 L (P=0.520). ADI was significantly lower in patients with FO ≥1.5 L and without edema compared to those with FO ≥1.5 L and edema (P=0.034). E/TBW ratio correlated positively with the ADI (r=0.60, P=0.001) and inversely with the OP (r=−0.54, P=0.002). Conclusion Overhydration may be clinically undetectable in PD patients. Assessing the hydration status and measuring the total serum albumin levels, including the oxidized fraction, should be considered in evaluating hydration status in PD patients. PMID:27069365

  3. Cu(II) Bis(thiosemicarbazone) Radiopharmaceutical Binding to Serum Albumin: Further Definition of Species-Dependence and Associated Substituent Effects

    PubMed Central

    Basken, Nathan E.; Green, Mark A.

    2009-01-01

    Introduction The Cu-PTSM (pyruvaldehyde bis(N4-methylthiosemicarbazonato)copper(II)) and Cu-ATSM (diacetyl bis(N4-methylthiosemicarbazonato)copper(II)) radiopharmaceuticals exhibit strong, species-dependent binding to the IIA site of human serum albumin (HSA), while the related Cu-ETS (ethylglyoxal bis(thiosemicarbazonato)copper(II)) radiopharmaceutical appears to only exhibit non-specific binding to human and animal serum albumins. Methods To further probe the structural basis for the species-dependence of this albumin binding interaction, protein binding of these three radiopharmaceuticals was examined in solutions of albumin and/or serum from a broader array of mammalian species (rat, sheep, donkey, rabbit, cow, pig, dog, baboon, mouse, cat, elephant). We also evaluated the albumin binding of several copper(II) bis(thiosemicarbazone) chelates offering more diverse substitution of the ligand backbone. Results Cu-PTSM and Cu-ATSM exhibit a strong interaction with HSA that is not apparent with the albumins of other species, while the binding of Cu-ETS to albumin is much less species-dependent. The strong interaction of Cu-PTSM with HSA does not appear to simply correlate with variation, relative to the animal albumins, of a single amino acid lining HSA's IIA site. Those agents that selectively interact with HSA share the common feature of only methyl or hydrogen substitution at the carbon atoms of the diimine fragment of the ligand backbone. Conclusions The interspecies variations in albumin binding of Cu-PTSM and Cu-ATSM are not simply explained by unique amino acid substitutions in the IIA binding pocket of the serum albumins. However, the specific affinity for this region of HSA is disrupted when substituents bulkier than a methyl group appear on the imine carbons of the copper bis(thiosemicarbazone) chelate. PMID:19520290

  4. Cationic isotachophoresis separation of the biomarker cardiac troponin I from a high-abundance contaminant, serum albumin

    PubMed Central

    Jacroux, Thomas; Bottenus, Danny; Rieck, Bennett; Ivory, Cornelius F.; Dong, Wen-ji

    2014-01-01

    Cationic ITP was used to separate and concentrate fluorescently tagged cardiac troponin I (cTnI) from two proteins with similar isoelectric properties in a PMMA straight-channel microfluidic chip. In an initial set of experiments, cTnI was effectively separated from R-Phycoerythrin using cationic ITP in a pH 8 buffer system. Then, a second set of experiments was conducted in which cTnI was separated from a serum contaminant, albumin. Each experiment took ~ 10 min or less at low electric field strengths (34 V/cm) and demonstrated that cationic ITP could be used as an on-chip removal technique to isolate cTnI from albumin. In addition to the experimental work, a 1D numerical simulation of our cationic ITP experiments has been included to qualitatively validate experimental observations. PMID:24723384

  5. Cationic isotachophoresis separation of the biomarker cardiac troponin I from a high-abundance contaminant, serum albumin.

    PubMed

    Jacroux, Thomas; Bottenus, Danny; Rieck, Bennett; Ivory, Cornelius F; Dong, Wen-Ji

    2014-07-01

    Cationic ITP was used to separate and concentrate fluorescently tagged cardiac troponin I (cTnI) from two proteins with similar isoelectric properties in a PMMA straight-channel microfluidic chip. In an initial set of experiments, cTnI was effectively separated from R-Phycoerythrin using cationic ITP in a pH 8 buffer system. Then, a second set of experiments was conducted in which cTnI was separated from a serum contaminant, albumin. Each experiment took ∼10 min or less at low electric field strengths (34 V/cm) and demonstrated that cationic ITP could be used as an on-chip removal technique to isolate cTnI from albumin. In addition to the experimental work, a 1D numerical simulation of our cationic ITP experiments has been included to qualitatively validate experimental observations. PMID:24723384

  6. Predictors of response to terlipressin plus albumin in hepatorenal syndrome (HRS) type 1: Relationship of serum creatinine to hemodynamics

    PubMed Central

    Boyer, Thomas D.; Sanyal, Arun J.; Garcia-Tsao, Guadalupe; Blei, Andres; Carl, Daniel; Bexon, Alice S.; Teuber, Peter

    2013-01-01

    Background & Aims Administration of terlipressin plus albumin is effective in reversing type 1 HRS as compared to albumin alone. However, only about 1/3 of patients respond to treatment, therefore, predictors of response and survival would help identify the patients most likely to benefit from treatment. Methods We analyzed our controlled trial of terlipressin vs. placebo (Gastroenterology 2008;134:1360) to define factors predictive of a response and to correlate hemodynamic changes to changes in renal function. Results Single variant analysis showed treatment with terlipressin, MELD score, and baseline serum creatinine to be predictive of HRS reversal. Alcoholic hepatitis, baseline serum creatinine, and MELD score were predictive of survival. When treatment was not considered as a variable, only baseline serum creatinine predicted HRS reversal. Baseline serum creatinine, presence of alcoholic hepatitis, and Child-Pugh score were also predictive of survival on multivariate analysis. The rise in mean arterial pressure (MAP) following terlipressin administration was not predictive of HRS reversal. However, in those who achieved HRS reversal from terlipressin, there was a significant rise in MAP from beginning to end of treatment. Conclusions The most consistent predictor of response to terlipressin and of survival is the baseline serum creatinine. Patients most likely to benefit from terlipressin have earlier onset renal failure (i.e. serum creatinine <5.0 mg/dl). A sustained rise in MAP is required for HRS reversal. As MAP is a surrogate marker for the hyperdynamic circulation, it is only with improvement in the hyperdynamic circulation that HRS reversal is observed. PMID:21167235

  7. Size-dependent interaction of silica nanoparticles with lysozyme and bovine serum albumin proteins

    NASA Astrophysics Data System (ADS)

    Yadav, Indresh; Aswal, Vinod K.; Kohlbrecher, Joachim

    2016-05-01

    The interaction of three different sized (diameter 10, 18, and 28 nm) anionic silica nanoparticles with two model proteins—cationic lysozyme [molecular weight (MW) 14.7 kDa)] and anionic bovine serum albumin (BSA) (MW 66.4 kDa) has been studied by UV-vis spectroscopy, dynamic light scattering (DLS), and small-angle neutron scattering (SANS). The adsorption behavior of proteins on the nanoparticles, measured by UV-vis spectroscopy, is found to be very different for lysozyme and BSA. Lysozyme adsorbs strongly on the nanoparticles and shows exponential behavior as a function of lysozyme concentration irrespective of the nanoparticle size. The total amount of adsorbed lysozyme, as governed by the surface-to-volume ratio, increases on lowering the size of the nanoparticles for a fixed volume fraction of the nanoparticles. On the other hand, BSA does not show any adsorption for all the different sizes of the nanoparticles. Despite having different interactions, both proteins induce similar phase behavior where the nanoparticle-protein system transforms from one phase (clear) to two phase (turbid) as a function of protein concentration. The phase behavior is modified towards the lower concentrations for both proteins with increasing the nanoparticle size. DLS suggests that the phase behavior arises as a result of the nanoparticles' aggregation on the addition of proteins. The size-dependent modifications in the interaction potential, responsible for the phase behavior, have been determined by SANS data as modeled using the two-Yukawa potential accounting for the repulsive and attractive interactions in the systems. The protein-induced interaction between the nanoparticles is found to be short-range attraction for lysozyme and long-range attraction for BSA. The magnitude of attractive interaction irrespective of protein type is enhanced with increase in the size of the nanoparticles. The total (attractive+repulsive) potential leading to two-phase formation is found to be

  8. The Effect of Hydrophobic Pockets in Human Serum Albumin Adsorption to Self-Assembled Monolayers

    NASA Astrophysics Data System (ADS)

    Choi, Eugene J.; Jia, Shijin; Petrash, Stanislaw; Foster, Mark D.

    2001-04-01

    Molecular properties of proteins and their interactions with surfaces have an effect on protein adsorption, which is one of the first and most important events that occurs when a biological fluid contacts a surface. For biomaterials applications, blood reaction to foreign objects can cause thrombosis. To understand thrombosis, it is necessary to understand the mechanism of adsorption of blood proteins onto artificial surfaces. Such interactions as hydrophobicity^1,2, electrostatics^3 and specific binding^4 have been found to be driving forces for protein adsorption. Self-assembled monolayers (SAMs) provide an ideal surface for which protein adsorption behavior can be studied.^1 SAMs provide chemical homogeneity, robustness, and variable surface functionality. The hydrophobicity of SAMs has been of great interest in studying surface interactions with proteins.^1, 2 The packing density of alkyl chains of SAMs can also be varied in order to obtain different surface properties. The most abundant protein in the blood is human serum albumin (HSA). Because HSA acts as a fatty acid transporter, it has six binding sites for fatty acids. Pitt and Cooper^4 have shown that alkylation of surfaces increases the initial adsorption rate of delipidized (fatty acid free) HSA. Petrash et al.^5 have shown that delipidized HSA binds more tenaciously to less densely packed alkyl SAMs than to densely packed alkyl SAMs when desorbed by sodium dodecyl sulfate. Using X-ray reflectivity to study the adsorbed protein layer thickness, lipidized HSA (fatty acid bound) adsorption and desorption studies showed that specific binding of HSA is one of the main factors in binding tenacity between HSA and less densely packed alkyl SAMs. Atomic force microscopy was used as a complementary technique to confirm these results, and neutron reflectivity and spectroscopy techniques will also be used to study the adsorption behaviors of HSA and other blood proteins in future work. 1. Prime, K. L.; Whitesides

  9. Size-dependent interaction of silica nanoparticles with lysozyme and bovine serum albumin proteins.

    PubMed

    Yadav, Indresh; Aswal, Vinod K; Kohlbrecher, Joachim

    2016-05-01

    The interaction of three different sized (diameter 10, 18, and 28 nm) anionic silica nanoparticles with two model proteins-cationic lysozyme [molecular weight (MW) 14.7 kDa)] and anionic bovine serum albumin (BSA) (MW 66.4 kDa) has been studied by UV-vis spectroscopy, dynamic light scattering (DLS), and small-angle neutron scattering (SANS). The adsorption behavior of proteins on the nanoparticles, measured by UV-vis spectroscopy, is found to be very different for lysozyme and BSA. Lysozyme adsorbs strongly on the nanoparticles and shows exponential behavior as a function of lysozyme concentration irrespective of the nanoparticle size. The total amount of adsorbed lysozyme, as governed by the surface-to-volume ratio, increases on lowering the size of the nanoparticles for a fixed volume fraction of the nanoparticles. On the other hand, BSA does not show any adsorption for all the different sizes of the nanoparticles. Despite having different interactions, both proteins induce similar phase behavior where the nanoparticle-protein system transforms from one phase (clear) to two phase (turbid) as a function of protein concentration. The phase behavior is modified towards the lower concentrations for both proteins with increasing the nanoparticle size. DLS suggests that the phase behavior arises as a result of the nanoparticles' aggregation on the addition of proteins. The size-dependent modifications in the interaction potential, responsible for the phase behavior, have been determined by SANS data as modeled using the two-Yukawa potential accounting for the repulsive and attractive interactions in the systems. The protein-induced interaction between the nanoparticles is found to be short-range attraction for lysozyme and long-range attraction for BSA. The magnitude of attractive interaction irrespective of protein type is enhanced with increase in the size of the nanoparticles. The total (attractive+repulsive) potential leading to two-phase formation is found to be

  10. Unraveling the binding mechanism of asiatic acid with human serum albumin and its biological implications.

    PubMed

    Gokara, Mahesh; Malavath, Tirupathi; Kalangi, Suresh Kumar; Reddana, Pallu; Subramanyam, Rajagopal

    2014-01-01

    Asiatic acid (AsA), a naturally occurring pentacyclictriterpenoid found in Centella asiatica, plays a major role in neuroprotection, anticancer, antioxidant, and hepatoprotective activities. Human serum albumin (HSA), a blood plasma protein, participates in the regulation of plasma osmotic pressure and transports endogenous and exogenous substances. The study undertaken to analyze the drug-binding mechanisms of HSA is crucial in understanding the bioavailability of drugs. In this study, we analyzed the cytotoxic activity of AsA on HepG2 (human hepatocellular carcinoma) cell lines and its binding, conformational, docking, molecular simulation studies with HSA under physiological pH 7.2. These studies revealed a clear decrease in the viability of HepG2 cells upon exposure to AsA in a dose-dependent manner with an IC50 of 45 μM. Further studies showed the quenching of intrinsic fluorescence of HSA by AsA with a binding constant of KAsA = 3.86 ± 0.01 × 10(4) M(-1), which corresponds to the free energy of (ΔG) -6.3 kcal M(-1) at 25 °C. Circular dichroism (CD) studies revealed that there is a clear decrease in the α-helical content from 57.50 ± 2.4 to 50% ± 2.3 and an increase in the β-turns from 25 ± 0.65 to 29% ± 0.91 and random coils from 17.5% ± 0.95 to 21% ± 1.2, suggesting partial unfolding of HSA. Autodock studies revealed that the AsA is bound to the subdomain IIA with hydrophobic and hydrophilic interactions. From molecular dynamics, simulation data (RMSD, Rg and RMSF) emphasized the local conformational changes and rigidity of the residues of both HSA and HSA-AsA complexes. PMID:23844909

  11. The Binding Constant of Estradiol to Bovine Serum Albumin: An Upper-Level Experiment Utilizing Tritium-Labeled Estradiol and Liquid Scintillation Counting

    ERIC Educational Resources Information Center

    Peihong Liang; Adhyaru, Bhavin; Pearson, Wright L.; Williams, Kathryn R.

    2006-01-01

    The experiment used [to the third power]H-labeled estradiol to determine the binding constant of estradiol to bovine serum albumin. Estradiol must complex with serum proteins for the transport in the blood stream because of its low solubility in aqueous systems and estradiol-protein binding constant, where K[subscript B] is important to understand…

  12. Understanding complex coacervation in serum albumin and pectin mixtures using a combination of the Boltzmann equation and Monte Carlo simulation.

    PubMed

    Li, Yunqi; Zhao, Qin; Huang, Qingrong

    2014-01-30

    A combination of turbidimetric titration, a sigmoidal Boltzmann equation approach and Monte Carlo simulation has been used to study the complex coacervation in serum albumin and pectin mixtures. The effects of the mass ratio of protein to polysaccharide on the critical pH values, the probability of complex coacervation and the electrostatic interaction from charge patches in serum albumin were investigated. Turbidimetric titration results showed an optimum pH for complex coacervation (pHm), which corresponded to the maximum turbidity in the protein/polysaccharide mixture. The pHm monotonically decreased as the ratio decreased, and could be fitted using the sigmoidal Boltzmann equation. It suggests that pHm could be a good ordering parameter to characterize the phase behavior associated with protein/polysaccharide complex coacervation. Qualitative understanding of pHm by taking into account the minimization of electrostatic interaction, as well as quantitative matching of pHm according to the concept of charge neutralization were both achieved. Our results suggest that the serum albumin/pectin complexes were ultimately neutralized by the partial charges originated from the titratable residues in protein and polysaccharide chains at pHm. The Monte Carlo simulation provided consistent phase boundaries for complex coacervation in the same system, and the intermolecular association strength was determined to be several kBT below the given ionic strength. The strongest binding site in the protein is convergent to the largest positive charge patch if pure electrostatic interaction was considered. Further inclusion of contribution from excluded volume resulted in the binding site distribution over five different positive charge patches at different protein/polysaccharide ratios and pH values. PMID:24299810

  13. Identification and mapping of linear antibody epitopes in human serum albumin using high-density Peptide arrays.

    PubMed

    Hansen, Lajla Bruntse; Buus, Soren; Schafer-Nielsen, Claus

    2013-01-01

    We have recently developed a high-density photolithographic, peptide array technology with a theoretical upper limit of 2 million different peptides per array of 2 cm(2). Here, we have used this to perform complete and exhaustive analyses of linear B cell epitopes of a medium sized protein target using human serum albumin (HSA) as an example. All possible overlapping 15-mers from HSA were synthesized and probed with a commercially available polyclonal rabbit anti-HSA antibody preparation. To allow for identification of even the weakest epitopes and at the same time perform a detailed characterization of key residues involved in antibody binding, the array also included complete single substitution scans (i.e. including each of the 20 common amino acids) at each position of each 15-mer peptide. As specificity controls, all possible 15-mer peptides from bovine serum albumin (BSA) and from rabbit serum albumin (RSA) were included as well. The resulting layout contained more than 200.000 peptide fields and could be synthesized in a single array on a microscope slide. More than 20 linear epitope candidates were identified and characterized at high resolution i.e. identifying which amino acids in which positions were needed, or not needed, for antibody interaction. As expected, moderate cross-reaction with some peptides in BSA was identified whereas no cross-reaction was observed with peptides from RSA. We conclude that high-density peptide microarrays are a very powerful methodology to identify and characterize linear antibody epitopes, and should advance detailed description of individual specificities at the single antibody level as well as serologic analysis at the proteome-wide level. PMID:23894373

  14. Site-Specific Albumination as an Alternative to PEGylation for the Enhanced Serum Half-Life in Vivo.

    PubMed

    Yang, Byungseop; Lim, Sung In; Kim, Jong Chul; Tae, Giyoong; Kwon, Inchan

    2016-05-01

    Polyethylene glycol (PEG) has been widely used as a serum half-life extender of therapeutic proteins. However, due to immune responses and low degradability of PEG, developing serum half-life extender alternatives to PEG is required. Human serum albumin (HSA) has several beneficial features as a serum half-life extender, including a very long serum half-life, good degradability, and low immune responses. In order to further evaluate the efficacy of HSA, we compared the extent of serum half-life extension of a target protein, superfolder green fluorescent protein (sfGFP), upon HSA conjugation with PEG conjugation side-by-side. Combination of site-specific incorporation of p-azido-l-phenylalanine into sfGFP and copper-free click chemistry achieved the site-specific conjugation of a single HSA, 20 kDa PEG, or 30 kDa PEG to sfGFP. These sfGFP conjugates exhibited the fluorescence comparable to or even greater than that of wild-type sfGFP (sfGFP-WT). In mice, HSA-conjugation to sfGFP extended the serum half-life 9.0 times compared to that of unmodified sfGFP, which is comparable to those of PEG-conjugated sfGFPs (7.3 times for 20 kDa PEG and 9.5 times for 30 kDa PEG). These results clearly demonstrated that HSA was as effective as PEG in extending the serum half-life of a target protein. Therefore, with the additional favorable features, HSA is a good serum half-life extender of a (therapeutic) protein as an alternative to PEG. PMID:27050863

  15. [Raman spectra of single human living erythrocyte with the effect of pH and serum albumin].

    PubMed

    Wu, Zheng-Jie; Wang, Cheng; Lin, Zheng-Chun; Jiao, Qing-Ze

    2014-05-01

    In the present work, a cell environment which mimicked the real body environment according to the concentration radio between serum albumin and hemoglobin was built, and the cell morphology, the membrane deformation capacity, and the structure of intracellular hemoglobin of single human living erythrocyte under the effect of pH and serum albumin were studied. It was found that at different suspension pH, the magnitude of variations in cell shape and membrane deformation capacity changes with the structural changes of the intracellular hemoglobin. At pH 4. 14, 4. 76 and 10. 18, the loss of helical structure for hemoglobin, exposing of the hydrophobic amino acid in the globin chains, and changing of the combination of heme and globin, would completely destroy the stability of hemoglobin's structure, which seriously changes RBC's morphology and membrane deformation capacity. While at pH 6. 51 and 7. 80, the Raman spectra of erythrocytes are found to have no such changes, indicating that the structure of intracellular hemoglobin was not varied, thus the cell morphology and membrane deformation capacity are quite close to the normal values. At pH 5. 49 and 8. 76, RBC's morphology and membrane deformation capacity have different degrees of variation, but the structure of intracellular hemoglobin has not changed, suggesting that the cell morphology and membrane deformation capacity may be reversible. The results suggest that in the suspension solution containing serum albumin, erythrocytes have better ability to regulate and control the variation of the extracellular pH. In summary, upon building an environment which contains the same concentration radio of serum albumin to hemoglobin in the blood, this work performed systematic studies on the effect of pH on human erythrocytes. It can not only help to solve the problems about the mechanism of the structural and functional changes of erythrocytes induced by environmental pH, but also elucidates the possible variation of

  16. Effect of bovine serum albumin on the structure and properties of Langmuir Blodgett films based phosphocholine and cholesterol

    NASA Astrophysics Data System (ADS)

    Dubatovka, K. I.; Zhavnerko, G. K.; Agabekov, V. E.

    2014-02-01

    Mono- and bilayer Langmuir-Blodgett films based on phosphocholine and cholesterol and prepared by horizontal and vertical deposition are investigated by atomic force microscopy. It was found that bovine serum albumin (BSA) included at the stage of film formation. At the same time, isolation has a considerable effect on their structure. It was shown that the globular formation of nanostructures with heights of 4-7 nm occurs as a result of transferring lipids to a hydrophobic surface from a subphase containing BSA, indicating the reorganization of monolayers during protein isolation and inclusion in its composition.

  17. Correlated and Anticorrelated Domain Movement of Human Serum Albumin: A Peek into the Complexity of the Crowded Milieu.

    PubMed

    Biswas, Saikat; Chowdhury, Pramit Kumar

    2016-06-01

    Protein dynamics in cells have been shown to be markedly different from that in dilute solutions because of the highly crowded cellular interior. The volume exclusion arising from the high concentration of macromolecules present can affect both equilibrium and kinetic processes involving protein conformational changes. While global changes in structure leading to modulations in the stability of the protein have been well-documented, local changes that can have a large bearing on the functional aspects of these biomolecules are rare to come across. Using the multidomain serum protein human serum albumin and a fluorescence resonance energy transfer (FRET)-based approach, with fluorescent reporters in each of its three domains, we, in this article, have provided a detailed mapping of variations in the interdomain distances (as a function of pH) in the presence of five macromolecular crowding agents, differing based on their constituent monomers and average molecular weight(s). From the observation of correlated domain movements for dextran based crowding agents to anticorrelated motion induced by Ficoll 70, and both correlated and anticorrelated action for PEG8000 (PEG8), our results reveal the inherent complexity of a crowded milieu with the serum protein serving as an able sensor for decoding such variations. Differences in the manner in which the macromolecular crowders of similar average molecular weights influence the protein conformational ensemble also provide insights into the possible variations at the molecular level that these polymeric molecules possess. Evidence is presented in support of the fact that for the large molecular weight crowding agents and PEG8, soft interactions predominate over hard sphere potentials. Finally, the nature of domain movements encountered for the serum protein are of immense significance with respect to the function of human serum albumin (HSA) as a prolific binder and transporter of small molecules. PMID:27163260

  18. Differential Effects of Methoxy Group on the Interaction of Curcuminoids with Two Major Ligand Binding Sites of Human Serum Albumin

    PubMed Central

    Sato, Hiroki; Chuang, Victor Tuan Giam; Yamasaki, Keishi; Yamaotsu, Noriyuki; Watanabe, Hiroshi; Nagumo, Kohei; Anraku, Makoto; Kadowaki, Daisuke; Ishima, Yu; Hirono, Shuichi; Otagiri, Masaki; Maruyama, Toru

    2014-01-01

    Curcuminoids are a group of compounds with a similar chemical backbone structure but containing different numbers of methoxy groups that have therapeutic potential due to their anti-inflammatory and anti-oxidant properties. They mainly bind to albumin in plasma. These findings influence their body disposition and biological activities. Spectroscopic analysis using site specific probes on human serum albumin (HSA) clearly indicated that curcumin (Cur), demethylcurcumin (Dmc) and bisdemethoxycurcumin (Bdmc) bind to both Site I (sub-site Ia and Ib) and Site II on HSA. At pH 7.4, the binding constants for Site I were relatively comparable between curcuminoids, while the binding constants for Site II at pH 7.4 were increased in order Cur < Dmc < Bdmc. Binding experiments using HSA mutants showed that Trp214 and Arg218 at Site I, and Tyr411 and Arg410 at Site II are involved in the binding of curcuminoids. The molecular docking of all curcuminoids to the Site I pocket showed that curcuminoids stacked with Phe211 and Trp214, and interacted with hydrophobic and aromatic amino acid residues. In contrast, each curcuminoid interacted with Site II in a different manner depending whether a methoxy group was present or absent. A detailed analysis of curcuminoids-albumin interactions would provide valuable information in terms of understanding the pharmacokinetics and the biological activities of this class of compounds. PMID:24498401

  19. Synthesis and mass-spectrometric characterization of human serum albumins modified by covalent binding of two non-steroidal anti-inflammatory drugs: tolmetin and zomepirac.

    PubMed Central

    Zia-Amirhosseini, P; Ding, A; Burlingame, A L; McDonagh, A F; Benet, L Z

    1995-01-01

    Human serum albumins modified by covalently bound tolmetin or zomepirac were synthesized as models for similar products formed in vivo from acyl glucuronides. Activated esters of both drugs were prepared with 1-ethyl-3-(3-dimethylaminopropyl)-carbodi-imide, and then allowed to react with human serum albumin. Tryptic digests of both protein products were analysed by HPLC to identify peptides containing covalently bound drugs, and binding sites on albumin were identified by high-performance tandem MS. Three binding sites were common to both products, i.e. lysine-195, -199 and -351. Three further modified residues were identified for the tolmetin-albumin product, i.e. aspartic acid 1, and lysine-524 and -536. PMID:7487878

  20. Influence of the binding of reduced NAMI-A to human serum albumin on the pharmacokinetics and biological activity.

    PubMed

    Novohradský, V; Bergamo, A; Cocchietto, M; Zajac, J; Brabec, V; Mestroni, G; Sava, G

    2015-01-28

    NAMI-A is a ruthenium-based drug endowed with the unique property of selectively targeting solid tumour metastases. Although two clinical studies had already been completed, limited information exists on the behavior of NAMI-A after injection into the bloodstream. PK data in humans informs us of a rather low free drug concentration, of a relatively high half-life time of elimination and of a linear relationship between the administered dose and the corresponding AUC for up to toxic doses. In the present study, we examined the chemical kinetics of albumin binding with or without the presence of reducing agents, and we evaluated how these chemical aspects might influence the in vivo PK and the in vitro ability of NAMI-A to inhibit cell migration, which is a bona fide, rapid and easy way to suggest anti-metastatic properties. The experimental data support the binding of NAMI-A to serum albumin. The reaction is facilitated when the drug is in its reduced form and, in agreement with already reported data, the adduct formed with albumin maintains the biological activity of the ruthenium drug. The formation of the adduct is favored by low ratios of NAMI-A : HSA and by the reduction of the drug with ascorbic acid. The difference in in vivo PK and the faster binding to albumin of the reduced NAMI-A seem to suggest that the drug is not rapidly reduced immediately upon injection, even at low doses. Most probably, cell and protein binding prevail over the reduction of the drug. This observation supports the thesis that the reduction of the drug before injection must be considered relevant for the pharmacological activity of NAMI-A against tumour metastases. PMID:25489765