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Sample records for recombinant human albumin

  1. Structural consistency analysis of recombinant and wild-type human serum albumin

    NASA Astrophysics Data System (ADS)

    Cao, Hui-Ling; Sun, Li-Hua; Liu, Li; Li, Jian; Tang, Lin; Guo, Yun-Zhu; Mei, Qi-Bing; He, Jian-Hua; Yin, Da-Chuan

    2017-01-01

    Recombinant human serum albumin (rHSA) is potential alternatives for human serum albumin (HSA) which may ease severe shortage of HSA worldwide. In theory, rHSA and HSA are the same. Structure decides function. Therefore, the 3D structural consistency analysis of rHSA and HSA is outmost importance, which is the base of their function consistency. In this paper, the crystal structures of rHSA at resolution limit of 2.22 Å and HSA at 2.30 Å were determined by X-ray diffraction (XRD), which were deposited in the Protein Data Bank (PDB) with accession codes 4G03 (rHSA) and 4G04 (HSA). The differences between rHSA and HSA were systematically analyzed from the crystallization behavior, diffraction data and three-dimensional (3D) structure. The superimposed contrasted analysis indicated that rHSA and HSA achieved a structural similarity of 99% with an r.m.s. deviation of 0.397 Å for the corresponding overall Cα atoms. In addition, the number of α-helices in the rHSA or HSA molecule was verified to be 30. As a result, rHSA can potentially replace HSA. The study provides a theoretical and experimental basis for the clinical and additional applications of rHSA. Meanwhile, it is also a good example for applications of genetic engineering.

  2. Quantitation of the residual DNA from rice-derived recombinant human serum albumin.

    PubMed

    Chen, Zhen; Dai, Huixia; Liu, Zhenwei; Zhang, Liping; Pang, Jianlei; Ou, Jiquan; Yang, Daichang

    2014-04-01

    Residual DNA in recombinant protein pharmaceuticals can potentially cause safety issues in clinical applications; thus, maximum residual limit has been established by drug safety authorities. Assays for residual DNA in Escherichia coli, yeast, and Chinese hamster ovary (CHO) cell expression systems have been established, but no rice residual DNA assay for rice expression systems has been designed. To develop an assay for the quantification of residual DNA that is produced from rice seed, we established a sensitive assay using quantitative real-time polymerase chain reaction (qPCR) based on the 5S ribosomal RNA (rRNA) genes. We found that a 40-cycle qPCR exhibited a linear response when the template concentration was in the range of 2×10(4) to 0.2pg of DNA per reaction in TaqMan and SYBR Green I assays. The amplification efficiency was 103 to 104%, and the amount of residual DNA from recombinant human serum albumin from Oryza sativa (OsrHSA) was less than 3.8ng per dosage, which was lower than that recommended by the World Health Organization (WHO). Our results indicate that the current purification protocol could efficiently remove residual DNA during manufacturing and processing. Furthermore, this protocol could be viable in other cereal crop endosperm expression systems for developing a residual DNA quantitation assay using the highly conserved 5S rRNA gene of the crops.

  3. Production of Recombinant Polypeptides Containing One GA-Module and Analysis of Their Ability to Bind to Human Albumin.

    PubMed

    Bormotova, E A; Gupalova, T V

    2016-11-01

    Surface proteins of many bacterial species interact with human serum albumin (HSA) via a special region of amino acid sequence termed GA module. For instance, surface peptostreptococcal albumin-binding protein of anaerobic bacteria Peptostreptococcus magnus contains one HSA-binding GA-module. Protein G from group G and C Streptococcus strains isolated from humans has HSA-binding region consisting of three GA-modules. HSA-binding protein containing two GA-modules was found in strains of group G Streptococcus of animal origin. We obtained two recombinant polypeptides GA1 and GA2 congaing one GA-module each. Recombinant polypeptide with two GA-modules binds HSA with a much higher affinity than polypeptides GA1 and GA2 containing one GA-module. Polypeptide with the second GAmodule more effectively binds HSA than polypeptides with the GA-module.

  4. Recombinant human albumin supports single cell cloning of CHO cells in chemically defined media.

    PubMed

    Zhu, Jiang; Wooh, Jong Wei; Hou, Jeff Jia Cheng; Hughes, Benjamin S; Gray, Peter P; Munro, Trent P

    2012-01-01

    Biologic drugs, such as monoclonal antibodies, are commonly made using mammalian cells in culture. The cell lines used for manufacturing should ideally be clonal, meaning derived from a single cell, which represents a technically challenging process. Fetal bovine serum is often used to support low cell density cultures, however, from a regulatory perspective, it is preferable to avoid animal-derived components to increase process consistency and reduce the risk of contamination from adventitious agents. Chinese hamster ovary (CHO) cells are the most widely used cell line in industry and a large number of serum-free, protein-free, and fully chemically defined growth media are commercially available, although these media alone do not readily support efficient single cell cloning. In this work, we have developed a simple, fully defined, single-cell cloning media, specifically for CHO cells, using commercially available reagents. Our results show that a 1:1 mixture of CD-CHO™ and DMEM/F12 supplemented with 1.5 g/L of recombinant albumin (Albucult®) supports single cell cloning. This formulation can support recovery of single cells in 43% of cultures compared to 62% in the presence of serum.

  5. Unfolding properties of recombinant human serum albumin products are due to bioprocessing steps.

    PubMed

    Lang, Brian E; Cole, Kenneth D

    2015-01-01

    We have used differential scanning calorimetry (DSC) to determine the unfolding properties of commercial products of human serum albumin (HSA) prepared from pooled human blood, transgenic yeast, and transgenic rice. The initial melting temperatures (Tm1 ) for the unfolding transitions of the HSA products varied from 62°C to 75°C. We characterized the samples for purity, fatty acid content, and molecular weight. The effects of adding fatty acids, heat pasteurization, and a low pH defatting technique on the transition temperatures were measured. Defatted HSA has a structure with the lowest stability (Tm of ∼62°C). When fatty acids are bound to HSA, the structure is stabilized (Tm of ∼64-72°C), and prolonged heating (pasteurization at 60°C) results in a heat-stabilized structural form containing fatty acids (Tm of ∼75-80°C). This process was shown to be reversible by a low pH defatting step. This study shows that the fatty acid composition and bioprocessing history of the HSA commercial products results in the large differences in the thermal stability.

  6. Human albumin: old, new, and emerging applications.

    PubMed

    Rozga, Jacek; Piątek, Tomasz; Małkowski, Piotr

    2013-05-10

    Human serum albumin has been widely used in an array of clinical settings for nearly 7 decades. Although there is no evidence to support the use of albumin rather than crystalloid in acute volume resuscitation, many clinicians continue to use albumin because it has other important physiologic effects besides the oncotic function. In keeping with the improved understanding of albumin physiology and pathophysiology of many acute and chronic diseases, use of albumin for medical applications has increased in recent years. This, along with increased costs of manufacturing and lower production volume of medical-grade albumin, has lead to an ongoing shortage and rapid increase in albumin prices. This review is based on the analysis of major publications, related to albumin chemistry, physiology, and medical uses including guidelines developed by professional and governmental organizations. Results reflect current knowledge about the role of albumin in health and disease and relevance of albumin therapy in specific clinical settings. Albumin therapy is currently recommended in spontaneous bacterial peritonitis with ascites, refractory ascites not responsive to diuretics, large-volume paracentesis, post-paracentesis syndrome, and the treatment of hepatorenal syndrome as an adjunct to vasoconstrictors. New indications for albumin therapy are linked to the antioxidant activity of albumin and its effects on capillary integrity. In recent years, large-pore hemofiltration and albumin exchange have emerged as promising liver support therapies for liver failure and other toxic syndromes. They are designed to remove a broad range of blood-borne toxins and to restore normal functions of the circulating albumin by replacing defective forms of albumin and albumin molecules saturated with toxins with normal albumin. In view of the ongoing worldwide shortage and high cost of human albumin (native and recombinant), new usage criteria, protocols, and guidelines for appropriate utilization

  7. Freeze-drying of HI-6-loaded recombinant human serum albumin nanoparticles for improved storage stability.

    PubMed

    Dadparvar, Miriam; Wagner, Sylvia; Wien, Sascha; Worek, Franz; von Briesen, Hagen; Kreuter, Jörg

    2014-10-01

    Severe intoxications with organophosphates require the immediate administration of atropine in combination with acetyl cholinesterase (AChE) reactivators such as HI-6. Although this therapy regimen enables the treatment of peripheral symptoms, the blood-brain barrier (BBB) restricts the access of the hydrophilic antidotes to the central nervous system which could lead to a fatal respiratory arrest. Therefore, HI-6-loaded albumin nanoparticles were previously developed to enhance the transport across this barrier and were able to reactivate organophosphate-(OP)-inhibited AChE in an in vitro BBB model. Since HI-6 is known to be moisture-sensitive, the feasibility of freeze-drying of the HI-6-loaded nanoparticles was investigated in the present study using different cryo- and lyoprotectants at different concentrations. Trehalose and sucrose (3%, w/v)-containing formulations were superior to mannitol concerning the physicochemical parameters of the nanoparticles whereas trehalose-containing samples were subject of a prolonged storage stability study at temperatures between -20°C and +40°C for predetermined time intervals. Shelf-life computations of the freeze-dried HI-6 nanoparticle formulations revealed a shelf-life time of 18 months when stored at -20°C. The formulations' efficacy was proven in vitro by reactivation of OP-inhibited AChE after transport over a porcine brain capillary endothelial cell layer model.

  8. Development of expression systems for the production of recombinant human serum albumin using the MOX promoter in Hansenula polymorpha DL-1.

    PubMed

    Kang, H A; Kang, W; Hong, W K; Kim, M W; Kim, J Y; Sohn, J H; Choi, E S; Choe, K B; Rhee, S K

    2001-09-01

    To optimize the secretory expression of recombinant human serum albumin (HSA) under the control of methanol oxidase (MOX) promoter in the methylotrophic yeast Hansenula polymorpha DL-1, we analyzed several parameters affecting the expression of HSA from the MOX promoter. Removal of the 5'-untranslated region derived from HSA cDNA in the expression cassette led to at least a fivefold improvement of HSA expression efficiency at the translational level. With the optimized expression cassette, the gene dosage effect on HSA expression was abolished and thus, a single copy of the expression vector integrated into the MOX locus became sufficient for the maximal expression of HSA. Northern blot analysis revealed that the levels of HSA transcript did not increase any further upon increasing copy number. The mox-disrupted (mox Delta) transformant was constructed, in which the genomic MOX gene was transplaced with the HSA expression cassette, to examine the effect of the methanol oxidase-deficient phenotype of the host on HSA expression. The mox Delta transformant showed higher levels of HSA production in shake-flask cultures than the MOX wild-type transformant, especially at low concentrations of methanol and a twofold higher specific HSA production rate in fed-batch fermentation with an abrupt induction mode. The native prepro signal sequence of HSA secreted in H. polymorpha was correctly processed and the mature recombinant protein had a pI value identical to that of the authentic HSA. Our results suggest that the H. polymorpha expression systems developed in this study are suitable for large-scale production of recombinant albumin.

  9. Determination of supplier-to-supplier and lot-to-lot variability in glycation of recombinant human serum albumin expressed in Oryza sativa.

    PubMed

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

    2014-01-01

    The use of different expression systems to produce the same recombinant human protein can result in expression-dependent chemical modifications (CMs) leading to variability of structure, stability and immunogenicity. Of particular interest are recombinant human proteins expressed in plant-based systems, which have shown particularly high CM variability. In studies presented here, recombinant human serum albumins (rHSA) produced in Oryza sativa (Asian rice) (OsrHSA) from a number of suppliers have been extensively characterized and compared to plasma-derived HSA (pHSA) and rHSA expressed in yeast (Pichia pastoris and Saccharomyces cerevisiae). The heterogeneity of each sample was evaluated using size exclusion chromatography (SEC), reversed-phase high-performance liquid chromatography (RP-HPLC) and capillary electrophoresis (CE). Modifications of the samples were identified by liquid chromatography-mass spectrometry (LC-MS). The secondary and tertiary structure of the albumin samples were assessed with far U/V circular dichroism spectropolarimetry (far U/V CD) and fluorescence spectroscopy, respectively. Far U/V CD and fluorescence analyses were also used to assess thermal stability and drug binding. High molecular weight aggregates in OsrHSA samples were detected with SEC and supplier-to-supplier variability and, more critically, lot-to-lot variability in one manufactures supplied products were identified. LC-MS analysis identified a greater number of hexose-glycated arginine and lysine residues on OsrHSA compared to pHSA or rHSA expressed in yeast. This analysis also showed supplier-to-supplier and lot-to-lot variability in the degree of glycation at specific lysine and arginine residues for OsrHSA. Both the number of glycated residues and the degree of glycation correlated positively with the quantity of non-monomeric species and the chromatographic profiles of the samples. Tertiary structural changes were observed for most OsrHSA samples which correlated well

  10. Evaluation of an Albumin-Binding Domain Protein Fused to Recombinant Human IL-2 and Its Effects on the Bioactivity and Serum Half-Life of the Cytokine

    PubMed Central

    Adabi, Elham; Saebi, Fateme; Hasan-Abad, Amin Moradi; Teimoori-Toolabi, Ladan; Kardar, Gholam Ali

    2017-01-01

    Background: Cancer immunotherapy is a promising strategy for cancer treatment. In this strategy, the immune system is triggered to destroy cancer cells. IL-2 is an important factor in passive cancer immunotherapy that helps modulating some important immune functions. One of the IL-2 limitations is low serum half-life; therefore, repetitive high doses of the injections are required to maintain effective concentrations. High-dose IL-2 therapy results in severe side effects; thus, improvement of its serum half-life would provide therapeutic benefits. Methods: We have investigated a strategy that is able to utilize an albumin-binding domain (ABD) from streptococcal protein G. In this strategy, the fusion protein ABD-rIL-2 binds to serum albumin, which results in improvement of the IL-2 serum half-life. PET26b+ plasmid was used as an expression vector, which encoded rIL-2 and ABD-rIL-2, both fused to pelB secretion signal under the control of the strong bacteriophage T7 promoter. The constructs were expressed in E. coli Rosetta (DE3), and the recombinant proteins were purified from periplasmic fractions. Results: The analysis of in vitro bioactivity proved that the fusion of ABD to rIL-2 does not interfere with its bioactivity. ABD-rIL-2 fusion protein indicated higher serum half-life compared to rIL-2, when it was tested in the BALB/c mice. Conclusion: The current study provides an alternative strategy to extend the half-life and improve pharmacokinetic properties of rIL-2 without reducing its bioactivity in vitro. PMID:27805072

  11. Production of recombinant albumin by a herd of cloned transgenic cattle.

    PubMed

    Echelard, Yann; Williams, Jennifer L; Destrempes, Margaret M; Koster, Julie A; Overton, Susan A; Pollock, Daniel P; Rapiejko, Karen T; Behboodi, Esmail; Masiello, Nicholas C; Gavin, William G; Pommer, Jerry; Van Patten, Scott M; Faber, David C; Cibelli, Jose B; Meade, Harry M

    2009-06-01

    Purified plasma derived human albumin has been available as a therapeutic product since World War II. However, cost effective recombinant production of albumin has been challenging due to the amount needed and the complex folding pattern of the protein. In an effort to provide an abundant source of recombinant albumin, a herd of transgenic cows expressing high levels of rhA in their milk was generated. Expression cassettes efficiently targeting the secretion of human albumin to the lactating mammary gland were obtained and tested in transgenic mice. A high expressing transgene was transfected in primary bovine cell lines to produce karyoplasts for use in a somatic cell nuclear transfer program. Founder transgenic cows were produced from four independent cell lines. Expression levels varying from 1-2 g/l to more than 40 g/l of correctly folded albumin were observed. The animals expressing the highest levels of rhA exhibited shortened lactation whereas cows yielding 1-2 g/l had normal milk production. This herd of transgenic cattle is an easily scalable and well characterized source of rhA for biomedical uses.

  12. 21 CFR 640.80 - Albumin (Human).

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... a sterile solution of the albumin derived from human plasma. (b) Source material. The source material of Albumin (Human) shall be plasma recovered from Whole Blood prepared as prescribed in §§ 640.1 through 640.5, or Source Plasma prepared as prescribed in §§ 640.60 through 640.76. (c) Additives...

  13. 21 CFR 640.80 - Albumin (Human).

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... a sterile solution of the albumin derived from human plasma. (b) Source material. The source material of Albumin (Human) shall be plasma recovered from Whole Blood prepared as prescribed in §§ 640.1 through 640.5, or Source Plasma prepared as prescribed in §§ 640.60 through 640.76. (c) Additives...

  14. 21 CFR 640.80 - Albumin (Human).

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... a sterile solution of the albumin derived from human plasma. (b) Source material. The source material of Albumin (Human) shall be plasma recovered from Whole Blood prepared as prescribed in §§ 640.1 through 640.5, or Source Plasma prepared as prescribed in §§ 640.60 through 640.76. (c) Additives...

  15. 21 CFR 640.80 - Albumin (Human).

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... a sterile solution of the albumin derived from human plasma. (b) Source material. The source material of Albumin (Human) shall be plasma recovered from Whole Blood prepared as prescribed in §§ 640.1 through 640.5, or Source Plasma prepared as prescribed in §§ 640.60 through 640.76. (c) Additives...

  16. 21 CFR 640.80 - Albumin (Human).

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... a sterile solution of the albumin derived from human plasma. (b) Source material. The source material of Albumin (Human) shall be plasma recovered from Whole Blood prepared as prescribed in §§ 640.1 through 640.5, or Source Plasma prepared as prescribed in §§ 640.60 through 640.76. (c) Additives...

  17. Albumin-deficient mouse models for studying metabolism of human albumin and pharmacokinetics of albumin-based drugs

    PubMed Central

    Roopenian, Derry C; Low, Benjamin E; Christianson, Gregory J; Proetzel, Gabriele; Sproule, Thomas J; Wiles, Michael V

    2015-01-01

    Serum albumin is the major determinant of blood colloidal osmotic pressure acting as a depot and distributor of compounds including drugs. In humans, serum albumin exhibits an unusually long half-life mainly due to protection from catabolism by neonatal Fc receptor (FcRn)-mediated recycling. These properties make albumin an attractive courier of therapeutically-active compounds. However, pharmaceutical research and development of albumin-based therapeutics has been hampered by the lack of appropriate preclinical animal models. To overcome this, we developed and describe the first mouse with a genetic deficiency in albumin and its incorporation into an existing humanized FcRn mouse model, B6.Cg-Fcgrttm1Dcr Tg(FCGRT)32Dcr/DcrJ (Tg32). Albumin-deficient strains (Alb-/-) were created by TALEN-mediated disruption of the albumin (Alb) gene directly in fertilized oocytes derived from Tg32 mice and its non-transgenic background control, C57BL/6J (B6). The resulting Alb-/- strains are analbuminemic but healthy. Intravenous administration of human albumin to Tg32-Alb-/- mFcRn-/- hFcRnTg/Tg) mice results in a remarkably extended human albumin serum half-life of ∼24 days, comparable to that found in humans, and in contrast to half-lives of 2.6–5.8 d observed in B6, B6-Alb-/- and Tg32 strains. This striking increase can be explained by the absence of competing endogenous mouse albumin and the presence of an active human FcRn. These novel albumin-deficient models provide unique tools for investigating the biology and pathobiology of serum albumin and are a more appropriate rodent surrogates for evaluating human serum albumin pharmacokinetics and albumin-based compounds. PMID:25654695

  18. 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.

  19. Recombinant albumin adsorption on mica studied by AFM and streaming potential measurements.

    PubMed

    Kujda, Marta; Adamczyk, Zbigniew; Morga, Maria; Sofińska, Kamila

    2015-03-01

    Recombinant human serum albumin (rHSA) in monomeric state is widely used in pharmaceutical industry as a drug excipient and for preparing coatings for medical devices. In this work the adsorption process of rHSA on model mica surface at pH 3.5 was studied using the atomic force microscopy (AFM) and in situ streaming potential measurements. The kinetics of albumin adsorption was determined by a direct enumeration of single molecules over various substrate areas. These results were consistent with streaming potential measurements carried out for the parallel-plate channel flow and with theoretical predictions derived from the random sequential adsorption (RSA) model. Desorption kinetics of albumin under flow conditions was also evaluated via the streaming potential measurements. In this way, the amount of irreversibly bound albumin was quantitatively evaluated to be 0.64 and 1.2 mg m(-2) for ionic strength of 0.01 and 0.15 M, respectively. This agrees with previous results obtained for HSA and theoretical calculations derived from the RSA model. Additionally, it was demonstrated that there existed a fraction of reversibly bound albumin that can be fully eluted within a few hours. The binding energy of these fraction of molecules was -18 kT that is consistent with the electrostatic controlled adsorption mechanism of albumin at this pH. It was concluded that the rHSA monolayers of well-defined coverage can find applications for quantitatively analyzing ligand binding and for performing efficient biomaterials and immunological tests.

  20. M-M-R(®)II manufactured using recombinant human albumin (rHA) and M-M-R(®)II manufactured using human serum albumin (HSA) exhibit similar safety and immunogenicity profiles when administered as a 2-dose regimen to healthy children.

    PubMed

    Wiedmann, Richard T; Reisinger, Keith S; Hartzel, Jonathan; Malacaman, Edgardo; Senders, Shelly D; Giacoletti, Katherine E D; Shaw, Eric; Kuter, Barbara J; Schödel, Florian; Musey, Luwy K

    2015-04-27

    Prior to 2006, M-M-R(®)II (measles, mumps, and rubella virus vaccine live) was manufactured using human serum albumin (HSA) and each dose of the vaccine contained a relatively small amount (≤0.3mg) of HSA. Because of specific regulatory requirements and limited suppliers of HSA acceptable for human use, there was a need to replace HSA with recombinant human albumin (rHA) to mitigate any potential risk to the availability of M-M-R(®)II. Two different formulations of M-M-R(®)II manufactured using either rHA or HSA were clinically evaluated for safety and immunogenicity when administered as a 2-dose regimen to healthy children 12-18 months and 3-4 years of age. Adverse events, including those indicative of a possible hypersensitivity reaction, were collected for 42 days after each dose. Antibodies to measles, mumps, and rubella were measured before and approximately 6 weeks after dose 1. Antibodies to rHA were measured before and approximately 6 weeks after dose 1 and dose 2. Antibody seroconversion rates to measles, mumps, and rubella were 97.0%, 99.5%, and 99.7%, respectively, for recipients of M-M-R(®)II with rHA and 97.2%, 97.9%, and 99.6%, respectively, for recipients of M-M-R(®)II with HSA, and geometric mean titers to all 3 vaccine viral antigens were comparable between the 2 vaccination groups. The proportions of subjects who reported adverse events, including those suggestive of hypersensitivity reactions, after each dose of study vaccine were comparable between the 2 vaccination groups. No subject had detectable antibodies to rHA immediately prior to or following receipt of either the first or second dose of study vaccine. Given the comparable immunogenicity and safety profiles of both formulations, rHA is an acceptable replacement for HSA in the manufacture of M-M-R(®)II.

  1. 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

  2. Serial coupling of ion-exchange and size-exclusion chromatography to determine aggregation levels in mAbs in the presence of a proteinaceous excipient, recombinant human serum albumin.

    PubMed

    Weisbjerg, Paul Luigi Gargani; Caspersen, Mikael Bjerg; Cook, Ken; Van De Weert, Marco

    2015-02-01

    Aggregation levels of therapeutic proteins may be difficult to determine in mixtures containing other proteinaceous excipients. We performed a feasibility study of using serial coupling of an anion exchange and size exclusion column to determine the aggregation levels of four different model monoclonal antibodies (mAb) mixed with the model proteinaceous excipient recombinant human serum albumin (rHSA). For three of the four mAbs suitable elution conditions could be established. From the limitations imposed by the pI of the rHSA, the pI of the mAb and the nature of the columns used, it was possible to propose a set of general conditions that allows quantification of the aggregation level of a therapeutic protein in the presence of a proteinaceous excipient: The excipient protein and protein of interest should differ in pI by a minimum of 0.5 units, and the pI of the protein of interest should not be higher than ca. 8.5.

  3. Pseudo-esterase Activity of Human Albumin

    PubMed Central

    Lockridge, Oksana; Xue, Weihua; Gaydess, Andrea; Grigoryan, Hasmik; Ding, Shi-Jian; Schopfer, Lawrence M.; Hinrichs, Steven H.; Masson, Patrick

    2008-01-01

    Human albumin is thought to hydrolyze esters because multiple equivalents of product are formed for each equivalent of albumin. Esterase activity with p-nitrophenyl acetate has been attributed to turnover at tyrosine 411. However, p-nitrophenyl acetate creates multiple, stable, acetylated adducts, a property contrary to turnover. Our goal was to identify residues that become acetylated by p-nitrophenyl acetate and determine the relationship between stable adduct formation and turnover. Fatty acid-free human albumin was treated with 0.5 mm p-nitrophenyl acetate for 5 min to 2 weeks, or with 10 mm p-nitrophenyl acetate for 48 h to 2 weeks. Aliquots were digested with pepsin, trypsin, or GluC and analyzed by mass spectrometry to identify labeled residues. Only Tyr-411 was acetylated within the first 5 min of reaction with 0.5 mm p-nitrophenyl acetate. After 0.5–6 h there was partial acetylation of 16–17 residues including Asp-1, Lys-4, Lys-12, Tyr-411, Lys-413, and Lys-414. Treatment with 10 mm p-nitrophenyl acetate resulted in acetylation of 59 lysines, 10 serines, 8 threonines, 4 tyrosines, and Asp-1. When Tyr-411 was blocked with diisopropylfluorophosphate or chlorpyrifos oxon, albumin had normal esterase activity with β-naphthyl acetate as visualized on a nondenaturing gel. However, after 82 residues had been acetylated, esterase activity was almost completely inhibited. The half-life for deacetylation of Tyr-411 at pH 8.0, 22 °C was 61 ± 4 h. Acetylated lysines formed adducts that were even more stable. In conclusion, the pseudo-esterase activity of albumin is the result of irreversible acetylation of 82 residues and is not the result of turnover. PMID:18577514

  4. (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.

  5. Site-selective conjugation of an anticoagulant aptamer to recombinant albumins and maintenance of neonatal Fc receptor binding.

    PubMed

    Schmøkel, Julie; Voldum, Anders; Tsakiridou, Georgia; Kuhlmann, Matthias; Cameron, Jason; Sørensen, Esben; Wengel, Jesper; Howard, Kenneth A

    2017-03-31

    Aptamers are an attractive molecular medicine that offers high target specificity. Nucleic acid-based aptamers however, are prone to nuclease degradation and rapid renal excretion that require blood circulatory half-life extension enabling technologies. The long circulatory half-life, predominately facilitated by engagement with the cellular recycling neonatal Fc receptor (FcRn), and ligand transport properties of albumin promote it as an attractive candidate to improve the pharmacokinetic profile of aptamers. This study investigates the effect of Cys34 site-selective covalent attachment of a factor IXa anticoagulant aptamer on aptamer functionality and FcRn engagement using recombinant human albumin (rHA) of either a wild type (WT) or an engineered human FcRn high binding variant (HB). Aptamer-albumin conjugates, connected covalently through a heterobifunctional succinimidyl 4-(N-maleimidomethyl)cyclohexane-1-carboxylate linker, were successfully prepared and purified by high performance liquid chromatography as confirmed by gel electrophoresis band-shift analysis and matrix-assisted laser desorption/ionization time of flight. Minimal reduction (~ 25%) in activity of WT-linked aptamer to that of aptamer alone was found using an anticoagulant activity assay measuring temporal levels of activated partial thrombin. Covalent aptamer-albumin conjugation, however, substantially compromised binding to FcRn, to 10% affinity of that of non-conjugated WT, determined by biolayer interferometry. Binding could be rescued by aptamer conjugation to recombinant albumin engineered for higher FcRn affinity (HB) that exhibited an 8-fold affinity compared to WT alone. This work describes a novel albumin-based aptamer delivery system whose FcRn binding can be increased using a high binding engineered albumin.

  6. Fatty acid binding sites of human and bovine albumins: Differences observed by spin probe ESR

    NASA Astrophysics Data System (ADS)

    Muravsky, Vladimir; Gurachevskaya, Tatjana; Berezenko, Stephen; Schnurr, Kerstin; Gurachevsky, Andrey

    2009-09-01

    Bovine and human serum albumins and recombinant human albumin, all non-covalently complexed with 5- and 16-doxyl stearic acids, were investigated by ESR spectroscopy in solution over a range of pH values (5.5-8.0) and temperatures (25-50 °C), with respect to the allocation and mobility of fatty acid (FA) molecules bound to the proteins and conformation of the binding sites. In all proteins bound FA undergo a permanent intra-albumin migration between the binding sites and inter-domain residence. Nature identity of the recombinant human albumin to its serum-derived analog was observed. However, the binding sites of bovine albumin appeared shorter in length and wider in diameter than those of human albumin. Presumably, less tightly folded domains in bovine albumin allow better penetration of water molecules in the interior of the globule that resulted in higher activation energy of FA dissociation from the binding site. Thus, the sensitive technique based on ESR non-covalent spin labeling allowed quantitative analysis and reliable comparison of the fine features of binding proteins.

  7. Recombinant albumins containing additional peptide sequences smaller than barbourin retain the ability of barbourin-albumin to inhibit platelet aggregation.

    PubMed

    Sheffield, William P; Wilson, Brianna; Eltringham-Smith, Louise J; Gataiance, Sharon; Bhakta, Varsha

    2005-05-01

    The previously described fusion protein BLAH(6) (Marques JA et al.,Thromb Haemost 2001; 86: 902-8) is a recombinant protein that combines the small disintegrin barbourin with hexahistidine-tagged rabbit serumalbumin (RSA) produced in Pichia pastoris yeast. We sought to determine: (1) if BLAH(6) was immunogenic; and (2) if its barbourin domain could be productively replaced with smaller peptides. Purified BLAH(6) was injected into rabbits, and anti-barbourin antibodies were universally detected in plasma 28 days later; BLAH(6) was, however, equally effective in reducing platelet aggregation in both naive and pre-treated rabbits. Thrombocytopenia was not observed, and complexing BLAH(6) to alpha(IIb)beta(3) had no effect on antibody detection. The barbourin moiety of BLAH(6) was replaced with each of four sequences: Pep I (VCKGDWPC); PepII (VCRGDWPC); PepIII (bar-bourin 41-54); and PepIV (LPSPGDWR). The corresponding fusion proteins were tested for their ability to inhibit ADP-induced platelet aggregation. PepIII-LAH(6) inhibited neither rabbit nor human platelets. PepI-LAH(6) and PepIV-LAH(6) inhibited rabbit platelet aggregation as effectively as BLAH(6), but PepIV-LAH(6) did not inhibit human platelet aggregation. PepI-LAH(6) and PepIILAH(6) inhibited human platelet aggregation with IC(50)s 10- and 20-fold higher than BLAH(6). Cross-immunoprecipitation assays with human platelet lysates confirmed that all proteins and peptides interacted with the platelet integrin alpha(IIb)beta(3), but with greatly varying affinities. Our results suggest that the antiplatelet activity of BLAH(6) can be retained in albumin fusion proteins in which smaller peptides replace the barbourin domain; these proteins may be less immunogenic than BLAH(6).

  8. Interaction of amphiphilic drugs with human and bovine serum albumins

    NASA Astrophysics Data System (ADS)

    Khan, Abbul Bashar; Khan, Javed Masood; Ali, Mohd. Sajid; Khan, Rizwan Hasan; Kabir-ud-Din

    2012-11-01

    To know the interaction of amphiphilic drugs nortriptyline hydrochloride (NOT) and promazine hydrochloride (PMZ) with serum albumins (i.e., human serum albumin (HSA) and bovine serum albumin (BSA)), techniques of UV-visible, fluorescence, and circular dichroism (CD) spectroscopies are used. The binding affinity is more in case of PMZ with both the serum albumins. The quenching rate constant (kq) values suggest a static quenching process for all the drug-serum albumin interactions. The UV-visible results show that the change in protein conformation of PMZ-serum albumin interactions are more prominent as compared to NOT-serum albumin interactions. The CD results also explain the conformational changes in the serum albumins on binding with the drugs. The increment in %α-helical structure is slightly more for drug-BSA complexes as compared to drug-HSA complexes.

  9. Interaction of amphiphilic drugs with human and bovine serum albumins.

    PubMed

    Khan, Abbul Bashar; Khan, Javed Masood; Ali, Mohd Sajid; Khan, Rizwan Hasan; Kabir-Ud-Din

    2012-11-01

    To know the interaction of amphiphilic drugs nortriptyline hydrochloride (NOT) and promazine hydrochloride (PMZ) with serum albumins (i.e., human serum albumin (HSA) and bovine serum albumin (BSA)), techniques of UV-visible, fluorescence, and circular dichroism (CD) spectroscopies are used. The binding affinity is more in case of PMZ with both the serum albumins. The quenching rate constant (k(q)) values suggest a static quenching process for all the drug-serum albumin interactions. The UV-visible results show that the change in protein conformation of PMZ-serum albumin interactions are more prominent as compared to NOT-serum albumin interactions. The CD results also explain the conformational changes in the serum albumins on binding with the drugs. The increment in %α-helical structure is slightly more for drug-BSA complexes as compared to drug-HSA complexes.

  10. Extending the pharmacokinetic half-life of coagulation factors by fusion to recombinant albumin.

    PubMed

    Metzner, H J; Pipe, S W; Weimer, T; Schulte, S

    2013-11-01

    The prophylactic treatment of haemophilia B and the management of haemophilia A or B with inhibitors demand frequent administrations of coagulation factors due to the suboptimal half-lives of the products commercially available and currently in use, e.g. recombinant factor IX (rFIX) and recombinant factor VIIa (rFVIIa), respectively. The extension of the half-lives of rFIX and rFVIIa could allow for longer intervals between infusions and could thereby improve adherence and clinical outcomes and may improve quality of life. Albumin fusion is one of a number of different techniques currently being examined to prolong the half-life of rFIX and rFVIIa. Results from a phase I clinical trial demonstrated that the recombinant fusion protein linking FIX to albumin (rIX-FP) has a five-times longer half-life than rFIX, and preclinical studies with the recombinant fusion protein linking FVIIa to albumin (rVIIa-FP) suggest that rVIIa-FP possesses a significantly extended half-life versus rFVIIa. In this review, we describe albumin fusion technology and examine the recent progress in the development of rIX-FP and rVIIa-FP.

  11. Thiophilic interaction chromatography of serum albumins.

    PubMed

    Bourhim, Mustapha; Rajendran, Anita; Ramos, Yanira; Srikrishnan, Thamarapu; Sulkowski, Eugene

    2008-07-01

    An investigation of the binding of native and recombinant human serum albumin and bovine serum albumin on three thiophilic gels, PyS, 2S, and 3S was performed. In addition to these proteins, we studied serum albumins from several species such as goat, rabbit, guinea pig, rat, hamster, baboon, and pig. Our results reveal that recombinant human serum albumin (rHSA) binds completely to PyS whereas native human serum albumin and bovine serum albumin bind only partially to PyS. The binding affinities of rHSA, human serum albumin and bovine serum albumin to 2S and 3S gels are less than their binding to PyS. Serum albumins from goat, rabbit, guinea pig, rat, hamster, baboon, and pig bind much stronger to 3S gel than human and bovine serum albumins. The binding of pig and hamster serum albumins is stronger than that of rat, goat, baboon, and rabbit.

  12. Antioxidant flavonoids bind human serum albumin

    NASA Astrophysics Data System (ADS)

    Kanakis, C. D.; Tarantilis, P. A.; Polissiou, M. G.; Diamantoglou, S.; Tajmir-Riahi, H. A.

    2006-10-01

    Human serum albumin (HSA) is a principal extracellular protein with a high concentration in blood plasma and carrier for many drugs to different molecular targets. Flavonoids are powerful antioxidants and prevent DNA damage. The antioxidative protections are related to their binding modes to DNA duplex and complexation with free radicals in vivo. However, flavonoids are known to inhibit the activities of several enzymes such as calcium phospholipid-dependent protein kinase, tyrosine protein kinase from rat lung, phosphorylase kinase, phosphatidylinositol 3-kinase and DNA topoisomerases that exhibit the importance of flavonoid-protein interaction. This study was designed to examine the interaction of human serum albumin (HSA) with quercetin (que), kaempferol (kae) and delphinidin (del) in aqueous solution at physiological conditions, using constant protein concentration of 0.25 mM (final) and various drug contents of 1 μM-1 mM. FTIR and UV-vis spectroscopic methods were used to determine the polyphenolic binding mode, the binding constant and the effects of flavonoid complexation on protein secondary structure. The spectroscopic results showed that flavonoids are located along the polypeptide chains through H-bonding interactions with overall affinity constant of Kque = 1.4 × 10 4 M -1, Kkae = 2.6 × 10 5 M -1 and Kdel = 4.71 × 10 5 M -1. The protein secondary structure showed no alterations at low pigment concentration (1 μM), whereas at high flavonoid content (1 mM), major reduction of α-helix from 55% (free HSA) to 42-46% and increase of β-sheet from 15% (free HSA) to 17-19% and β-anti from 7% (free HSA) to 10-20% occurred in the flavonoid-HSA adducts. The major reduction of HSA α-helix is indicative of a partial protein unfolding upon flavonoid interaction.

  13. 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.

  14. Resveratrol binding to human serum albumin.

    PubMed

    N' soukpoe-Kossi, C N; St-Louis, C; Beauregard, M; Subirade, M; Carpentier, R; Hotchandani, S; Tajmir-Riahi, H A

    2006-12-01

    Resveratrol (Res), a polyphenolic compound found largely in the skin of red grape and wine, exhibits a wide range of pharmaceutical properties and plays a role in prevention of human cardiovascular diseases [Pendurthi et al., Arterioscler. Thromb. Vasc. Biol. 19, 419-426 (1999)]. It shows a strong affinity towards protein binding and used as inhibitor for cyclooxygenase and ribonuclease reductase. The aim of this study was to examine the interaction of resveratrol with human serum albumin (HSA) in aqueous solution at physiological conditions, using a constant protein concentration (0.3 mM) and various pigment contents (microM to mM). FTIR, UV-Visible, CD, and fluorescence spectroscopic methods were used to determine the resveratrol binding mode, the binding constant and the effects of pigment complexation on protein secondary structure. Structural analysis showed that resveratrol bind non-specifically (H-bonding) via polypeptide polar groups with overall binding constant of K(Res) = 2.56 x 10(5) M(-1). The protein secondary structure, analysed by CD spectroscopy, showed no major alterations at low resveratrol concentrations (0.125 mM), whereas at high pigment content (1 mM), major increase of alpha-helix from 57% (free HSA) to 62% and a decrease of beta-sheet from 10% (free HSA) to 7% occurred in the resveratrol-HSA complexes. The results indicate a partial stabilization of protein secondary structure at high resveratrol content.

  15. Production of Human Albumin in Pigs Through CRISPR/Cas9-Mediated Knockin of Human cDNA into Swine Albumin Locus in the Zygotes.

    PubMed

    Peng, Jin; Wang, Yong; Jiang, Junyi; Zhou, Xiaoyang; Song, Lei; Wang, Lulu; Ding, Chen; Qin, Jun; Liu, Liping; Wang, Weihua; Liu, Jianqiao; Huang, Xingxu; Wei, Hong; Zhang, Pumin

    2015-11-12

    Precise genome modification in large domesticated animals is desirable under many circumstances. In the past it is only possible through lengthy and burdensome cloning procedures. Here we attempted to achieve that goal through the use of the newest genome-modifying tool CRISPR/Cas9. We set out to knockin human albumin cDNA into pig Alb locus for the production of recombinant human serum albumin (rHSA). HSA is a widely used human blood product and is in high demand. We show that homologous recombination can occur highly efficiently in swine zygotes. All 16 piglets born from the manipulated zygotes carry the expected knockin allele and we demonstrated the presence of human albumin in the blood of these piglets. Furthermore, the knockin allele was successfully transmitted through germline. This success in precision genomic engineering is expected to spur exploration of pigs and other large domesticated animals to be used as bioreactors for the production of biomedical products or creation of livestock strains with more desirable traits.

  16. Review: Glycation of human serum albumin

    PubMed Central

    Anguizola, Jeanethe; Matsuda, Ryan; Barnaby, Omar S.; Joseph, K.S.; Wa, Chunling; DeBolt, Erin; Koke, Michelle; Hage, David S.

    2013-01-01

    Glycation involves the non-enzymatic addition of reducing sugars and/or their reactive degradation products to amine groups on proteins. This process is promoted by the presence of elevated blood glucose concentrations in diabetes and occurs with various proteins that include human serum albumin (HSA). This review examines work that has been conducted in the study and analysis of glycated HSA. The general structure and properties of HSA are discussed, along with the reactions that can lead to modification of this protein during glycation. The use of glycated HSA as a short-to-intermediate term marker for glycemic control in diabetes is examined, and approaches that have been utilized for measuring glycated HSA are summarized. Structural studies of glycated HSA are reviewed, as acquired for both in vivo and in vitro glycated HSA, along with data that have been obtained on the rate and thermodynamics of HSA glycation. In addition, this review considers various studies that have investigated the effects of glycation on the binding of HSA with drugs, fatty acids and other solutes and the potential clinical significance of these effects. PMID:23891854

  17. Nephroprotective Potential of Human Albumin Infusion: A Narrative Review

    PubMed Central

    Wiedermann, Christian J.; Joannidis, Michael

    2015-01-01

    Albumin infusion improves renal function in cirrhosis; however, mechanisms are incompletely understood. In clinical practice, human albumin is used in various intensive care unit indications to deal with a wide range of problems, from volume replacement in hypovolemic shock, or sepsis, to treatment of ascites in patients with liver cirrhosis. Against the background of the results of recent studies on the use of human albumin in septic patients, the importance of the natural colloid in these critically ill patients is being redefined. In addition to the hemodynamic effects of administration of human albumin impacting on sympathetic tone, attention is being paid to other effects in which its pharmacodynamics is associated with the physiological importance of endogenous albumin. The morbidity and mortality data discussed in this paper support the importance of both the hemodynamic and the pharmacological effects of the administration of human albumin in various indications. The contribution that human albumin could make towards the maintenance of renal function in the course and treatment of severe sepsis and cirrhosis of the liver is the subject of this narrative review. PMID:26136776

  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. 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.

  20. Polyamine analogues bind human serum albumin.

    PubMed

    Beauchemin, R; N'soukpoé-Kossi, C N; Thomas, T J; Thomas, T; Carpentier, R; Tajmir-Riahi, H A

    2007-10-01

    Polyamine analogues show antitumor activity in experimental models, and their ability to alter activity of cytotoxic chemotherapeutic agents in breast cancer is well documented. Association of polyamines with nucleic acids and protein is included in their mechanism of action. The aim of this study was to examine the interaction of human serum albumin (HSA) with several polyamine analogues, such as 1,11-diamino-4,8-diazaundecane (333), 3,7,11,15-tetrazaheptadecane.4HCl (BE-333), and 3,7,11,15,19-pentazahenicosane.5HCl (BE-3333), in aqueous solution at physiological conditions using a constant protein concentration and various polyamine contents (microM to mM). FTIR, UV-visible, and CD spectroscopic methods were used to determine the polyamine binding mode and the effects of polyamine complexation on protein stability and secondary structure. Structural analysis showed that polyamines bind nonspecifically (H-bonding) via polypeptide polar groups with binding constants of K333 = 9.30 x 10(3) M(-1), KBE-333 = 5.63 x 10(2) M(-1), and KBE-3333 = 3.66 x 10(2) M(-1). The protein secondary structure showed major alterations with a reduction of alpha-helix from 55% (free protein) to 43-50% and an increase of beta-sheet from 17% (free protein) to 29-36% in the 333, BE-333, and BE-3333 complexes, indicating partial protein unfolding upon polyamine interaction. HSA structure was less perturbed by polyamine analogues compared to those of the biogenic polyamines.

  1. 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.

  2. Recombinant fusion protein of albumin-retinol binding protein inactivates stellate cells

    SciTech Connect

    Choi, Soyoung; Park, Sangeun; Kim, Suhyun; Lim, Chaeseung; Kim, Jungho; Cha, Dae Ryong; Oh, Junseo

    2012-02-03

    Highlights: Black-Right-Pointing-Pointer We designed novel recombinant albumin-RBP fusion proteins. Black-Right-Pointing-Pointer Expression of fusion proteins inactivates pancreatic stellate cells (PSCs). Black-Right-Pointing-Pointer Fusion proteins are successfully internalized into and inactivate PSCs. Black-Right-Pointing-Pointer RBP moiety mediates cell specific uptake of fusion protein. -- Abstract: Quiescent pancreatic- (PSCs) and hepatic- (HSCs) stellate cells store vitamin A (retinol) in lipid droplets via retinol binding protein (RBP) receptor and, when activated by profibrogenic stimuli, they transform into myofibroblast-like cells which play a key role in the fibrogenesis. Despite extensive investigations, there is, however, currently no appropriate therapy available for tissue fibrosis. We previously showed that the expression of albumin, composed of three homologous domains (I-III), inhibits stellate cell activation, which requires its high-affinity fatty acid-binding sites asymmetrically distributed in domain I and III. To attain stellate cell-specific uptake, albumin (domain I/III) was coupled to RBP; RBP-albumin{sup domain} {sup III} (R-III) and albumin{sup domain} {sup I}-RBP-albumin{sup III} (I-R-III). To assess the biological activity of fusion proteins, cultured PSCs were used. Like wild type albumin, expression of R-III or I-R-III in PSCs after passage 2 (activated PSCs) induced phenotypic reversal from activated to fat-storing cells. On the other hand, R-III and I-R-III, but not albumin, secreted from transfected 293 cells were successfully internalized into and inactivated PSCs. FPLC-purified R-III was found to be internalized into PSCs via caveolae-mediated endocytosis, and its efficient cellular uptake was also observed in HSCs and podocytes among several cell lines tested. Moreover, tissue distribution of intravenously injected R-III was closely similar to that of RBP. Therefore, our data suggest that albumin-RBP fusion protein comprises

  3. Selection of Recombinant Human Antibodies.

    PubMed

    Tomszak, Florian; Weber, Susanne; Zantow, Jonas; Schirrmann, Thomas; Hust, Michael; Frenzel, André

    2016-01-01

    Since the development of therapeutic antibodies the demand of recombinant human antibodies is steadily increasing. Traditionally, therapeutic antibodies were generated by immunization of rat or mice, the generation of hybridoma clones, cloning of the antibody genes and subsequent humanization and engineering of the lead candidates. In the last few years, techniques were developed that use transgenic animals with a human antibody gene repertoire. Here, modern recombinant DNA technologies can be combined with well established immunization and hybridoma technologies to generate already affinity maturated human antibodies. An alternative are in vitro technologies which enabled the generation of fully human antibodies from antibody gene libraries that even exceed the human antibody repertoire. Specific antibodies can be isolated from these libraries in a very short time and therefore reduce the development time of an antibody drug at a very early stage.In this review, we describe different technologies that are currently used for the in vitro and in vivo generation of human antibodies.

  4. TALEN-mediated modification of the bovine genome for large-scale production of human serum albumin.

    PubMed

    Moghaddassi, Shaida; Eyestone, Will; Bishop, Colin E

    2014-01-01

    As an initial step towards creating genetically modified cattle as a biopharming source of recombinant human serum albumin (rHSA), we report modification of the bovine albumin (bA) locus by transcription activator-like effector nuclease (TALEN)-stimulated homology-directed repair (HDR). Pedigreed bovine fibroblasts were co-transfected with TALENs and an 11.5-kb human serum albumin (HSA) minigene donor construct, designed to simultaneously disrupt and replace bovine serum albumin (BSA) expression with controlled rHSA expression in both the liver and the milk. Targeted integration of the HSA minigene was confirmed in transfected fibroblasts at a frequency of approximately 11% and transgenic bovine embryos were produced from targeted fibroblasts using somatic cell nuclear transfer (SCNT). The research delineated here lays the foundation for the future generation of transgenic rHSA cattle with the potential to provide a large-scale, reliable, and quality-controlled source of rHSA.

  5. The exclusion of human serum albumin by human dermal collagenous fibres and within human dermis.

    PubMed Central

    Bert, J L; Mathieson, J M; Pearce, R H

    1982-01-01

    Preparations of dermal collagenous fibres and slices of human dermis have been equilibrated with 125I-labelled monomeric human serum albumin. The space inaccessible to the albumin in the fibres and in the dermis was determined by subtraction of the accessible space, calculated from the radioactivity of the specimen, from its total fluid. For a fibre preparation examined in detail, the fluid exclusion was independent of the concentration of either albumin or collagen. Binding of albumin to the fibres was not demonstrable. Three fibre preparations excluded albumin from 3.75 +/- 0.96, 3.55 +/- 0.67, and 2.05 +/- 0.39 g of fluid/g of collagen (+/-S.D.). Slices from three specimens of dermis excluded albumin from 1.45 +/- 0.08 g of fluid/g of insoluble solids or 1.57 +/- 0.11 g of fluid/g of collagen (+/-S.D.). Thus the exclusion of albumin by dermis was much less than expected from its content of collagenous fibres. On the basis of these data and the published composition of dermis, the concentration of albumin in the accessible interstitial space was estimated to be close to that in the plasma. PMID:7082298

  6. Interaction of mycotoxin zearalenone with human serum albumin.

    PubMed

    Poór, Miklós; Kunsági-Máté, Sándor; Bálint, Mónika; Hetényi, Csaba; Gerner, Zsófia; Lemli, Beáta

    2017-03-27

    Zearalenone (ZEN) is a mycotoxin produced mainly by Fusarium species. Fungal contamination of cereals and plants can result in the formation of ZEN, leading to its presence in different foods, animal feeds, and drinks. Because ZEN is an endocrine disruptor, it causes reproductive disorders in farm animals and hyperoestrogenic syndromes in humans. Despite toxicokinetic properties of ZEN were studied in more species, we have no information regarding the interaction of ZEN with serum albumin. Since albumin commonly plays an important role in the toxicokinetics of different toxins, interaction of ZEN with albumin has of high biological importance. Therefore the interaction of ZEN with human serum albumin (HSA) was investigated using spectroscopic methods, ultrafiltration, and molecular modeling studies. Fluorescence spectroscopic studies demonstrate that ZEN forms complex with HSA. Binding constant (K) of ZEN-HSA complex was quantified with fluorescence quenching technique. The determined binding constant (logK=5.1) reflects the strong interaction of ZEN with albumin suggesting the potential biological importance of ZEN-HSA complex formation. Based on the results of the investigations with site markers as well as docking studies, ZEN occupies a non-conventional binding site on HSA. Considering the above listed observations, we should keep in mind this interaction if we would like to precisely understand the toxicokinetic behavior of ZEN.

  7. Biocompatibility of electrospun human albumin: a pilot study.

    PubMed

    Noszczyk, B H; Kowalczyk, T; Łyżniak, M; Zembrzycki, K; Mikułowski, G; Wysocki, J; Kawiak, J; Pojda, Z

    2015-03-02

    Albumin is rarely used for electrospinning because it does not form fibres in its native globular form. This paper presents a novel method for electrospinning human albumin from a solution containing pharmaceutical grade protein and 25% polyethylene oxide (PEO) used as the fibre-forming agent. After spontaneous cross-linking at body temperature, with no further chemicals added, the fibres become insoluble and the excess PEO can be washed out. Albumin deposited along the fibres retains its native characteristics, such as its non-adhesiveness to cells and its susceptibility for degradation by macrophages. To demonstrate this we evaluated the mechanical properties, biocompatibility and biodegradability of this novel product. After subcutaneous implantation in mice, albumin mats were completely resorbable within six days and elicited only a limited local inflammatory response. In vitro, the mats suppressed cell attachment and migration. As this product is inexpensive, produced from human pharmaceutical grade albumin without chemical modifications, retains its native protein properties and fulfils the specific requirements for anti-adhesive dressings, its clinical use can be expedited. We believe that it could specifically be used when treating paediatric patients with epidermolysis bullosa, in whom non-healing wounds occur after minor hand injuries which lead to rapid adhesions and devastating contractures.

  8. Development of Recombinant Lactococcus lactis Displaying Albumin-Binding Domain Variants against Shiga Toxin 1 B Subunit

    PubMed Central

    Zadravec, Petra; Marečková, Lucie; Petroková, Hana; Hodnik, Vesna; Perišić Nanut, Milica; Anderluh, Gregor; Štrukelj, Borut; Malý, Petr; Berlec, Aleš

    2016-01-01

    Infections with shiga toxin-producing bacteria, like enterohemorrhagic Escherichia coli and Shigella dysenteriae, represent a serious medical problem. No specific and effective treatment is available for patients with these infections, creating a need for the development of new therapies. Recombinant lactic acid bacterium Lactococcus lactis was engineered to bind Shiga toxin by displaying novel designed albumin binding domains (ABD) against Shiga toxin 1 B subunit (Stx1B) on their surface. Functional recombinant Stx1B was produced in Escherichia coli and used as a target for selection of 17 different ABD variants (named S1B) from the ABD scaffold-derived high-complex combinatorial library in combination with a five-round ribosome display. Two most promising S1Bs (S1B22 and S1B26) were characterized into more details by ELISA, surface plasmon resonance and microscale thermophoresis. Addition of S1Bs changed the subcellular distribution of Stx1B, completely eliminating it from Golgi apparatus most likely by interfering with its retrograde transport. All ABD variants were successfully displayed on the surface of L. lactis by fusing to the Usp45 secretion signal and to the peptidoglycan-binding C terminus of AcmA. Binding of Stx1B by engineered lactococcal cells was confirmed using flow cytometry and whole cell ELISA. Lactic acid bacteria prepared in this study are potentially useful for the removal of Shiga toxin from human intestine. PMID:27606705

  9. Conjugation of organoruthenium(II) 3-(1H-benzimidazol-2-yl)pyrazolo[3,4-b]pyridines and indolo[3,2-d]benzazepines to recombinant human serum albumin: a strategy to enhance cytotoxicity in cancer cells.

    PubMed

    Stepanenko, Iryna N; Casini, Angela; Edafe, Fabio; Novak, Maria S; Arion, Vladimir B; Dyson, Paul J; Jakupec, Michael A; Keppler, Bernhard K

    2011-12-19

    Following our strategy of coupling cyclin-dependent kinase (Cdk) inhibitors with organometallic moieties to improve their physicochemical properties and bioavailability, five organoruthenium complexes (1c-5c) of the general formula [RuCl(η(6)-arene)(L)]Cl have been synthesized in which the arene is 4-formylphenoxyacetyl-η(6)-benzylamide and L is a Cdk inhibitor [3-(1H-benzimidazol-2-yl)-1H-pyrazolo[3,4-b]pyridines (L1-L3) and indolo[3,2-d]benzazepines (L4 and L5)]. All of the compounds were characterized by spectroscopic and analytical methods. Upon prolonged standing (2-3 months) at room temperature, the dimethyl sulfoxide (DMSO) solutions of 1c and 2c(-HCl) afforded residues, which after recrystallization from EtOH and EtOH/H(2)O, respectively, were shown by X-ray diffraction to be cis,cis-[Ru(II)Cl(2)(DMSO)(2)(L1)]·H(2)O and mer-[Ru(II)Cl(DMSO)(3)(L2-H)]·H(2)O. Compound 5c, with a coordinated amidine unit, undergoes E/Z isomerization in solution. The antiproliferative activities and effects on the cell cycle of the new compounds were evaluated. Complexes 1c-5c are moderately cytotoxic to cancer cells (CH1, SW480, A549, A2780, and A2780cisR cell lines). Therefore, in order to improve their antiproliferative effects, as well as their drug targeting and delivery to cancer cells, 1c-5c were conjugated to recombinant human serum albumin, potentially exploiting the so-called "enhanced permeability and retention" effect that results in the accumulation of macromolecules in tumors. Notably, a marked increase in cytotoxicity of the albumin conjugates was observed in all cases.

  10. Interactive association of drugs binding to human serum albumin.

    PubMed

    Yang, Feng; Zhang, Yao; Liang, Hong

    2014-02-27

    Human serum albumin (HSA) is an abundant plasma protein, which attracts great interest in the pharmaceutical industry since it can bind a remarkable variety of drugs impacting their delivery and efficacy and ultimately altering the drug's pharmacokinetic and pharmacodynamic properties. Additionally, HSA is widely used in clinical settings as a drug delivery system due to its potential for improving targeting while decreasing the side effects of drugs. It is thus of great importance from the viewpoint of pharmaceutical sciences to clarify the structure, function, and properties of HSA-drug complexes. This review will succinctly outline the properties of binding site of drugs in IIA subdomain within the structure of HSA. We will also give an overview on the binding characterization of interactive association of drugs to human serum albumin that may potentially lead to significant clinical applications.

  11. 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.

  12. 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.

  13. Binding of furosemide to albumin isolated from human fetal and adult serum.

    PubMed

    Viani, A; Cappiello, M; Silvestri, D; Pacifici, G M

    1991-01-01

    Albumin was isolated from pooled fetal serum from 58 placentas obtained at normal delivery at term and from pooled adult plasma from 8 individuals. Albumin isolation was carried out by means of PEG precipitation followed by ion-exchange chromatography on DEAE-Sephadex A 50 and then on SP-Sephadex C 50. The electrophoresis on SDS-polyacrylamide gels showed only one spot that comigrated with commercial human albumin. Binding to albumin was measured by equilibrium dialysis of an aliquot of albumin solution (0.7 ml) against the same volume of 0.13 M sodium orthophosphate buffer (pH 7.4). At a total concentration of 2 micrograms/ml (therapeutic range), the unbound fraction of furosemide was 2.71% (fetal albumin) and 2.51% (adult albumin). Two classes of binding sites for furosemide were observed in fetal and adult albumin. The number of binding sites (moles of furosemide per mole of albumin) was 1.22 (fetal albumin) and 1.58 (adult albumin) for the high-affinity site and 2.97 (fetal albumin) and 3.25 (adult albumin) for the low-affinity site. The association constants (M-1) were 3.1 X 10(4) (fetal albumin) and 2.6 X 10(4) (adult albumin) for the high-affinity set of sites and 0.83 X 10(4) (fetal albumin) and 1.0 X 10(4) (adult albumin) low-affinity site. The displacement of furosemide from albumin was studied with therapeutic concentrations of several drugs. Valproic acid, salicylic acid, azapropazone and tolbutamide had the highest displacing effects which were significantly higher with fetal than with adult albumin.

  14. Interaction of human serum albumin and its clinically relevant modification with oligoribonucleotides.

    PubMed

    Gerasimova, Yuliya V; Erchenko, Irina A; Shakirov, Makhmut M; Godovikova, Tatyana S

    2008-08-15

    Human serum albumin (HSA) was shown to mediate oligoribonucleotide cleavage. Nonenzymatic glycation of HSA decreased the ribonuclease-like activity of the protein. According to (31)P NMR data, both native and glycated albumins induced hydrolysis of RNA molecule through 2',3'-cyclophosphate intermediates. A feasible mechanism of RNA hydrolysis by native albumin and its clinically relevant modification was discussed.

  15. 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.

  16. 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.

  17. Biomolecular Interaction Study of Cyclolinopeptide A with Human Serum Albumin

    PubMed Central

    Rempel, Ben; Gui, Bo; Maley, Jason; Reaney, Martin; Sammynaiken, Ramaswami

    2010-01-01

    The kinetics, energetics, and structure of Cyclolinopeptide A binding with Human Serum Albumin were investigated with surface plasmon resonance and circular dichroism. The complex is formed through slow recognition kinetics that is temperature sensitive in the range of 20°C–37°C. The overall reaction was observed to be endothermic (ΔH = 204 kJ mol−1) and entropy driven (ΔS = 746 J mol−1K−1) with overall small changes to the tertiary structure. PMID:21436992

  18. Photoexcited riboflavin induces oxidative damage to human serum albumin

    NASA Astrophysics Data System (ADS)

    Hirakawa, Kazutaka; Yoshioka, Takuto

    2015-08-01

    Photoexcited riboflavin induced damage of human serum albumin (HSA), a water soluble protein, resulting in the diminishment of fluorescence from the tryptophan residue. Because riboflavin hardly photosensitized singlet oxygen generation and sodium azide, a singlet oxygen quencher, did not inhibit protein damage, electron transfer-mediated oxidation of HSA was speculated. Fluorescence lifetime of riboflavin was not affected by HSA, suggesting that the excited triplet state of riboflavin is responsible for protein damage through electron transfer. In addition, the preventive effect of xanthone derivatives, triplet quenchers, on photosensitized protein damage could be evaluated using this photosensitized reaction system of riboflavin and HSA.

  19. A New Application for Albumin Dialysis in Extracorporeal Organ Support: Characterization of a Putative Interaction Between Human Albumin and Proinflammatory Cytokines IL-6 and TNFα.

    PubMed

    Pfensig, Claudia; Dominik, Adrian; Borufka, Luise; Hinz, Michael; Stange, Jan; Eggert, Martin

    2016-04-01

    Albumin dialysis in extracorporeal organ support is often performed in the treatment of liver failure as it facilitates the removal of toxic components from the blood. Here, we describe a possible effect of albumin dialysis on proinflammatory cytokine levels in vitro. Initially, albumin samples were incubated with different amounts of cytokines and analyzed by enzyme-linked immunosorbent assay (ELISA). Analysis of interleukin 6 (IL-6) and tumor necrosis factor alpha (TNFα) levels indicated that increased concentrations of albumin reduce the measureable amount of the respective cytokines. This led to the hypothesis that the used proinflammatory cytokines may interact with albumin. Size exclusion chromatography of albumin spiked with cytokines was carried out using high-performance liquid chromatography analysis. The corresponding fractions were evaluated by immunoblotting. We detected albumin and cytokines in the same fractions indicating an interaction of the small-sized cytokines IL-6 and TNFα with the larger-sized albumin. Finally, a two-compartment albumin dialysis in vitro model was used to analyze the effect of albumin on proinflammatory cytokines in the recirculation circuit during 6-h treatment. These in vitro albumin dialysis experiments indicated a significant decrease of IL-6, but not of TNFα, when albumin was added to the dialysate solution. Taken together, we were able to show a putative in vitro interaction of human albumin with the proinflammatory cytokine IL-6, but with less evidence for TNFα, and demonstrated an additional application for albumin dialysis in liver support therapy where IL-6 removal might be indicated.

  20. Comparison of albumin receptors expressed on bovine and human group G streptococci.

    PubMed Central

    Raeder, R; Otten, R A; Boyle, M D

    1991-01-01

    The albumin receptor expressed by bovine group G streptococci was extracted and affinity purified. The protein was characterized for species reactivity, and monospecific antibodies were prepared to the purified receptor. The bovine group G albumin receptor was compared functionally, antigenically, and for DNA homology with the albumin-binding protein expressed by human group G streptococci. In agreement with previous reports, the albumin-binding activity of human strains was mediated by a unique domain of the type III immunoglobulin G-Fc-binding molecule, protein G. The albumin receptor expressed by bovine group G strains was found to lack any immunoglobulin G-binding potential but displayed a wider profile of species albumin reactivity than protein G. Both albumin receptors could inhibit the binding of the other to immobilized human serum albumin, and each displayed similar binding properties. Antigenic comparison of the two albumin receptors demonstrated a low level of cross-reactivity; however comparison at the DNA level, using an oligonucleotide probe specific for the albumin-binding region of protein G, demonstrated that the two albumin receptors expressed by human and bovine group G streptococcal strains do not display significant homology. Images PMID:1846128

  1. 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.

  2. DNA recombination. Recombination initiation maps of individual human genomes.

    PubMed

    Pratto, Florencia; Brick, Kevin; Khil, Pavel; Smagulova, Fatima; Petukhova, Galina V; Camerini-Otero, R Daniel

    2014-11-14

    DNA double-strand breaks (DSBs) are introduced in meiosis to initiate recombination and generate crossovers, the reciprocal exchanges of genetic material between parental chromosomes. Here, we present high-resolution maps of meiotic DSBs in individual human genomes. Comparing DSB maps between individuals shows that along with DNA binding by PRDM9, additional factors may dictate the efficiency of DSB formation. We find evidence for both GC-biased gene conversion and mutagenesis around meiotic DSB hotspots, while frequent colocalization of DSB hotspots with chromosome rearrangement breakpoints implicates the aberrant repair of meiotic DSBs in genomic disorders. Furthermore, our data indicate that DSB frequency is a major determinant of crossover rate. These maps provide new insights into the regulation of meiotic recombination and the impact of meiotic recombination on genome function.

  3. [Excess mortality in critically ill patients after treatment with human albumin].

    PubMed

    Offringa, M; Gemke, R J; Henny, C P

    1998-08-15

    According to the results of a systematic review of randomized clinical studies administration of human albumin to critically ill patients is associated with excess mortality, compared with withholding albumin or administration of crystalloid fluids. The study appears to be well done. Also, there are various explanatory pathophysiological mechanisms supporting the association. However, a favourable effect of albumin in certain patient groups cannot be excluded. Alternatives to albumin are available in most clinical situations, but unfortunately, they are not completely without drawbacks. The use of albumin has to be limited; it might only be abolished when a better effect of other fluids, such as synthetic solutions, is demonstrated.

  4. Human Insulin from Recombinant DNA Technology

    NASA Astrophysics Data System (ADS)

    Johnson, Irving S.

    1983-02-01

    Human insulin produced by recombinant DNA technology is the first commercial health care product derived from this technology. Work on this product was initiated before there were federal guidelines for large-scale recombinant DNA work or commercial development of recombinant DNA products. The steps taken to facilitate acceptance of large-scale work and proof of the identity and safety of such a product are described. While basic studies in recombinant DNA technology will continue to have a profound impact on research in the life sciences, commercial applications may well be controlled by economic conditions and the availability of investment capital.

  5. Recombinant Human Papillomavirus (HPV) Quadrivalent Vaccine

    Cancer.gov

    This page contains brief information about recombinant human papillomavirus (HPV) quadrivalent vaccine and a collection of links to more information about the use of this vaccine, research results, and ongoing clinical trials.

  6. Recombinant Human Papillomavirus (HPV) Bivalent Vaccine

    Cancer.gov

    This page contains brief information about recombinant human papillomavirus (HPV) bivalent vaccine and a collection of links to more information about the use of this vaccine, research results, and ongoing clinical trials.

  7. Recombinant Human Papillomavirus (HPV) Nonavalent Vaccine

    Cancer.gov

    This page contains brief information about recombinant human papillomavirus (HPV) nonavalent vaccine and a collection of links to more information about the use of this vaccine, research results, and ongoing clinical trials.

  8. A monoclonal IgM protein with antibody-like activity for human albumin.

    PubMed

    Hauptman, S; Tomasi, T B

    1974-03-01

    The serum of a patient (L'ec) with an IgM lambda monoclonal protein was noted to bind albumin on immunoelectrophoresis. Analytical ultracentrifugation of the L'ec serum demonstrated 23S and 12S peaks, but no 4S (albumin) boundary. Immunologically identical 20S and 9S IgM proteins were isolated from the serum and the addition in vitro of either the patient's albumin or albumin isolated from normal serum was shown to reconstitute the 23S and 12S boundaries. The binding of high molecular weight IgM to albumin was demonstated by Sephadex G200 chromatography with (125)I-labeled albumin and isolated IgM. Immunoelectrophoresis of the L'ec IgM developed with aggregated albumin (reverse immunoelectrophoresis) also demonstrated the binding of albumin to IgM. That all of the patient's IgM complexed with albumin was shown by affinity chromatography employing an aggregated albumin-immunoadsorbent column. Binding was shown to be of the noncovalent type by polyacrylamide gel electrophoresis in 8 M urea. With hot trypsin proteolysis, Fabmu and Fcmu5 fragments were isolated, and monomer albumin was shown to complex only with the Fabmu fragment by both analytical ultracentrifugation and molecular sieve chromatogaphy employing (125)I-labeled Fab fragments. 1 mol of Fabmu fragment bound 1 mol of monomer albumin. Polymers of human albumin, produced by heat aggregation, precipitated with the isolated L'ec protein on gel diffusion analysis and, when coated on sheep red blood cells, gave a hemagglutination titer greater than 1 million with the whole L'ec serum. 50 additional monoclonal IgM, 33 IgA, and 80 IgG sera failed to show precipitation or hemagglutination with aggregated albumin. Native monomer albumin inhibited precipitation only at high concentrations (> 50 mg/ml); dimer albumin or fragments of albumin produced by trypsin digestion inhibited at low concentrations (0.4 mg/ml). No reactivity occurred with the albumin of five other mammalian species, including bovine. The L

  9. 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.

  10. 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.

  11. 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.

  12. A Micrograting Sensor for DNA Hybridization and Antibody Human Serum Albumin-Antigen Human Serum Albumin Interaction Experiments

    NASA Astrophysics Data System (ADS)

    Chathirat, Naphat; Atthi, Nithi; Hruanun, Charndet; Poyai, Amporn; Leasen, Suthisa; Osotchan, Tanakorn; Hodak, Jose H.

    2011-01-01

    A biosensor structure comprising silicon nitride (Si3N4) micrograting arrays coated with a spin-on-glass (SOG) material was investigated. This grating structure was located on a silicon groove, which was etched by a deep reactive ion etching (DRIE) process. The biosensor was used as a specific detector of DNA molecules and antibody-antigen interactions. In our DNA sensing experiments, the first step was the activation of the grating surface with amine functional groups, followed by attachment of a 23-base oligonucleotide probe layer for hybridization with a complementary target DNA. The sensing device was tested for detecting specific antigen/antibody interactions for human serum albumin (HSA) and antigen bovine serum albumin (BSA). The readout system consisted of a white light lamp that illuminated a small spot on the grating surface at normal incidence through a fiber optic probe with a spectrometer used to collect the reflected light through a second fiber. We show that these sensing devices have the capability to detect DNA as well as antigen-antibody binding for HSA. The detection sensitivity for HSA was better than that for DNA mainly owing to the larger size and concomitant refractive index changes upon binding to the sensor. We show that it is possible to quantify the amount of biomolecules bound to the grating surface by measuring the wavelength shift of the reflectance spectra upon exposure to the samples.

  13. [Study on the interaction of doxycycline with human serum albumin].

    PubMed

    Hu, Tao-Ying; Chen, Lin; Liu, Ying

    2014-05-01

    The present study was designed to investigate the interaction of doxycycline (DC) with human serum albumin (HSA) by the inner filter effects, displacement experiments and molecular docking methods, based on classic multi-spectroscopy. With fluorescence quenching method at 298 and 310 K, the binding constants Ka, were determined to be 2. 73 X 10(5) and 0. 74X 10(5) L mol-1, respectively, and there was one binding site between DC and HSA, indicating that the binding of DC to HSA was strong, and the quenching mechanism was a static quenching. The thermodynamic parameters (enthalpy change, AH and enthropy change, delta S) were calculated to be -83. 55 kJ mol-1 and -176. 31 J mol-1 K-1 via the Vant' Hoff equation, which indicated that the interaction of DC with HSA was driven mainly by hydrogen bonding and van der Waals forces. Based on the Föster's theory of non-radiation energy transfer, the specific binding distance between Trp-214 (acceptor) and DC (donor) was 4. 98 nm, which was similar to the result confirmed by molecular docking. Through displacement experiments, sub-domain IIA of HSA was assigned to possess the high-affinity binding site of DC. Three-dimensional fluorescence spectra indicated that the binding of DC to HSA induced the conformation change of HSA and increased the disclosure of some part of hydrophobic regions that had been buried before. The results of FTIR spectroscopy showed that DC bound to HSA led to the slight unfolding of the polypeptide chain of HSA. Furthermore, the binding details between DC and HSA were further confirmed by molecular docking methods, which revealed that DC was bound at sub-domain IIA through multiple interactions, such as hydrophobic effect, polar forces and pi-pi interactions. The experimental results provide theoretical basis and reliable data for the study of the interaction between small drug molecule and human serum albumin

  14. Pyrogen reactions to human serum albumin during plasma exchange.

    PubMed

    Pool, M; McLeod, B C

    1995-01-01

    Reactions to human serum albumin (HSA) in therapeutic plasma exchange (TPE) are rare. Nevertheless, older literature describes possible adverse effects, including specific immune responses to albumin or other proteins, and reactions due to contaminating organisms or pyrogen. During an eight day period three patients in our unit had unusual reactions after infusion of 1.5-2 L of HSA. Patient 1 had trembling that persisted for 20 min. Patient 2 had shaking for 40 min despite calcium gluconate infusion, and fever to 100.8 degrees F. Patient 3 had severe rigors that subsided after 90 min when meperidine was finally given, and fever to 103.5 degrees F. Record reviews revealed that all three patients had received HSA from the same lot, and that only one other TPE patient had received HSA from that lot. Neither our pharmacy nor the manufacturer was aware of other reactions associated with that lot. Material from a bottle only partially infused to patient 3 was negative in culture and was negative for pyrogen when retested by the manufacturer. Nevertheless, because patients 1 and 2 had each had multiple previous uneventful TPEs and because all three patients tolerated subsequent TPEs without incident when another brand of HSA was used, we conclude that these patients had pyrogen reactions to the implicated HSA lot. This experience illustrates the value of cluster recognition in arousing suspicion of unusual reactions to HSA and the value of recorded lot numbers in pursuing such suspicions. Apheresis personnel should be aware of the potential for pyrogen reactions with HSA and should record lot numbers of all fluids infused during TPE.

  15. Surface-bound bovine serum albumin carrier protein as present in recombinant cytokine preparations amplifies T helper 17 cell polarization

    PubMed Central

    Dong, Lei; Helmke, Alexandra; Waisman, Ari; Haller, Hermann; Pich, Andreas; von Vietinghoff, Sibylle

    2016-01-01

    Understanding of T helper 17 lineage (TH17) polarization has been significantly promoted by cell culture experiments that reduce the complexity of the in vivo environment. We here investigated TH17 amplification by coating of cytokine preparations. Cytokine preparations coated to the surface compared to the same amount given in solution significantly enhanced TH17 polarization assessed by flow cytometry and interleukin (IL)-17A, IL-17F and RORγt mRNA expression. T cell proliferation and TH1 polarization were similarly enhanced while TREG polarization was impeded. TH17 amplification was replicated by coating the plate with low amounts of FCS or albumin as used as carrier protein for cytokines (0.5 μl 0.1%). It was unaltered by filtration, protein digestion and arylhydrocarbon receptor blockade, not replicated by LPS and independent of integrin stimulation. TH17 amplification required anti-CD3 stimulation and was T cell intrinsic. Supernatants of CD4+ cells polarized on coated cytokine preparations with carrier albumin conferred amplification to fresh splenocytes. Coating markedly elevated CD4+ IL-22 mRNA expression and IL-22 blockade significantly reduced TH17 amplification. Our data show TH17 amplification by coated albumin in the low amounts present in recombinant cytokine preparations. This unexpected adjuvant like effect underscores the need for controls also for temporal and spatial factors in cell culture. PMID:27808281

  16. Non-enzymatic glucosylation induced neo-epitopes on human serum albumin: A concentration based study

    PubMed Central

    Neelofar, Km; Arif, Zarina; Ahmad, Jamal; Alam, Khursheed

    2017-01-01

    Hyperglycaemia induced non enzymatic glycation is accelerated in diabetic patients and aggressively involved in diabetes progression. Human serum albumin (HSA) is the most abundant protein in blood circulation. In hyperglycaemia, it undergoes fast glycation and results in the impairment of structure. Our previous study has demonstrated structural alterations in Amadori-albumin modified with different glucose concentrations from physiological to pathophysiological range. Here, we focused on immunological characterization of Amadori-albumin. Immunogenicity of Amadori-albumin was analysed by direct binding and competitive ELISA. Amadori-albumin was found to be highly immunogenic (expect albumin modified with 5mM) and induced high titre antibodies depending upon the extent of modification. Very high titre antibodies were obtained with albumin modified with 75mM glucose as compared to native albumin. Anti-Amadori-albumin-IgG from rabbit sera exhibited increased recognition of Amadori-albumin than native albumin in competitive immunoassay. Alteration induced in albumin after glucosylation has made it highly immunogenic. Induced antibodies were quite specific for respective immunogens but showed cross-reaction with other Amadori/native proteins. It suggests that glucosylation has generated highly immunogenic epitopes on albumin. Formation of high molecular weight immune complex with retarded mobility further supports specificity of anti-Amadori-albumin-IgG towards Amadori-albumin. It may be concluded that due to early glycation, an array of modification occurred in HSA structure. Such gross structural changes might favour polymerization of most of the native epitopes into potent immunogenic neo-epitopes, but some original epitopes were still active and has contributed in the immunogenicity. It could be concluded that induction of anti-Amadori-albumin antibodies may be due to protection of glucose modified albumin from protiolytic breakdown. We assumed that this type of

  17. 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.

  18. Gold nanoparticle shape effects on human serum albumin corona interface: a molecular dynamic study

    NASA Astrophysics Data System (ADS)

    Ramezani, Fatemeh; Amanlou, Massoud; Rafii-Tabar, Hashem

    2014-07-01

    In recent years, there has been considerable progress in the design and study of gold nanoparticles that geared toward biomedical applications. In most imaging and therapeutic applications, gold nanoparticles enter the bloodstream directly by intravenous administration forming molecular complexes with encountered proteins termed as the protein corona. Since albumin is the most abundant protein in human blood plasma, in this study, gold nanoparticle interactions and its shape effects on human serum albumin were studied by molecular dynamic simulation. These results revealed that in the interaction of albumin with any shapes of gold nanoparticle, human serum albumin unfolds and helix amount decreases. Cubic gold nanoparticles showed stronger unfolding effects on the albumin than the spherical gold nanoparticles.

  19. Binding interactions of pefloxacin mesylate with bovine lactoferrin and human serum albumin*

    PubMed Central

    Fan, Ji-cai; Chen, Xiang; Wang, Yun; Fan, Cheng-ping; Shang, Zhi-cai

    2006-01-01

    The binding of pefloxacin mesylate (PFLX) to bovine lactoferrin (BLf) and human serum albumin (HSA) in dilute aqueous solution was studied using fluorescence spectra and absorbance spectra. The binding constant K and the binding sites n were obtained by fluorescence quenching method. The binding distance r and energy-transfer efficiency E between pefloxacin mesylate and bovine lactoferrin as well as human serum albumin were also obtained according to the mechanism of Förster-type dipole-dipole nonradiative energy-transfer. The effects of pefloxacin mesylate on the conformations of bovine lactoferrin and human serum albumin were also analyzed using synchronous fluorescence spectroscopy. PMID:16691639

  20. [Preparation of Human Serum Albumin Micro/Nanotubes].

    PubMed

    Jiao, Pei-pei; Guo, Yan-li; Niu, Ai-hua; Kang, Xiao-feng

    2016-01-01

    In this research, protein micro/nanotubes were fabricated by alternate layer-by-layer (LbL) assembly of human serum albumin (HSA) and polyethyleneimine (PEI) into polycarbonate (PC) membranes. The experimental conditions of pH values, ionic strength, the depositions cycles and the diameter of porous membrane were discussed. The morphology and composition of tubes were characterized by scanning electron microscope (SEM), transmission electron microscope (TEM), fourier transform infrared spectroscopy (FTIR) and energy dispersive spectroscopy (EDS). The results show that pH and ionic strength of the solution are the key factors that influence the effect of assembly. Micro/nanotubes with good opening hollow tubular structure were obtained when pH 7.4 HSA solution and pH 10.3 PEI solution without NaCl were used in synthesis procedure. The outer diameter of tube was dependent on the PC template, thus the micro/nanotubes size was controlled by the wall thickness, which can be adjusted by the number of layers of the HSA and PEI deposited along the pore walls. To avoid the thin wall being damaged in dissolving the template and vacuum drying, the PEI/HSA bilayer number should not be less than 3. The polar solvent N,N-dimethylformamide (DMF) can dissolve PC template to release the micro/nanotubes.

  1. Photoreactions of macrocyclic dyes bound to human serum albumin.

    PubMed

    Davila, J; Harriman, A

    1990-01-01

    The photophysical properties of tetrakis(4-sulfonatophenyl)porphyrin (H2TSPP), its tin (IV) complex (SnTSPP), aluminium(III) trisulfonatophthalocyanine (AIPCS), and the corresponding zinc(II) complex (ZnPCS), have been measured in H2O, D2O, and upon binding to human serum albumin (HSA). The triplet excited states of the various macrocyclic dyes generate singlet molecular oxygen, O2(1 delta g) in high quantum yield upon illumination in O2-saturated solution, even in the presence of HSA. The triplet states also abstract an electron from 4-aminophenol, forming the radical anion of the macrocycle. Quenching rate constants and quantum yields have been measured for the various processes in the presence and absence of HSA. It is found that HSA binds all the dyes at nonspecific sites close to the interface in such a manner that the dyes remain accessible to species residing in the solution phase. Dyes that do not possess axial ligands complexed to the central cation (e.g. H2TSPP, ZnPCS) are able to bind also at a deeper, more specific site on the protein where they are protected from species in solution. Under such conditions, triplet quenching by 4-aminophenol is restricted to long-distance electron tunnelling, for which the rate is relatively slow.

  2. Hydrophobically derivatized hyperbranched polyglycerol as a human serum albumin substitute.

    PubMed

    Kainthan, Rajesh K; Janzen, Johan; Kizhakkedathu, Jayachandran N; Devine, Dana V; Brooks, Donald E

    2008-04-01

    There is a huge clinical demand for Human Serum Albumin (HSA), with a world market of approximately $1.5B/year. Concern over prion and viral transmission in the blood supply has led to a need for safer substitutes and offers the opportunity for development of materials with enhanced properties over the presently available plasma expanders. We report here the synthesis and testing of a new synthetic plasma expander that can replace not only the osmotic and volume expansion properties of HSA but, uniquely, its binding and transport properties. We have synthesized several hyperbranched polyglycerols derivatized with hydrophobic groups and short poly(ethylene glycol) (PEG) chains. The hydrophobic groups provide regions for binding fatty acids and other hydrophobic materials while PEG imparts the necessary protection from host defense systems and enhances circulation longevity. These polymers, being hyperbranched, have only a small effect on plasma viscosity. We have shown in vitro that our materials bind 2-3 moles palmitic acid per mole, do not activate the platelet, coagulation or complement systems and do not cause red cell aggregation. In mice these materials are non-toxic with circulation half-lives as high as 34h, controllable by manipulating the molecular weight and the degree of PEG derivatization.

  3. Denaturation of Human Serum Albumin by Cerium (iii) Chloride

    NASA Astrophysics Data System (ADS)

    Behbahani, G. Rezaei; Shalbafan, M.; Gheibi, N.; Barzegar, L.; Behbahani, H. Rezaei; Yaghdavaei, N.; Behbahani, Z. Rezaei

    2013-08-01

    Cerium (III) Chloride-induced conformational changes of human serum albumin, HSA, in phosphate buffer, 10 mM at pH 7.4 was investigated, using isothermal titration calorimetry (ITC), UV and fluorescence emission spectroscopic methods. The results indicate that CeCl3, Ce3+, induces irreversible denaturation of the HSA structure. The UV absorption intensity of HSA + Ce3+ shows a slight blueshift in the absorbance wavelength with increasing Ce3+ concentration. The fluorescence intensity was increased regularly and a slight redshift was observed in the emission wavelength. The HSA + Ce3+ complex quenches the fluorescence of HSA and changes the microenvironment of tryptophan residue. The emission intensity increases suggesting the loss of the tertiary structure of HSA. The results obtained from the ITC data are in agreement with the spectroscopic methods. The strong negative cooperativity of Ce3+ binding with HSA (Table 1) recovered from the extended solvation model, indicates that HSA has been denatured as a result of its interaction with Ce3+ ions.

  4. 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.

  5. Virus-Enabled Biosensor for Human Serum Albumin.

    PubMed

    Ogata, Alana F; Edgar, Joshua M; Majumdar, Sudipta; Briggs, Jeffrey S; Patterson, Shae V; Tan, Ming X; Kudlacek, Stephan T; Schneider, Christine A; Weiss, Gregory A; Penner, Reginald M

    2017-01-17

    The label-free detection of human serum albumin (HSA) in aqueous buffer is demonstrated using a simple, monolithic, two-electrode electrochemical biosensor. In this device, both millimeter-scale electrodes are coated with a thin layer of a composite containing M13 virus particles and the electronically conductive polymer poly(3,4-ethylenedioxy thiophene) or PEDOT. These virus particles, engineered to selectively bind HSA, serve as receptors in this biosensor. The resistance component of the electrical impedance, Zre, measured between these two electrodes provides electrical transduction of HSA binding to the virus-PEDOT film. The analysis of sample volumes as small as 50 μL is made possible using a microfluidic cell. Upon exposure to HSA, virus-PEDOT films show a prompt increase in Zre within 5 s and a stable Zre signal within 15 min. HSA concentrations in the range from 100 nM to 5 μM are detectable. Sensor-to-sensor reproducibility of the HSA measurement is characterized by a coefficient-of-variance (COV) ranging from 2% to 8% across this entire concentration range. In addition, virus-PEDOT sensors successfully detected HSA in synthetic urine solutions.

  6. 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.

  7. Interactions of human serum albumin with doxorubicin in different media

    NASA Astrophysics Data System (ADS)

    Gun'ko, Vladimir M.; Turov, Vladimir V.; Krupska, Tetyana V.; Tsapko, Magdalina D.

    2017-02-01

    Interactions of human serum albumin (10 wt% H2O and 0.3 wt% sodium caprylate) with doxorubicin hydrochloride (1 wt%) were studied alone or with addition of HCl (3.6 wt% HCl) using 1H NMR spectroscopy. A model of hydrated HSA/12DOX was calculated using PM7 method with COSMO showing large variations in the binding constant depending on structural features of DOX/HSA complexes. DOX molecules/ions displace bound water from narrow intramolecular voids in HSA that leads to diminution of freezing-melting point depression of strongly bound water (SBW). Structure of weakly bound water (WBW) depends much weaker on the presence of DOX than SBW because a major fraction of DOX is bound to adsorption sites of HSA. Addition of HCl results in strong changes in structure of macromolecules and organization of water in hydration shells of HSA (i.e., mainly SBW) and in the solution (i.e., WBW + non-bound bulk water).

  8. Mechanism of singlet oxygen chemiluminescence enhancement by human serum albumin

    NASA Astrophysics Data System (ADS)

    Zhou, Jing; Xing, Da; Chen, Qun

    2006-02-01

    Fluoresceinyl Cypridina Luciferin Analog (FCLA) is a chemiluminescence (CL) probe for detecting reactive oxygen species (ROS). Its detection efficiency of singlet oxygen can be significantly enhanced in the presence of human serum albumin (HSA). In the current study, the mechanism of the FCLA-HSA CL system is studied by means of direct CL measurement and spectroscopy techniques. Our results show that FCLA can combine with HSA via a single binding site to form a complex. The CL efficiency of the system is largely governed by an inter-system energy transfer between the two components upon interaction with singlet oxygen. The CL production reaches maximum in a synergetic manner when equal amount of FCLA and HSA are present simultaneously, but the production is less efficient at other ratios. This suggests that the FCLA-HSA system maybe used as a singlet oxygen detecting technique with higher sensitivity compared with that of conventional CL techniques. It may also provide a potential new technique for quantitatively analyze the presence of HSA in a sample.

  9. 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.

  10. Synthetic human serum albumin Sudlow I binding site mimics.

    PubMed

    Karlsson, Björn C G; Rosengren, Annika M; Näslund, Inga; Andersson, Per Ola; Nicholls, Ian A

    2010-11-25

    Here, we report the design, synthesis, and characterization of molecularly imprinted polymer (MIP) derived mimics of the human serum albumin (HSA) Sudlow I site-the binding site for the anticoagulant warfarin. MIP design was based upon a combination of experimental ((1)H NMR) and computational (molecular dynamics) methods. Two MIPs and corresponding nonimprinted reference polymers were synthesized and characterized (scanning electron microscopy; nitrogen sorption; and Fourier transform infrared spectroscopy). MIP-ligand recognition was examined using radioligand binding studies, where the largest number of selective sites was found in a warfarin-imprinted methacrylic acid-ethylene dimethacrylate copolymer (MAA-MIP). The warfarin selectivity of this MIP was confirmed using radioligand displacement and zonal chromatographic studies. A direct comparison of MIP-warfarin binding characteristics with those of the HSA Sudlow I binding site was made, and similarities in site population (per gram polymer or protein) and affinities were observed. The warfarin selectivity of the MIP suggests its potential for use as a recognition element in a MIP-based warfarin sensor and even as a model to aid in understanding and steering blood-plasma protein-regulated transport processes or even for the development of warfarin sensors.

  11. 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

  12. Protein Crystal Recombinant Human Insulin

    NASA Technical Reports Server (NTRS)

    1994-01-01

    The comparison of protein crystal, Recombiant Human Insulin; space-grown (left) and earth-grown (right). On STS-60, Spacehab II indicated that space-grown crystals are larger and of greater optical clarity than their earth-grown counterparts. Recombiant Human Insulin facilitates the incorporation of glucose into cells. In diabetics, there is either a decrease in or complete lack of insulin, thereby leading to several harmful complications. Principal Investigator is Larry DeLucas.

  13. Human serum albumin complexes with chlorophyll and chlorophyllin.

    PubMed

    Ouameur, A Ahmed; Marty, R; Tajmir-Riahi, H A

    2005-02-15

    Porphyrins and their metal derivatives are strong protein binders. Some of these compounds have been used for radiation sensitization therapy of cancer and are targeted to interact with cellular DNA and protein. The presence of several high-affinity binding sites on human serum albumin (HSA) makes it possible target for many organic and inorganic molecules. Chlorophyll a and chlorophyllin (a food-grade derivative of chlorophyll), the ubiquitous green plant pigment widely consumed by humans, are potent inhibitors of experimental carcinogenesis and interact with protein and DNA in many ways. This study was designed to examine the interaction of HSA with chlorophyll (Chl) and chlorophyllin (Chln) in aqueous solution at physiological conditions. Fourier transform infrared, UV-visible, and CD spectroscopic methods were used to determine the pigment binding mode, the binding constant, and the effects of porphyrin complexation on protein secondary structure. Spectroscopic results showed that chlorophyll and chlorophyllin are located along the polypeptide chains with no specific interaction. Stronger protein association was observed for Chl than for Chln, with overall binding constants of K(Chl) = 2.9 x 10(4)M(-1) and K(Chln) = 7.0 x 10(3)M(-1). The protein conformation was altered (infrared data) with reduction of alpha-helix from 55% (free HSA) to 41-40% and increase of beta-structure from 22% (free HSA) to 29-35% in the pigment-protein complexes. Using the CDSSTR program (CD data) also showed major reduction of alpha-helix from 66% (free HSA) to 58 and 55% upon complexation with Chl and Chln, respectively.

  14. Anti-hemophilic factor (recombinant), plasma/albumin-free method (octocog-alpha; ADVATE) in the management of hemophilia A.

    PubMed

    Shapiro, Amy D

    2007-01-01

    Removal of blood-based additives from recombinant clotting factor concentrates continues to be advocated by the hemophilia community due to the history of infectious disease transmission with previous blood-derived clotting factor concentrates. In 2003, octocog-alpha, antihemophilic factor (recombinant), plasma/albumin-free method (ADVATE) was introduced, providing the first third-generation recombinant factor VIII (rFVIII) concentrate. Completed clinical trials have demonstrated ADVATE to be safe and effective in adult and pediatric subjects utilizing both prophylactic and on-demand treatment regimens, and for perioperative hemostatic coverage. In the five completed studies involving more than 200 previously treated patients (PTPs), a single incidence of low-titer, non-persistent inhibitor was reported. Active post authorization safety surveillance (PASS) is being performed to expand the efficacy and safety profile of ADVATE in routine clinical practice. Laboratory studies have documented the storage and post-reconstitution stability of ADVATE, conferring the desired versatility for home treatment. The evolving real-world experience and ongoing studies will provide further insight into ADVATE pharmacokinetics, alternative prophylactic dosing regimens, methods for perioperative hemostatic management, and utility in immune tolerance induction. Experience with ADVATE, and its place in today's treatment paradigm, is the focus of this article.

  15. 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.

  16. Low molecular weight silicones particularly facilitate human serum albumin denaturation.

    PubMed

    Nayef, Lamees M; Khan, Madiha F; Brook, Michael A

    2015-04-01

    There is a market trend towards the administration of therapeutic proteins using sterilized, pre-filled glass syringes lubricated with silicone oil. It has been widely reported that initially clear solutions of proteins can become turbid during transport and storage, with unclear outcomes with respect to bioefficacy. While the basic processes of interactions of proteins with hydrophobic entities, leading to denaturation and aggregation, are increasingly well understood, the apparently random occurrence of such processes in syringes is not. To better understand the parameters that may be responsible for this change, we report the systematic examination of a series of factors that can affect the behavior of the protein human serum albumin (HSA) when in contact with silicone oil in water. Fluorescence spectroscopy showed that greater mixing times and greater concentrations of silicones (polydimethylsiloxane (PDMS)), especially lower molecular weight hydrophobic silicones like octamethyltetracyclosiloxane (D4), were associated with increased protein denaturation. The turbidity of HSA solutions, due to the formation both of silicone oil-in-water (O/W) emulsions and protein aggregates, was also facilitated by the presence of D4. A series of mixtures of silicone oils, all of which exhibited a viscosity of 1000 cSt but which were comprised of different silicone constituents, clearly showed a correlation between the presence of lower molecular silicones and enhanced solution turbidity. While the addition of a non-ionic silicone-polyether surfactant led to greater turbidity by increasing the number of stabilized oil droplets, it was not accompanied by protein denaturation. These results are consistent with HSA denaturation and subsequent aggregation as a consequence of contact particularly with low molecular weight, hydrophobic silicones that are more mobile, leading to more efficient protein/silicone contact.

  17. 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.

  18. Behavior of human serum albumin on strong cation exchange resins: I. experimental analysis.

    PubMed

    Voitl, Agnes; Butté, Alessandro; Morbidelli, Massimo

    2010-08-20

    Experiments with human serum albumin on the strong cation exchange resin Fractogel EMD SE Hicap (M) were carried out. Even though human serum albumin was used at high purity, two peaks in gradient elution experiments occurred. The obtained data can be explained by considering that human serum albumin binds to Fractogel EMD SE Hicap (M) in two different binding conformations: the protein adsorbs instantaneously in the first conformation and then changes into the second one with a kinetic limitation. The two-peak behavior of human serum albumin was analyzed in detail, especially at various gradient lengths, concentrations and temperatures. Breakthrough curves were performed at four modifier concentrations and three velocities. The characteristic adsorption behavior, found for gradient experiments, was confirmed by the breakthrough curves. The two-peak elution pattern of human serum albumin was also found for other strong cation exchange resins, but not for weak cation exchange resins. It is concluded that the described behavior is peculiar for the interaction of human serum albumin with the strong cation exchange ligand of the resin.

  19. Actions of serum and plasma albumin on intracellular Ca2+ in human endothelial cells.

    PubMed Central

    Fuentes, E; Nadal, A; Jacob, R; McNaughton, P

    1997-01-01

    1. The effects of serum and plasma albumin on [Ca2+]i in human endothelial cells were examined using single-cell Ca2+ imaging. Two types of endothelial cell were used: human umbilical vein endothelial cells (HUVEC) in primary culture, and the endothelial-derived cell line ECV304. 2. Serum albumin caused a large and transient rise in [Ca2+]i, due to Ca2+ release from an IP3-sensitive internal store, followed by a maintained elevation in [Ca2+]i attributable to Ca2+ influx from the external medium. A half-maximal rise in [Ca2+]i was produced by a concentration of serum albumin of about 1 microgram ml-1. 3. The Ca(2+)-releasing action of serum albumin is abolished by methanol extraction and is therefore attributable to an attached polar lipid. A possible candidate is lysophosphatidic acid, known to be released from platelets during blood coagulation, which produced similar effects to those of serum albumin. 4. In HUVEC, plasma albumin caused a sustained decrease in [Ca2+]i from the mean resting level of 114 nM to 58 nM. No effect of plasma albumin was observed in ECV304 cells. 5. The decrease in [Ca2+]i caused by plasma albumin is due to an uptake into intracellular stores. The store loading substantially potentiates the action of Ca(2+)-releasing agonists such as histamine. 6. The results show that normal plasma albumin, which carries few lipids, lowers [Ca2+]i and potentiates the actions of Ca(2+)-releasing agonists by promoting Ca2+ uptake into intracellular stores. When converted to the serum form, by binding lysophosphatidic acid released during blood coagulation, albumin has a potent effect in elevating [Ca2+]i. Blood coagulation may therefore play a role in regulating vascular tone and capillary permeability. PMID:9365906

  20. Glycation alters ligand binding, enzymatic, and pharmacological properties of human albumin.

    PubMed

    Baraka-Vidot, Jennifer; Planesse, Cynthia; Meilhac, Olivier; Militello, Valeria; van den Elsen, Jean; Bourdon, Emmanuel; Rondeau, Philippe

    2015-05-19

    Albumin, the major circulating protein in blood plasma, can be subjected to an increased level of glycation in a diabetic context. Albumin exerts crucial pharmacological activities through its drug binding capacity, i.e., ketoprofen, and via its esterase-like activity, allowing the conversion of prodrugs into active drugs. In this study, the impact of the glucose-mediated glycation on the pharmacological and biochemical properties of human albumin was investigated. Aggregation product levels and the redox state were quantified to assess the impact of glycation-mediated changes on the structural properties of albumin. Glucose-mediated changes in ketoprofen binding properties and esterase-like activity were evaluated using fluorescence spectroscopy and p-nitrophenyl acetate hydrolysis assays, respectively. With the exception of oxidative parameters, significant dose-dependent alterations in biochemical and functional properties of in vitro glycated albumin were observed. We also found that the dose-dependent increase in levels of glycation and protein aggregation and average molecular mass changes correlated with a gradual decrease in the affinity of albumin for ketoprofen and its esterase-like property. In parallel, significant alterations in both pharmacological properties were also evidenced in albumin purified from diabetic patients. Partial least-squares regression analyses established a significant correlation between glycation-mediated changes in biochemical and pharmacological properties of albumin, highlighting the important role for glycation in the variability of the drug response in a diabetic situation.

  1. 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).

  2. Safety and pharmacokinetics of a novel recombinant fusion protein linking coagulation factor IX with albumin (rIX-FP) in hemophilia B patients

    PubMed Central

    Negrier, Claude; Klamroth, Robert; Tiede, Andreas; Pabinger-Fasching, Ingrid; Voigt, Christine; Jacobs, Iris; Morfini, Massimo

    2012-01-01

    A recombinant fusion protein linking coagulation factor IX (FIX) with human albumin (rIX-FP) has been developed to facilitate hemophilia B treatment by less frequent FIX dosing. This first-in-human dose-escalation trial in 25 previously treated subjects with hemophilia B (FIX ≤ 2 IU/dL) examined the safety and pharmacokinetics of 25, 50, and 75 IU/kg rIX-FP. Patients in the 50-IU/kg cohort underwent a comparative pharmacokinetics assessment with their previous FIX product (plasma-derived or recombinant). No allergic reactions or inhibitors were observed. Four mild, possibly treatment-related adverse events were reported. In the 50-IU/kg cohort (13 subjects), the mean half-life of rIX-FP was 92 hours, more than 5 times longer than the subjects' previous FIX product. After 25 or 50 IU/kg rIX-FP administration, the baseline-corrected mean FIX activity remained elevated at day 7 (7.4 IU/dL and 13.4 IU/dL, respectively) and day 14 (2.5 IU/dL and 5.5 IU/dL, respectively). The incremental recovery of rIX-FP was higher than both recombinant and plasma-derived FIX (1.4 vs 0.95 and 1.1 IU/dL per IU/kg, respectively). These results demonstrated both the safety and improved pharmacokinetics of rIX-FP, thus indicating this new product with extended half-life as possibly able to control and prevent bleeding with less frequent injection. The trial was registered at www.clinicaltrials.gov as no. NCT01233440. PMID:22859609

  3. Separation of Albumin, Ceruloplasmin, and Transferrin from Human Plasma.

    ERIC Educational Resources Information Center

    Barnes, Grady; Frieden, Earl

    1982-01-01

    Procedures are provided for separating the principal metalloproteins (albumin, ceruloplasmin, and transferrin) from plasma using column chromatographic techniques. The experiment can be completed in two separate three-hour laboratory periods during which column chromatography is illustrated and the effect of pH on charge and affinity of a protein…

  4. Glucose and Fluoxetine Induce Fine Structural Change in Human Serum Albumin

    PubMed Central

    Shahani, Minoo; Daneshi-Mehr, Fatemeh; Tadayon, Roya; Hoseinzade Salavati, Behrooz; Akbar Zadeh-Baghban, Ali-Reza; Zamanian, Abbas; Rezaei-Tavirani, Mostafa

    2013-01-01

    Human serum albumin has been used as a model protein for protein folding and ligand binding studies over many decades. Due to its long life period and high concentration in plasma, HSA is highly sensitive to glycation. It is reported that 175 mg/dL glucose concentration is a threshold of kidney activity for the beginning of excretion of glucose. pH denaturation of HSA in absence and presence of different concentrations of glucose is studied and based on the Pace two-state model, the findings are analyzed. In addition, florescence emission data of albumin range in the period of 300-500 nm was depicted. The amounts of free energy change and [D]1/2 parameters of unfolding in correspond to florescence date indicate that glucose induces fine structural change in human serum albumin. Results showed that 175 mg/dL glucose concentration is a critical point for albumin structural and functional alteration. PMID:24250587

  5. Bayesian inference of shared recombination hotspots between humans and chimpanzees.

    PubMed

    Wang, Ying; Rannala, Bruce

    2014-12-01

    Recombination generates variation and facilitates evolution. Recombination (or lack thereof) also contributes to human genetic disease. Methods for mapping genes influencing complex genetic diseases via association rely on linkage disequilibrium (LD) in human populations, which is influenced by rates of recombination across the genome. Comparative population genomic analyses of recombination using related primate species can identify factors influencing rates of recombination in humans. Such studies can indicate how variable hotspots for recombination may be both among individuals (or populations) and over evolutionary timescales. Previous studies have suggested that locations of recombination hotspots are not conserved between humans and chimpanzees. We made use of the data sets from recent resequencing projects and applied a Bayesian method for identifying hotspots and estimating recombination rates. We also reanalyzed SNP data sets for regions with known hotspots in humans using samples from the human and chimpanzee. The Bayes factors (BF) of shared recombination hotspots between human and chimpanzee across regions were obtained. Based on the analysis of the aligned regions of human chromosome 21, locations where the two species show evidence of shared recombination hotspots (with high BFs) were identified. Interestingly, previous comparative studies of human and chimpanzee that focused on the known human recombination hotspots within the β-globin and HLA regions did not find overlapping of hotspots. Our results show high BFs of shared hotspots at locations within both regions, and the estimated locations of shared hotspots overlap with the locations of human recombination hotspots obtained from sperm-typing studies.

  6. Serum albumins - unusual allergens

    PubMed Central

    Chruszcz, Maksymilian; Mikolajczak, Katarzyna; Mank, Nicholas; Majorek, Karolina A.; Porebski, Przemyslaw J.; Minor, Wladek

    2015-01-01

    Background Albumins are multifunctional proteins present in the blood serum of animals. They can bind and transport a wide variety of ligands which they accommodate due to their conformational flexibility. Serum albumins are highly conserved both in amino acid sequence and three-dimensional structure. Several mammalian and avian serum albumins (SAs) are also allergens. Sensitization to one of the SAs coupled with the high degree of conservation between SAs may result in cross-reactive antibodies in allergic individuals. Sensitivity to SA generally begins with exposure to an aeroallergen, which can then lead to cross-sensitization to serum albumins present in food. Scope of Review This review focuses on the allergenicity of SAs presented in a structural context. Major Conclusions SA allergenicity is unusual taking into account the high sequence identity and similarity between SA from different species and human serum albumin. Cross-reactivity of human antibodies towards different SAs is one of the most important characteristics of these allergens. General Significance Establishing a relationship between sequence and structure of different SAs and their interactions with antibodies is crucial for understanding the mechanisms of cross-sensitization of atopic individuals. Structural information can also lead to better design and production of recombinant SAs to replace natural proteins in allergy testing and desensitization. Therefore, structural analyses are important for diagnostic and treatment purposes. PMID:23811341

  7. Caveolae may enable albumin to enter human renal glomerular endothelial cells.

    PubMed

    Moriyama, Takahito; Takei, Takashi; Itabashi, Mitsuyo; Uchida, Keiko; Tsuchiya, Ken; Nitta, Kosaku

    2015-06-01

    Caveolae on human renal glomerular endothelial cells (HRGECs) are increased in glomerular disease and correlate with the degree of albuminuria. To assess the mechanism by which caveolae contribute to albuminuria, we investigated whether albumin enters into HRGECs through caveolae. HRGECs were incubated with Alexa Fluor 488 labeled BSA or transferrin, followed by immunofluorescence localization with antibody to caveolin-1 (Cav-1), the main structural protein of caveolae, or clathrin, the major structural protein of clathrin coated pits, to assess whether BSA colocalized with Cav-1. HRGECs were also incubated with albumin and caveolae disrupting agents, including methyl beta cyclodextrin (MBCD) and nystatin, to determine whether disrupting caveolae interfered with albumin endocytosis into HRGECs. HRGECs were also incubated with albumin after transfection with Cav-1 small interfering RNAs (siRNAs). Labeled BSA colocalized with Cav-1, but not with clathrin. In contrast, labeled transferrin colocalized with clathrin, but not with Cav-1. Incubation of HRGECs with MBCD or nystatin, or transfection with Cav-1 siRNA, significantly reduced the intracellular amounts of albumin and Cav-1, relative to normal HRGECs, as shown by western blotting and immunofluorescence. These findings indicate that albumin enters HRGECs through the caveolae, suggesting that caveolae play an important role in the pathogenesis of albuminuria by providing a pathway through which albumin can enter glomerular endothelial cells.

  8. Genetically engineered mannosylated-human serum albumin as a versatile carrier for liver-selective therapeutics.

    PubMed

    Hirata, Kenshiro; Maruyama, Toru; Watanabe, Hiroshi; Maeda, Hitoshi; Nakajou, Keisuke; Iwao, Yasunori; Ishima, Yu; Katsumi, Hidemasa; Hashida, Mitsuru; Otagiri, Masaki

    2010-07-01

    Human serum albumin (HSA), a non-glycosylated protein, is widely employed as carrier for drug delivery systems. A series of recombinant, mannosylated-HSA mutants (Man-rHSAs: D63N, A320T and D494N) and their triple mutant (TM-rHSA: D63N/A320T/D494N) were prepared, that can be selectively delivered to the liver via mannose receptor (MR) on the liver non-parenchymal cells. A pharmacokinetic analysis of (111)In-Man-rHSAs in mice showed that they were rapidly cleared from the blood circulation, and were largely taken up by the liver rapidly in the order: TM-rHSA>D494N>A320T=D63N, consistent with their degree of mannosylation. In vivo competition experiments with an excess amount of chemically modified Man-BSA or mannan suggested that the hepatic uptake of TM-rHSA was selectively mediated by MR on Kupffer cells. Lastly, a TM-rHSA-NO conjugate, S-nitrosylated TM-rHSA, effectively delivered NO to the liver and then exhibited a significant inhibitory effect against hepatic ischemia/reperfusion injury model rats, accompanied by the induction of heme oxygenase-1.

  9. Human albumin use at hospitals in the Metropolitan Region of Rio de Janeiro, Brazil.

    PubMed

    Matos, Guacira Corrêa de; Rozenfeld, Suely; Martins, Monica

    2010-05-01

    The study analyzes the use of human albumin in hospitals in Rio de Janeiro, Brazil, using inpatient data from the information system of Brazil's health system between 1999 and 2001. Death was the main outcome as patients died in 32% of admissions in which human albumin was used as compared with 4% of all admissions in the same period and region. The Charlson Comorbidity Index was included for risk adjustment. Human albumin was used in 10,111 in-patients more than 1 year old. 87,774 50-ml bottles of 20% human albumin were consumed at a cost of US$ 1,755. The main diagnoses were neoplasms (29.1%), diseases of the digestive system (17.5%) and circulatory system (16%). Death rate increased with age, public ownership of the hospital, clinical services (as opposed to surgical services), length of stay and use of intensive care. Death was associated with use of more than four bottles of human albumin (PR: 1.30; 99%CI: 1.23-1.37), adjusted for severity and speciality. The results are cause for concern as they may be related to poor compliance with guidelines, excess of risk to patients and unnecessary expenses for the public health system.

  10. 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.

  11. The secretion of human serum albumin from the yeast Saccharomyces cerevisiae using five different leader sequences.

    PubMed

    Sleep, D; Belfield, G P; Goodey, A R

    1990-01-01

    We demonstrate the secretion of human serum albumin into the culture supernatant from the yeast Saccharomyces cerevisiae. Studies with five KEX2 processed leader sequences, namely the S. cerevisiae alpha factor, the natural human serum albumin, the Kluyveromyces lactis killer, a natural human serum albumin/alpha factor fusion, and a Kluyveromyces lactis killer/alpha factor fusion leader, are described. We show that the leader sequence used to direct secretion influences the quantity and quality of the secreted product. In designing secretion systems for heterologous proteins, one aims to maximise both the yield and fidelity of the product. Our results indicate that the choice of leader sequence and its relationship to the structural protein under study are crucial to the success of this process.

  12. Comparison of Posttranslational Modification and the Functional Impairment of Human Serum Albumin in Commercial Preparations.

    PubMed

    Miyamura, Shigeyuki; Imafuku, Tadashi; Anraku, Makoto; Taguchi, Kazuaki; Yamasaki, Keishi; Tominaga, Yuna; Maeda, Hitoshi; Ishima, Yu; Watanabe, Hiroshi; Otagiri, Masaki; Maruyama, Toru

    2016-03-01

    On account of its long circulating half-life, human serum albumin (HSA) is susceptible to posttranslational modifications that can alter its functions. Here, we comprehensively compared the degree of posttranslational modifications with the functional impairment of HSA derived from 5 different commercially available albumin preparations and clarified their relationships. We used electrospray ionization-time of flight mass spectrometry to evaluate the degree of posttranslational modification of the entire HSA molecule that was associated with disease development and found that the fraction of Cys34-cysteinylated HSA (Cys-Cys34-HSA), a major form of oxidative modification, varied substantially among the albumin preparations. Meanwhile, no remarkable difference was found in the degree of glycated or N-terminal truncated HSA among the preparations tested. The nonosmotic pressure maintenance functions of HSA, such as its antioxidative and ligand-binding activities significantly differed among the preparations. Interestingly, the alternations of these functions showed a significantly negative correlation only with the Cys-Cys34-HSA fraction. These findings suggest that the Cys-Cys34-HSA fraction, as estimated by electrospray ionization-time of flight mass spectrometry can be used as a predictive marker for the functional impairment of albumin preparations and that it would be preferable to use albumin preparations with higher contents of functionally effective albumin that correspond to a lower degree of cysteinylation of Cys34 in clinical practice.

  13. Antigenic changes in human albumin caused by reactivity with the occupational allergen diphenylmethane diisocyanate

    PubMed Central

    Wisnewski, Adam V.; Liu, Jian; Redlich, Carrie A.

    2010-01-01

    Diphenylmethane diisocyanate (MDI), the chemical commonly used as a cross-linking agent in commercial polyurethane production, is a well-recognized cause of asthma. Reaction products between MDI and “self” proteins are hypothesized to act as antigens capable of inducing airway inflammation and asthma; however, such MDI antigens remain incompletely understood. We used a variety of analytical methods to characterize the range of MDI–albumin reaction products that form under physiological conditions. Sites of MDI conjugation on antigenic MDI–albumin products, as defined by serum immunoglobulin G (IgG) from MDI-exposed workers, were determined by high-performance liquid chromatography (HPLC) followed by tandem mass spectrometry (MS/MS). The data identified 14 MDI conjugation sites (12 lysines and 2 asparagines) on human albumin and highlight reaction specificity for the second lysine in dilysine (KK) motifs, and this may be a common characteristic of “immune-sensitizing” chemicals. Several of the MDI conjugation sites are not conserved in albumin from other species, and this may suggest species differences in epitope specificity for self protein (albumin)–isocyanate conjugates. The study also describes new applications of contemporary proteomic methodology for characterizing and standardizing MDI–albumin conjugates destined for use in clinical research. PMID:20123080

  14. The pharmacokinetics of albumin conjugates of D-penicillamine in humans.

    PubMed

    Joyce, D A; Day, R O; Murphy, B R

    1991-01-01

    D-penicillamine (D-PEN) is incompletely recovered during short-term balance studies, despite rapid elimination of D-PEN and its low molecular weight metabolites. Urinary excretion of metabolites of D-PEN also persists long after cessation of chronic therapy. A study was performed to determine whether the formation and later breakdown of a stable disulfide between D-PEN and plasma albumin could explain these aspects of D-PEN pharmacokinetics. Five human volunteers received D-penicillamine, 250 mg orally, daily for 21 days. Plasma concentration-time profiles for D-PEN and D-PEN-albumin disulfide (D-PEN-albumin) were determined during the first day and pre-dose concentrations were measured on five further occasions. The pharmacokinetics of D-PEN on the first day were similar to those reported previously. No D-PEN was found in any of the pre-dose specimens. The concentration of D-PEN-albumin rose rapidly during the first day, with an estimated 8.6% of the bioavailable D-PEN being transformed to D-PEN-albumin. Pseudo-steady-state concentrations of D-PEN-albumin were achieved in three subjects at between 14 and 21 days. The mean trough concentration of D-PEN-albumin at 21 days (19.5 microM) exceeded the peak concentration of D-PEN (during the first day) by 5.7-fold. The terminal elimination half-life of D-PEN-albumin was 1.65 +/- 0.29 days, which compared with an elimination half-life of 59 +/- 8.4 min for D-PEN.(ABSTRACT TRUNCATED AT 250 WORDS)

  15. 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.

  16. 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.

  17. Effect of oxidatively modified and non-modified human serum albumin on luminol-dependent chemiluminescence of human peripheral blood leukocytes stimulated with opsonized zymosan.

    PubMed

    Piryazev, A P; Azizova, A P; Aseichev, A V; Sergienko, V I

    2014-07-01

    We studied the effects of native and oxidized human serum albumin on luminol-dependent chemiluminescence of human peripheral blood leukocytes stimulated with opsonized zymosan. Human serum albumin was added simultaneously with opsonized zymosan at the beginning of the chemiluminescent reaction. Otherwise, leukocytes were incubated with human serum albumin at 37°C for various periods before addition of opsonized zymosan. Oxidized human serum albumin was obtained by the method of metal-catalyzed oxidation. In control to non-modified albumin, oxidized albumin produced an inhibitory effect on luminol-dependent chemiluminescence of leukocytes. These changes were observed in experiments with addition of oxidized albumin at the beginning of a chemiluminescent reaction and after incubation of study agent with cells.

  18. 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

  19. Patterns of recombination on human chromosome 22

    SciTech Connect

    Schlumpf, K.S.; Kim, D.; Haines, J.L.

    1994-09-01

    Virtually all genetic linkage maps generated to date are gross averages across individuals, ages, and (often) sexes. In addition, although some level of positive interference has been assumed, until recently little evidence to support this in humans has been available. The major stumbling block has been the quality of the data available, since even a few genotypic errors can have drastic effects on both the map length and the number of apparent recombinants. In addition, variation in recombination by factors other than sex have pretty much been ignored. To explore recombination in more detail, we have generated a microsatellite marker map of human chromosome 22. This map includes 32 markers genotyped through 46 sibships of the Venezuelan Reference Pedigree (VRP). Extensive error checking and regenotyping was performed to remove as many genotypic errors as possible, but no genotypes were removed simply because they created unlikely events. The following 1000:1 odds map has been obtained: cen--F8VWFP1--11--S264--3-S311--4--S257--2--TOP1P2--3--S156--1--CRYB2--1--S258--2--S310--6--S193--1--S275--3--S268--1--S280--4--S304--3--S283--2--LiR1--3--IL2RB--3--S299--1--S302--1--S537--2--S270--4--PDGF--8--S274--qter. The female map (91 cM) is twice as long as the male map (46 cM) and the log-likelihood difference in the maps (22.3) is highly significant (P=0.001, df=22) and appears constant across the chromosome. Analysis of recombination with age showed no particular trends for either males or females when chromosomes were grouped into three categories (20, 20-30, 30+) by parental age at birth of child. Positive interference was found in maternally derived chromosomes ({chi}{sup 2}=30.5 (4), p<0.005), but not in paternally derived chromosomes ({chi}{sup 2}=6.24 (3), P=0.10). This contrasts to data from chromosomes 9 and 21 where positive interference was found for both sexes. More detailed analyses are in progress.

  20. Expression of Jug r 1, the 2S albumin allergen from walnut (Juglans regia), as a correctly folded and functional recombinant protein.

    PubMed

    Sordet, Camille; Culerrier, Raphaël; Granier, Claude; Rancé, Fabienne; Didier, Alain; Barre, Annick; Rougé, Pierre

    2009-07-01

    Jug r 1, the 2S albumin allergen from walnut, was isolated from ripe nuts as a native allergen and expressed in Escherichia coli using the Gateway technology as a recombinant allergen. The recombinant Jug r 1 (15 kDa) differs from the native allergen by the absence of cleavage of the polypeptide chain in two covalently associated light (3.5 kDa) and heavy (8 kDa) chains. Recombinant rJug r 1 adopts the canonical alpha-helical fold of plant 2S albumins as checked on CD spectra. Four IgE-binding epitopic stretches were identified along the amino acid sequence of Jug r 1 and localized on the molecular surface of the modeled allergen. Both native and recombinant allergens exhibit similar IgE-binding activity and similarly trigger the degranulation of a FcepsilonRI-expressing rat basophilic leukaemia cell line previously treated by IgE-containing sera. Native Jug r 1 resists to heat denaturation and to the proteolytic attack of trypsin and chymotrypsin but is readily hydrolyzed in the presence of pepsin at acidic pH after 1 h of incubation at 37 degrees C in vitro. Recombinant Jug r 1 could be used for a component-resolved diagnosis of food-allergy.

  1. An in-depth view of human serum albumin corona on gold nanoparticles.

    PubMed

    Ramezani, Fatemeh; Rafii-Tabar, Hashem

    2015-02-01

    Upon entering biological systems, such as the blood stream, nanoparticles form molecular complexes with the proteins encountered called protein coronas, which shield the surface of the exogenous nanoparticle. The most abundant blood proteins, such as albumin, initially occupy the surface of the nanoparticle. Owing to the widespread applications of gold nanoparticles in medicine, in this study, the docking of human serum albumin to gold nanoparticles was examined and the changes in protein structure were investigated by a molecular dynamic simulation and GOLP force field. The results showed that after the adsorption of albumin on the gold nanoparticle, human serum albumin was denatured and the amount of alpha-helix significantly decreased. Domain III, which has a large cavity of fatty acids binding sites, plays an important role in the adsorption on the gold nanoparticles. Lys464, Thr504, Phe505, and Leu581 are critical amino acids in HSA adsorption on the GNPs. After the adsorption of albumin on the surface of gold nanoparticles, the fluctuations in some of the domains of the protein increased. Variations in the helix properties, such as helix length, dipole, radius, average phi and psi angles, and the length of hydrogen bonds, were calculated in detail.

  2. Metal-catalyzed oxidation of human serum albumin: conformational and functional changes. Implications in protein aging.

    PubMed

    Meucci, E; Mordente, A; Martorana, G E

    1991-03-15

    Mild oxidative stress, as elicited by ascorbate, oxygen, and trace metals, affects the binding properties of human serum albumin via purely conformational changes. In fact, no gross alteration can be observed in the electrophoretic and chromatographic patterns of albumin, whereas localized modifications are indicated by the changes in absorption and fluorescence spectra and in polarization degree. The oxidized protein presents a small increase of bityrosine production and a time-dependent increase in the content of carbonyl groups, whereas proteolytic susceptibility is unchanged. A higher affinity for cis-parinaric acid and a slight loss of solubility in high salt indicate a greater surface hydrophobicity. Pinpoint denaturation of the albumin molecule is also suggested by a decreased "esterase" activity in the presence of p-nitrophenyl acetate. Conformational stability evaluated through thermal shock and addition of moderate amounts of guanidine indicate that the oxidized protein is more heat-resistant, less flexible, and more rigid than the native one. Although limited, structural damages afforded by the oxidative stress cause alterations of albumin binding properties as documented by experiments with probes and physiological ligands. The loss of biological activity of human serum albumin induced by ascorbate system appears of medical relevance, because it can affect drug metabolism and particularly drug tolerance in the elderly.

  3. A spectroscopic and molecular docking approach on the binding of tinzaparin sodium with human serum albumin

    NASA Astrophysics Data System (ADS)

    Abdullah, Saleh M. S.; Fatma, Sana; Rabbani, Gulam; Ashraf, Jalaluddin M.

    2017-01-01

    Protein bound toxins are poorly removed by conventional extracorporeal therapies. Venous thromboembolism (VTE) is a major cause of morbidity and mortality in patients with cancer. The interaction between tinzaparin, an inhibitor of angiotensin converting enzyme and human serum albumin, a principal plasma protein in the liver has been investigated in vitro under a simulated physiological condition by UV-vis spectrophotometry and fluorescence spectrometry. The intrinsic fluorescence intensity of human serum albumin was strongly quenched by tinzaparin (TP). The binding constants and binding stoichiometry can be calculated from the data obtained from fluorescence quenching experiments. The negative value of ΔG° reveals that the binding process is a spontaneous process. Thermodynamic analysis shows that the HSA-TP complex formation occurs via hydrogen bonds, hydrophobic interactions and undergoes slight structural changes as evident by far-UV CD. It indicated that the hydrophobic interactions play a main role in the binding of TP to human serum albumin. In addition, the distance between TP (acceptor) and tryptophan residues of human serum albumin (donor) was estimated to be 2.21 nm according to the Förster's resonance energy transfer theory. For the deeper understanding of the interaction, thermodynamic, and molecular docking studies were performed as well. Our docking results suggest that TP forms stable complex with HSA (Kb ∼ 104) and its primary binding site is located in subdomain IIA (Sudlow Site I). The results obtained herein will be of biological significance in pharmacology and clinical medicine.

  4. 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

  5. Kinetics of refolding of completely reduced human-serum albumin. Regain of immunochemical reactivity.

    PubMed

    Wichman, A; Svenson, A; Andersson, L O

    1977-10-03

    The kinetics of refolding of completely reduced human serum albumin has been studied by various methods including immunological techniques. The decrease in thiol content is very rapid in the beginning of the reoxidation process and rather slow in the later stages. Polyacrylamide gel electrophoresis studies show that, in the earlier stages of refolding, the main part of the albumin is present as various oligomers and that a slow conversion to monomer occurs as reoxidation proceeds. Rocket immunoelectrophoresis shows that the completely reduced protein is devoid of native albumin antigenic determinants but that a rapid regain of immunoprecipitability is obtained upon reoxidation. A new 'consumption' rocket immunoelectrophoretic method has been used to estimate the total regain of antigenicity. The data obtained indicate that there is a preferential rapid folding to native structure in certain parts of the molecule but that areas with wrong or incomplete foldings exist a considerable time after the inital refolding period.

  6. Effect of the conditions of isolation on the physicochemical properties of human serum albumin in the norm and with pathology

    NASA Astrophysics Data System (ADS)

    Ivanov, A. I.; Zhbankov, R. G.; Korolenko, E. A.; Korolik, E. V.; Meleshchenko, L. A.; Sarnatskaya, V. V.; Nikolaev, V. G.; Nikolaichik, V. V.; Yushko, L. A.

    1997-01-01

    Differential scanning calorimetry and IR spectrosocopy were used to investigate the effect of the procedure of isolation of human serum albumin on its physicochemical characteristics. It is shown that fractionation of blood plasma with ethylene glycol followed by ion exchange chromatography can be used to obtain albumin of normal donors that is similar to the albumin in the nonfractionated plasma according to melting thermograms. Endotherms of human serum albumin samples that were obtained by affinity chromatography and preparative electrophoresis are bimodal, unlike the monophasic for albumin obtained by polyethylene glycol precipitation. These changes result from a higher content of nonetherified fatty acids in the albumin samples obtained by affinity chromatography and from modification of the secondary protein structure in the samples obtained by electrophoresis. Analysis of melting thermograms of serum albumin from patients with uremia, chronic hepatitis, and peritonitis shows that fractionation of blood with polyethylene glycol preserves the thermodynamic characteristics of the various pathological serum albumins to the greatest extent. The present results demonstrate the advantage of polyethylene glycol fractionation for isolation of native preparations of normal and “pathological” human serum albumin.

  7. Long-Acting Recombinant Fusion Protein Linking Coagulation Factor IX with Albumin (rIX-FP) in Children

    PubMed Central

    Chambost, Hervé; Male, Christoph; Lambert, Thierry; Halimeh, Susan; Chernova, Tatiana; Mancuso, Maria Elisa; Curtin, Julie; Voigt, Christine; Li, Yanyan; Jacobs, Iris; Santagostino, Elena

    2016-01-01

    Summary A global phase 3 study evaluated the pharmacokinetics, efficacy and safety of a recombinant fusion protein linking coagulation factor IX with albumin (rIX-FP) in 27 previously treated male children (1–11 years) with severe and moderately severe haemophilia B (factor IX [FIX] activity ≤2 IU/dl). All patients received routine prophylaxis once every seven days for up to 77 weeks, and treated any bleeding episodes on-demand. The mean terminal half-life of rIX-FP was 91.4 hours (h), 4.3-fold longer than previous FIX treatment and clearance was 1.11 ml/h/kg, 6.4-fold slower than previous FIX treatment. The median (Q1, Q3) annualised spontaneous bleeding rate was 0.00 (0.00, 0.91) and was similar between the <6 years and ≥6 years age groups, with a weekly median prophylactic dose of 46 IU/kg. In addition, patients maintained a median trough level of 13.4 IU/dl FIX activity on weekly prophylaxis. Overall, 97.2% of bleeding episodes were successfully treated with one or two injections of rIX-FP (95% CI: 92% to 99%), 88.7% with one injection, and 96% of the treatments were rated effective (excellent or good) by the Investigator. No patient developed FIX inhibitors and no safety concerns were identified. These results indicate that rIX-FP is safe and effective for preventing and treating bleeding episodes in children with haemophilia B with weekly prophylaxis. Routine prophylaxis with rIX-FP at treatment intervals of up to 14 days are currently being investigated in children with severe and moderately severe haemophilia B. Clinicaltrials.gov (NCT01662531) PMID:27583313

  8. Luminescent probe in the study of surfactant-induced structural changes in serum albumin in human blood plasma

    NASA Astrophysics Data System (ADS)

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

    2005-06-01

    The luminescence-kinetic technique of the monitoring of structural changes in albumins of human blood plasma that uses a luminescent probe-eosin is proposed. Phosphorescence of eosin bound to the globular proteins of blood plasma-albumins was recorded at room temperature. It is found that under the action of sodium dodecylsulfate on the albumins the rate constant of eosin phosphorescence decay grows and the intensity of eosin phosphorescence decreases. It is assumed that these changes are connected with the denaturing of blood plasma albumins by sodium dodecylsulfate.

  9. Albumin infusion in humans does not model exercise induced hypervolaemia after 24 hours

    NASA Technical Reports Server (NTRS)

    Haskell, A.; Gillen, C. M.; Mack, G. W.; Nadel, E. R.

    1998-01-01

    We rapidly infused 234 +/- 3 mL of 5% human serum albumin in eight men while measuring haematocrit, haemoglobin concentration, plasma volume (PV), albumin concentration, total protein concentration, osmolality, sodium concentration, renin activity, aldosterone concentration, and atrial natriuretic peptide concentration to test the hypotheses that plasma volume expansion and plasma albumin content expansion will not persist for 24 h. Plasma volume and albumin content were expanded for the first 6 h after infusion (44.3 +/- 1.9-47.2 +/- 2.0 mL kg-1 and 1.9 +/- 0.1-2.1 +/- 0.1 g kg-1 at pre-infusion and 1 h, respectively, P < 0.05), but by 24 h plasma volume and albumin content decreased significantly from 1 h post-infusion and were not different from pre-infusion (44.8 +/- 1.9 mL kg-1 and 1.9 +/- 0.1 g kg-1, respectively). Plasma aldosterone concentration showed a significant effect of time over the 24 h after infusion (P < 0.05), and showed a trend to decrease at 2 h after infusion (167.6 +/- 32.5(-1) 06.2 +/- 13.4 pg mL-1, P = 0.07). These data demonstrate that a 6.8% expansion of plasma volume and 10.5% expansion of plasma albumin content by infusion does not remain in the vascular space for 24 h and suggest a redistribution occurs between the intravascular space and interstitial fluid space.

  10. The thiol pool in human plasma: The central contribution of albumin to redox processes

    PubMed Central

    Turell, Lucía; Radi, Rafael; Alvarez, Beatriz

    2013-01-01

    The plasma compartment has particular features regarding the nature and concentration of low and high molecular weight thiols and oxidized derivatives. Plasma is relatively poor in thiol-based antioxidants; thiols are in lower concentrations than in cells and mostly oxidized. The different thiol-disulfide pairs are not in equilibrium and the steady-state concentrations of total thiols as well as reduced versus oxidized ratios are maintained by kinetic barriers, including the rates of reactions and transport processes. The single thiol of human serum albumin (HSA-SH) is the most abundant plasma thiol. It is an important target for oxidants and electrophiles due to its reactivity with a wide variety of species and its relatively high concentration. A relatively stable sulfenic (HSA-SO3H) acid can be formed in albumin exposed to oxidants. Plasma increases in mixed disulfides (HSA-SSR) or in sulfinic (HSA-SO2H) and sulfonic (HSA-SO3H) acids are associated with different pathologies and may constitute biomarkers of the antioxidant role of the albumin thiol. In this work we provide a critical review of the plasma thiol pool with a focus on human serum albumin. PMID:23747983

  11. Albumin Redhill (-1 Arg, 320 Ala yields Thr): A glycoprotein variant of human serum albumin whose precursor has an aberrant signal peptidase cleavage site

    SciTech Connect

    Brennan, S.O.; Myles, T.; Peach, R.J.; George, P.M. ); Donaldson, D. )

    1990-01-01

    Albumin Redhill is an electrophoretically slow genetic variant of human serum albumin that does not bind {sup 63}Ni{sup 2+} and has a molecular mass 2.5 kDa higher than normal albumin. Its inability to bind Ni{sup 2+} was explained by the finding of an additional residue of Arg at position -1. This did not explain the molecular basis of the genetic variation or the increase in apparent molecular mass. Fractionation of tryptic digests on concanavalin A-Sepharose followed by peptide mapping of the bound and unbound fractions and sequence analysis of the glycopeptides identified a mutation of 320 Ala {yields} Thr. This introduces as Asn-Tyr-Thr oligosaccharide attachment sequence centered on Asn-318 and explains the increase in molecular mass. This, however, did not satisfactorily explain the presence of the additional Arg residue at position -1. DNA sequencing of polymerase chain reaction-amplified genomic DNA encoding the prepro sequence of albumin indicated an additional mutation of -2 Arg {yields} Cys. The authors propose that the new Phe-Cys-Arg sequence in the propeptide is an aberrant signal peptidase cleavage site and that the signal peptidase cleaves the propeptide of albumin Redhill in the lumen of the endoplasmic reticulum before it reaches the Golgi vesicles, the site of the diarginyl-specific proalbumin convertase.

  12. Amino acid substitutions in genetic variants of human serum albumin and in sequences inferred from molecular cloning

    SciTech Connect

    Takahashi, N.; Takahashi, Y.; Blumberg, B.S.; Putnam, F.W.

    1987-07-01

    The structural changes in four genetic variants of human serum albumin were analyzed by tandem high-pressure liquid chromatography (HPLC) of the tryptic peptides, HPLC mapping and isoelectric focusing of the CNBr fragments, and amino acid sequence analysis of the purified peptides. Lysine-372 of normal (common) albumin A was changed to glutamic acid both in albumin Naskapi, a widespread polymorphic variant of North American Indians, and in albumin Mersin found in Eti Turks. The two variants also exhibited anomalous migration in NaDodSO/sub 4//PAGE, which is attributed to a conformational change. The identity of albumins Naskapi and Mersin may have originated through descent from a common mid-Asiatic founder of the two migrating ethnic groups, or it may represent identical but independent mutations of the albumin gene. In albumin Adana, from Eti Turks, the substitution site was not identified but was localized to the region from positions 447 through 548. The substitution of aspartic acid-550 by glycine was found in albumin Mexico-2 from four individuals of the Pima tribe. Although only single-point substitutions have been found in these and in certain other genetic variants of human albumin, five differences exist in the amino acid sequences inferred from cDNA sequences by workers in three other laboratories. However, our results on albumin A and on 14 different genetic variants accord with the amino acid sequence of albumin deduced from the genomic sequence. The apparent amino acid substitutions inferred from comparison of individual cDNA sequences probably reflect artifacts in cloning or in cDNA sequence analysis rather than polymorphism of the coding sections of the albumin gene.

  13. Photosensitizer-Conjugated Human Serum Albumin Nanoparticles for Effective Photodynamic Therapy

    PubMed Central

    Jeong, Hayoung; Huh, MyungSook; Lee, So Jin; Koo, Heebeom; Kwon, Ick Chan; Jeong, Seo Young; Kim, Kwangmeyung

    2011-01-01

    Photodynamic therapy (PDT) is an emerging theranostic modality for various cancers and diseases. The focus of this study was the development of tumor-targeting albumin nanoparticles containing photosensitizers for efficient PDT. To produce tumor-targeting albumin nanoparticles, the hydrophobic photosensitizer, chlorin e6 (Ce6), was chemically conjugated to human serum albumin (HSA). The conjugates formed self-assembled nanoparticle structures with an average diameter of 88 nm under aqueous conditions. As expected, the Ce6-conjugated HSA nanoparticles (Ce6-HSA-NPs) were nontoxic in their native state, but upon illumination with the appropriate wavelength of light, they produced singlet oxygen and damaged target tumor cells in a cell culture system. Importantly, when the nanoparticles were injected through the tail vein into tumor-bearing HT-29 mice, Ce6-HSA-NPs compared with free Ce6 revealed enhanced tumor-specific biodistribution and successful therapeutic results following laser irradiation. These results suggest that highly tumor-specific albumin nanoparticles have the potential to serve not only as efficient therapeutic agents, but also as photodynamic imaging (PDI) reagents in cancer treatment. PMID:21562630

  14. 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.

  15. Reversible binding of ethacrynic acid to human serum albumin: difference circular dichroism study.

    PubMed

    Bertucci, C; Nanni, B; Salvadori, P

    1999-01-01

    The reversible binding of ethacrynic acid was characterized by a difference circular dichroism method. A 2/1 stoichiometry was determined for the [drug]/[HSA] (human serum albumin) complex. The reversible binding of ethacrynic acid to HSA determines direct competition with ligands that selectivity bind to site II and to the fatty acid site. Furthermore, indirect competition was shown for ligands for site I (anti-cooperative) and to site III (cooperative).

  16. Radiopharmaceutical development based on human blood albumin microspheres and 90Y

    NASA Astrophysics Data System (ADS)

    Petriev, V. M.; Vlasova, O. P.; Postnov, A. A.; Epstein, N. B.

    2017-01-01

    New radiopharmaceutial (RP) based on human serum albumin microspheres (MSA) and 90Y was developed for treatment of liver cancer. The optimized synthesis using chelation resulted in approximately 80% yield with high specific activity. The RP developed was tested in mice with inoculated sarcoma-37. In two weeks the tumor size reduced by 43% after the treatment with the dose of 500 μCi injected into the tumor site.

  17. Maintenance of Hepatic Functions in Primary Human Hepatocytes Cultured on Xeno-Free and Chemical Defined Human Recombinant Laminins.

    PubMed

    Watanabe, Masaaki; Zemack, Helen; Johansson, Helene; Hagbard, Louise; Jorns, Carl; Li, Meng; Ellis, Ewa

    2016-01-01

    Refined methods for maintaining specific functions of isolated hepatocytes under xeno-free and chemical defined conditions is of great importance for the development of hepatocyte research and regenerative therapy. Laminins, a large family of heterotrimeric basement membrane adhesion proteins, are highly cell and tissue type specific components of the extracellular matrix and strongly influence the behavior and function of associated cells and/or tissues. However, detailed biological functions of many laminin isoforms are still to be evaluated. In this study, we determined the distribution of laminin isoforms in human liver tissue and isolated primary human hepatocytes by western blot analysis, and investigated the efficacy of different human recombinant laminin isoforms on hepatic functions during culture. Protein expressions of laminin-chain α2, α3, α4, β1, β3, γ1, and γ2 were detected in both isolated human hepatocytes and liver tissue. No α1 and α5 expression could be detected in liver tissue or hepatocytes. Hepatocytes were isolated from five different individual livers, and cultured on human recombinant laminin isoforms -111, -211, -221, -332, -411, -421, -511, and -521 (Biolamina AB), matrigel (extracted from Engelbreth-Holm-Swarm sarcoma), or collagen type IV (Collagen). Hepatocytes cultured on laminin showed characteristic hexagonal shape in a flat cell monolayer. Viability, double stranded DNA concentration, and Ki67 expression for hepatocytes cultured for six days on laminin were comparable to those cultured on EHS and Collagen. Hepatocytes cultured on laminin also displayed production of human albumin, alpha-1-antitrypsin, bile acids, and gene expression of liver-enriched factors, such as hepatocyte nuclear factor 4 alpha, glucose-6-phosphate, cytochrome P450 3A4, and multidrug resistance-associated protein 2. We conclude that all forms of human recombinant laminin tested maintain cell viability and liver-specific functions of primary human

  18. Recombinant expression of hydroxylated human collagen in Escherichia coli.

    PubMed

    Rutschmann, Christoph; Baumann, Stephan; Cabalzar, Jürg; Luther, Kelvin B; Hennet, Thierry

    2014-05-01

    Collagen is the most abundant protein in the human body and thereby a structural protein of considerable biotechnological interest. The complex maturation process of collagen, including essential post-translational modifications such as prolyl and lysyl hydroxylation, has precluded large-scale production of recombinant collagen featuring the biophysical properties of endogenous collagen. The characterization of new prolyl and lysyl hydroxylase genes encoded by the giant virus mimivirus reveals a method for production of hydroxylated collagen. The coexpression of a human collagen type III construct together with mimivirus prolyl and lysyl hydroxylases in Escherichia coli yielded up to 90 mg of hydroxylated collagen per liter culture. The respective levels of prolyl and lysyl hydroxylation reaching 25 % and 26 % were similar to the hydroxylation levels of native human collagen type III. The distribution of hydroxyproline and hydroxylysine along recombinant collagen was also similar to that of native collagen as determined by mass spectrometric analysis of tryptic peptides. The triple helix signature of recombinant hydroxylated collagen was confirmed by circular dichroism, which also showed that hydroxylation increased the thermal stability of the recombinant collagen construct. Recombinant hydroxylated collagen produced in E. coli supported the growth of human umbilical endothelial cells, underlining the biocompatibility of the recombinant protein as extracellular matrix. The high yield of recombinant protein expression and the extensive level of prolyl and lysyl hydroxylation achieved indicate that recombinant hydroxylated collagen can be produced at large scale for biomaterials engineering in the context of biomedical applications.

  19. Investigation of the interaction of deltamethrin (DM) with human serum albumin by multi-spectroscopic method

    NASA Astrophysics Data System (ADS)

    Wang, Jiaman; Ma, Liang; Zhang, Yuhao; Jiang, Tao

    2017-02-01

    The interaction of Deltamethrin (DM) with human serum albumin (HSA) under the condition of simulating human blood pH environment (pH = 7.4) was investigated by fluorescence, UV-Vis absorbance and circular dichroism (CD) spectroscopy. It was shown that DM was a static quencher of HSA. The binding constants (Ka) are 3.598 × 104 L mol-1 (25 °C); the thermodynamic parameters (ΔH = -3.269 × 104 kJ mol-1, ΔS = -22.81 kJ mol-1 k-1, ΔG = -25889.8 kJ mol-1) obtained with the thermodynamic equation. The hydrogen bond and Vander Waals were the main driving force. The effect of DM on the conformation of HSA was observed by three-dimensional (3D) fluorescence and circular dichroism spectra, indicating that the interaction between DM and HSA was achieved through the binding of DM with the tryptophan and tyrosine residues of HSA. The study on the interaction of DM and Bovine Serum Albumin (BSA) was researched and compared. Difference exists in the interactions of with each of the serum albumins. We will verify and supplement that DM residue in animals and human metabolism, toxicology and other mechanisms are different.

  20. Chemical modification of human albumin at cys34 by ethacrynic acid: structural characterisation and binding properties.

    PubMed

    Bertucci, C; Nanni, B; Raffaelli, A; Salvadori, P

    1998-10-01

    Derivatization of the free cys3,4 in human albumin, which is reported to occur under physiological conditions, has been performed in vitro by reaction of the protein with ethacrynic acid. This modification has been investigated by mass spectrometry and circular dichroism. Ethacrynic acid has been proven to bind human albumin either covalently and non-covalently. This post-translational modification does not determine significant changes in the secondary structure of the protein, as shown by the comparable circular dichroism spectra of the native and the modified proteins. Furthermore, the binding properties of the human albumin samples have been investigated by circular dichroism and equilibrium dialysis. The affinity to the higher affinity binding sites does not change either for drugs binding to site I, like phenylbutazone, or to site II, like diazepam, while a small but significant increase has been observed for bilirubin, known to bind to site III. Nevertheless significant decreases of the affinity at the lower affinity binding sites of the modified protein were observed for both drugs binding to site I or to site II.

  1. Porphyrin mediated photo-modification of the structure and function of human serum albumin

    NASA Astrophysics Data System (ADS)

    Rozinek, Sarah C.

    Photosensitization reactions involve irradiating (with visible light) molecules with a high efficiency for either electron transfer or entering an excited triplet state (photosensitizer). Such reactions are applied to photodynamic cancer therapy, many medical laser-treatments, and a potential array of disinfection and pest elimination techniques. To understand the biophysical mechanisms of how these applications are effective at the protein level, the group of Dr. Brancaleon (UTSA) has investigated the irradiation of several dye-protein combinations, and discovered effects on protein structure and function. To further that work, we have investigated irradiation of the protein, human serum albumin (HSA), photosensitized by either protoporphyrin IX (PPIX) or meso-tetrakis(4-sulfonatophenyl)porphyrin (TSPP). HSA is the most abundant plasma protein, making it a likely substrate in PDT, and it possesses a specific binding pocket for iron-PPIX (heme) and possibly other porphyrin derivatives. The results of our research are summarized as follows. First, a thorough characterization of the binding of each photosensitizer to albumin was completed, elucidating a probable binding location for TSPP. Next, fluorescence lifetime emission of the single tryptophan residue, alongside circular dichroism, found tertiary structural changes around tryptophan and an overall 20% decrease in protein secondary structure after irradiation with TSPP bound. Finally, to determine if protein function was lost after photosensitization, size exclusion chromatography found modified albumin still recognizable by its receptor-protein, and comparative ex vivo up-take studies revealed that modified albumin is not processed the same way as native albumin in live tapeworm larva (Mesocestoides corti). Thus we found that visible light can induce partial unfolding of a protein by using a photo-activated ligand. These small structural modifications were sufficient to affect the protein's biological function.

  2. α-Galactosidase delivery using 30Kc19-human serum albumin nanoparticles for effective treatment of Fabry disease.

    PubMed

    Lee, Hong Jai; Park, Hee Ho; Sohn, Youngsoo; Ryu, Jina; Park, Ju Hyun; Rhee, Won Jong; Park, Tai Hyun

    2016-12-01

    Fabry disease is a genetic lysosomal storage disease caused by deficiency of α-galactosidase, the enzyme-degrading neutral glycosphingolipid that is transported to lysosome. Glycosphingolipid accumulation by this disease causes multi-organ dysfunction and premature death of the patient. Currently, enzyme replacement therapy (ERT) using recombinant α-galactosidase is the only treatment available for Fabry disease. To maximize the efficacy of treatment, enhancement of cellular delivery and enzyme stability is a challenge in ERT using α-galactosidase. In this study, protein nanoparticles using human serum albumin (HSA) and 30Kc19 protein, originating from silkworm, were used to enhance the delivery and intracellular α-galactosidase stability. 30Kc19-HSA nanoparticles loaded with the α-galactosidase were formed by desolvation method. 30Kc19-HSA nanoparticles had a uniform spherical shape and were well dispersed in cell culture media. 30Kc19-HSA nanoparticles had negligible toxicity to human cells. The nanoparticles exhibited enhanced cellular uptake and intracellular stability of delivered α-galactosidase in human foreskin fibroblast. Additionally, they showed enhanced globotriaosylceramide degradation in Fabry patients' fibroblasts. It is expected that 30Kc19-HSA protein nanoparticles could be used as an effective tool for efficient delivery and enhanced stability of drugs.

  3. A highly efficient modified human serum albumin signal peptide to secrete proteins in cells derived from different mammalian species.

    PubMed

    Attallah, Carolina; Etcheverrigaray, Marina; Kratje, Ricardo; Oggero, Marcos

    2017-01-10

    Signal peptides (SPs) are key elements in the production of recombinant proteins; however, little information is available concerning different SP in mammalian cells other than CHO. In order to study the efficiency of different SPs to direct the traffic along the secretory pathway of the green fluorescence protein (GFP) and a scFv-Fc fusion protein; CHO-K1, HEK293 and NS0 cell lines were transfected in a transient and stable way. SP of human azurocidin (AZ), modified human albumin (mSA), modified Cricetulus griseus Ig kappa chain V III region MOPC 63 like (mIgκ C) and modified human Ig kappa chain V III region VG (mIgκ H) were evaluated. The efficiency of SPs to translocate a propeptide across the ER membrane was evaluated by fluorescence microscopy and flow cytometry for the GFP inside the secretory pathway, and by antigen-specific indirect ELISA for the scFv-Fc outside the cell. The mSA SP was successful in directing the secretion of the active proteins in these different types of mammalian cells, regardless of the transgene copy number. The goal of this work was to demonstrate that a modified version of SA SP might be used in different mammalian cells employing the same expression vector.

  4. Two distinct receptors account for recognition of maleyl-albumin in human monocytes during differentiation in vitro.

    PubMed Central

    Haberland, M E; Rasmussen, R R; Olch, C L; Fogelman, A M

    1986-01-01

    A comparison of the receptor-mediated interaction of malondialdehyde-low density lipoprotein and maleyl-albumin has been examined in human monocytes during differentiation in vitro. The recognition of both ligands by the scavenger receptor of these cells has been confirmed. We now report that human monocytes express a second cellular surface receptor for maleyl-albumin that is distinct from the scavenger receptor. The activity of the maleyl-albumin receptor, determined by both binding and lysosomal hydrolytic assays, substantially exceeds that of the scavenger receptor in freshly isolated monocytes. A dramatic and rapid decline in the activity of the maleyl-albumin receptor occurs within 72 to 96 h during differentiation in vitro. At day 7, while only 5-10% of the original activity of the maleyl-albumin receptor remains, it is similar to that of the maximally expressed scavenger receptor. Both the binding and hydrolysis of ligand mediated by the maleyl-albumin receptor are specifically inhibited by alpha-casein and alkaline-treated albumin; neither of these proteins is recognized by the scavenger receptor. The occurrence of the exceptionally active maleyl-albumin receptor on freshly isolated human monocytes suggests that it participates in processes necessary to the function of the cells that diminish in importance after differentiation of the monocytes into macrophages in vitro. Furthermore, while maleyl-albumin is a useful adjunct to studies of cellular events mediated by the scavenger receptor, the presence of a second receptor for maleyl-albumin must be taken into account as a potential contributing and complicating event. Images PMID:3949974

  5. Human Serum Albumin (HSA) Suppresses the Effects of Glycerol Monolaurate (GML) on Human T Cell Activation and Function

    PubMed Central

    Zhang, Michael S.; Houtman, Jon C. D.

    2016-01-01

    Glycerol monolaurate (GML) is a monoglyceride with well characterized anti-microbial properties. Because of these properties, GML is widely used in food, cosmetics, and personal care products and currently being tested as a therapeutic for menstrual associated toxic shock syndrome, superficial wound infections, and HIV transmission. Recently, we have described that GML potently suppresses select T cell receptor (TCR)-induced signaling events, leading to reduced human T cell effector functions. However, how soluble host factors present in the blood and at sites of infection affect GML-mediated human T cell suppression is unknown. In this study, we have characterized how human serum albumin (HSA) affects GML-induced inhibition of human T cells. We found that HSA and other serum albumins bind to 12 carbon acyl side chain of GML at low micromolar affinities and restores the TCR-induced formation of LAT, PLC-γ1, and AKT microclusters at the plasma membrane. Additionally, HSA reverses GML mediated inhibition of AKT phosphorylation and partially restores cytokine production in GML treated cells. Our data reveal that HSA, one of the most abundant proteins in the human serum and at sites of infections, potently reverses the suppression of human T cells by GML. This suggests that GML-driven human T cell suppression depends upon the local tissue environment, with albumin concentration being a major determinant of GML function. PMID:27764189

  6. In vitro inhibition of human neutrophil elastase by oleic acid albumin formulations from derivatized cotton wound dressings.

    PubMed

    Edwards, J Vincent; Howley, Phyllis; Cohen, I Kelman

    2004-10-13

    Human neutrophil elastase (HNE) is elevated in chronic wounds. Oleic acid albumin formulations that inhibit HNE may be applicable to treatment modalities for chronic wounds. Oleic acid/albumin formulations with mole ratios of 100:1, 50:1, and 25:1 (oleic acid to albumin) were prepared and found to have dose response inhibition properties against HNE. The IC50 values for inhibition of HNE with oleic acid/albumin formulations were 0.029-0.049 microM. Oleic acid/albumin (BSA) formulations were bound to positively and negatively charged cotton wound dressings and assessed for elastase inhibition using a fiber bound formulation in an assay designed to mimic HNE inhibition in the wound. Cotton derivatized with both carboxylate and amine functional groups were combined with oleic acid/albumin formulations at a maximum loading of 0.030 mg oleic acid + 0.14 mg BSA/mg fiber. The IC50 values for inhibition of HNE with oleic acid/albumin formulations bound to derivatized cotton were 0.26-0.42 microM. Release of the oleic acid/albumin formulation from the fiber was measured by measuring oleic acid levels with quantitative GC analysis. Approximately, 35-50% of the fiber bound formulation was released into solution within the first 15 min of incubation. Albumin was found to enhance the rate of elastase hydrolysis of the substrate within a concentration range of 0.3-50 g/L. The acceleration of HNE substrate hydrolysis by albumin required increased concentration of inhibitor in the formulation to obtain complete inhibition of HNE. Oleic acid formulations prepared with albumin enable transport, solubility and promote dose response inhibition of HNE from derivatized cotton fibers under aqueous conditions mimicking the chronic wound.

  7. 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.

  8. 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.

  9. Interactions of hybrid gold-tannic acid nanoparticles with human serum albumin.

    PubMed

    Sekowski, Szymon; Tomaszewska, Emilia; Soliwoda, Katarzyna; Celichowski, Grzegorz; Grobelny, Jaroslaw

    2017-01-01

    Nanoparticles present a wide spectrum of chemical, biological, and physical properties which result in their usage in many branches of science. We present an investigation of the interaction between human serum albumin and hybrid gold-tannic acid nanoparticles synthesized via a chemical reduction method. The results obtained demonstrate that tannic acid can be a very effective reducing and stabilizing agent and allows monodisperse hybrid gold nanomaterial to be obtained. The synthesized hybrid gold-tannic acid nanoparticles strongly interact with human serum albumin by formation of protein-corona complexes. The strength of the interaction with albumin depends on the number of tannic acid molecules on the surface of the nanoparticles and the presence of citric acid. Nanoparticles of large size and rich in tannic acid react more strongly with the protein [K SV = (8.00 ± 0.2) × 10(5) M(-1)] compared with smaller ones [K SV = (6.83 ± 0.5) × 10(4) M(-1)] containing citric acid and low concentration of tannic acid.

  10. Zinc phthalocyanine-conjugated with bovine serum albumin mediated photodynamic therapy of human larynx carcinoma

    NASA Astrophysics Data System (ADS)

    Silva, E. P. O.; Santos, E. D.; Gonçalves, C. S.; Cardoso, M. A. G.; Soares, C. P.; Beltrame, M., Jr.

    2016-10-01

    Phthalocyanines, which are classified as second-generation photosensitizers, have advantageous photophysical properties, and extensive studies have demonstrated their potential applications in photodynamic therapy. The present work describes the preparation of a new zinc phthalocyanine conjugated to bovine serum albumin (compound 4a) and its photodynamic efficiency in human larynx-carcinoma cells (HEp-2 cells). The unconjugated precursor (compound 4) was also studied. Compounds 4 and 4a penetrated efficiently into the cell, exhibiting cytoplasmic localization, and showed no cytotoxicity in the dark. However, high photodynamic activities were observed in HEp-2 cells after treatments with 5 µM photosensitizers and 4.5 J cm-2 light. These conditions were sufficient to decrease the cell viability to 57.93% and 32.75% for compounds 4 and 4a, respectively. The present results demonstrated high photodynamic efficiency of zinc phthalocyanine conjugated with bovine serum albumin in destroying the larynx-carcinoma cells.

  11. Fluorescence quenching studies on binding fluoreno-9-spiro-oxazolidinedione to human serum albumin.

    PubMed

    Gonzalez-Jimenez, J; Jacquotte, H; Cayre, I

    1992-11-16

    Human serum albumin fluorescence quenching by fluorene-9-spiro-oxazolidinedione has been analyzed as a function of temperature. Such temperature dependence suggests that the mechanism of the quenching process is static in origin. This type of quenching implies that a non-fluorescent complex between oxazolidinedione and serum albumin has been formed and following the Stern-Volmer relationship we have calculated the binding constant. Thermodynamic parameters were also determined. The positive and large values of entropy and the negative value for enthalpy suggest that both hydrophobic and electrostatic interactions may play an important role in the stabilization of the complex. Finally, the irreversible changes in the spectral properties of HSA are interpreted in binding terms.

  12. β-Carotene and astaxanthin with human and bovine serum albumins.

    PubMed

    Li, Xiangrong; Wang, Gongke; Chen, Dejun; Lu, Yan

    2015-07-15

    β-Carotene and astaxanthin are two carotenoids with powerful antioxidant properties. In this study, the interaction of these two carotenoids with human serum albumin (HSA) and bovine serum albumin (BSA) under physiological conditions was investigated using several spectroscopic techniques. The experimental results indicate the quenching mechanism of HSA/BSA, by the two carotenoids, is a static process. The binding constants and number of binding sites were evaluated at different temperatures. Thermodynamic investigations revealed the interaction between the two carotenoids and HSA/BSA is synergistically driven by enthalpy and entropy, and hydrophobic forces and electrostatic attraction have a significant role in the reactions. Binding site I was found to be the primary binding site for β-carotene and astaxanthin. In addition, as shown by synchronous fluorescence spectroscopy and FT-IR, the two carotenoids may induce conformational and micro-environmental changes in HSA/BSA.

  13. Covalent modification of human serum albumin by the natural sesquiterpene lactone parthenolide.

    PubMed

    Plöger, Michael; Sendker, Jandirk; Langer, Klaus; Schmidt, Thomas J

    2015-04-09

    The reactivity of parthenolide (PRT), a natural sesquiterpene lactone from Tanacetum parthenium (Asteraceae), with human serum albumin (HSA) was studied by UHPLC/+ESI-QqTOF MS analysis after tryptic digestion of albumin samples after incubation with this compound. It was found that the single free cysteine residue, C34, of HSA (0.6 mM) reacted readily with PRT when incubated at approximately 13-fold excess of PRT (8 mM). Time-course studies with PRT and its 11β,13-dihydro derivative at equimolar ratios of the reactants revealed that PRT under the chosen conditions reacts preferably with C34 and does so exclusively via its α-methylene-γ-lactone moiety, while the epoxide structure is not involved in the reaction.

  14. Ligand binding strategies of human serum albumin: how can the cargo be utilized?

    PubMed

    Varshney, Ankita; Sen, Priyankar; Ahmad, Ejaz; Rehan, Mohd; Subbarao, Naidu; Khan, Rizwan Hasan

    2010-01-01

    Human serum albumin (HSA), being the most abundant carrier protein in blood and a modern day clinical tool for drug delivery, attracts high attention among biologists. Hence, its unfolding/refolding strategies and exogenous/endogenous ligand binding preference are of immense use in therapeutics and clinical biochemistry. Among its fellow proteins albumin is known to carry almost every small molecule. Thus, it is a potential contender for being a molecular cargo/or nanovehicle for clinical, biophysical and industrial purposes. Nonetheless, its structure and function are largely regulated by various chemical and physical factors to accommodate HSA to its functional purpose. This multifunctional protein also possesses enzymatic properties which may be used to convert prodrugs to active therapeutics. This review aims to highlight current overview on the binding strategies of protein to various ligands that may be expected to lead to significant clinical applications.

  15. Interaction of Cis- and Trans-RuCl 2(DMSO)4 With Human Serum Albumin

    PubMed Central

    Kozlowski, Henryk; Katsaros, Nikolas

    2000-01-01

    The interaction between cis- and trans- RuCl2(DMSO)4 and human serum albumin have been investigated through UV-Vis, circular dichroism, fluorescence spectroscopy and inductively couplet plasma atomic emission spectroscopy (ICP(AES)) method Albumin can specifically bind 1 mole of cis-isomer and 2 moles of the trans-isomer RuCl2(DMSO)4 complex. The interaction of RuCl2(DMSO)4 with HSA causes: a conformational change with the loss of helical stability of protein; the strong quenching of the Trp 214 fluorescence indicating that the conformational change of the hydrophobic binding pocked in subdomain IIA takes place; a local perturbation of the warfarin binding site and induce some conformational changes at neighbour domains, a changing of the binding abilities towards heme. PMID:18475961

  16. Characterization of isomeric VX nerve agent adducts on albumin in human plasma using liquid chromatography-tandem mass spectrometry.

    PubMed

    Saeidian, Hamid; Mirkhani, Valioallah; Mousavi Faraz, Sajjad; Taghi Naseri, Mohammad; Babri, Mehran

    2015-01-01

    This study includes the characterization of isomeric VX organophosphorus adducts on albumin in human plasma using liquid chromatography-tandem mass spectrometry (LC-MS/MS). VX or its structural isomers were spiked into a vial containing plasma in order to obtain phosphorylated albumin. After pronase and trypsin digestion, the resulting solutions were analyzed to confirm adduct formation with the amino acid tyrosine on the albumin in human plasma. The LC-MS/MS experiments show that VX and its isomers can be attached to tyrosine on the albumin in human blood. Mass spectrometric studies revealed some interesting fragmentation pathways during the ionization process, such as ethylene, formic acid and ammonia elimination and an intermolecular electrophilic aromatic substitution reaction. The proposed mechanisms for the formation of the fragments were confirmed through the analysis of fragments of deuterated adducts.

  17. Binding of human serum albumin to N-(p-ethoxy-phenyl)-N'-(1-naphthyl)thiourea and synchronous fluorescence determination of human serum albumin.

    PubMed

    Cui, Fengling; Wang, Junli; Cui, Yanrui; Li, Jianping; Lu, Yan; Fan, Jing; Yao, Xiaojun

    2007-06-01

    The binding of N-(p-ethoxy-phenyl)-N'-(1-naphthyl)thiourea (EPNT) to human serum albumin (HSA) was investigated under simulative physiological conditions by fluorescence spectra in combination with UV absorption spectroscopy and a molecular modeling method. A strong fluorescence quenching reaction of EPNT to HSA was observed, and the quenching mechanism was suggested to be static quenching according to the Stern-Volmer equation. The binding constants (K) at different temperatures as well as thermodynamic parameters, enthalpy change (DeltaH) and entropy change (DeltaS), were calculated according to relevant fluorescent data and the vant' Hoff equation. This indicated that a hydrophobic interaction was a predominant intermolecular force for stabilizing the complex, which is in agreement with the results of molecule modeling study. The effects of energy transfer and other ions on the binding constant were considered. In addition, synchronous fluorescence technology was successfully applied to the determination of HSA added into the EPNT solution.

  18. Biosensor analysis of the interaction between immobilized human serum albumin and drug compounds for prediction of human serum albumin binding levels.

    PubMed

    Frostell-Karlsson, A; Remaeus, A; Roos, H; Andersson, K; Borg, P; Hämäläinen, M; Karlsson, R

    2000-05-18

    The interactions between a set of drugs, selected on the basis of reported human serum albumin (HSA) binding levels, and immobilized HSA were investigated using surface plasmon resonance technology. Major HSA binding sites were available after immobilization. The intensity of the signal obtained from the interaction of the drug with the HSA surface was correlated with the reported HSA binding level. Drugs were classified into groups corresponding to high, medium, or low HSA binding based on the injection of the drug at 80 microM concentration. A set of 10 drugs binding to alpha(1)-acid glycoprotein (AGP) was also investigated and correlated with reported AGP binding data. The throughput of the presented assay is 100 compounds/24 h, and the sample consumption is less than 100 microL (8 nmol).

  19. Investigation into the interaction of losartan with human serum albumin and glycated human serum albumin by spectroscopic and molecular dynamics simulation techniques: A comparison study.

    PubMed

    Moeinpour, Farid; Mohseni-Shahri, Fatemeh S; Malaekeh-Nikouei, Bizhan; Nassirli, Hooriyeh

    2016-09-25

    The interaction between losartan and human serum albumin (HSA), as well as its glycated form (gHSA) was studied by multiple spectroscopic techniques and molecular dynamics simulation under physiological conditions. The binding information, including the binding constants, effective quenching constant and number of binding sites showed that the binding partiality of losartan to HSA was higher than to gHSA. The findings of three-dimensional fluorescence spectra demonstrated that the binding of losartan to HSA and gHSA would alter the protein conformation. The distances between Trp residue and the binding sites of the drug were evaluated on the basis of the Förster theory, and it was indicated that non-radiative energy transfer from HSA and gHSA to the losartan happened with a high possibility. According to molecular dynamics simulation, the protein secondary and tertiary structure changes were compared in HSA and gHSA for clarifying the obtained results.

  20. Effectiveness of Recombinant Human Growth Hormone for Pharyngocutaneous Fistula Closure

    PubMed Central

    Sari, Murat; Midi, Ahmet; Yumusakhuylu, Ali Cemal; Findik, Ozan; Binnetoglu, Adem

    2015-01-01

    Objectives In laryngeal cancer, which comprises 25% of head and neck cancer, chemotherapy has come into prominence with the increase in organ-protective treatments. With such treatment, salvage surgery has increased following recurrence; the incidence of pharyngocutaneous fistula has also increased in both respiratory and digestive system surgery. We investigated the effects of recombinant human growth hormone on pharyngocutaneous fistula closure in Sprague-Dawley rats, based on an increase in amino acid uptake and protein synthesis for wound healing, an increase in mitogenesis, and enhancement of collagen formation by recombinant human growth hormone. Methods This study was experimental animal study. Forty Sprague-Dawley rats were separated into two groups, and pharyngoesophagotomy was performed. The pharyngoesophagotomy was sutured with vicryl in both groups. Rats in group 1 (control group) received no treatment, while those in group 2 were administered a subcutaneous injection of recombinant human growth hormone daily. On day 14, the pharynx, larynx, and upper oesophagus were excised and examined microscopically. Results Pharyngocutaneous fistula exhibited better closure macroscopically in the recombinant human growth hormone group. There was a significant difference in collagen formation and epithelisation in the recombinant human growth hormone group compared to the control group. Conclusion This study is believed to be the first in which the effect of recombinant human growth hormone on pharyngocutaneous fistula closure was evaluated, and the findings suggest the potential of use of growth hormone for treatment of pharyngocutaneous fistula. PMID:26622960

  1. The effect of methylamine on the solution structures of human and bovine serum albumins

    NASA Astrophysics Data System (ADS)

    Hamdani, S.; Joly, D.; Carpentier, R.; Tajmir-Riahi, H. A.

    2009-11-01

    Serum albumins are the major soluble protein constituents of the circulatory system and have many physiological functions including transporting a variety of compounds. Methylamine, a monoamine with one positive charge complexes with protein and alters protein secondary structure. The aim of this study was to examine the interactions of human serum albumin (HSA) and bovine serum albumin (BSA) with methylamine at physiological conditions, using constant protein concentration and various monoamine concentrations. FTIR, UV-vis, CD and fluorescence spectroscopic methods were used to analyse methylamine binding mode, the binding constant and the effects of monoamine on HSA and BSA stability and conformations. Structural analysis showed that methylamine binds HSA and BSA via hydrophilic (polypeptide and amine polar groups) and hydrophobic interactions with overall binding constants of Kmet-HSA = 2.42 (±0.5) × 10 2 M -1 and Kmet-BSA = 1.34 (±0.3) × 10 3 M -1 with the number of bound methylamine around one molecule per protein. Methylamine complexation alters protein conformation by major reduction of α-helix and increase in random coil and turn structures indicating a partial protein unfolding.

  2. 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.

  3. Soluble copolymer of wasp venom with human albumin for venom immunotherapy.

    PubMed

    Gewurz, A; Grammer, L C; Shaughnessy, M A; Patterson, R

    1986-03-01

    Polymerization of allergens decreases allergenicity while retaining immunogenicity, as we have demonstrated for ragweed, grass, and tree pollens. We have also polymerized bee venom with human albumin to form soluble, high-molecular-weight copolymers that are immunogenic in rabbits. We now have prepared a soluble wasp venom-albumin polymer (WVAP), molecular weight greater than or equal to 240,000 daltons, by glutaraldehyde treatment and Sephacryl S-300 column fractionation. Rabbits immunized with WVAP produced IgG to both WVAP and wasp venom (WV), as measured by ELISA. IgG against WVAP was totally inhibitable by a mixture of WV and albumin, demonstrating both retention of native antigens and absence of new antigenic determinants in WVAP. IgG against WV in serum from patients receiving maintenance doses of WV immunotherapy was inhibited by WVAP. In summary, we have synthesized a soluble, high-molecular-weight copolymer of WV that retains the immunogenicity of native WV, contains no new antigenic determinants, and has potential value in the treatment of patients with WV anaphylaxis.

  4. Study of the binding interaction between fluorinated matrix metalloproteinase inhibitors and Human Serum Albumin.

    PubMed

    Digilio, Giuseppe; Tuccinardi, Tiziano; Casalini, Francesca; Cassino, Claudio; Dias, David M; Geraldes, Carlos F G C; Catanzaro, Valeria; Maiocchi, Alessandro; Rossello, Armando

    2014-05-22

    Fluorinated, arylsulfone-based inhibitors of Matrix Metalloproteinases (MMP) have been used, in the [(18)F]-radiolabelled version, as radiotracers targeted to MMP-2/9 for Positron Emission Tomography (PET). Although they showed acceptable tumour uptake, specificity was rather low. To get further insights into the reason of low specificity, the binding interaction of these compounds with Human Serum Albumin (HSA) has been investigated. (19)F NMR spectroscopy showed that all compounds considered partition between multiple HSA binding sites, being characterized by either slow-exchange kinetics (with Ka in the order of 10(5) M(-1)) and fast-exchange kinetics (with Ka in the order of 10(4) M(-1)). For 2-(2-(4'-(2-fluoroethoxy)biphenyl-4-ylsulfonyl)phenyl)acetic acid (1a) and 2-(2-(4'-(2-fluoroacetamido)biphenyl-4-ylsulfonyl)phenyl)acetic acid (1c), these slow and fast-exchanging binding sites could be mapped to Sudlow's site I and II, respectively. It is shown that high affinity albumin binding constitutes a theoretical limitation for the specificity achievable by MMP-inhibitors as MMP-targeted PET tracers in cancer imaging, because albumin accumulating aspecifically in tumours lowers the binding potential of radiotracers.

  5. Thiolated human serum albumin cross-linked dextran hydrogels as a macroscale delivery system.

    PubMed

    Gao, Yue; Kieltyka, Roxanne E; Jesse, Wim; Norder, Ben; Korobko, Alexander V; Kros, Alexander

    2014-07-21

    Hydrogels play an important role in macroscale delivery systems by enabling the transport of cells and molecules. Here we present a facile and benign method to prepare a dextran-based hydrogel (Dex-sHSA) using human serum albumin (HSA) as a simultaneous drug carrier and covalent cross-linker. Drug binding affinity of the albumin protein was conserved in the thiolation step using 2-iminothiolane and subsequently, in the in situ gelation step. Oscillation rheometry studies confirmed the formation of a three-dimensional viscoelastic network upon reaction of dextran and the HSA protein. The mechanical properties of Dex-sHSA hydrogel can be tuned by the protein concentration, and the degree of thiolation of sHSA. Sustained release of hydrophobic drugs, such as ibuprofen, paclitaxel and dexamethasone, from the Dex-sHSA network was shown over one week. Hence, this albumin-based dextran hydrogel system demonstrates its potential as a macroscale delivery system of hydrophobic therapeutics for a wide range of biomedical applications.

  6. PEGylated Human Serum Albumin: Review of PEGylation, Purification and Characterization Methods

    PubMed Central

    Akbarzadehlaleh, Parvin; Mirzaei, Mona; Mashahdi-Keshtiban, Mahdiyeh; Shamsasenjan, Karim; Heydari, Hamidreza

    2016-01-01

    Human serum albumin (HSA) is a non-glycosylated, negatively charged protein (Mw: about 65-kDa) that has one free cystein residue (Cys 34), and 17 disulfide bridges that these bridges have main role in its stability and longer biological life-time (15 to 19 days). As HSA is a multifunctional protein, it can also bind to other molecules and ions in addition to its role in maintaining colloidal osmotic pressure (COP) in various diseases. In critical illnesses changes in the level of albumin between the intravascular and extravascular compartments and the decrease in its serum concentration need to be compensated using exogenous albumin; but as the size of HSA is an important parameter in retention within the circulation, therefore increasing its molecular size and hydrodynamic radius of HSA by covalent attachment of poly ethylene glycol (PEG), that is known as PEGylation, provides HSA as a superior volume expander that not only can prevent the interstitial edema but also can reduce the infusion frequency. This review focuses on various PEGylation methods of HSA (solid phase and liquid phase), and compares various methods to purifiy and characterize the pegylated form. PMID:27766215

  7. Radioactive excretion in human milk following administration of /sup 99m/Tc macroaggregated albumin

    SciTech Connect

    Pittard, W.B.; Merkatz, R.; Fletcher, B.D.

    1982-08-01

    Albumin-tagged sodium pertechnetate (technetium) is routinely used in nuclear medicine for scanning procedures of the lung. The rate of excretion of this radionuclide into breast milk and the resultant potential radiation hazard to the nursing infant have received little attention. Therefore the milk from a nursing mother who required a lung scan because of suspected pulmonary emboli using an intravenous injection of 4 mCi of /sup 99m/Tc macroaggregated human serum albumin was monitored. Albumin tagging severely limited the entrance of technetium into her milk and the radioactivity of the milk returned to base line by 24 hours. A total of 2.02 muCi of technetium was measured in the 24-hour milk collection after technetium injection and 94% of this amount was excreted by 15.5 hours. This amount of technetium administered orally to a newborn would deliver a total body radiation dose of .3 mrad. Therefore, an infant would receive trivial doses of radiation if breast-feeding were resumed 15.5 hours after administration of the radionuclide to the mother and nursing can clearly be resumed safely 24 hours after injection.

  8. 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.

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

    PubMed

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

    2016-03-01

    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.

  10. New Perspectives in the Renin-Angiotensin-Aldosterone System (RAAS) II: Albumin Suppresses Angiotensin Converting Enzyme (ACE) Activity in Human

    PubMed Central

    Fagyas, Miklós; Úri, Katalin; Siket, Ivetta M.; Fülöp, Gábor Á.; Csató, Viktória; Daragó, Andrea; Boczán, Judit; Bányai, Emese; Szentkirályi, István Elek; Maros, Tamás Miklós; Szerafin, Tamás; Édes, István; Papp, Zoltán; Tóth, Attila

    2014-01-01

    About 8% of the adult population is taking angiotensin-converting enzyme (ACE) inhibitors to treat cardiovascular disease including hypertension, myocardial infarction and heart failure. These drugs decrease mortality by up to one-fifth in these patients. We and others have reported previously that endogenous inhibitory substances suppress serum ACE activity, in vivo, similarly to the ACE inhibitor drugs. Here we have made an effort to identify this endogenous ACE inhibitor substance. ACE was crosslinked with interacting proteins in human sera. The crosslinked products were immunoprecipitated and subjected to Western blot. One of the crosslinked products was recognized by both anti-ACE and anti-HSA (human serum albumin) antibodies. Direct ACE-HSA interaction was confirmed by binding assays using purified ACE and HSA. HSA inhibited human purified (circulating) and human recombinant ACE with potencies (IC50) of 5.7±0.7 and 9.5±1.1 mg/mL, respectively. Effects of HSA on the tissue bound native ACE were tested on human saphenous vein samples. Angiotensin I evoked vasoconstriction was inhibited by HSA in this vascular tissue (maximal force with HSA: 6.14±1.34 mN, without HSA: 13.54±2.63 mN), while HSA was without effects on angiotensin II mediated constrictions (maximal force with HSA: 18.73±2.17 mN, without HSA: 19.22±3.50 mN). The main finding of this study is that HSA was identified as a potent physiological inhibitor of the ACE. The enzymatic activity of ACE appears to be almost completely suppressed by HSA when it is present in its physiological concentration. These data suggest that angiotensin I conversion is limited by low physiological ACE activities, in vivo. PMID:24691203

  11. On the interaction of luminol with human serum albumin: Nature and thermodynamics of ligand binding

    NASA Astrophysics Data System (ADS)

    Moyon, N. Shaemningwar; Mitra, Sivaprasad

    2010-09-01

    The mechanism and thermodynamic parameters for the binding of luminol (LH 2) with human serum albumin was explored by steady state and picosecond time-resolved fluorescence spectroscopy. It was shown that out of two possible LH 2 conformers present is solution, only one is accessible for binding with HSA. The thermodynamic parameters like enthalpy (Δ H) and entropy (Δ S) change corresponding to the ligand binding process were also estimated by performing the experiment at different temperatures. The ligand replacement experiment with bilirubin confirms that LH 2 binds into the sub-domain IIA of the protein.

  12. Radiation-induced chemical transformations of human serum albumin in aqueous solutions

    SciTech Connect

    Kondakova, N.V.; Ripa, N.V.; Kuznetsova, N.V.

    1994-11-01

    A rate constant of the reaction of human serum albumin (HSA) with OH radicals was determined using the method of competing scavengers. Changes in the amino acid composition and some biochemical properties of HSA on radiolysis in a borate buffer (pH 7.4) saturated with N{sub 2}O or O{sub 2} were correlated quantitatively. It was found that the yield of peptide bonds that lost the ability to be cleaved by trypsin is higher than the total yield of arginine and lysine residues in HSA. The possibility of accumulation of modified HSA in blood upon irradiation was considered.

  13. Nanoparticle Albumin Bound Paclitaxel in the Treatment of Human Cancer: Nanodelivery Reaches Prime-Time?

    PubMed Central

    Cucinotto, Iole; Fiorillo, Lucia; Gualtieri, Simona; Arbitrio, Mariamena; Ciliberto, Domenico; Staropoli, Nicoletta; Grimaldi, Anna; Luce, Amalia; Tassone, Pierfrancesco; Caraglia, Michele; Tagliaferri, Pierosandro

    2013-01-01

    Nanoparticle albumin bound paclitaxel (nab-paclitaxel) represents the first nanotechnology-based drug in cancer treatment. We discuss the development of this innovative compound and report the recent changing-practice results in breast and pancreatic cancer. A ground-breaking finding is the demonstration that nab-paclitaxel can not only enhance the activity and reduce the toxicity of chromophore-diluted compound, but also exert activity in diseases considered refractory to taxane-based treatment. This is the first clinical demonstration of major activity of nanotechnologically modified drugs in the treatment of human neoplasms. PMID:23738077

  14. Generation of TALE nickase-mediated gene-targeted cows expressing human serum albumin in mammary glands.

    PubMed

    Luo, Yan; Wang, Yongsheng; Liu, Jun; Cui, Chenchen; Wu, Yongyan; Lan, Hui; Chen, Qi; Liu, Xu; Quan, Fusheng; Guo, Zekun; Zhang, Yong

    2016-02-08

    Targeting exogenous genes at milk protein loci via gene-targeting technology is an ideal strategy for producing large quantities of pharmaceutical proteins. Transcription-activator-like effector (TALE) nucleases (TALENs) are an efficient genome-editing tool. However, the off-target effects may lead to unintended gene mutations. In this study, we constructed TALENs and TALE nickases directed against exon 2 of the bovine β-lactoglobulin (BLG) locus. The nickases can induce a site-specific DNA single-strand break, without inducing double-strand break and nonhomologous end joining mediated gene mutation, and lower cell apoptosis rate than TALENs. After co-transfecting the bovine fetal fibroblasts with human serum albumin (HSA) gene-targeting vector and TALE nickase expression vectors, approximately 4.8% (40/835) of the cell clones contained HSA at BLG locus. Unexpectedly, one homozygous gene-targeted cell clone (1/835, 0.1%) was obtained by targeting both alleles of BLG in a single round of transfection. The recombinant protein mimicking the endogenous BLG was highly expressed and correctly folded in the mammary glands of the targeted cows, and the expression level of HSA was significantly increased in the homozygous targeted cows. Results suggested that the combination of TALE nickase-mediated gene targeting and somatic cell nuclear transfer is a feasible and safe approach in producing gene-targeted livestock.

  15. Generation of TALE nickase-mediated gene-targeted cows expressing human serum albumin in mammary glands

    PubMed Central

    Luo, Yan; Wang, Yongsheng; Liu, Jun; Cui, Chenchen; Wu, Yongyan; Lan, Hui; Chen, Qi; Liu, Xu; Quan, Fusheng; Guo, Zekun; Zhang, Yong

    2016-01-01

    Targeting exogenous genes at milk protein loci via gene-targeting technology is an ideal strategy for producing large quantities of pharmaceutical proteins. Transcription- activator-like effector (TALE) nucleases (TALENs) are an efficient genome-editing tool. However, the off-target effects may lead to unintended gene mutations. In this study, we constructed TALENs and TALE nickases directed against exon 2 of the bovine β-lactoglobulin (BLG) locus. The nickases can induce a site-specific DNA single-strand break, without inducing double-strand break and nonhomologous end joining mediated gene mutation, and lower cell apoptosis rate than TALENs. After co-transfecting the bovine fetal fibroblasts with human serum albumin (HSA) gene-targeting vector and TALE nickase expression vectors, approximately 4.8% (40/835) of the cell clones contained HSA at BLG locus. Unexpectedly, one homozygous gene-targeted cell clone (1/835, 0.1%) was obtained by targeting both alleles of BLG in a single round of transfection. The recombinant protein mimicking the endogenous BLG was highly expressed and correctly folded in the mammary glands of the targeted cows, and the expression level of HSA was significantly increased in the homozygous targeted cows. Results suggested that the combination of TALE nickase-mediated gene targeting and somatic cell nuclear transfer is a feasible and safe approach in producing gene-targeted livestock. PMID:26853907

  16. The expression and processing of two recombinant 2S albumins from soybean (Glycine max) in the yeast Pichia pastoris.

    PubMed

    Lin, Jing; Fido, Roger; Shewry, Peter; Archer, David B; Alcocer, Marcos J C

    2004-05-06

    Soybean seeds contain two 2S albumin storage proteins (AL1 and AL3) which may contribute to their industrial processing quality and allergenicity. We show that these proteins (AL1 and AL3) are well expressed by the methylotrophic yeast Pichia pastoris and that one of the secreted proteins (AL3) has a similar conformation and stability to that purified from soybean seeds. Further, we show that the subunits are post-translationally processed within the same loop region as the native protein but with some differences in the precise sites. This internal processing provides useful information on the endoproteolytic activity in P. pastoris. We also show that, similar to many plant allergens, the 2S albumins from soybean are stable to heat and chemical treatments.

  17. Effects of Fenton Reaction on Human Serum Albumin: An In Vitro Study

    PubMed Central

    Khosravifarsani, Meysam; Monfared, Ali Shabestani; Pouramir, Mahdi; Zabihi, Ebrahim

    2016-01-01

    Introduction Human serum albumin (HSA) is a critical protein in human blood plasma, which can be highly damaged by oxidative stress. The aim of this study was to analyze modifications of this protein after oxidation using a Fenton system. Methods In this 2015 experiment, different ratios of Fenton reagent (Fe2+/H2O2) was incubated with one concentration of human serum albumin (1mg/ml). Hence, HSA was incubated 30 min with various combinations of a Fenton system and quantified oxidation products such as carbonyl groups, fragmentations, degradations, and oxidized free thiol group using reliable techniques. Image and data analysis were carried out using ImageJ software and Excel (version 2007), respectively. Results An SDS-PAGE profile showed no cross link and aggregation. However, protein band intensity has decreased to 50% in the highest ratio of H2O2/Fe. Carbonylation assay indicated carbonyl/protein (molc/molp) ratio increased linearly in lower ratios and the values plateau at higher levels of H2O2/Fe 2+. The only free sulfhydryl group on HSA was oxidized in all ratios of the Fenton system. Conclusion To sum, the structure of HSA has been changed following treatment with Hydroxyl Radical as the main product of Fenton reaction. These data confirm the antioxidant activity of HSA. PMID:27790352

  18. Comparative studies on drug binding to the purified and pharmaceutical-grade human serum albumins: Bridging between basic research and clinical applications of albumin.

    PubMed

    Ashrafi-Kooshk, Mohammad Reza; Ebrahimi, Farangis; Ranjbar, Samira; Ghobadi, Sirous; Moradi, Nastaran; Khodarahmi, Reza

    2015-09-01

    Human serum albumin (HSA), the most abundant protein in blood plasma, is a monomeric multidomain protein that possesses an extraordinary capacity for binding, so that serves as a circulating depot for endogenous and exogenous compounds. During the heat sterilization process, the structure of pharmaceutical-grade HSA may change and some of its activities may be lost. In this study, to provide deeper insight on this issue, we investigated drug-binding and some physicochemical properties of purified albumin (PA) and pharmaceutical-grade albumin (PGA) using two known drugs (indomethacin and ibuprofen). PGA displayed significantly lower drug binding capacity compared to PA. Analysis of the quenching and thermodynamic parameters indicated that intermolecular interactions between the drugs and the proteins are different from each other. Surface hydrophobicity as well as the stability of PGA decreased compared to PA, also surface hydrophobicity of PA and PGA increased upon drugs binding. Also, kinetic analysis of pseudo-esterase activities indicated that Km and Vmax parameters for PGA enzymatic activity are more and less than those of PA, respectively. This in vitro study demonstrates that the specific drug binding of PGA is significantly reduced. Such studies can act as connecting bridge between basic research discoveries and clinical applications.

  19. Evidence of recombination within human alpha-papillomavirus

    PubMed Central

    Angulo, Manuel; Carvajal-Rodríguez, Antonio

    2007-01-01

    Background Human papillomavirus (HPV) has a causal role in cervical cancer with almost half a million new cases occurring each year. Presence of the carcinogenic HPV is necessary for the development of the invasive carcinoma of the genital tract. Therefore, persistent infection with carcinogenic HPV causes virtually all cervical cancers. Some aspects of the molecular evolution of this virus, as the putative importance of recombination in its evolutionary history, are an opened current question. In addition, recombination could also be a significant issue nowadays since the frequency of co-infection with more than one HPV type is not a rare event and, thus, new recombinant types could be currently being generated. Results We have used human alpha-PV sequences from the public database at Los Alamos National Laboratory to report evidence that recombination may exist in this virus. A model-based population genetic approach was used to infer the recombination signal from the HPV DNA sequences grouped attending to phylogenetic and epidemiological information, as well as to clinical manifestations. Our results agree with recently published ones that use a different methodology to detect recombination associated to the gene L2. In addition, we have detected significant recombination signal in the genes E6, E7, L2 and L1 at different groups, and importantly within the high-risk type HPV16. The method used has recently been shown to be one of the most powerful and reliable procedures to detect the recombination signal. Conclusion We provide new support to the recent evidence of recombination in HPV. Additionally, we performed the recombination estimation assuming the best-fit model of nucleotide substitution and rate variation among sites, of the HPV DNA sequence sets. We found that the gene with recombination in most of the groups is L2 but the highest values were detected in L1 and E6. Gene E7 was recombinant only within the HPV16 type. The topic deserves further study

  20. Comparison of human serum and bovine serum albumins on oxidation dynamics induced by talaporfin sodium photosensitization reaction with albumin rich conditions: solution experiments

    NASA Astrophysics Data System (ADS)

    Kurotsu, Mariko; Nakamura, Tetsuya; Takahashi, Mei; Ogawa, Emiyu; Arai, Tsunenori

    2014-02-01

    In order to understand extracellular-photosensitization reaction (PR) using talaporfin sodium, we studied comparison of oxidation dynamics of albumin and talaporfin sodium in solution system by visible and ultraviolet absorption spectrum measurements. Almost all talaporfin sodium particles may be bound to albumin in interstitial fluid, and this binding would affect the oxidation dynamics during this PR. Bovine serum albumin (BSA) is commonly used in vitro study but its binding characteristics with talaporfin sodium are different from human serum albumin (HSA). PR was operated in a solution composed of 20 μg/ml talaporfin sodium and 1.3 mg/ml HSA or BSA to simulate myocardial extracellular PR condition. Laser radiation of 662 nm was irradiated to this solution with irradiance of 0.29 W/cm2. Absorption spectra of these solutions were measured during the PR. We estimated oxidized ratio by absorption difference around 240 nm before and after the PR. Talaporfin sodium was oxidized 100% with HSA and BSA by the PR of 100 J/cm2 in radiant exposure. On the other hand, HSA and BSA were oxidized 60% and 94%, respectively in this radiant exposure. Q-band absorption peak of talaporfin sodium with HSA was shifted to 1 nm longer wavelength increasing radiant exposure up to 100 J/cm2. This longer wavelength shift would mean binding ratio of non-oxidized talaporfin sodium to non-oxidized HSA was increased with increasing radiant exposure. Therefore it would be possible that PR with talaporfin sodium bound to HSA might present efficient PDT than PR bound to BSA.

  1. Extended in vivo half-life of human soluble complement receptor type 1 fused to a serum albumin-binding receptor.

    PubMed

    Makrides, S C; Nygren, P A; Andrews, B; Ford, P J; Evans, K S; Hayman, E G; Adari, H; Uhlén, M; Toth, C A

    1996-04-01

    A new approach has been used to extend the T(1/2) of human soluble complement receptor type 1 (sCR1) in rats. The albumin-binding domains B2A3 (BA) and B1A2B2A3 (BABA) from Streptococcal protein G were fused to the carboxyl terminus of sCR1, and the recombinant genes were expressed and amplified in Chinese hamster ovary cells. Western blot analysis and surface plasmon resonance measurements demonstrated the binding of rat serum albumin to both sCR1-BA and sCR1-BABA but not to sCR1. The in vitro complement inhibitory activity of the fusion proteins was shown to be similar to that of sCR1, indicating that neither the albumin-binding domains nor the presence of bovine serum albumin interfere with sCR1 function. Pharmacokinetic analysis showed that the T(1/2) of the distribution phase (T(1/2alpha)) was 3.3, 20.0 and 6.0 min for sCR1, sCR1-BA and sCR1-BABA, respectively. The T(1/2) of the elimination phase (T(1/2beta)) was 103, 297 and 170 min for sCR1, sCR1-BA and sCR1-BABA, respectively. The plasma elimination of sCR1-BA and sCR1-BABA was significantly (P < .05) prolonged as compared to sCR1. The proteins showed similar tissue distribution; at 4-hr postdosing, the highest levels of 125I-radioactivity per gram of tissue were localized in the urine, blood, liver, stomach, and small intestine.

  2. 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

  3. Preparation and analysis of peptide fragments produced by pepsin hydrolysis of human plasma albumin and their relationship to its structure

    PubMed Central

    Franglen, G.; Swaniker, G. R. E.

    1968-01-01

    Human plasma albumin was prepared and subjected to proteolysis by pepsin at pH2·45 at 25° for 10min. with albumin/pepsin ratio 3000:1. Five peptide fragments were detected in the proteolysate by means of zone electrophoresis and gel filtration; these were separated and purified. Molecular weights, amino acid composition and disulphide bond content of the purified fragments were determined. The results show that a high proportion of the polypeptide chain of albumin appears to have a low cystine content, and at low pH values the molecule would be expected to have a considerable degree of freedom in its structure in these regions of the chain. A tripartite model for the structure of plasma albumin is proposed. PMID:4876098

  4. 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.

  5. Interaction of cyproheptadine hydrochloride with human serum albumin using spectroscopy and molecular modeling methods.

    PubMed

    Jiang, Hua; Chen, Rongrong; Wang, Hongcui; Pu, Hanlin

    2013-01-01

    The interaction between cyproheptadine hydrochloride (CYP) and human serum albumin (HSA) was investigated by fluorescence spectroscopy, UV-vis absorption spectroscopy, Fourier transform infrared spectroscopy (FT-IR) and molecular modeling at a physiological pH (7.40). Fluorescence of HSA was quenched remarkably by CYP and the quenching mechanism was considered as static quenching since it formed a complex. The association constants Ka and number of binding sites n were calculated at different temperatures. According to Förster's theory of non-radiation energy transfer, the distance r between donor (human serum albumin) and acceptor (cyproheptadine hydrochloride) was obtained. The effect of common ions on the binding constant was also investigated. The effect of CYP on the conformation of HSA was analyzed using FT-IR, synchronous fluorescence spectroscopy and 3D fluorescence spectra. The thermodynamic parameters ΔH and ΔS were calculated to be -14.37 kJ mol(-1) and 38.03 J mol(-1) K(-1), respectively, which suggested that hydrophobic forces played a major role in stabilizing the HSA-CYP complex. In addition, examination of molecular modeling indicated that CYP could bind to site I of HSA and that hydrophobic interaction was the major acting force, which was in agreement with binding mode studies.

  6. Dye attached poly(hydroxyethyl methacrylate) cryogel for albumin depletion from human serum.

    PubMed

    Andac, Muge; Galaev, Igor; Denizli, Adil

    2012-05-01

    Cibacron Blue F3GA was immobilized on poly(hydroxyethyl methacrylate) cryogel and it was used for selective and efficient depletion of albumin from human serum. The poly(hydroxyethyl methacrylate) was selected as the basic component because of its inertness, mechanical strength, chemical and biological stability, and biocompatibility. Cibacron Blue F3GA was covalently attached to the poly(hydroxyethyl methacrylate) cryogel to produce poly(hydroxyethyl methacrylate)-Cibacron Blue F3GA cryogel affinity column. The poly(hydroxyethyl methacrylate)-Cibacron Blue F3GA cryogel was characterized with respect to gelation yield, swelling degree, total volume of macropores, Fourier Transform Infrared spectroscopy, and scanning electron microscopy. It was found that the maximum amount of adsorption (343 mg/g of dry cryogel) obtained from experimental results is very close to the calculated Langmuir adsorption capacity (345 mg/g of dry cryogel). The maximum adsorption capacity for poly(hydroxyethyl methacrylate)-Cibacron Blue F3GA cryogel column was obtained as 950 mg/g of dry cryogel for nondiluted serum. The adsorption capacity decreased with increasing dilution ratios while the depletion ratio of albumin remained as 77% in serum sample. Finally, the poly(hydroxyethyl methacrylate)-Cibacron Blue F3GA cryogel was optimized for using in the fast protein liquid chromatography system for rapid removal of the high abundant proteins from the human serum.

  7. Depletion of albumin and immunoglobulin G from human serum using epitope-imprinted polymers as artificial antibodies.

    PubMed

    Yang, Hsueh-Hui; Lu, Kuo-Hao; Lin, Yee-Fung; Tsai, Sheng-Hung; Chakraborty, Subrata; Zhai, Wei-Jun; Tai, Dar-Fu

    2013-07-01

    Serum is a readily available source for noninvasive studies in clinical research, but it contains abundant proteins such as albumin and immunoglobulin G that can hinder the presence of low-abundant proteins as well as decrease sample loading capacity of analytical methods. Therefore, depletion of these two proteins is required to observe low-abundance serum proteins. Molecularly imprinted polymers are template-induced artificial antibodies with the ability to recognize and selectively bind the target molecule. In this study, artificial albumin and immunoglobulin G antibodies were developed by using two epitopes of human serum albumin and immunoglobulin G as templates. Acrylic acid, acrylamide, and N-acryl tyramine were the corresponding monomers; N,N'-ethylene bisacrylamide served as a cross-linker, and cellulosic fibers were used as a supporting matrix. The adsorption capacity of these artificial antibodies was 15.2 mg, 10 mg, and 15 μL per gram for human serum albumin, immunoglobulin G, and human serum, respectively. The dissociation constant (Kd ) of these artificial antibodies toward the human serum albumin and immunoglobulin G was 1 μM and 0.6 μM, respectively. The biomimetic properties of these artificial antibodies, coupled with their economical and rapid production, high specificity and their reusability, make them attractive for protein separation and analysis.

  8. Binding site identification of metformin to human serum albumin and glycated human serum albumin by spectroscopic and molecular modeling techniques: a comparison study.

    PubMed

    Rahnama, Elaheh; Mahmoodian-Moghaddam, Maryam; Khorsand-Ahmadi, Sabra; Saberi, Mohammad Reza; Chamani, Jamshidkhan

    2015-01-01

    The interaction between metformin and human serum albumin (HSA), as well as its glycated form (gHSA) was investigated by multiple spectroscopic techniques, zeta potential, and molecular modeling under physiological conditions. The steady state and time-resolved fluorescence data displayed the quenching mechanism of HSA-metformin and gHSA-metformin was static. The binding information, including the binding constants, number of binding sites, effective quenching constant showed that the binding affinity of metformin to HSA was greater than to gHSA which also confirmed by anisotropy measurements. It was determined that metformin had two and one set of binding sites on HSA and gHSA, respectively. Far-UV CD spectra of proteins demonstrated that the α-helical content decreased with increasing metformin concentration. The zeta potential and resonance light scattering (RLS) diagrams provided that lower drug concentration induced metformin aggregation on gHSA surface as compare to HSA. The increase in polarizability was one of the important factors for the enhancement of RLS and the formation of drug/protein complexes. The zeta potential results suggested that both hydrophobic and electrostatic interactions played important roles in the protein-metformin complex formation. Site marker experiments and molecular modeling showed that the metformin bound to subdomain IIIA (Sudlow's site II) on HSA and gHSA.

  9. Interaction of VO2+ ion with human serum transferrin and albumin.

    PubMed

    Sanna, Daniele; Garribba, Eugenio; Micera, Giovanni

    2009-04-01

    The complexation of VO(2+) ion with the high molecular mass components of the blood serum, human serum transferrin (hTf) and albumin (HSA), has been re-examined using EPR spectroscopy. In the case of transferrin, the results confirm those previously obtained, showing that VO(2+) ion occupies three different binding sites, A, B(1) and B(2), distinguishable in the X-band anisotropic spectrum recorded in D(2)O. With albumin the results show that a dinuclear complex (VO)(2)(d)HSA is formed in equimolar aqueous solutions or with an excess of protein; in the presence of an excess of VO(2+), the multinuclear complex (VO)(x)(m)HSA is the prevalent species, where x=5-6 indicates the equivalents of metal ion coordinated by HSA. The structure of the dinuclear species is discussed and the donor atoms involved in the metal coordination are proposed on the basis of the measured EPR parameters. Two different binding modes of albumin can be distinguished varying the pH, with only one species being present at the physiological value. The results show that the previously named "strong" site is not the N-terminal copper binding site, and some hypothesis on the metal coordination is discussed, with the (51)V A(z) values for the proposed donor sets obtained by DFT (density functional theory) calculations. Finally, preliminary results obtained in the ternary system VO(2+)/hTf/HSA are shown in order to determine the different binding strength of the two proteins. Due to the low VO(2+) concentration used, the recording of the EPR spectra through the repeated acquisition of the weak signals is essential to obtain a good signal to noise ratio in these systems.

  10. Spectrofluorimetric determination of human serum albumin using terbium-danofloxacin probe.

    PubMed

    Ramezani, Amir M; Manzoori, Jamshid L; Amjadi, Mohammad; Jouyban, Abolghasem

    2012-01-01

    A spectrofluorimetric method is proposed for the determination of human serum albumin (HSA) and bovine serum albumin (BSA) using terbium-danofloxacin (Tb(3+)-Dano) as a fluorescent probe. These proteins remarkably enhance the fluorescence intensity of the Tb(3+)-Dano complex at 545 nm, and the enhanced fluorescence intensity of Tb(3+)-Dano is proportional to the concentration of proteins (HSA and BSA). Optimum conditions for the determination of HSA were investigated and found that the maximum response was observed at: pH = 7.8, [Tb(3+)] = 8.5 × 10(-5) mol L(-1), [Dano] = 1.5 × 10(-4) mol L(-1). The calibration graphs for standard solutions of BSA, HSA, and plasma samples of HSA were linear in the range of 0.2 × 10(-6) - 1.3 × 10(-6) mol L(-1), 0.2 × 10(-6) - 1.4 × 10(-6) mol L(-1), and 0.2 × 10(-6) - 1 × 10(-6) mol L(-1), respectively. The detection limits (S/N = 3) for BSA, HSA, and plasma sample of HSA were 8.7 × 10(-8) mol L(-1), 6.2 × 10(-8) mol L(-1), and 8.1 × 10(-8) mol L(-1), respectively. The applicability of the method was checked using a number of real biological plasma samples and was compared with the UV spectrometric reference method. The results was showed that the method could be regarded as a simple, practical, and sensitive alternative method for determination of albumin in biological samples.

  11. Time-insensitive fluorescent sensor for human serum albumin and its unusual red shift.

    PubMed

    Smith, Sara E; Williams, Jessica M; Ando, Shin; Koide, Kazunori

    2014-03-04

    The concentration of human serum albumin (HSA) indicates the health state of individuals and is routinely measured by UV spectroscopy with bromocresol. However, this method tends to overestimate HSA, and more critically, depends highly on the timing, in seconds, of the measurements. Here, we report an analog of 2',7'-dichlorofluorescein that can be used as a fluorescent sensor to quantify HSA in human sera. The accuracy of this new method proved superior to that of bromocresol when an international standard serum sample was analyzed. This method is more convenient than the bromocresol method because it allows for fluorescence measurements during a >15 min period. Colorimetric analysis was also performed to further investigate the effects of the binding of the sensor to HSA. These spectroscopic studies suggest that absorption and emission changes upon HSA binding may be due to the dehydration of the dye and/or stabilization of the tritylic cation species.

  12. 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.

  13. Human serum albumin adsorption on TiO2 from single protein solutions and from plasma.

    PubMed

    Sousa, S R; Moradas-Ferreira, P; Saramago, B; Melo, L Viseu; Barbosa, M A

    2004-10-26

    In the present work, the adsorption of human serum albumin (HSA) on commercially pure titanium with a titanium oxide layer formed in a H(2)O(2) solution (TiO(2) cp) and on TiO(2) sputtered on Si (TiO(2) sp) was analyzed. Adsorption isotherms, kinetic studies, and work of adhesion determinations were carried out. HSA exchangeability was also evaluated. Surface characterization was performed by atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), and wettability studies. The two TiO(2) surfaces have very distinct roughnesses, the TiO(2) sp having a mean R(a) value 14 times smaller than the one of TiO(2) cp. XPS analysis revealed consistent peaks representative of TiO(2) on sputtered samples as well as on Ti cp substrate after 48 h of H(2)O(2) immersion. Nitrogen was observed as soon as protein was present, while sulfur, present in disulfide bonds in HSA, was observed for concentrations of protein higher than 0.30 mg/mL. The work of adhesion was determined from contact angle measurements. As expected from the surface free energy values, the work of adhesion of HSA solution is higher for the TiO(2) cp substrate, the more hydrophilic one, and lower for the TiO(2) sp substrate, the more hydrophobic one. The work of adhesion between plasma and the substrates assumed even higher values for the TiO(2) cp surface, indicating a greater interaction between the surface and the complex protein solutions. Adsorption studies by radiolabeling of albumin ((125)I-HSA) suggest that rapid HSA adsorption takes place on both surfaces, reaching a maximum value after approximately 60 min of incubation. For the higher HSA concentrations in solution, a multilayer coverage was observed on both substrates. After the adsorption step from single HSA solutions, the exchangeability of adsorbed HSA molecules by HSA in solution was evaluated. The HSA molecules adsorbed on TiO(2) sp seem to be more easily exchanged by HSA itself than those adsorbed on TiO(2) cp after 24 h. In

  14. Human serum albumin nanoparticles for efficient delivery of Cu, Zn superoxide dismutase gene

    PubMed Central

    Mo, Yun; Barnett, Micheal E.; Takemoto, Dolores; Davidson, Harriet

    2007-01-01

    Purpose To assess the potential of human serum albumin nanoparticles (HSA NP) as a nonviral vector for ocular delivery of Cu, Zn superoxide dismutase (SOD1) gene. Methods Cu, Zn superoxide dismutase (SOD1) gene-encapsulated nanoparticles (NP) were developed using human serum albumin (HSA), an endogenous protein, by a desolvation-crosslinking method. The pSOD-loaded HSA NP was evaluated for in vitro release characteristics, stability against DNase I and vitreous humor degradation, cytotoxicity, cellular uptake mechanisms, in vitro transfection efficiency, and in vivo gene expression. In vitro studies employed cultured human retinal pigment epithelial (ARPE-19) cells and in vivo studies employed a mouse model. For cell uptake analysis, fluorescein isothiocyanate (FITC)-labeled human serum albumin (HSA) was used. Results Plasmid containing SOD1 gene was encapsulated in HSA by a desolvation-crosslinking method. Gene-loaded HSA NP has a mean size of 120 nm, zeta potential of -44 mV, and plasmid encapsulation efficiency of 84%. At high crosslinking degree, HSA NP sustained the in vitro release of plasmid over 6 days, and stabilized plasmid DNA against DNase I and vitreous humor degradation. No cytotoxicity was observed in ARPE 19 cells treated with blank HSA NP at concentrations up to 5 mg/ml for 96 h. Cellular uptake of HSA NP was via receptor-mediated endocytosis that involves primarily caveolae-pathways. Confocal analysis indicated rapid endo/lysosomal escape of HSA NP. Further, confocal studies indicated that HSA readily enters the cell nucleus. In vitro, pSOD-HSA NP resulted in more than 80% transfection efficiency in ARPE-19 cells, which was 5 fold higher than Lipofectamine. HSA NP-transfected cells exhibited enhanced SOD1 activity that was 5 fold higher than untreated cells, indicating the overexpression of the functional gene. Intravitreal injection of HSA NP to the mouse eye at a dose of 130 ng of plasmid produced detectable level of fusion protein expression at

  15. Porphyrin conjugated with serum albumins and monoclonal antibodies boosts efficiency in targeted destruction of human bladder cancer cells.

    PubMed

    Pereira, Patrícia M R; Carvalho, José J; Silva, Sandrina; Cavaleiro, José A S; Schneider, Rudolf J; Fernandes, Rosa; Tomé, João P C

    2014-03-21

    The synthesis of a novel PS conjugated with bovine and human serum albumin (BSA and HSA) and a monoclonal antibody anti-CD104 is reported, as well as their biological potential against the human bladder cancer cell line UM-UC-3. No photodynamic effect was detected when the non-conjugated porphyrin was used. Yet, when it was coupled covalently with the mAb anti-CD104, BSA and HSA, the resulting photosensitizer conjugates demonstrated high efficacy in destroying the cancer cells, the mAb anti-CD104 efficacy overruling the albumins.

  16. Reviewing the binding of a series of parabens to human serum albumin.

    PubMed

    Greige-Gerges, Hélène; Kaissi, Rana; Magdalou, Jacques; Jraij, Alia

    2013-04-01

    To better understand the factors that contribute to the accumulation of unmetabolized parabens (p-hydroxybenzoic acid esters) in breast cancer tissue, the binding of a series of parabens (methyl-, ethyl-, butyl-, benzyl-paraben) to human serum albumin (HSA) was investigated by fluorescence spectroscopy and also their ability to modify the binding parameters of albumin site markers. Emission spectra of HSA upon fluorescence excitation of Trp 214 residue at 295 nm were recorded at different molar ratios of PB/HSA and data were corrected for the inner-filter effect. A significant inner-filter effect was obtained for molar ratios of 2.0 and above. For lower molar ratios, a slight increase in fluorescence of HSA was detected. p-Hydroxybenzoic acid, the main metabolite of parabens, did not modify the fluorescence of HSA whatever the molar ratio used. Binding parameters for compounds that are markers of site I, bilirubin and warfarin, were determined in the absence and presence of methyl, butyl and benzyl paraben at molar ratios of PB/HSA of 0, 1 and 2. No variation of the binding constants of these markers was observed. The results indicate that parabens weakly interact with HSA thus suggesting that they are in a free form in blood and therefore more available to reach tissues.

  17. 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.

  18. Human serum albumin binding to silica nanoparticles--effect of protein fatty acid ligand.

    PubMed

    Ang, Joo Chuan; Henderson, Mark J; Campbell, Richard A; Lin, Jhih-Min; Yaron, Peter N; Nelson, Andrew; Faunce, Thomas; White, John W

    2014-06-07

    Neutron reflectivity shows that fatted (F-HSA) and defatted (DF-HSA) versions of human serum albumin behave differently in their interaction with silica nanoparticles premixed in buffer solutions although these proteins have close to the same surface excess when the silica is absent. In both cases a silica containing film is quickly established at the air-water interface. This film is stable for F-HSA at all relative protein-silica concentrations measured. This behaviour has been verified for two small silica nanoparticle radii (42 Å and 48 Å). Contrast variation and co-refinement have been used to find the film composition for the F-HSA-silica system. The film structure changes with protein concentration only for the DF-HSA-silica system. The different behaviour of the two proteins is interpreted as a combination of three factors: increased structural stability of F-HSA induced by the fatty acid ligand, differences in the electrostatic interactions, and the higher propensity of defatted albumin to self-aggregate. The interfacial structures of the proteins alone in buffer are also reported and discussed.

  19. Serum Albumin and Ca2+ Are Natural Competence Inducers in the Human Pathogen Acinetobacter baumannii.

    PubMed

    Traglia, German Matias; Quinn, Brettni; Schramm, Sareda T J; Soler-Bistue, Alfonso; Ramirez, Maria Soledad

    2016-08-01

    The increasing frequency of bacteria showing antimicrobial resistance (AMR) raises the menace of entering into a postantibiotic era. Horizontal gene transfer (HGT) is one of the prime reasons for AMR acquisition. Acinetobacter baumannii is a nosocomial pathogen with outstanding abilities to survive in the hospital environment and to acquire resistance determinants. Its capacity to incorporate exogenous DNA is a major source of AMR genes; however, few studies have addressed this subject. The transformation machinery as well as the factors that induce natural competence in A. baumannii are unknown. In this study, we demonstrate that naturally competent strain A118 increases its natural transformation frequency upon the addition of Ca(2+)or albumin. We show that comEA and pilQ are involved in this process since their expression levels are increased upon the addition of these compounds. An unspecific protein, like casein, does not reproduce this effect, showing that albumin's effect is specific. Our work describes the first specific inducers of natural competence in A. baumannii Overall, our results suggest that the main protein in blood enhances HGT in A. baumannii, contributing to the increase of AMR in this threatening human pathogen.

  20. Serum Albumin and Ca2+ Are Natural Competence Inducers in the Human Pathogen Acinetobacter baumannii

    PubMed Central

    Traglia, German Matias; Quinn, Brettni; Schramm, Sareda T. J.; Soler-Bistue, Alfonso

    2016-01-01

    The increasing frequency of bacteria showing antimicrobial resistance (AMR) raises the menace of entering into a postantibiotic era. Horizontal gene transfer (HGT) is one of the prime reasons for AMR acquisition. Acinetobacter baumannii is a nosocomial pathogen with outstanding abilities to survive in the hospital environment and to acquire resistance determinants. Its capacity to incorporate exogenous DNA is a major source of AMR genes; however, few studies have addressed this subject. The transformation machinery as well as the factors that induce natural competence in A. baumannii are unknown. In this study, we demonstrate that naturally competent strain A118 increases its natural transformation frequency upon the addition of Ca2+or albumin. We show that comEA and pilQ are involved in this process since their expression levels are increased upon the addition of these compounds. An unspecific protein, like casein, does not reproduce this effect, showing that albumin's effect is specific. Our work describes the first specific inducers of natural competence in A. baumannii. Overall, our results suggest that the main protein in blood enhances HGT in A. baumannii, contributing to the increase of AMR in this threatening human pathogen. PMID:27270286

  1. Interaction of weakly bound antibiotics neomycin and lincomycin with bovine and human serum albumin: biophysical approach.

    PubMed

    Keswani, Neelam; Choudhary, Sinjan; Kishore, Nand

    2010-07-01

    The thermodynamics of interaction of neomycin and lincomycin with bovine serum albumin (BSA) and human serum albumin (HSA) has been studied using isothermal titration calorimetry (ITC), in combination with UV-visible, steady state and time resolved fluorescence spectroscopic measurements. Neomycin is observed to bind weakly to BSA and HSA whereas lincomycin did not show any evidence for binding with the native state of these proteins, rather it interacts in the presence of surfactants. The ITC results suggest 1 : 1 binding stoichiometry for neomycin in the studied temperature range. The values of the van't Hoff enthalpy do not agree with the calorimetric enthalpy in the case of neomycin, suggesting conformational changes in the protein upon ligand binding, as well as with the rise in the temperature. Experiments at different ionic strengths, and in the presence of tetrabutyl ammonium bromide and surfactants suggest the predominant involvement of electrostatic interactions in the complexation process of neomycin with BSA and HSA, and non-specific interaction behaviour of lincomycin with these proteins.

  2. Binding of ring-substituted indole-3-acetic acids to human serum albumin.

    PubMed

    Soskić, Milan; Magnus, Volker

    2007-07-01

    The plant hormone, indole-3-acetic acid (IAA), and its ring-substituted derivatives have recently attracted attention as promising pro-drugs in cancer therapy. Here we present relative binding constants to human serum albumin for IAA and 34 of its derivatives, as obtained using the immobilized protein bound to a support suitable for high-performance liquid chromatography. We also report their octanol-water partition coefficients (logK(ow)) computed from retention data on a C(18) coated silica gel column. A four-parameter QSPR (quantitative structure-property relationships) model, based on physico-chemical properties, is put forward, which accounts for more than 96% of the variations in the binding affinities of these compounds. The model confirms the importance of lipophilicity as a global parameter governing interaction with serum albumin, but also assigns significant roles to parameters specifically related to the molecular topology of ring-substituted IAAs. Bulky substituents at ring-position 6 increase affinity, those at position 2 obstruct binding, while no steric effects were noted at other ring-positions. Electron-withdrawing substituents at position 5 enhance binding, but have no obvious effect at other ring positions.

  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. Recombinant human gamma interferon inhibits simian malaria.

    PubMed Central

    Maheshwari, R K; Czarniecki, C W; Dutta, G P; Puri, S K; Dhawan, B N; Friedman, R M

    1986-01-01

    Prophylactic treatment with 0.1 mg of human gamma interferon per kg (body weight) per day completely suppressed experimental infection with Plasmodium cynomolgi B sporozoites in rhesus monkeys. Treatment with lower doses partially suppressed this infection. Prophylactic treatment with human gamma interferon, however, had no protective effect against trophozoite-induced infection, suggesting that the interferon effect was limited to the exoerythrocytic stage of parasitic development. PMID:3091507

  5. Recombinant genetic libraries and human monoclonal antibodies.

    PubMed

    Adams, Jarrett J; Nelson, Bryce; Sidhu, Sachdev S

    2014-01-01

    In order to comprehensively manipulate the human proteome we require a vast repertoire of pharmacological reagents. To address these needs we have developed repertoires of synthetic antibodies by phage display, where diversified oligonucleotides are used to modify the complementarity-determining regions (CDRs) of a human antigen-binding fragment (Fab) scaffold. As diversity is produced outside the confines of the mammalian immune system, synthetic antibody libraries allow us to bypass several limitations of hybridoma technology while improving the experimental parameters under which pharmacological reagents are produced. Here we describe the methodologies used to produce synthetic antibody libraries from a single human framework with diversity restricted to four CDRs. These synthetic repertoires can be extremely functional as they produce highly selective, high affinity Fabs to the majority of soluble human antigens. Finally we describe selection methodologies that allow us to overcome immuno-dominance in our selections to target a variety of epitopes per antigen. Together these methodologies allow us to produce human monoclonal antibodies to manipulate the human proteome.

  6. Recombination in the Human Pseudoautosomal Region PAR1

    PubMed Central

    Hinch, Anjali G.; Altemose, Nicolas; Noor, Nudrat; Donnelly, Peter; Myers, Simon R.

    2014-01-01

    The pseudoautosomal region (PAR) is a short region of homology between the mammalian X and Y chromosomes, which has undergone rapid evolution. A crossover in the PAR is essential for the proper disjunction of X and Y chromosomes in male meiosis, and PAR deletion results in male sterility. This leads the human PAR with the obligatory crossover, PAR1, to having an exceptionally high male crossover rate, which is 17-fold higher than the genome-wide average. However, the mechanism by which this obligatory crossover occurs remains unknown, as does the fine-scale positioning of crossovers across this region. Recent research in mice has suggested that crossovers in PAR may be mediated independently of the protein PRDM9, which localises virtually all crossovers in the autosomes. To investigate recombination in this region, we construct the most fine-scale genetic map containing directly observed crossovers to date using African-American pedigrees. We leverage recombination rates inferred from the breakdown of linkage disequilibrium in human populations and investigate the signatures of DNA evolution due to recombination. Further, we identify direct PRDM9 binding sites using ChIP-seq in human cells. Using these independent lines of evidence, we show that, in contrast with mouse, PRDM9 does localise peaks of recombination in the human PAR1. We find that recombination is a far more rapid and intense driver of sequence evolution in PAR1 than it is on the autosomes. We also show that PAR1 hotspot activities differ significantly among human populations. Finally, we find evidence that PAR1 hotspot positions have changed between human and chimpanzee, with no evidence of sharing among the hottest hotspots. We anticipate that the genetic maps built and validated in this work will aid research on this vital and fascinating region of the genome. PMID:25033397

  7. Recombination in the human Pseudoautosomal region PAR1.

    PubMed

    Hinch, Anjali G; Altemose, Nicolas; Noor, Nudrat; Donnelly, Peter; Myers, Simon R

    2014-07-01

    The pseudoautosomal region (PAR) is a short region of homology between the mammalian X and Y chromosomes, which has undergone rapid evolution. A crossover in the PAR is essential for the proper disjunction of X and Y chromosomes in male meiosis, and PAR deletion results in male sterility. This leads the human PAR with the obligatory crossover, PAR1, to having an exceptionally high male crossover rate, which is 17-fold higher than the genome-wide average. However, the mechanism by which this obligatory crossover occurs remains unknown, as does the fine-scale positioning of crossovers across this region. Recent research in mice has suggested that crossovers in PAR may be mediated independently of the protein PRDM9, which localises virtually all crossovers in the autosomes. To investigate recombination in this region, we construct the most fine-scale genetic map containing directly observed crossovers to date using African-American pedigrees. We leverage recombination rates inferred from the breakdown of linkage disequilibrium in human populations and investigate the signatures of DNA evolution due to recombination. Further, we identify direct PRDM9 binding sites using ChIP-seq in human cells. Using these independent lines of evidence, we show that, in contrast with mouse, PRDM9 does localise peaks of recombination in the human PAR1. We find that recombination is a far more rapid and intense driver of sequence evolution in PAR1 than it is on the autosomes. We also show that PAR1 hotspot activities differ significantly among human populations. Finally, we find evidence that PAR1 hotspot positions have changed between human and chimpanzee, with no evidence of sharing among the hottest hotspots. We anticipate that the genetic maps built and validated in this work will aid research on this vital and fascinating region of the genome.

  8. Molecular characteristics of methylglyoxal-modified bovine and human serum albumins. Comparison with glucose-derived advanced glycation endproduct-modified serum albumins.

    PubMed

    Westwood, M E; Thornalley, P J

    1995-07-01

    The amino acid modification, gel filtration chromatographic, and electrophoretic characteristics of bovine and human serum albumins irreversibly modified by methylglyoxal (MG-SA) and by glucose-derived advanced glycation endproducts (AGE-SA) were investigated. Methylglyoxal selectively modified arginine residues at low concentration (1 mM); at high methylglyoxal concentration (100 mM), the extent of arginine modification increased and lysine residues were also modified. Both arginine and lysine residues were modified in AGE-SA. Analytical gel filtration HPLC of serum albumin derivatives suggested that the proportion of dimers and oligomers increased with modification in both low and highly modified MG-SA and AGE-SA derivatives relative to unmodified serum albumins. In SDS-PAGE analysis, dimers and oligomers of low-modified MG-SA were dissociated into monomers, but not in highly modified MG-SA. MG-SA had increased anodic electrophoretic mobility under nondenaturing conditions at pH 8.6, indicating an increased net negative charge, which increased with extent of modification; highly modified MG-SA and AGE-SA had similar high electrophoretic mobilities. MG-SA derivatives were fluorescent: the fluorescence was characteristic of the arginine-derived imidazolone N delta-(5-methyl-4-imidazolon-2-yl)ornithine, but other fluorophores were also present. AGE-SA had similar fluorescence, attributed, in part, to glucose-derived imidazolones. AGE formed from glucose-modified proteins and AGE-like compounds formed from methylglyoxal-modified proteins may both be signals for recognition and degradation of senescent macromolecules.

  9. Limited human infection due to recombinant raccoon pox virus

    USGS Publications Warehouse

    Rocke, T.E.; Dein, F.J.; Fuchsberger, M.; Fox, B.C.; Stinchcomb, D.T.; Osorio, J.G.

    2004-01-01

    A laboratory accident resulted in human exposure to a recombinant raccoon poxvirus (RCN) developed as a vaccine vector for antigens of Yersinia pestis for protection of wild rodents (and other animals) against plague. Within 9 days, the patient developed a small blister that healed within 4 weeks. Raccoon poxvirus was cultured from the lesion, and the patient developed antibody to plague antigen (F1) and RCN. This is the first documented case of human exposure to RCN.

  10. Influence of the galloyl moiety in tea catechins on binding affinity for human serum albumin.

    PubMed

    Minoda, Kanako; Ichikawa, Tatsuya; Katsumata, Tomoharu; Onobori, Ken-ichi; Mori, Taiki; Suzuki, Yukiko; Ishii, Takeshi; Nakayama, Tsutomu

    2010-01-01

    The major catechins of green tea extract are (-)-epicatechin (EC), (-)-epigallocatechin (EGC), (-)-epicatechin gallate (ECg), and (-)-epigallocatechin gallate (EGCg). Recent research has indicated that catechins form complexes with human serum albumin (HSA) in blood, and differences in their binding affinity toward HSA are believed to modulate their bioavailability. In this study, we kinetically investigated the interaction between the catechins and HSA immobilized on a quartz-crystal microbalance (QCM). The association constants obtained from the frequency changes of QCM revealed interactions of ECg and EGCg with HSA that are 100 times stronger than those of EC and EGC. Furthermore, comparisons of these catechins by native-gel electrophoresis/blotting with redox-cycling staining revealed that, in a phosphate buffer, ECg and EGCg have a higher binding affinity toward HSA than EC and EGC. These observations indicate that catechins with a galloyl moiety have higher binding affinities toward HSA than catechins lacking a galloyl moiety.

  11. Behavior of human serum albumin on strong cation exchange resins: II. model analysis.

    PubMed

    Voitl, Agnes; Butté, Alessandro; Morbidelli, Massimo

    2010-08-20

    Experiments with human serum albumin on a strong cation exchange resin exhibit a peculiar elution pattern: the protein elutes with two peaks in a modifier gradient. This behavior is modeled with a general rate model, where the two elution peaks are modeled with two binding conformations, one of which is at equilibrium conditions, while for the other, the adsorption process is rate limited. Isocratic experiments under nonadsorbing conditions were used to characterize the mass transfer process. The isotherm of both adsorption conformations as well as the kinetic of adsorption and desorption for the second conformation are functions of the modifier concentration. They are evaluated with linear modifier gradient experiments and step experiments with various adsorption times. All experimental features are well reproduced by the proposed modified general rate model.

  12. Interaction of cromolyn sodium with human serum albumin: a fluorescence quenching study.

    PubMed

    Hu, Yan-Jun; Liu, Yi; Pi, Zhen-Bang; Qu, Song-Sheng

    2005-12-15

    The interaction between cromolyn sodium (CS) and human serum albumin (HSA) was investigated using tryptophan fluorescence quenching. In the discussion of the mechanism, it was proved that the fluorescence quenching of HSA by CS is a result of the formation of a CS-HSA complex. Quenching constants were determined using the Sterns-Volmer equation to provide a measure of the binding affinity between CS and HSA. The thermodynamic parameters DeltaG, DeltaH, and DeltaS at different temperatures were calculated. The distance r between donor (Trp214) and acceptor (CS) was obtained according to fluorescence resonance energy transfer (FRET). Furthermore, synchronous fluorescence spectroscopy data and UV-vis absorbance spectra have suggested that the association between CS and HSA changed the molecular conformation of HSA and the electrostatic interactions play a major role in CS-HSA association.

  13. [Influence of direct electric current on hydrodynamic diameter of human serum albumin].

    PubMed

    Korpan, M I; Gorchev, V F; Chekman, I S; Gun'ko, V M; Fialko-Moser, V

    2008-01-01

    The effect of the weak electric current (2 mA/cm2) on structural characteristics (hydrodynamic diameter and molecular weight) of the human serum albumin (HSA) was studied using photon correlation spectroscopy (PCS). The average diameter of initial HSA globule is approximately 7 nm (66.8 kDa). After electric current treatment during 2-5 min the diameter of HSA monomer increases to 7.5 nm. The duration of electric current treatment being increased to 20 min the size of HSA monomers decreases to 6.4 nm. The behaviour of HSA oligomers is close to that of monomers. Consequently, changes in the sizes of monomers and oligomers of HSA under the electric current treatment are caused by the change in the charge density stimulating change of tertiary structure of molecules and possible addition of ions from the buffer solution to them.

  14. DNA-duplex linker for AFM-SELEX of DNA aptamer against human serum albumin.

    PubMed

    Takenaka, Musashi; Okumura, Yuzo; Amino, Tomokazu; Miyachi, Yusuke; Ogino, Chiaki; Kondo, Akihiko

    2017-02-15

    DNA-duplex interactions in thymines and adenins are used as a linker for the novel methodology of Atomic Force Microscope-Systematic Evolution of Ligands by EXpotential enrichment (AFM-SELEX). This study used the hydrogen bonds in 10 mer of both thymines (T10) and adenines (A10). Initially, the interactive force in T10-A10 was measured by AFM, which returned an average interactive force of approximately 350pN. Based on this result, DNA aptamers against human serum albumin could be selected in the 4th round, and 15 different clones could be sequenced. The lowest dissociation constant of the selected aptamer was identified via surface plasmon resonance, and it proved to be identical to that of the commercial aptamer. Therefore, specific hydrogen bonds in DNA can be useful linkers for AFM-SELEX.

  15. Fluorescence spectroscopy and molecular simulation on the interaction of caffeic acid with human serum albumin.

    PubMed

    Xiang, Yuhong; Duan, Lili; Ma, Qiang; Lv, Zizheng; Ruohua, Zhu; Zhang, Zhuoyong

    2016-12-01

    Fluorescence spectroscopy and molecular simulation were explored to study the interaction between caffeic acid and human serum albumin (HSA). The experimental results indicated that the fluorescence quenching mechanism between caffeic acid and HSA is a static quenching, which was proved again by the analysis of fluorescence lifetime by time-correlated single photon counting. The binding process is spontaneous and the hydrophobic force is the main force between caffeic acid and HSA. In addition, the binding of caffeic acid to HSA was modeled by molecular dynamics simulations. The root mean square deviations, root mean square fluctuations, radius of gyration and the number of hydrogen bonds of the molecular dynamic (MD) simulation process were analyzed. Both experimental and modeling results demonstrated strong binding between HSA and caffeic acid. HSA had a slight conformational change when it binds with caffeic acid. The obtained information is useful for HSA drug design. Copyright © 2016 John Wiley & Sons, Ltd.

  16. Investigation of ketoprofen binding to human serum albumin by spectral methods

    NASA Astrophysics Data System (ADS)

    Bi, Shuyun; Yan, Lili; Sun, Yantao; Zhang, Hanqi

    2011-01-01

    The binding of ketoprofen with human serum albumin (HSA) was studied by fluorescence and absorption spectroscopic methods. Quenching of fluorescence of HSA was found to be a static quenching process. At 288.15, 298.15, 308.15 and 318.15 K, the binding constants and binding sites were obtained. The effects of Cu 2+, Al 3+, Ca 2+, Pb 2+ and K + on the binding at 288.15 K were also studied. The thermodynamic parameters, Δ H, Δ G and Δ S were got and the main sort of acting force between ketoprofen and HSA was studied. Based on the Förster's theory of non-radiation energy transfer, the binding average distance, r, between the acceptor (ketoprofen) and the donor (HSA) was calculated.

  17. 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.

  18. Weak interactive forces govern the interaction between a non-ionic surfactant with human serum albumin

    NASA Astrophysics Data System (ADS)

    Ghosh, Narayani; Mondal, Ramakanta; Deshmukh, Arundhati; Dutta, Sanjay; Mukherjee, Saptarshi

    2015-08-01

    The effect of the non-ionic surfactant Tween 40 (TW40) on Human Serum Albumin (HSA) has been studied by spectroscopic and isothermal titration calorimetric (ITC) methods. Our steady-state and time-resolved spectroscopic results reveal the perturbation of the native protein conformation upon interaction with TW40. The interaction of TW40 with HSA does not occur in a sequential manner unlike another anionic surfactant, sodium dodecyl sulfate (SDS). Our major conclusion is that the HSA-TW40 interaction is mainly driven by weak forces like van der Waal/hydrogen bonding interactions. This is also generalized from the results of interaction of HSA with another non-ionic surfactant TW80.

  19. 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.

  20. Insights into the molecular interaction between two polyoxygenated cinnamoylcoumarin derivatives and human serum albumin.

    PubMed

    Khammari, Anahita; Saboury, Ali Akbar; Karimi-Jafari, Mohammad Hossein; Khoobi, Mehdi; Ghasemi, Atiyeh; Yousefinejad, Saeed; Abou-Zied, Osama K

    2017-04-03

    Ligand binding studies on human serum albumin (HSA) are crucial in determining the pharmacological properties of drug candidates. Here, two representatives of coumarin-chalcone hybrids were selected and their binding mechanism was identified via thermodynamics techniques, curve resolution analysis and computational methods at molecular levels. The binding parameters were derived using spectroscopic approaches and the results point to only one pocket located near the Trp214 residue in subdomain IIA of HSA. The protein tertiary structure was altered during ligand binding and formed an intermediate structure to create stronger ligand binding interactions. The best binding mode of the ligand was initially estimated by docking on an ensemble of HSA crystallographic structures and by molecular dynamics (MD) simulations. Per residue interaction energies were calculated over the MD trajectories as well. Reasonable agreement was found between experimental and theoretical results about the nature of binding, which was dominated by hydrogen bonding and van der Waals contributions.

  1. 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.

  2. A Comparative Interaction between Copper Ions with Alzheimer's β Amyloid Peptide and Human Serum Albumin.

    PubMed

    Behbehani, G Rezaei; Barzegar, L; Mohebbian, M; Saboury, A A

    2012-01-01

    The interaction of Cu(2+) with the first 16 residues of the Alzheimer's amyliod β peptide, Aβ(1-16), and human serum albumin (HSA) were studied in vitro by isothermal titration calorimetry at pH 7.2 and 310 K in aqueous solution. The solvation parameters recovered from the extended solvation model indicate that HSA is involved in the transport of copper ion. Complexes between Aβ(1-16) and copper ions have been proposed to be an aberrant interaction in the development of Alzheimer's disease, where Cu(2+) is involved in Aβ(1-16) aggregation. The indexes of stability indicate that HSA removed Cu(2+) from Aβ(1-16), rapidly, decreased Cu-induced aggregation of Aβ(1-16), and reduced the toxicity of Aβ(1-16) + Cu(2+) significantly.

  3. A Comparative Interaction between Copper Ions with Alzheimer's β Amyloid Peptide and Human Serum Albumin

    PubMed Central

    Behbehani, G. Rezaei; Barzegar, L.; Mohebbian, M.; Saboury, A. A.

    2012-01-01

    The interaction of Cu2+ with the first 16 residues of the Alzheimer's amyliod β peptide, Aβ(1–16), and human serum albumin (HSA) were studied in vitro by isothermal titration calorimetry at pH 7.2 and 310 K in aqueous solution. The solvation parameters recovered from the extended solvation model indicate that HSA is involved in the transport of copper ion. Complexes between Aβ(1–16) and copper ions have been proposed to be an aberrant interaction in the development of Alzheimer's disease, where Cu2+ is involved in Aβ(1–16) aggregation. The indexes of stability indicate that HSA removed Cu2+ from Aβ(1–16), rapidly, decreased Cu-induced aggregation of Aβ(1–16), and reduced the toxicity of Aβ(1–16) + Cu2+ significantly. PMID:22844264

  4. Disruption of human serum albumin fibrils by a static electric field

    NASA Astrophysics Data System (ADS)

    Pandey, Nitin K.; Mitra, Subhadeep; Chakraborty, Monojit; Ghosh, Sudeshna; Sen, Shubhatam; Dasgupta, Swagata; DasGupta, Sunando

    2014-07-01

    Protein self-association leads to toxic filamentous plaques believed to be the key reason behind several neurodegenerative diseases. Stabilization of the fibrillar architecture is guided by several forces; primarily electrostatic, hydrophobic, and the extent of hydrogen bonding. In this study, we experimentally demonstrate, for the first time, the effect of varying static electric fields on preformed fibrils of human serum albumin (HSA) in an electrowetting on dielectric type setup using spectroscopic and microscopic techniques. We have found appreciable and continuous reduction in the β-sheet content of HSA fibrils up to an applied field of ˜8 × 106 V m-1. The observed disruption of the fibrils has been attributed to the combined effects of electrostatic interactions and electrowetting phenomena. Kinetic studies indicate a prior intermediate formation followed by disruption of HSA fibrils after application of the electric field.

  5. Structural basis of non-steroidal anti-inflammatory drug diclofenac binding to human serum albumin.

    PubMed

    Zhang, Yao; Lee, Philbert; Liang, Shichu; Zhou, Zuping; Wu, Xiaoyang; Yang, Feng; Liang, Hong

    2015-11-01

    Human serum albumin (HSA) is the most abundant protein in plasma, which plays a central role in drug pharmacokinetics because most compounds bound to HSA in blood circulation. To understand binding characterization of non-steroidal anti-inflammatory drugs to HSA, we resolved the structure of diclofenac and HSA complex by X-ray crystallography. HSA-palmitic acid-diclofenac structure reveals two distinct binding sites for three diclofenac in HSA. One diclofenac is located at the IB subdomain, and its carboxylate group projects toward polar environment, forming hydrogen bond with one water molecule. The other two diclofenac molecules cobind in big hydrophobic cavity of the IIA subdomain without interactive association. Among them, one binds in main chamber of big hydrophobic cavity, and its carboxylate group forms hydrogen bonds with Lys199 and Arg218, as well as one water molecule, whereas another diclofenac binds in side chamber, its carboxylate group projects out cavity, forming hydrogen bond with Ser480.

  6. 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

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

    PubMed

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

    2012-09-01

    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.

  8. 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.

  9. Curcumin promotes fibril formation in F isomer of human serum albumin via amorphous aggregation.

    PubMed

    Mothi, Nivin; Muthu, Shivani A; Kale, Avinash; Ahmad, Basir

    2015-12-01

    We here describe the amyloid fibrils promoting behavior of curcumin, which ability to inhibit amyloid fibrillization of several globular proteins is well documented. Transmission electron microscopy (TEM), 90° light scattering (RLS), thioflavine T (ThT) and Congo red (CR) binding studies demonstrated that both F (pH3.4) and E (pH1.8) isomers of human serum albumin (HSA) in the absence and presence of curcumin initially converted into amorphous aggregates. Interestingly, only the sample containing F isomer preincubated with curcumin formed fibrils on incubation for longer period. We also found that curcumin strongly bind to the F isomer, alter its secondary, tertiary structures and thermal stability. We conclude that the conversion of intermediate states into amorphous aggregate to fibrils is dictated by its conformation. This study provides unique insights into ligand-controlled HSA aggregation pathway and should provide a useful model system to study both amorphous and the fibrillar aggregation of multidomain proteins.

  10. Spectroscopic investigations of the interaction of the anti‑hypertension drug valsartan with human serum albumin.

    PubMed

    Jing, Jian; Qu, Xin; Tu, Zhi; Zheng, Chenhoo; Zheng, Zhicheng

    2014-06-01

    The aim of the present study was to investigate the interaction between valsartan, an anti-hypertension drug, and human serum albumin (HSA) using spectroscopic techniques, including fluorescence, ultraviolet-visible absorption, synchronous fluorescence and circular dichroism (CD). The results demonstrated that valsartan and HSA form a complex and that a static quenching mechanism occurs. In addition, the binding constant and the number of binding sites for valsartan on HSA were analyzed. Hydrophobic interactions and hydrogen bonds were the predominant forces in the association reaction based on thermodynamic parameters. The distance between the donor (HSA) and the acceptor (valsartan) was 1.994 nm as derived from Forster's theory. Alterations in the secondary structure of HSA in the presence of valsartan were assessed using synchronous fluorescence and CD. This study provides an enhanced understanding of the pharmacodynamic effects of valsartan on the physiologically important protein HSA.

  11. Binding of coumarins to site I of human serum albumin. Effect of the fatty acids.

    PubMed

    Zatón, A M; Ferrer, J M; Ruiz de Gordoa, J C; Marquínez, M A

    1995-07-14

    It is known that binding site I on human serum albumin (HSA) consists of a zone of two overlapping regions: the specific binding region represented by warfarin binding and the specific binding region represented by azapropazone and phenylbutazone binding. In this paper binding parameters to defatted HSA and to HSA with fatty acids (molar ratio of fatty acid/HSA = 4) were compared. High-affinity binding sites for warfarin, 4-chromanol, 4-hydroxycoumarin, coumarin, 3-acetylcoumarin and phenylbutazone (759,549 M-1 > Ka > 67,024 M-1) constitute binding site I on HSA. In this binding area defatted HSA can bind two molecules of warfarin, but the presence of fatty acids diminish the binding capacity of warfarin to HSA (2 > n > 1).

  12. Differential receptor targeting of liver cells using 99mTc-neoglycosylated human serum albumins.

    PubMed

    Kim, Sungeun; Jeong, Jae Min; Hong, Mee Kyung; Jang, Ja-June; Lee, Jaetae; Lee, Dong Soo; Chung, June-Key; Lee, Myung Chul

    2008-01-01

    Neolactosyl human serum albumin (LSA) targets asialoglycoprotein receptor and shows high liver uptake due to accumulation in hepatocytes. Although neomannosyl human serum albumin (MSA) also shows high liver uptake, it has been reported to be taken up by Kupffer cells and endothelial cells. We compared the biological properties of LSA and MSA. 99mTc-LSA and 99mTc-MSA biodistribution in mice were investigated after intravenous injection. In vivo localization of rhodaminisothiocyanate (RITC)-LSA and fluoresceineisothiocyanate (FITC)-MSA were investigated in mouse liver. Excretion routes of 99mTc-LSA and 99mTc-MSA metabolites were examined. Both 99mTc-LSA and 99mTc-MSA showed high liver uptakes. RITC-LSA was taken up by hepatocytes whereas FITC-MSA was taken up by Kupffer cells and endothelial cells. 99mTc-MSA showed higher spleen and kidney uptakes than 99mTc-LSA. 99mTc-LSA metabolites excreted in urine and feces accounted for 44.4 and 50.0% of 99mTc-LSA injected, respectively, while 99mTc-MSA metabolites accounted for 51.5 and 10.3%, respectively. In conclusion, LSA is specifically taken up by hepatcytes while MSA by Kupffer cells and endothelial cells. After taken up by the liver, LSA is metabolized by the hepatocytes and then excreted through both the hepatobiliary tract and kidney, whereas MSA is metabolized by Kupffer cells and endoghelial cells and then excreted mainly through the kidney.

  13. [Study of the content of alpha-fetoprotein and serum albumin in the vitreous body of the eye of human embryos].

    PubMed

    Panova, I G; Tatikolov, A S

    2011-01-01

    The content of serum albumin and alpha-fetoprotein in the vitreous body of the eyes of human embryos from the 16th through the 24th week was investigated. It was detected that albumin and alpha-fetoprotein in the vitreous body of human eyes are presented in equal molar concentrations in the 16th week. There is 1.5-fold increased concentration of alpha-fetoprotein in comparison to albumin during the 17th week. Seventeen weeks later, there was a reduction in the concentration of both proteins. It was reported that cyanine dye, used for detection of albumin, does not interact with alpha-fetoprotein.

  14. Generation of hybrid human immunodeficiency virus by homologous recombination.

    PubMed Central

    Srinivasan, A; York, D; Jannoun-Nasr, R; Kalyanaraman, S; Swan, D; Benson, J; Bohan, C; Luciw, P A; Schnoll, S; Robinson, R A

    1989-01-01

    Human immunodeficiency virus (HIV) type 1, isolated from diverse sources, exhibits genomic diversity. The mechanisms by which the genomic diversity takes place in individuals exposed to multiple virus isolates is yet to be elucidated. Genetic variation, in general, might result from mutagenic events such as point mutations, rearrangements (insertions and deletions), and recombination. In an attempt to evaluate the process of genetic diversity, we designed experiments to analyze recombination between HIV DNAs by using DNA transfection in cell cultures. Here we report the successful recombination between truncated HIV proviral DNAs with an overlap homology of 53 base pairs that leads to the formation of viable hybrid virus. Recombination was also seen between exogenous DNA introduced into cells and homologous HIV sequences resident in the cells. These results indicate that recombination among various HIV isolates may play a significant role in the generation of genetic diversity of HIV. Further, the method used here enables the construction of hybrid HIV genomes to identify the viral determinants responsible for tropism, replication, and cytopathic effects. Images PMID:2474834

  15. Optimization of human serum albumin production in methylotrophic yeast Pichia pastoris by repeated fed-batch fermentation.

    PubMed

    Ohya, Tomoshi; Ohyama, Masao; Kobayashi, Kaoru

    2005-06-30

    An optimization method for repeated fed-batch fermentation was established with the aim of improving the recombinant human serum albumin (rHSA) production in Pichia pastoris. A simulation model for fed-batch fermentation was formulated and the optimal methanol-feeding policy calculated by dynamic programming method using five different methanol-feeding periods. The necessary state variables were collected from the calculated results and used for further optimization of repeated fed-batch fermentation. The optimal operation policy was investigated using the pre-collected state variables by estimating the overall profit per total methanol-feeding time. The calculated results indicated that the initial cell mass from the 2nd fed-batch fermentation on should be set at 35 or 40 g and methanol-feeding time at 264 h. In repeated fed-batch fermentation using the optimal operation policy, actual culture volume was in good agreement with the values simulated by model equations, but some discrepancy was observed in rHSA production. Minimum experiments were therefore carried out to re-evaluate rHSA production levels, which were then applied in re-calculations to determine the optimal operation policy. The optimal policy for repeated fed-batch fermentation established in the present study (i.e., 4-times-repeated fed-batch fermentation) achieved a 47% increase in annual rHSA production. Optimization of the culture period also brought about a 28% increase in annual rHSA production even in simple (not repeated) fed-batch fermentation.

  16. Correlation of serum cytokine and acute phase reactant levels with alterations in weight and serum albumin in patients receiving immunotherapy with recombinant IL-2.

    PubMed Central

    Deehan, D J; Heys, S D; Simpson, W; Herriot, R; Broom, J; Eremin, O

    1994-01-01

    Recombinant IL-2 (rIL-2) has been used alone or in combination with other chemotherapeutic agents to enhance host defences against cancer. Prolonged administration of high doses, required for clinical efficacy, may precipitate serious dose-limiting toxicity. rIL-2-induced 'vascular leak syndrome' leads to hypotension, renal insufficiency, respiratory disturbances and other organ dysfunctions. Serial measurements of serum cytokines and the acute phase protein C-reactive protein (CRP) were performed on nine patients who received high-dose i.v. continuous therapy with rIL-2. The influence of these immunological parameters upon alterations in patients' weight and serum albumin, as indicators of toxicity, was assessed. All patients experienced weight increases during the cycle (3-11% of total body weight). The serum levels of tumour necrosis factor (TNF-alpha) and CRP were highly predictive of alterations in patients' weight (both P < 0.001), while no correlation was found with IL-6 and weight change. Serum albumin fell linearly throughout the infusion cycle, but this showed no correlation with variations in serum levels of IL-6, TNF-alpha, or CRP. The complement components C3 and C4 were significantly reduced at the end of the infusion, suggesting a possible role for this cascade system in mediating these clinical changes. The strong association between serum TNF-alpha and weight change, not previously documented, further supports the hypothesis that TNF-alpha is a key mediator in the pathogenesis of the 'vascular leak syndrome'. PMID:7511074

  17. Isolation of human anti-serum albumin Fab antibodies with an extended serum-half life.

    PubMed

    Kang, Hyeon-Ju; Kim, Hye-Jin; Cha, Sang-Hoon

    2016-01-01

    The serum albumin (SA) has been exploited to generate long-acting biotherapeutics by taking advantage of the FcRn-mediated recycling mechanism in a direct or an indirect way. Since Fab fragments have been proven to be clinically safe for human usage, we assumed that human anti-SA Fab antibodies could have a great potential as a carrier molecule to extend the serum half-life of therapeutic proteins. We, herein, had attempted to isolate anti-SA Fab antibodies from HuDVFab-8L antibody library via a phage display technology, and identified eight discrete human Fab antibodies. One of the Fab antibodies, SL335, showed the strongest binding reactivity to human SA with nM range of affinity at both pH 6 and pH 7.4, and cross-reacted to SAs from various species including rat, mouse, canine and monkey. The in vivo pharmacokinetic assay using a rat model indicated that SL335 has approximately 10 fold longer serum half-life and 26 to 44-fold increase in AUC0 → ∞ compared to the negative control Fab molecule in both intravenous and subcutaneous administrations. Knowing that Fabs have proven to be safe in clinics for a long time, SL335 seems to have a great potential in generating long-acting protein drugs by tagging effector molecules with either chemical conjugation or genetic fusion.

  18. Influence of MLS laser radiation on erythrocyte membrane fluidity and secondary structure of human serum albumin.

    PubMed

    Pasternak, Kamila; Nowacka, Olga; Wróbel, Dominika; Pieszyński, Ireneusz; Bryszewska, Maria; Kujawa, Jolanta

    2014-03-01

    The biostimulating activity of low level laser radiation of various wavelengths and energy doses is widely documented in the literature, but the mechanisms of the intracellular reactions involved are not precisely known. The aim of this paper is to evaluate the influence of low level laser radiation from an multiwave locked system (MLS) of two wavelengths (wavelength = 808 nm in continuous emission and 905 nm in pulsed emission) on the human erythrocyte membrane and on the secondary structure of human serum albumin (HSA). Human erythrocytes membranes and HSA were irradiated with laser light of low intensity with surface energy density ranging from 0.46 to 4.9 J cm(-2) and surface energy power density 195 mW cm(-2) (1,000 Hz) and 230 mW cm(-2) (2,000 Hz). Structural and functional changes in the erythrocyte membrane were characterized by its fluidity, while changes in the protein were monitored by its secondary structure. Dose-dependent changes in erythrocyte membrane fluidity were induced by near-infrared laser radiation. Slight changes in the secondary structure of HSA were also noted. MLS laser radiation influences the structure and function of the human erythrocyte membrane resulting in a change in fluidity.

  19. Human DNA repair and recombination genes

    SciTech Connect

    Thompson, L.H.; Weber, C.A.; Jones, N.J.

    1988-09-01

    Several genes involved in mammalian DNA repair pathways were identified by complementation analysis and chromosomal mapping based on hybrid cells. Eight complementation groups of rodent mutants defective in the repair of uv radiation damage are now identified. At least seven of these genes are probably essential for repair and at least six of them control the incision step. The many genes required for repair of DNA cross-linking damage show overlap with those involved in the repair of uv damage, but some of these genes appear to be unique for cross-link repair. Two genes residing on human chromosome 19 were cloned from genomic transformants using a cosmid vector, and near full-length cDNA clones of each gene were isolated and sequenced. Gene ERCC2 efficiently corrects the defect in CHO UV5, a nucleotide excision repair mutant. Gene XRCC1 normalizes repair of strand breaks and the excessive sister chromatid exchange in CHO mutant EM9. ERCC2 shows a remarkable /approximately/52% overall homology at both the amino acid and nucleotide levels with the yeast RAD3 gene. Evidence based on mutation induction frequencies suggests that ERCC2, like RAD3, might also be an essential gene for viability. 100 refs., 4 tabs.

  20. Human Recombinant Insulin 1g - ug

    NASA Technical Reports Server (NTRS)

    2004-01-01

    Proteins are the building blocks of our bodies and the living world around us. Within our bodies proteins make it possible for red blood cells to carry oxygen throughout the body. Others help transmit nerve impulses so we can hear, smell and feel the world around us. While others play a crucial role in preventing or causing disease. If the structure of a protein is known, then companies can develop new or improved drugs to fight the disease of which the protein is a part. To determine protein structure, researchers must grow near-perfect crystals of the protein. On Earth convection currents, sedimentation and other gravity-induced phenomena hamper crystal growth efforts. In microgravity researchers can grow near-perfect crystals in an environment free of these effects. Because of the enormous potential for new pharmaceutical products the Center for Macromolecular Crystallography--the NASA Commercial Space Center responsible for commercial protein crystal growth efforts has more than fifty major industry and academic partners. Research on crystals of human insulin could lead to improved treatments for diabetes.

  1. Preparation and in vitro characterization of gallic acid-loaded human serum albumin nanoparticles

    NASA Astrophysics Data System (ADS)

    Mohammad-Beigi, Hossein; Shojaosadati, Seyed Abbas; Morshedi, Dina; Arpanaei, Ayyoob; Marvian, Amir Tayaranian

    2015-04-01

    Gallic acid (GA), as an antioxidant and antiparkinson agent, was loaded onto cationic human serum albumin nanoparticles (HSA NPs). Polyethylenimine (PEI)-coated HSA (PEI-HSA) NPs were prepared using three different methods: (I) coating negatively charged HSA NPs with positively charged PEI through attractive electrostatic interactions, (II) coating HSA NPs with PEI via covalent amide bond formation using N-(3-dimethylaminopropyl)- N-ethylcarbodiimide hydrochloride, and (III) coating HSA NPs with PEI via covalent bonding using glutaraldehyde for linking amine groups of PEI and amine groups of albumin NPs. Method II was selected since it resulted in a higher shift in the zeta potential value (mV) and less zeta potential value deviation, and also less size polydispersity. GA was loaded by adsorption onto the surface of PEI-HSA NPs of two different sizes: 117 ± 2.9 nm (PEI-P1) and 180 ± 3.1 nm (PEI-P2) NPs. Both GA-entrapment and GA-loading efficiencies increased slightly with the increasing size of NPs, and were affected intensely by the mass ratio of GA to PEI-HSA NPs. Free radical scavenging of GA was quantified based on the 2,2-diphenyl-1-picrylhydrazyl method. The obtained results showed that GA remains active during the preparation of GA-loaded PEI-HSA NPs. The cytotoxicities of HSA, PEI-HSA, and GA-loaded PEI-HSA NPs on the PC-12 cells, as the neuroendocrine cell line, were measured. Our results indicate that positively charged PEI-HSA NPs are good candidates for efficient and safe delivery of GA to the brain.

  2. SMALL VOLUME RESUSCITATION FROM HEMORRHAGIC SHOCK WITH POLYMERIZED HUMAN SERUM ALBUMIN

    PubMed Central

    Messmer, Catalina; Yalcin, Ozlem; Palmer, Andre F.; Cabrales, Pedro

    2011-01-01

    Human serum albumin (HSA) is used as a plasma expander (PE); however, albumin is readily eliminated from the intravascular space. The objective of this study was to establish the effects of various sized polymerized HSAs (PolyHSAs) during small volume resuscitation from hemorrhagic shock on systemic parameters, microvascular hemodynamics and functional capillary density (FCD) in the hamster window chamber model. PolyHSA size was controlled by varying the cross-link density (i.e. molar ratio of glutaraldehyde to HSA). Hemorrhage was induced by controlled arterial bleeding of 50% of the animal’s blood volume (BV) and hypovolemic shock maintained for 1 h. Resuscitation was implemented in two phases, first by infusion of 3.5% of the BV of hypertonic saline (HTS, 7.5 wt% NaCl), followed by infusion of 10% of BV of each PolyHSAs. Resuscitation provided rapid recovery of blood pressure, blood gas parameters and microvascular perfusion. PolyHSA at a glutaraldehyde to HSA molar ratio of 60:1 (PolyHSA60:1) provided superior recovery of blood pressure, microvascular blood flow and FCD, and acid-base balance, with sustained volume expansion in relation to the volume infused. The high molecular weigh of PolyHSA60:1 increased hydrodynamic radius and solution viscosity. Pharmacokinetic analysis of PolyHSA60:1 indicates reduced clearance and increased circulatory half-life compared to monomeric HSA and other PolyHSA formulations. In conclusion, HSA molecular size and solution viscosity affects central hemodynamics, microvascular blood flow, volume expansion and circulation persistence during small volume resuscitation from hemorrhagic shock. Additionally, PolyHSA can be an alternative to HSA in situations with compromised vascular permeability. PMID:22100469

  3. Relations between high-affinity binding sites of markers for binding regions on human serum albumin.

    PubMed Central

    Kragh-Hansen, U

    1985-01-01

    Binding of warfarin, digitoxin, diazepam, salicylate and Phenol Red, individually or in different pair combinations, to defatted human serum albumin at ligand/protein molar ratios less than 1:1 was studied at pH 7.0. The binding was determined by ultrafiltration. Some of the experiments were repeated with the use of equilibrium dialysis in order to strengthen the results. Irrespective of the method used, all ligands bind to one high-affinity binding site with an association constant in the range 10(4)-10(6) M-1. High-affinity binding of the following pair of ligands took place independently: warfarin-Phenol Red, warfarin-diazepam, warfarin-digitoxin and digitoxin-diazepam. Simultaneous binding of warfarin and salicylate led to a mutual decrease in binding of one another, as did simultaneous binding of digitoxin and Phenol Red. Both effects could be accounted for by a coupling constant. The coupling constant is the factor by which the primary association constants are affected; in these examples of anti-co-operativity the factor has a value between 0 and 1. In the first example it was calculated to be 0.8 and in the latter 0.5. Finally, digitoxin and salicylate were found to compete for a common high-affinity binding site. The present findings support the proposal of four separate primary binding sites for warfarin, digitoxin (and salicylate), diazepam and Phenol Red. An attempt to correlate this partial binding model for serum albumin with other models in the literature is made. PMID:3977850

  4. Mechanisms of fever induced by recombinant human interferon.

    PubMed Central

    Dinarello, C A; Bernheim, H A; Duff, G W; Le, H V; Nagabhushan, T L; Hamilton, N C; Coceani, F

    1984-01-01

    Since the early trials using human interferon (hIFN) derived from blood leukocytes or cell lines, fever has been a prominent component of IFN therapy. Human protein impurities might account for the fever to cell-derived hIFN, but recombinant hIFN, free of extraneous human proteins, has produced fever in nearly all recipients during clinical trials. Our present studies were carried out to determine the mechanisms of fever due to recombinant hIFN currently being used in humans. Because recombinant hIFN is produced in Escherichia coli, in these experiments we considered contaminating endotoxin as the cause of fever. Polymyxin B, which blocks endotoxin, had no effect on the pyrogenicity of hIFN in rabbits. In addition, hIFN injected into an endotoxin-resistant strain of mice produced fever. The pyrogenicity of hIFN does not appear to involve production of leukocytic pyrogen (LP), since no circulating LP was detected in rabbits during IFN fever. Furthermore, human mononuclear cells incubated with hIFN in vitro at 10(4)-10(6) U/ml did not release LP. However, hIFN stimulated prostaglandin E2 (PGE2) release from rabbit hypothalamic tissue in vitro. Intracerebroventricular injection of hIFN into the awake cat also produced fever and a rise in PGE2 levels in the cerebrospinal fluid; both effects were reversed by treatment with indomethacin. We conclude that the fever of recombinant hIFN is not due to endotoxin but that hIFN is intrinsically pyrogenic by inducing PGE2 in the hypothalamus. PMID:6590569

  5. Biphasic modulation of cell growth by recombinant human galectin-1.

    PubMed

    Adams, L; Scott, G K; Weinberg, C S

    1996-06-13

    Human soluble galactose-binding lectin (galectin-1) has been expressed as an Escherichia coli fusion protein, following the amplification by polymerase chain reaction of cDNA prepared from a human osteosarcoma cell line. The fusion protein is a functional beta-galactoside-binding lectin, as is the recombinant galectin when purified from the cleaved fusion protein. The recombinant galectin has a biphasic effect on cell proliferation. Unlike the fusion protein, it functions as a human cell growth inhibitor, confirming earlier findings with natural human galectin-1, though it is less effective than the natural galectin. This reaction is not significantly inhibited by lactose, and is thus largely independent of the beta-galactoside-binding site. At lower concentrations, recombinant galectin-1 is mitogenic, this activity being susceptible to inhibition by lactose, and thus attributable to the beta-galactoside-binding ability of the protein. Some tumour cells are susceptible to the growth-inhibitory effect, and the galectin-1 gene is expressed in both normal and tumour cells.

  6. Bioinformatic Analysis of the Human Recombinant Iduronate 2-Sulfate Sulfatase

    PubMed Central

    Morales-Álvarez, Edwin D.; Rivera-Hoyos, Claudia M.; Landázuri, Patricia; Poutou-Piñales, Raúl A.; Pedroza-Rodríguez, Aura M.

    2016-01-01

    Mucopolysaccharidosis type II is a human recessive disease linked to the X chromosome caused by deficiency of lysosomal enzyme Iduronate 2-Sulfate Sulfatase (IDS), which leads to accumulation of glycosaminoglycans in tissues and organs. The human enzyme has been expressed in Escherichia coli and Pichia pastoris in attempt to develop more successful expression systems that allow the production of recombinant IDS for Enzyme Replacement Therapy (ERT). However, the preservation of native signal peptide in the sequence has caused conflicts in processing and recognition in the past, which led to problems in expression and enzyme activity. With the main object being the improvement of the expression system, we eliminate the native signal peptide of human recombinant IDS. The resulting sequence showed two modified codons, thus, our study aimed to analyze computationally the nucleotide sequence of the IDSnh without signal peptide in order to determine the 3D structure and other biochemical properties to compare them with the native human IDS (IDSnh). Results showed that there are no significant differences between both molecules in spite of the two-codon modifications detected in the recombinant DNA sequence. PMID:27335624

  7. Effect of human serum albumin upon the permeabilizing activity of sticholysin II, a pore forming toxin from Stichodactyla heliantus.

    PubMed

    Celedón, Gloria; González, Gustavo; Gulppi, Felipe; Pazos, Fabiola; Lanio, María E; Alvarez, Carlos; Calderón, Cristian; Montecinos, Rodrigo; Lissi, Eduardo

    2013-12-01

    Sticholysin II (St II) is a haemolytic toxin isolated from the sea anemone Stichodactyla helianthus. The high haemolytic activity of this toxin is strongly dependent on the red cell status and the macromolecule conformation. In the present communication we evaluate the effect of human serum albumin on St II haemolytic activity and its capacity to form pores in the bilayer of synthetic liposomes. St II retains its pore forming capacity in the presence of large concentrations (up to 500 μM) of human serum albumin. This effect is observed both in its capacity to produce red blood cells haemolysis and to generate functional pores in liposomes. In particular, the capacity of the toxin to lyse red blood cells increases in the presence of human serum albumin (HSA). Regarding the rate of the pore forming process, it is moderately decreased in liposomes and in red blood cells, in spite of an almost total coverage of the interface by albumin. All the data obtained in red cells and model membranes show that St II remains lytically active even in the presence of high HSA concentrations. This stubbornness can explain why the toxin is able to exert its haemolytic activity on membranes immersed in complex plasma matrixes such as those present in living organisms.

  8. Biophysical studies of interaction between hydrolysable tannins isolated from Oenothera gigas and Geranium sanguineum with human serum albumin.

    PubMed

    Sekowski, Szymon; Ionov, Maksim; Kaszuba, Mateusz; Mavlyanov, Saidmukhtar; Bryszewska, Maria; Zamaraeva, Maria

    2014-11-01

    Tannins, secondary plant metabolites, possess diverse biological activities and can interact with biopolymers such as lipids or proteins. Interactions between tannins and proteins depend on the structures of both and can result in changes in protein structure and activity. Because human serum albumin is the most abundant protein in plasma and responsible for interactions with important biological compounds (e.g. bilirubin) and proper blood pressure, therefore, it is very important to investigate reactions between HSA and tannins. This paper describes the interaction between human serum albumin (HSA) and two tannins: bihexahydroxydiphenoyl-trigalloylglucose (BDTG) and 1-O-galloyl-4,6-hexahydroxydiphenoyl-β-d-glucose (OGβDG), isolated from Geranium sanguineum and Oenothera gigas leafs, respectively. Optical (spectrofluorimetric) and chiral optical (circular dichroism) methods were used in this study. Fluorescence analysis demonstrated that OGβDG quenched HSA fluorescence more strongly than BDTG. Both OGβDG and BDTG formed complexes with albumin and caused a red shift of the fluorescence spectra but did not significantly change the protein secondary structure. Our studies clearly demonstrate that the tested tannins interact very strongly with human serum albumin (quenching constant K=88,277.26±407.04 M(-1) and K=55,552.67±583.07 M(-1) respectively for OGβDG and BDTG) in a manner depending on their chemical structure.

  9. Biomonitoring Human Albumin Adducts: The Past, the Present, and the Future

    PubMed Central

    2016-01-01

    Serum albumin (Alb) is the most abundant protein in blood plasma. Alb reacts with many carcinogens and/or their electrophilic metabolites. Studies conducted over 20 years ago showed that Alb forms adducts with the human carcinogens aflatoxin B1 and benzene, which were successfully used as biomarkers in molecular epidemiology studies designed to address the role of these chemicals in cancer risk. Alb forms adducts with many therapeutic drugs or their reactive metabolites such as β-lactam antibiotics, acetylsalicylic acid, acetaminophen, nonsteroidal anti-inflammatory drugs, chemotherapeutic agents, and antiretroviral therapy drugs. The identification and characterization of the adduct structures formed with Alb have served to understand the generation of reactive metabolites and to predict idiosyncratic drug reactions and toxicities. The reaction of candidate drugs with Alb is now exploited as part of the battery of screening tools to assess the potential toxicities of drugs. The use of gas chromatography-mass spectrometry, liquid chromatography, or liquid chromatography-mass spectrometry (LC-MS) enabled the identification and quantification of multiple types of Alb xenobiotic adducts in animals and humans during the past three decades. In this perspective, we highlight the history of Alb as a target protein for adduction to environmental and dietary genotoxicants, pesticides, and herbicides, common classes of medicinal drugs, and endogenous electrophiles, and the emerging analytical mass spectrometry technologies to identify Alb-toxicant adducts in humans. PMID:27989119

  10. Methyl-triclosan binding to human serum albumin: multi-spectroscopic study and visualized molecular simulation.

    PubMed

    Lv, Wenjuan; Chen, Yonglei; Li, Dayong; Chen, Xingguo; Leszczynski, Jerzy

    2013-10-01

    Methyl-triclosan (MTCS), a transformation product and metabolite of triclosan, has been widely spread in environment through the daily use of triclosan which is a commonly used anti-bacterial and anti-fungal substance in consumer products. Once entering human body, MTCS could affect the conformation of human serum albumin (HSA) by forming MTCS-HSA complex and alter function of protein and endocrine in human body. To evaluate the potential toxicity of MTCS, the binding mechanism of HSA with MTCS was investigated by UV-vis absorption, circular dichroism and Fourier transform infrared spectroscopy. Binding constants, thermodynamic parameters, the binding forces and the specific binding site were studied in detail. Binding constant at room tempreture (T = 298K) is 6.32 × 10(3)L mol(-1); ΔH(0), ΔS(0) and ΔG(0) were 22.48 kJ mol(-1), 148.16 J mol(-1)K(-1) and -21.68 kJ mol(-1), respectively. The results showed that the interactions between MTCS and HSA are mainly hydrophobic forces. The effects of MTCS on HSA conformation were also discussed. The binding distance (r = 1.2 nm) for MTCS-HSA system was calculated by the efficiency of fluorescence resonance energy transfer. The visualized binding details were also exhibited by molecular modeling method and the results could agree well with that from the experimental study.

  11. Repeated intravenous injection of recombinant human hepatocyte growth factor ameliorates liver cirrhosis but causes albuminuria in rats.

    PubMed

    Kusumoto, Kazunori; Ido, Akio; Moriuchi, Akihiro; Katsura, Toshiya; Kim, Ildeok; Takahama, Yuka; Numata, Masatsugu; Kodama, Mayumi; Hasuike, Satoru; Nagata, Kenji; Uto, Hirofumi; Inui, Ken-Ichi; Tsubouchi, Hirohito

    2006-03-01

    Hepatocyte growth factor (HGF) is a promising agent for the treatment of liver cirrhosis because of its mitogenic and anti-fibrotic effects. We investigated the effect of recombinant human HGF (rh-HGF) on cirrhosis development; its pharmacokinetics and nephrotoxicity in rats with liver cirrhosis induced by 4-week treatment with dimethylnitrosamine (DMN). rh-HGF (0.3 mg/kg) was intravenously administered to rats once a day for 4 weeks in parallel with DMN treatment or twice a day for the last 2 weeks of DMN treatment. Repeated doses of rh-HGF increased the liver weight and serum albumin, and reduced serum ALT. The development of hepatic fibrosis was inhibited more efficiently by extended low-dose treatment with rh-HGF. In cirrhotic rats, serum levels of rh-HGF increased and clearance was decreased, leading to an increase in the area under the plasma-concentration time curve and a decrease in the steady-state volume of distribution. Repeated doses of rh-HGF led to increased urinary albumin excretion, but no rh-HGF-treated animals developed increased serum creatinine levels. Urinary albumin excretion returned to baseline after the cessation of rh-HGF. These results suggest that extended treatment with rh-HGF is required for the attenuation of cirrhosis, and repeated doses of rh-HGF cause adverse effects in extra-hepatic organs. These issues must be resolved before the widespread application of rh-HGF in the treatment of liver cirrhosis.

  12. [Use of human recombinant erythropoietin in children with cancer].

    PubMed

    Guyot, D; Margueritte, G

    2005-09-01

    Eighty percent of children with cancer suffer from anemia at the time of diagnosis. The physiopathology of anemia is complex. Although anemia can be life threatening, its consequences on the physical, psychological and social state of the child are often minimized. Blood transfusion is the main treatment of anemia: its efficacy is immediate but shortlasting, and it involves infectious and hemolytic risks. The human recombinant erythropoietin has been used for more than 25-years, and is often prescribed to adults with cancer and anemia. The human recombinant erythropoietin rHuEPO is nowadays used when blood transfusion is contra-indicated because of religious or cultural considerations, although several promising studies have been conducted about rHuEPO and children with cancer since 1996: it might be soon the preferential alternative treatment to anemia in children with cancer.

  13. Plant-based biopharming of recombinant human lactoferrin.

    PubMed

    Yemets, Alla I; Tanasienko, Iryna V; Krasylenko, Yuliya A; Blume, Yaroslav B

    2014-09-01

    Recombinant proteins are currently recognized as pharmaceuticals, enzymes, food constituents, nutritional additives, antibodies and other valuable products for industry, healthcare, research, and everyday life. Lactoferrin (Lf), one of the promising human milk proteins, occupies the expanding biotechnological food market niche due to its important versatile properties. Lf shows antiviral, antimicrobial, antiprotozoal and antioxidant activities, modulates cell growth rate, binds glycosaminoglycans and lipopolysaccharides, and also inputs into the innate/specific immune responses. Development of highly efficient human recombinant Lf expression systems employing yeasts, filamentous fungi and undoubtedly higher plants as bioreactors for the large-scale Lf production is a biotechnological challenge. This review highlights the advantages and disadvantages of the existing non-animal Lf expression systems from the standpoint of protein yield and its biological activity. Special emphasis is put on the benefits of monocot plant system for Lf expression and the biosafety aspects of the transgenic Lf-expressing plants.

  14. Transient Expression of Tetrameric Recombinant Human Butyrylcholinesterase in Nicotiana benthamiana

    PubMed Central

    Alkanaimsh, Salem; Karuppanan, Kalimuthu; Guerrero, Andrés; Tu, Aye M.; Hashimoto, Bryce; Hwang, Min Sook; Phu, My L.; Arzola, Lucas; Lebrilla, Carlito B.; Dandekar, Abhaya M.; Falk, Bryce W.; Nandi, Somen; Rodriguez, Raymond L.; McDonald, Karen A.

    2016-01-01

    To optimize the expression, extraction and purification of plant-derived tetrameric recombinant human butyrylcholinesterase (prBChE), we describe the development and use of plant viral amplicon-based gene expression system; Tobacco Mosaic Virus (TMV) RNA-based overexpression vector (TRBO) to express enzymatically active FLAG-tagged plant made recombinant butyrylcholinesterase (rBChE) in Nicotiana benthamiana leaves using transient agroinfiltration. Two gene expression cassettes were designed to express the recombinant protein in either the ER or to the apoplastic compartment. Leaf homogenization was used to isolate ER-retained recombinant butyrylcholinesterase (prBChE-ER) while apoplast-targeted rBChE was isolated by either leaf homogenization (prBChE) or vacuum-extraction of apoplastic wash fluid (prBChE-AWF). rBChE from apoplast wash fluid had a higher specific activity but lower enzyme yield than leaf homogenate. To optimize the isolation and purification of total recombinant protein from leaf homogenates, an acidic extraction buffer was used. The acidic extraction buffer yielded >95% enzymatically active tetrameric rBChE as verified by Coomassie stained and native gel electrophoresis. Furthermore, when compared to human butyrylcholinesterase, the prBChE was found to be similar in terms of tetramerization and enzyme kinetics. The N-linked glycan profile of purified prBChE-ER was found to be mostly high mannose structures while the N-linked glycans on prBChE-AWF were primarily complex. The glycan profile of the prBChE leaf homogenates showed a mixture of high mannose, complex and paucimannose type N-glycans. These findings demonstrate the ability of plants to produce rBChE that is enzymatically active and whose oligomeric state is comparable to mammalian butyrylcholinesterase. The process of plant made rBChE tetramerization and strategies for improving its pharmacokinetics properties are also discussed. PMID:27379103

  15. Construction of human artificial chromosome vectors by recombineering.

    PubMed

    Kotzamanis, George; Cheung, Wing; Abdulrazzak, Hassan; Perez-Luz, Sara; Howe, Steven; Cooke, Howard; Huxley, Clare

    2005-05-23

    Human artificial chromosomes (HACs) can be formed de novo by transfection of large fragments of cloned alphoid DNA into human HT1080 cells in tissue culture. In order to generate HACs carrying a gene of interest, one can either co-transfect the alphoid DNA and the gene of interest, or one can clone both into a single vector prior to transfection. Here we describe linking approximately 70 kb of alphoid DNA onto a 156-kb BAC carrying the human HPRT gene using Red homologous recombination in the EL350 Escherichia coli host [Lee et al., Genomics 73 (2001) 56-65]. A selectable marker and EGFP marker were then added by loxP/Cre recombination using the arabinose inducible cre gene in the EL350 bacteria. The final construct generates minichromosomes in HT1080 cells and the HPRT gene is expressed. The retrofitting vector can be used to add the approximately 70 kb of alphoid DNA to any BAC carrying a gene of interest to generate a HAC vector. The method can also be used to link any unrelated BAC or PAC insert onto another BAC clone. The EL350 bacteria are an excellent host for building up complex vectors by a combination of homologous and loxP/Cre recombination.

  16. Recombinant Human Peptidoglycan Recognition Proteins Reveal Antichlamydial Activity.

    PubMed

    Bobrovsky, Pavel; Manuvera, Valentin; Polina, Nadezhda; Podgorny, Oleg; Prusakov, Kirill; Govorun, Vadim; Lazarev, Vassili

    2016-07-01

    Peptidoglycan recognition proteins (PGLYRPs) are innate immune components that recognize the peptidoglycan and lipopolysaccharides of bacteria and exhibit antibacterial activity. Recently, the obligate intracellular parasite Chlamydia trachomatis was shown to have peptidoglycan. However, the antichlamydial activity of PGLYRPs has not yet been demonstrated. The aim of our study was to test whether PGLYRPs exhibit antibacterial activity against C. trachomatis Thus, we cloned the regions containing the human Pglyrp1, Pglyrp2, Pglyrp3, and Pglyrp4 genes for subsequent expression in human cell lines. We obtained stable HeLa cell lines that secrete recombinant human PGLYRPs into culture medium. We also generated purified recombinant PGLYRP1, -2, and -4 and confirmed their activities against Gram-positive (Bacillus subtilis) and Gram-negative (Escherichia coli) bacteria. Furthermore, we examined the activities of recombinant PGLYRPs against C. trachomatis and determined their MICs. We also observed a decrease in the infectious ability of chlamydial elementary bodies in the next generation after a single exposure to PGLYRPs. Finally, we demonstrated that PGLYRPs attach to C. trachomatis elementary bodies and activate the expression of the chlamydial two-component stress response system. Thus, PGLYRPs inhibit the development of chlamydial infection.

  17. Recombinant Human Peptidoglycan Recognition Proteins Reveal Antichlamydial Activity

    PubMed Central

    Manuvera, Valentin; Polina, Nadezhda; Podgorny, Oleg; Prusakov, Kirill; Govorun, Vadim; Lazarev, Vassili

    2016-01-01

    Peptidoglycan recognition proteins (PGLYRPs) are innate immune components that recognize the peptidoglycan and lipopolysaccharides of bacteria and exhibit antibacterial activity. Recently, the obligate intracellular parasite Chlamydia trachomatis was shown to have peptidoglycan. However, the antichlamydial activity of PGLYRPs has not yet been demonstrated. The aim of our study was to test whether PGLYRPs exhibit antibacterial activity against C. trachomatis. Thus, we cloned the regions containing the human Pglyrp1, Pglyrp2, Pglyrp3, and Pglyrp4 genes for subsequent expression in human cell lines. We obtained stable HeLa cell lines that secrete recombinant human PGLYRPs into culture medium. We also generated purified recombinant PGLYRP1, -2, and -4 and confirmed their activities against Gram-positive (Bacillus subtilis) and Gram-negative (Escherichia coli) bacteria. Furthermore, we examined the activities of recombinant PGLYRPs against C. trachomatis and determined their MICs. We also observed a decrease in the infectious ability of chlamydial elementary bodies in the next generation after a single exposure to PGLYRPs. Finally, we demonstrated that PGLYRPs attach to C. trachomatis elementary bodies and activate the expression of the chlamydial two-component stress response system. Thus, PGLYRPs inhibit the development of chlamydial infection. PMID:27160295

  18. Human recombinant type I collagen produced in plants.

    PubMed

    Shoseyov, Oded; Posen, Yehudit; Grynspan, Frida

    2013-07-01

    As a central element of the extracellular matrix, collagen is intimately involved in tissue development, remodeling, and repair and confers high tensile strength to tissues. Numerous medical applications, particularly, wound healing, cell therapy, bone reconstruction, and cosmetic technologies, rely on its supportive and healing qualities. Its synthesis and assembly require a multitude of genes and post-translational modifications, where even minor deviations can be deleterious or even fatal. Historically, collagen was always extracted from animal and human cadaver sources, but bare risk of contamination and allergenicity and was subjected to harsh purification conditions resulting in irreversible modifications impeding its biofunctionality. In parallel, the highly complex and stringent post-translational processing of collagen, prerequisite of its viability and proper functioning, sets significant limitations on recombinant expression systems. A tobacco plant expression platform has been recruited to effectively express human collagen, along with three modifying enzymes, critical to collagen maturation. The plant extracted recombinant human collagen type I forms thermally stable helical structures, fibrillates, and demonstrates bioactivity resembling that of native collagen. Deployment of the highly versatile plant-based biofactory can be leveraged toward mass, rapid, and low-cost production of a wide variety of recombinant proteins. As in the case of collagen, proper planning can bypass plant-related limitations, to yield products structurally and functionally identical to their native counterparts.

  19. Selective ex-vivo photothermal ablation of human pancreatic cancer with albumin functionalized multiwalled carbon nanotubes

    PubMed Central

    Mocan, Lucian; Tabaran, Flaviu A; Mocan, Teodora; Bele, Constantin; Orza, Anamaria Ioana; Lucan, Ciprian; Stiufiuc, Rares; Manaila, Ioana; Iulia, Ferencz; Dana, Iancu; Zaharie, Florin; Osian, Gelu; Vlad, Liviu; Iancu, Cornel

    2011-01-01

    The process of laser-mediated ablation of cancer cells marked with biofunctionalized carbon nanotubes is frequently called “nanophotothermolysis”. We herein present a method of selective nanophotothermolisys of pancreatic cancer (PC) using multiwalled carbon nanotubes (MWCNTs) functionalized with human serum albumin (HSA). With the purpose of testing the therapeutic value of these nanobioconjugates, we have developed an ex-vivo experimental platform. Surgically resected specimens from patients with PC were preserved in a cold medium and kept alive via intra-arterial perfusion. Additionally, the HSA-MWCNTs have been intra-arterially administered in the greater pancreatic artery under ultrasound guidance. Confocal and transmission electron microscopy combined with immunohistochemical staining have confirmed the selective accumulation of HSA-MWCNTs inside the human PC tissue. The external laser irradiation of the specimen has significantly produced extensive necrosis of the malign tissue after the intra-arterial administration of HSA-MWCNTs, without any harmful effects on the surrounding healthy parenchyma. We have obtained a selective photothermal ablation of the malign tissue based on the selective internalization of MWCNTs with HSA cargo inside the pancreatic adenocarcinoma after the ex-vivo intra-arterial perfusion. PMID:21720504

  20. 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.

  1. Locating the binding sites of Pb(II) ion with human and bovine serum albumins.

    PubMed

    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 K(Pb-HSA) = 8.2 (±0.8)×10(4) M(-1) and K(Pb-BSA) = 7.5 (±0.7)×10(4) 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.

  2. Interaction of prometryn to human serum albumin: insights from spectroscopic and molecular docking studies.

    PubMed

    Wang, Yaping; Zhang, Guowen; Wang, Langhong

    2014-01-01

    Prometryn possesses much potential hazard to environment because of its chemical stability and biological toxicity. Here, the binding properties of prometryn with human serum albumin (HSA) and the protein structural changes were determined under simulative physiological conditions (pH 7.4) by multispectroscopic methods including fluorescence, UV-vis absorption, Fourier transform infrared (FT-IR) and circular dichroism (CD) spectroscopy, coupled with molecular modeling technique. The result of fluorescence titration suggested that the fluorescence quenching of HSA by prometryn was considered as a static quenching procedure. The negative enthalpy change (ΔH(○)) and positive entropy change (ΔS(○)) values indicated that the binding process was governed mainly by hydrophobic interactions and hydrogen bonds. The site marker displacement experiments suggested the location of prometryn binding to HSA was Sudlow's site I in subdomain IIA. Furthermore, molecular docking studies revealed prometryn can bind in the large hydrophobic activity of subdomain IIA. Analysis of UV-vis absorption, synchronous fluorescence, CD and FT-IR spectra demonstrated that the addition of prometryn resulted in rearrangement and conformational alteration of HSA with reduction in α-helix and increases in β-sheet, β-turn and random coil structures. This work provided reasonable model helping us further understand the transportation, distribution and toxicity effect of prometryn when it spreads into human blood serum.

  3. Study the interactions between human serum albumin and two antifungal drugs: fluconazole and its analogue DTP.

    PubMed

    Zhang, Shao-Lin; Yao, Huankai; Wang, Chenyin; Tam, Kin Y

    2014-11-01

    Binding affinities of fluconazole and its analogue 2-(2,4-dichlorophenyl)-1,3-di(1H-1,2,4-triazol-yl)-2-propanol (DTP) to human serum albumin (HSA) were investigated under approximately human physiological conditions. The obtained result indicated that HSA could generate fluorescent quenching by fluconazole and DTP because of the formation of non-fluorescent ground-state complexes. Binding parameters calculated from the Stern-Volmer and the Scatchard equations showed that fluconazole and DTP bind to HSA with binding affinities of the order 10(4)L/mol. The thermodynamic parameters revealed that the binding was characterized by negative enthalpy and positive entropy changes, suggesting that the binding reaction was exothermic. Hydrogen bonds and hydrophobic interaction were found to be the predominant intermolecular forces stabilizing the drug-protein. The effect of metal ions on the binding constants of fluconazole-HSA complex suggested that the presence of Mg(2+) and Zn(2+) ions could decrease the free drug level and extend the half-life in the systematic circulation. Docking experiments revealed that fluconazole and DTP binds in HSA mainly by hydrophobic interaction with the possibility of hydrogen bonds formation between the drugs and the residues Arg 222, Lys 199 and Lys 195 in HSA.

  4. Determination of energies and sites of binding of PFOA and PFOS to human serum albumin.

    PubMed

    Salvalaglio, Matteo; Muscionico, Isabella; Cavallotti, Carlo

    2010-11-25

    Structure and energies of the binding sites of perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) to human serum albumin (HSA) were determined through molecular modeling. The calculations consisted of a compound approach based on docking, followed by molecular dynamics simulations and by the estimation of the free binding energies adopting WHAM-umbrella sampling and semiempirical methodologies. The binding sites so determined are common either to known HSA fatty acids sites or to other HSA sites known to bind to pharmaceutical compounds such as warfarin, thyroxine, indole, and benzodiazepin. Among the PFOA binding sites, five have interaction energies in excess of -6 kcal/mol, which become nine for PFOS. The calculated binding free energy of PFOA to the Trp 214 binding site is the highest among the PFOA complexes, -8.0 kcal/mol, in good agreement with literature experimental data. The PFOS binding site with the highest energy, -8.8 kcal/mol, is located near the Trp 214 binding site, thus partially affecting its activity. The maximum number of ligands that can be bound to HSA is 9 for PFOA and 11 for PFOS. The calculated data were adopted to predict the level of complexation of HSA as a function of the concentration of PFOA and PFOS found in human blood for different levels of exposition. The analysis of the factors contributing to the complex binding energy permitted to outline a set of guidelines for the rational design of alternative fluorinated surfactants with a lower bioaccumulation potential.

  5. HPLC separation of human serum albumin isoforms based on their isoelectric points

    PubMed Central

    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

  6. Potential toxicity of amphenicol antibiotic: binding of chloramphenicol to human serum albumin.

    PubMed

    Chen, Huilun; Rao, Honghao; He, Pengzhen; Qiao, Yongxiang; Wang, Fei; Liu, Haijun; Cai, Minmin; Yao, Jun

    2014-10-01

    Antibiotics are widely used in daily life but their abuse has posed a potential threat to human health. To evaluate the toxicity of chloramphenicol (CAP) at the protein level, the interaction between CAP and human serum albumin (HSA) was investigated by fluorescence, Ultraviolet-visible (UV-Vis) absorption, Fourier transform infrared (FT-IR) spectroscopy and molecular docking methods. Fluorescence data revealed that the fluorescence quenching of HSA by CAP was the result of the formation of CAP-HSA complex, and the binding constant was determined to be 3.196 × 10(4) L mol(-1) at 310 K. The thermodynamic determination indicated that the interaction was driven by enthalpy change and entropy change together, where the multiple hydrogen bonds (CAP and the residues Arg 222 and His 242 of HSA) and van der Waals forces were the dominant binding force. The site marker competition revealed that CAP bound into sub-domain IIA of HSA. The binding of CAP induced the drastic reduction in α-helix conformation and the significant enhancement in β-sheet conformation of HSA. Molecular docking study further confirmed the binding mode obtained by experimental study. This work provides a new quantitative evaluation method for antibiotics to cause the protein damage.

  7. Enhancement mechanism of FCLA-1O II chemiluminescence by human serum albumin

    NASA Astrophysics Data System (ADS)

    Zhou, Jing; Xing, Da; Chen, Qun

    2006-09-01

    Fluoresceinyl Cypridina Lucifenn Analog (FCLA) is a reactive oxygen species (ROS) specific chemiluminescence (CL) probe. Its detection efficiency of singlet oxygen (10 II)couldbe significantly enhanced in the presence of human serum albumin (HSA). The enhancement mechanism of HSA-FCLA CL is studied in the current work by means ofdirect CL measurement and spectroscopy. The results show that, FCLA can combine with HSA. HSA is an effective 1O II quencher. It can react with 10 II and produce a protein carbonyl group with an elevated energy state. The HSA protein carbonyl group can transfer its energy to FCLA in the FCLA-HSA complex. Via this irradiative de-excitation pathway of the excited FCLA, luminescence production from FCLA is greatly enhanced, in addition to the chemiluminescence from the direct interaction of FCLA and 10 II FCLA has been reported for cancer diagnosis in vivo. Considering HSA is a natural protein that is present in all parts of a human body, the efficacy of FCLA used in vivo is expected to be enhanced through the coupling of FCLA and HSA.

  8. Interaction of oridonin with human serum albumin by isothermal titration calorimetry and spectroscopic techniques.

    PubMed

    Li, Xiangrong; Yang, Zhenhua

    2015-05-05

    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.

  9. 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

  10. Evaluation of capillary zone electrophoresis for the determination of protein composition in therapeutic immunoglobulins and human albumins.

    PubMed

    Christians, Stefan; van Treel, Nadine Denise; Bieniara, Gabriele; Eulig-Wien, Annika; Hanschmann, Kay-Martin; Giess, Siegfried

    2016-07-01

    Capillary zone electrophoresis (CZE) provides an alternative means of separating native proteins on the basis of their inherent electrophoretic mobilities. The major advantage of CZE is the quantification by UV detection, circumventing the drawbacks of staining and densitometry in the case of gel electrophoresis methods. The data of this validation study showed that CZE is a reliable assay for the determination of protein composition in therapeutic preparations of human albumin and human polyclonal immunoglobulins. Data obtained by CZE are in line with "historical" data obtained by the compendial method, provided that peak integration is performed without time correction. The focus here was to establish a rapid and reliable test to substitute the current gel based zone electrophoresis techniques for the control of protein composition of human immunoglobulins or albumins in the European Pharmacopoeia. We believe that the more advanced and modern CZE method described here is a very good alternative to the procedures currently described in the relevant monographs.

  11. Adductomics Pipeline for Untargeted Analysis of Modifications to Cys34 of Human Serum Albumin.

    PubMed

    Grigoryan, Hasmik; Edmands, William; Lu, Sixin S; Yano, Yukiko; Regazzoni, Luca; Iavarone, Anthony T; Williams, Evan R; Rappaport, Stephen M

    2016-11-01

    An important but understudied class of human exposures is comprised of reactive electrophiles that cannot be measured in vivo because they are short-lived. An avenue for assessing these meaningful exposures focuses on adducts from reactions with nucleophilic loci of blood proteins, particularly Cys34 of human serum albumin, which is the dominant scavenger of reactive electrophiles in serum. We developed an untargeted analytical scheme and bioinformatics pipeline for detecting, quantitating, and annotating Cys34 adducts in tryptic digests of human serum/plasma. The pipeline interrogates tandem mass spectra to find signatures of the Cys34-containing peptide, obtains accurate masses of putative adducts, quantitates adduct levels relative to a "housekeeping peptide", and annotates modifications based on a combination of retention time, accurate mass, elemental composition, and database searches. We used the adductomics pipeline to characterize 43 adduct features in archived plasma from healthy human subjects and found several that were highly associated with smoking status, race, and other covariates. Since smoking is a strong risk factor for cancer and cardiovascular disease, our ability to discover adducts that distinguish smokers from nonsmokers with untargeted adductomics indicates that the pipeline is suitable for use in epidemiologic studies. In fact, adduct features were both positively and negatively associated with smoking, indicating that some adducts arise from reactions between Cys34 and constituents of cigarette smoke (e.g., ethylene oxide and acrylonitrile) while others (Cys34 oxidation products and disulfides) appear to reflect alterations in the serum redox state that resulted in reduced adduct levels in smokers.

  12. Unique cyanide adduct in human serum albumin: potential as a surrogate exposure marker.

    PubMed

    Fasco, Michael J; Stack, Robert F; Lu, Shijun; Hauer, Charles R; Schneider, Erasmus; Dailey, Michael; Aldous, Kenneth M

    2011-04-18

    Cyanide (CN = HCN + CN(-)) is a renowned poison and neurotoxicant that is prevalent throughout the environment. Despite a plethora of studies conducted over the last half century, relatively little is known of its potential to cause adverse health outcomes at sublethal exposures. CN exposure is normally determined from blood, but because CN is rapidly metabolized and cleared from this compartment (t(1/2) < 1 h), it is common for several half-lives to have passed before blood samples are drawn for analysis. This variable, coupled with a very narrow toxic index and metabolic diversity within the human population, has rendered accurate assessment of CN exposure, and consequently any predictions of possible adverse health outcomes, highly problematic. Prior studies by us showed the potential of Cys-SCN adducts within human serum albumin (HSA) to act as retrospective surrogates of CN exposure. Here, we report the discovery of a stable, SCN adduct at Cys(567) formed by the reaction of CN with the C-terminal Cys(558)Cys(567) disulfide bond of HSA. Treatment of HSA purified from human serum with base in guanidine hydrochloride releases a readily detectable, uniquely modified, C-terminal-19-mer peptide from Cys(567)-SCN moieties in all the samples examined thus far. Inclusion of a HSA-Cys(567)-S(13)C(15)N labeled internal standard permits quantitation of the Cys(567)-SCN adduct by LC-MS/MS in selective reaction monitoring (SRM) of the surrogate peptide with high sensitivity and good precision. Reaction of CN in vitro with the Cys(558)Cys(567) disulfide bond in HSA is specific, rapid, and concentration dependent within a putative, physiologically relevant range. Data from various human sera demonstrate the potential usefulness of this adduct as a biomarker of CN exposure.

  13. Human recombinant soluble guanylyl cyclase: expression, purification, and regulation

    NASA Technical Reports Server (NTRS)

    Lee, Y. C.; Martin, E.; Murad, F.

    2000-01-01

    The alpha1- and beta1-subunits of human soluble guanylate cyclase (sGC) were coexpressed in the Sf9 cells/baculovirus system. In addition to the native enzyme, constructs with hexahistidine tag at the amino and carboxyl termini of each subunit were coexpressed. This permitted the rapid and efficient purification of active recombinant enzyme on a nickel-affinity column. The enzyme has one heme per heterodimer and was readily activated with the NO donor sodium nitroprusside or 3-(5'-hydroxymethyl-2'furyl)-1-benzyl-indazole (YC-1). Sodium nitroprusside and YC-1 treatment potentiated each other in combination and demonstrated a remarkable 2,200-fold stimulation of the human recombinant sGC. The effects were inhibited with 1H-(1,2, 4)oxadiazole(4,3-a)quinoxalin-1one (ODQ). The kinetics of the recombinant enzyme with respect to GTP was examined. The products of the reaction, cGMP and pyrophosphate, inhibited the enzyme. The extent of inhibition by cGMP depended on the activation state of the enzyme, whereas inhibition by pyrophosphate was not affected by the enzyme state. Both reaction products displayed independent binding and cooperativity with respect to enzyme inhibition. The expression of large quantities of active enzyme will facilitate structural characterization of the protein.

  14. Human recombinant soluble guanylyl cyclase: Expression, purification, and regulation

    PubMed Central

    Lee, Yu-Chen; Martin, Emil; Murad, Ferid

    2000-01-01

    The α1- and β1-subunits of human soluble guanylate cyclase (sGC) were coexpressed in the Sf9 cells/baculovirus system. In addition to the native enzyme, constructs with hexahistidine tag at the amino and carboxyl termini of each subunit were coexpressed. This permitted the rapid and efficient purification of active recombinant enzyme on a nickel-affinity column. The enzyme has one heme per heterodimer and was readily activated with the NO donor sodium nitroprusside or 3-(5′-hydroxymethyl-2′furyl)-1-benzyl-indazole (YC-1). Sodium nitroprusside and YC-1 treatment potentiated each other in combination and demonstrated a remarkable 2,200-fold stimulation of the human recombinant sGC. The effects were inhibited with 1H-(1,2,4)oxadiazole(4,3-a)quinoxalin-1one (ODQ). The kinetics of the recombinant enzyme with respect to GTP was examined. The products of the reaction, cGMP and pyrophosphate, inhibited the enzyme. The extent of inhibition by cGMP depended on the activation state of the enzyme, whereas inhibition by pyrophosphate was not affected by the enzyme state. Both reaction products displayed independent binding and cooperativity with respect to enzyme inhibition. The expression of large quantities of active enzyme will facilitate structural characterization of the protein. PMID:10995472

  15. Albumin Test

    MedlinePlus

    ... may also be ordered to evaluate a person's nutritional status. ^ Back to top When is it ordered? An ... albumin test to check or monitor a person's nutritional status. However, since albumin concentrations respond to a variety ...

  16. Recombinant production of TEV cleaved human parathyroid hormone.

    PubMed

    Audu, Christopher O; Cochran, Jared C; Pellegrini, Maria; Mierke, Dale F

    2013-08-01

    The parathyroid hormone, PTH, is responsible for calcium and phosphate ion homeostasis in the body. The first 34 amino acids of the peptide maintain the biological activity of the hormone and is currently marketed for calcium imbalance disorders. Although several methods for the production of recombinant PTH(1-34) have been reported, most involve the use of cleavage conditions that result in a modified peptide or unfavorable side products. Herein, we detail the recombinant production of (15) N-enriched human parathyroid hormone, (15) N PTH(1-34), generated via a plasmid vector that gives reasonable yield, low-cost protease cleavage (leaving the native N-terminal serine in its amino form), and purification by affinity and size exclusion chromatography. We characterize the product by multidimensional, heteronuclear NMR, circular dichroism, and LC/MS.

  17. Albumin holograms

    NASA Astrophysics Data System (ADS)

    Ordóñez-Padilla, M. J.; Olivares-Pérez, A.; Vega-Criollo, R.; Berriel-Valdos, L. R.; Mejias-Brizuela, N. Y.

    2011-02-01

    A Characterization is made with performance analysis of new photosensitive films of albumin to certain conditions for holographic recording based on interferometric array. We carried out the photo-oxidation of gallus gallus albumin albumin chemically combining powdered sugar (Glass ®) to an aqueous solution of ammonium dichromate. It was the analysis of the behavior of diffraction efficiency parameter through the intensity diffraction pattern produced by the gratings made with albumin.

  18. Nickel(II)-Schiff base complex recognizing domain II of bovine and human serum albumin: Spectroscopic and docking studies

    NASA Astrophysics Data System (ADS)

    Ray, Aurkie; Koley Seth, Banabithi; Pal, Uttam; Basu, Samita

    It has been spectroscopically monitored that a mononuclear nickel(II)-Schiff base complex {[NiL]·CH3OH = NSC} exhibits greater binding affinity for bovine serum albumin (BSA) than that of its human counterpart (HSA). Moreover the modes of binding of NSC with the two serum albumins also differ significantly. Docking studies predict a relatively rare type of 'superficial binding' of NSC at domain IIB of HSA with certain mobility whereas for BSA such phenomena has not been detected. The mobile nature of NSC at domain IIB of HSA has been well correlated with the spectroscopic results. It is to be noted that thermodynamic parameters for the NSC interaction also differ for the two serum albumins. Occurrence of energy transfer between the donor (Trp of BSA and HSA) and acceptor (NSC) has been obtained by means of Förster resonance energy transfer (FRET). The protein stability on NSC binding has also been experimented by the GuHCl-induced protein unfolding studies. Interestingly it has been found that NSC-HSA interaction enhances the protein stability whereas NSC-BSA binding has no such impact. Such observations are indicative of the fact that the conformation of NSC is responsible in recognizing the two serum albumins and selectively enhancing protein stability.

  19. Nickel(II)-Schiff base complex recognizing domain II of bovine and human serum albumin: spectroscopic and docking studies.

    PubMed

    Ray, Aurkie; Seth, Banabithi Koley; Pal, Uttam; Basu, Samita

    2012-06-15

    It has been spectroscopically monitored that a mononuclear nickel(II)-Schiff base complex {[NiL]·CH(3)OH=NSC} exhibits greater binding affinity for bovine serum albumin (BSA) than that of its human counterpart (HSA). Moreover the modes of binding of NSC with the two serum albumins also differ significantly. Docking studies predict a relatively rare type of 'superficial binding' of NSC at domain IIB of HSA with certain mobility whereas for BSA such phenomena has not been detected. The mobile nature of NSC at domain IIB of HSA has been well correlated with the spectroscopic results. It is to be noted that thermodynamic parameters for the NSC interaction also differ for the two serum albumins. Occurrence of energy transfer between the donor (Trp of BSA and HSA) and acceptor (NSC) has been obtained by means of Förster resonance energy transfer (FRET). The protein stability on NSC binding has also been experimented by the GuHCl-induced protein unfolding studies. Interestingly it has been found that NSC-HSA interaction enhances the protein stability whereas NSC-BSA binding has no such impact. Such observations are indicative of the fact that the conformation of NSC is responsible in recognizing the two serum albumins and selectively enhancing protein stability.

  20. Spectroscopic investigation of the interaction between human serum albumin and three organic acids

    NASA Astrophysics Data System (ADS)

    Liu, Yuan; Xie, Meng-Xia; Jiang, Min; Wang, Ying-Dian

    2005-07-01

    The interactions of human serum albumin (HSA) with sinapic acid (SA), gallic acid (GA) and shikimic acid (SI) were investigated by fluorescence and Fourier transformed infrared spectrometry. Fluorescence results showed that one molecule of protein combined with one molecule of GA at the molar ratio of drug to HSA ranging from 0.1 to 30, and their binding constant ( KA) is 1.1 × 10 4 M -1. While one HSA molecule combined with one or two molecule of SA at the molar ratio of drug to HSA ranging from 0.1 to 4.26 or 4.26 to 30, and their binding affinities ( KA) are 1.92 × 10 3 M -1 and 6.87 × 10 8 M -1, respectively. There is no specific interaction between HSA and SI. Combining the curve-fitting results of infrared amide I and amide III bands, the alterations of protein secondary structures induced by drugs were estimated. The drug-protein combination brought gradual reductions of the protein α-helix structure with increasing the concentrations of SA and GA, but SI did not change the protein secondary structure. From the fluorescence and FT-IR results, the binding mode was discussed in relation to the structures of the organic acids.

  1. Investigation the interaction of Daphnin with human serum albumin using optical spectroscopy and molecular modeling methods

    NASA Astrophysics Data System (ADS)

    Zhu, Jinhua; Wu, Liye; Zhang, Qingyou; Chen, Xingguo; Liu, Xiuhua

    2012-09-01

    The interaction between Daphnin with human serum albumin has been studied for the first time by spectroscopic methods including fluorescence quenching technology, circular dichroism (CD) spectroscopy and Fourier transform infrared (FT-IR) spectroscopy under simulative physiological conditions. The results of fluorescence titration revealed that Daphnin can quench the intrinsic fluorescence of HSA by static quenching and there is a single class of binding site on HSA. In addition, the studies of CD spectroscopy and FT-IR spectroscopy showed that the protein secondary structure changed with increases of α-helices at the drug to protein molar ratio of 2. Furthermore, the thermodynamic functions ΔH0 and ΔS0 for the reaction were calculated to be 11.626 kJ mol-1 and 118.843 J mol-1 K-1 according to Van't Hoff equation. The thermodynamic parameters (ΔH0 and ΔS0) and the molecular modeling study indicated that hydrophobic force played an important role to stabilize the Daphnin-HSA complex, and Daphnin could bind within the subdomain IIA of the HSA.

  2. Structural characteristics of green tea catechins for formation of protein carbonyl in human serum albumin.

    PubMed

    Ishii, Takeshi; Mori, Taiki; Ichikawa, Tatsuya; Kaku, Maiko; Kusaka, Koji; Uekusa, Yoshinori; Akagawa, Mitsugu; Aihara, Yoshiyuki; Furuta, Takumi; Wakimoto, Toshiyuki; Kan, Toshiyuki; Nakayama, Tsutomu

    2010-07-15

    Catechins are polyphenolic antioxidants found in green tea leaves. Recent studies have reported that various polyphenolic compounds, including catechins, cause protein carbonyl formation in proteins via their pro-oxidant actions. In this study, we evaluate the formation of protein carbonyl in human serum albumin (HSA) by tea catechins and investigate the relationship between catechin chemical structure and its pro-oxidant property. To assess the formation of protein carbonyl in HSA, HSA was incubated with four individual catechins under physiological conditions to generate biotin-LC-hydrazide labeled protein carbonyls. Comparison of catechins using Western blotting revealed that the formation of protein carbonyl in HSA was higher for pyrogallol-type catechins than the corresponding catechol-type catechins. In addition, the formation of protein carbonyl was also found to be higher for the catechins having a galloyl group than the corresponding catechins lacking a galloyl group. The importance of the pyrogallol structural motif in the B-ring and the galloyl group was confirmed using methylated catechins and phenolic acids. These results indicate that the most important structural element contributing to the formation of protein carbonyl in HSA by tea catechins is the pyrogallol structural motif in the B-ring, followed by the galloyl group. The oxidation stability and binding affinity of tea catechins with proteins are responsible for the formation of protein carbonyl, and consequently the difference in these properties of each catechin may contribute to the magnitude of their biological activities.

  3. Camptothecin-binding site in human serum albumin and protein transformations induced by drug binding.

    PubMed

    Fleury, F; Ianoul, A; Berjot, M; Feofanov, A; Alix, A J; Nabiev, I

    1997-07-14

    Circular dichroism (CD) and Raman spectroscopy were employed in order to locate a camptothecin (CPT)-binding site within human serum albumin (HSA) and to identify protein structural transformations induced by CPT binding. A competitive binding of CPT and 3'-azido-3'-deoxythymidine (a ligand occupying IIIA structural sub-domain of the protein) to HSA does not show any competition and demonstrates that the ligands are located in the different binding sites, whereas a HSA-bound CPT may be replaced by warfarin, occupying IIA structural sub-domain of the protein. Raman and CD spectra of HSA and HSA/CPT complexes show that the CPT-binding does not induce changes of the global protein secondary structure. On the other hand, Raman spectra reveal pronounced CPT-induced local structural modifications of the HSA molecule, involving changes in configuration of the two disulfide bonds and transfer of a single Trp-residue to hydrophilic environment. These data suggest that CPT is bound in the region of interdomain connections within the IIA structural domain of HSA and it induces relative movement of the protein structural domains.

  4. 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.

  5. Mn(II) binding to human serum albumin: a ¹H-NMR relaxometric study.

    PubMed

    Fanali, Gabriella; Cao, Yu; Ascenzi, Paolo; Fasano, Mauro

    2012-12-01

    Human serum albumin (HSA) displays several metal binding sites, participating to essential and toxic metal ions disposal and transport. The major Zn(II) binding site, called Site A, is located at the I/II domain interface, with residues His67, Asn99, His247, and Asp249 contributing with five donor atoms to the metal ion coordination. Additionally, one water molecule takes part of the octahedral coordination geometry. The occurrence of the metal-coordinated water molecule allows the investigation of the metal complex geometry by water (1)H-NMR relaxation, provided that the diamagnetic Zn(II) is replaced by the paramagnetic Mn(II). Here, the (1)H-NMR relaxometric study of Mn(II) binding to HSA is reported. Mn(II) binding to HSA is modulated by Zn(II), pH, and myristate through competitive inhibition and allosteric mechanisms. The body of results indicates that the primary binding site of Zn(II) corresponds to the secondary binding site of Mn(II), i.e. the multimetal binding site A. Excess Zn(II) completely displaces Mn(II) from its primary site suggesting that the primary Mn(II) site corresponds to the secondary Zn(II) site. This uncharacterized site is functionally-linked to FA1; moreover, metal ion binding is modulated by myristate and pH. Noteworthy, water (1)H-NMR relaxometry allowed a detailed analysis of thermodynamic properties of HSA-metal ion complexes.

  6. Regulation of amantadine hydrochloride binding with IIA subdomain of human serum albumin by fatty acid chains.

    PubMed

    Yang, Feng; Lee, Philbert; Ma, Zhiyuan; Ma, Li; Yang, Guoping; Wu, Xiaoyang; Liang, Hong

    2013-01-01

    Human serum albumin (HSA) is a major protein component of blood plasma that has been exploited to bind and transport a wide variety of endogenous and exogenous organic compounds. Although anionic drugs readily associate with the IIA subdomain of HSA, most cationic drugs poorly associate with HSA at this subdomain. In this study, we propose to improve the association between cationic drugs and HSA by modifying HSA with fatty acid chains. For our experiments, we tested amantadine hydrochloride, a cationic drug with antiviral and antiparkinsonian effects. Our results suggest that extensive myristoylation of HSA can help stabilize the interaction between amantadine and HSA in vitro. Our X-ray crystallography data further elucidate the structural basis of this regulation. Additionally, our crystallography data suggest that anionic drugs, with a functional carboxylate group, may enhance the association between amantadine and HSA by a mechanism similar to myristoylation. Ultimately, our results provide critical structural insight into this novel association between cationic drugs and the HSA IIA subdomain, raising the tempting possibility to fully exploit the unique binding capacity of HSA's IIA subdomain to achieve simultaneous delivery of anionic and cationic drugs.

  7. Screening major binding sites on human serum albumin by affinity capillary electrophoresis.

    PubMed

    Kim, Hee Seung; Austin, John; Hage, David S

    2004-01-01

    A screening method is described for determining whether a drug or small solute has significant interactions at the two major binding sites on human serum albumin (HSA). This method uses affinity capillary electrophoresis (ACE) to perform a mobility shift assay, where the solute of interest is injected in both the presence of pH 7.4, 0.067 M phosphate buffer, and the same buffer containing a known concentration of HSA. Dextran is also used in the running buffer to adjust the mobility of HSA. Two types of modified HSA are used in this assay. The first is modified with 2-hydroxy-5-nitrobenzyl bromide (HNB), which selectively blocks HSA's warfarin-azapropazone site. The second type of HSA is modified with tetranitromethane (TNM), which decreases binding at the indole-benzodiazepine site. By comparing the mobility of a solute in the presence of these two modified forms of HSA vs normal HSA, it is possible to detect solute interactions at these binding sites. This approach is illustrated using warfarin and ibuprofen as examples of test solutes.

  8. 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).

  9. Effects of titania nanotubes with or without bovine serum albumin loaded on human gingival fibroblasts.

    PubMed

    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.

  10. 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.

  11. Comparative Studies of Interactions between Fluorodihydroquinazolin Derivatives and Human Serum Albumin with Fluorescence Spectroscopy.

    PubMed

    Wang, Yi; Zhu, Meiqing; Liu, Feng; Wu, Xiangwei; Pan, Dandan; Liu, Jia; Fan, Shisuo; Wang, Zhen; Tang, Jun; Na, Risong; Li, Qing X; Hua, Rimao; Liu, Shangzhong

    2016-10-14

    In the present study, 3-(fluorobenzylideneamino)-6-chloro-1-(3,3-dimethylbutanoyl)-phenyl-2,3-dihydroquinazolin-4(1H)-one (FDQL) derivatives have been designed and synthesized to study the interaction between fluorine substituted dihydroquinazoline derivatives with human serum albumin (HSA) using fluorescence, circular dichroism and Fourier transform infrared spectroscopy. The results indicated that the FDQL could bind to HSA, induce conformation and the secondary structure changes of HSA, and quench the intrinsic fluorescence of HSA through a static quenching mechanism. The thermodynamic parameters, ΔH, ΔS, and ΔG, calculated at different temperatures, revealed that the binding was through spontaneous and hydrophobic forces and thus played major roles in the association. Based on the number of binding sites, it was considered that one molecule of FDQL could bind to a single site of HSA. Site marker competition experiments indicated that the reactive site of HSA to FDQL mainly located in site II (subdomain IIIA). The substitution by fluorine in the benzene ring could increase the interactions between FDQL and HSA to some extent in the proper temperature range through hydrophobic effect, and the substitution at meta-position enhanced the affinity greater than that at para- and ortho-positions.

  12. Binding of hydroxylated polybrominated diphenyl ethers with human serum albumin: Spectroscopic characterization and molecular modeling.

    PubMed

    Yang, Lulu; Yang, Wu; Wu, Zhiwei; Yi, Zhongsheng

    2017-02-21

    Three hydroxylated polybrominated diphenyl ethers (OH-PBDEs), 3-OH-BDE-47, 5-OH-BDE-47, and 6-OH-BDE-47, were selected to investigate the interactions between OH-PBDEs with human serum albumin (HSA) under physiological conditions. The observed fluorescence quenching can be attributed to the formation of complexes between HSA and OH-PBDEs. The thermodynamic parameters at different temperatures indicate that the binding was caused by hydrophobic forces and hydrogen bonds. Molecular modeling and three-dimensional fluorescence spectrum showed conformational and microenvironmental changes in HSA. Circular dichroism analysis showed that the addition of OH-PBDEs changed the conformation of HSA with a minor reduction in α-helix content and increase in β-sheet content. Furthermore, binding distance r between the donor (HSA) and acceptor (three OH-PBDEs) calculated using Förster's nonradiative energy transfer theory was <7 nm; therefore, the quenching mechanisms for the binding between HSA and OH-PBDEs involve static quenching and energy transfer. Combined with molecular dynamics simulations, the binding free energies (ΔGbind ) were calculated using molecular mechanics/Poisson - Boltzmann surface area method, and the crucial residues in HSA were identified.

  13. 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.

  14. 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

  15. Stabilization of Human Serum Albumin against Urea Denaturation by Diazepam and Ketoprofen.

    PubMed

    Manoharan, Pralad; Wong, Yin H; Tayyab, Saad

    2015-01-01

    Stabilizing effect of diazepam and ketoprofen, Sudlow's site II markers on human serum albumin (HSA) against urea denaturation was studied using fluorescence spectroscopy. The two-step, three-state urea transition of HSA was transformed into a single-step, two-state transition with the abolishment of the intermediate state along with a shift of the transition curve towards higher urea concentrations in the presence of diazepam or ketoprofen. Interestingly, a greater shift in the transition curve of HSA was observed in the presence of ketoprofen compared to diazepam. A comparison of the intrinsic fluorescence and three-dimensional fluorescence spectra of HSA and partially-denatured HSAs, obtained in the absence and the presence of diazepam or ketoprofen suggested significant retention of native-like conformation in the partially-denatured states of HSA in the presence of Sudlow's site II markers. Taken together, all these results suggested stabilization of HSA in the presence of diazepam or ketoprofen, being greater in the presence of ketoprofen.

  16. [Microcalorimetric study of the parameters of dicloxacillin binding with human serum albumin at different temperatures].

    PubMed

    Markovich, M N; Isakovich, L G; Klinichev, V F

    1986-08-01

    The thermodynamic parameters of human serum albumin (HSA) binding with dicloxacillin, an antibiotic widely used in clinical practice, were determined with the method of differential flow microcalorimetry at 18, 25, 30, 37 and 45 degrees C. The experiments were performed at two ionic strengths: 0.02 and 0.15. Two hypothetic models of interaction in the HSA-drug system were considered in processing the data for the curves of calorimetric titration. The first model implies the presence of independent homogeneous active sites on the protein. In accordance with the second model there are one primary and secondary independent homogeneous active sites on the biopolymer molecule. It is shown that dicloxacillin association with HSA proceeds according to the mechanism suggesting the presence of one primary and one secondary active sites on the protein molecule. The binding process in the system studied is exothermic, the enthalpy increasing at the temperature change from 18 to 45 degrees C. At the same time the binding constant and enthropy of the system decrease. The influence of the solution ionic strength on the binding process was practically lacking. On the basis of the analysis of the thermodynamic data it is concluded that the character of the binding in the HSA-dicloxacillin system at 18-30 degrees C is hydrophobic. With an increase in the temperature the hydrophoby level decreases.

  17. 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.

  18. Study on the interaction of levocetirizine dihydrochloride with human serum albumin by molecular spectroscopy

    NASA Astrophysics Data System (ADS)

    Liu, Xiangping; Du, Yingxiang; Sun, Wen; Kou, Junping; Yu, Boyang

    2009-12-01

    The interaction between cetirizine dihydrochloride and human serum albumin (HSA) has been examined by the spectroscopic techniques first. According to Stern-Volmer equation at different temperatures and the UV-vis spectra examination it was demonstrated that HSA fluorescence quenching initiated by levocetirizine was static. The values of binding constant ( KA) and the number of binding sites ( n) for levocetirizine and HSA were smaller than those for cetirizine and HSA, which meant that the transport of drug was regulated by the stereoselectivity of HSA to the enantiomer. The effect of the non-enzymatic glycosylation (NEG) on the interaction between levocetirizine and HSA signified that the administration of levocetirizine for diabetes should be different from the normal. The positive Δ S° and negative Δ H° indicated that ionic interaction played a major role between levocetirizine and HSA. Circular dichroism (CD) measurement showed that the secondary structure of HSA has changed in the presence of levocetirizine, and α-helical content decreased from 63.1% for free HSA to 54.9% for combined HSA, and accordingly the other secondary structure (β-strand, β-turns and others) contents increased to some extent. Finally, by the competitive binding experiments it was deduced that levocetirizine specifically bound to HSA in the region of site II, which meant the curative effect of levocetirizine should be reconsidered when it was administrated together with other site II drugs.

  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. Development of an affinity silica monolith containing human serum albumin for chiral separations.

    PubMed

    Mallik, Rangan; Hage, David S

    2008-04-14

    An affinity monolith based on silica and containing immobilized human serum albumin (HSA) was developed and evaluated in terms of its binding, efficiency and selectivity in chiral separations. The results were compared with data obtained for the same protein when used as a chiral stationary phase with HPLC-grade silica particles or a monolith based on a copolymer of glycidyl methacrylate (GMA) and ethylene dimethacrylate (EDMA). The surface coverage of HSA in the silica monolith was similar to values obtained with silica particles and a GMA/EDMA monolith. However, the higher surface area of the silica monolith gave a material that contained 1.3-2.2-times more immobilized HSA per unit volume when compared to silica particles or a GMA/EDMA monolith. The retention, efficiency and resolving power of the HSA silica monolith were evaluated using two chiral analytes: d/l-tryptophan and R/S-warfarin. The separation of R- and S-ibuprofen was also considered. The HSA silica monolith gave higher retention and higher or comparable resolution and efficiency when compared with HSA columns that contained silica particles or a GMA/EDMA monolith. The silica monolith also gave lower back pressures and separation impedances than these other materials. It was concluded that silica monoliths can be valuable alternatives to silica particles or GMA/EDMA monoliths when used with immobilized HSA as a chiral stationary phase.

  1. Quantification of specific glycation sites in human serum albumin as prospective type 2 diabetes mellitus biomarkers.

    PubMed

    Spiller, Sandro; Frolov, Andrej; Hoffmann, Ralf

    2017-02-02

    Type 2 diabetes mellitus (T2DM) is the most common lifestyle disease affecting all countries. Due to its asymptomatic onset, it is often diagnosed after irreversible vascular complications have been initiated. Therefore, specific markers characteristic for very early disease stages and suitable for early diagnostics are required. Glycation of plasma proteins, such as human serum albumin (HSA), has been often suggested as marker. However, the total glycation degree of HSA does not provide sufficient information about short-term fluctuations of blood glucose concentrations due to the large number of glycation sites. Analysis of individual modification sites might be more informative, but methods for reliable quantifications are still missing. Here, we present a precise and robust quantitative strategy based on boronic acid affinity chromatography (BAC) to enrich glycated peptides in tryptic digests of plasma samples and to quantify them by LC-MS/MS (multiple reaction monitoring, MRM) using internal calibration or standard isotope dilution (stable isotope-labeled peptides). The high selectivity and precision (relative standard deviations below 10%) of the overall approach appeared to be well suited for the identification of prospective biomarkers. Indeed, six glycated peptides corresponding to different glycation sites of HSA were present in plasma samples obtained from T2DM patients at significantly higher levels than in non-diabetic men matched for age. Additionally, each of the studied glycation site of HSA appeared to be affected at different degrees.

  2. Replica exchange Monte Carlo simulation of human serum albumin-catechin complexes.

    PubMed

    Li, Yunqi; An, Lijia; Huang, Qingrong

    2014-09-04

    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.

  3. Fluorescence study on the interaction of human serum albumin with bromsulphalein

    NASA Astrophysics Data System (ADS)

    Cheng, Fang-Qin; Wang, Ya-Ping; Li, Zhong-Ping; Dong, Chuan

    2006-12-01

    The binding of bromsulphalein (BSP) with human serum albumin was investigated at different temperatures, 298 and 308 K, by the fluorescence spectroscopy at pH 7.24. The binding constant was determined by Stern-Volmer equation based on the quenching of the fluorescence HSA in the presence of bromsulphalein. The effect of various metal ions on the binding constants of BSP with HSA was investigated. The thermodynamic parameters were calculated according to the dependence of enthalpy change on the temperature as follows: Δ H and Δ S possess small negative (9.3 kJ mol -1) and positive values (22.3 J K -l mol -l), respectively. The experimental results revealed that BSP has a strong ability to quench the intrinsic fluorescence of HSA through a static quenching procedure. The binding constants between BSP to HSA were remarkable and independent on temperature. The binding constants between HSA and BSP decreased in the presence of various ions, commonly decreased by 30-55%. The hydrophobic force played a major role in the interaction of BSP with HSA. All these experimental results and theoretical data clarified that BSP could bind to HSA and be effectively transported and eliminated in body, which could be a useful guideline for further drug design.

  4. 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

  5. Ruthenium (II) complexes interact with human serum albumin and induce apoptosis of tumor cells.

    PubMed

    Sun, Jing; Huang, Yongchao; Zheng, Chuping; Zhou, Yanhui; Liu, Ying; Liu, Jie

    2015-02-01

    The interaction of ruthenium (II) complex [Ru(bpy)2(mal)](2+) (RBM) and [Ru(phen)2(mal)](2+) (RPM) (bpy = 2, 2-bipyridine, phen = 1,10-phenanthroline, mal = malonyl carboxylate) with human serum albumin (HSA) has been investigated by using fluorescence, UV absorption and circular dichroism (CD) spectroscopy approaches. A strong fluorescence quenching reaction of complexes to HSA was observed and the quenching mechanism was suggested as static quenching according to the Stern-Volmer (S-V) equation. The number of binding sites n and observed binding constant Kb was measured by fluorescence quenching method. The thermodynamic parameters ΔH, ΔS, and ΔG at different temperatures were calculated and the results indicate the binding reaction is mainly entropy-driven and Vander Waals force played a major role in the reaction. The result of CD showed that the secondary structure of HSA molecules was changed in the presence of the ruthenium (II) complexes. Furthermore, the cell viability of ruthenium (II) complexes was evaluated by MTT and complex RPM has shown significant higher anticancer potency than RBM against all the cell lines screened. RPM showed a significant antitumor activity through induction of apoptosis in A549 cells.

  6. Characterization of interaction between esculin and human serum albumin in membrane mimetic environments

    NASA Astrophysics Data System (ADS)

    Zhang, Yaheng; Li, Jiazhong; Dong, Lijun; Li, Ying; Chen, Xingguo

    2008-10-01

    In this study the interaction between esculin and human serum albumin (HSA) in AOT/isooctane/water microemulsions was studied for the first time using fluorescence quenching technique in combination with UV absorption spectroscopy, Fourier transform infrared (FT-IR) spectroscopy, circular dichroism (CD) spectroscopy and dynamic light scattering (DLS) technique. Fluorescence data in ω o 20 microemulsions revealed the presence of the binding site of esculin on HSA and its binding constants at four different temperatures were obtained. The affinities in microemulsions are similar to that in buffer solution. The alterations of protein secondary structure in the microemulsions in the absence and presence of esculin compared with the free form of HSA in buffer were qualitatively and quantitatively analyzed by the evidence from CD and FT-IR spectroscopes. The displacement experiments confirmed that esculin could bind to the site I of HSA, which was in agreement with the result of the molecular modeling study. Furthermore, the DLS data suggested that HSA may locate at the interface of the microemulsion and esculin could interact with them.

  7. Determination on the binding of thiadiazole derivative to human serum albumin: a spectroscopy and computational approach.

    PubMed

    Karthikeyan, Subramani; Bharanidharan, Ganesan; Mani, Karthik Ananth; Srinivasan, Narasimhan; Kesherwani, Manish; Velmurugan, Devadasan; Aruna, Prakasarao; Ganesan, Singaravelu

    2017-03-01

    4-[3-acetyl-5-(acetylamino)-2,3-dihydro-1,3,4-thiadiazole-2-yl]phenyl benzoate from the family of thiadiazole derivative has been newly synthesized. It has good anticancer activity as well as antibacterial and less toxic in nature, its binding characteristics are therefore of huge interest for understanding pharmacokinetic mechanism of the drug. The binding of thiadiazole derivative to human serum albumin (HSA) has been investigated by studying its quenching mechanism, binding kinetics and the molecular distance, r between the donor (HSA) and acceptor (thiadiazole derivative) was estimated according to Forster's theory of non-radiative energy transfer. The Gibbs free energy (ΔG), enthalpy (ΔH) and entropy (ΔS) changes of temperature-dependent Kb was calculated, which explains that the reaction is spontaneous and exothermic. The microenvironment of HSA have also been studied using synchronous fluorescence spectroscopy, and the feature of thiadiazole derivative-induced structural changes of HSA have been carried using Fourier transform infrared spectroscopy and the Molecular modelling simulations explore the hydrophobic and hydrogen bonding interactions.

  8. 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.

  9. [Regularities of formation of chlorophyll-human serum albumin functionally active complexes in the aqueous medium].

    PubMed

    Semichaevskiĭ, V D

    1975-01-01

    In the system with constant content of the chlorophyll a and increasing amounts of human serum albumin, dependence of pigment incorporation into the complex upon interaction of its aqueous associates with protein solutions was studied by applying the gel filtration on Sephadex G-75 and by measuring light scattering and rate of sensitized photoreduction of the methyl red by ascorbic-acid. The curves were obtained after extraction of the chlorophyll by acetone from dry pigment-protein films formed after desiccation of the aqueous systems. Sigmoid character of the above dependences, their linearization in Hill's coordinates and the value of cooperativity coefficient close to 2 testifies in favour of the cooperative character of the complex formation, two pigment molecules reacting with a single protein molecule. Measurement of adsorption isotherms and their treatment with use of the Brunauer-Emmett-Teller theory of polymolecular adsorption make it possible to evaluate the maximum molar ratio of the pigment to the protein in the complex (close to 2). The pigment-pigment interaction suggests that the chlorophyll molecules adsorbed on the protein are in the state of loosely packed dimers. Deaggregation of aqueus pigment associates by the protein in the course of complex formation results in a considerable increase of the protosensitizing chlorophyll activity.

  10. 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.

  11. Ibuprofen and propofol cobinding effect on human serum albumin unfolding in urea.

    PubMed

    Del Giudice, Alessandra; Leggio, Claudia; Balasco, Nicole; Galantini, Luciano; Pavel, Nicolae V

    2014-08-28

    The unfolding pathway of the defatted human serum albumin (HSA) binding ibuprofen and propofol has been studied by using small-angle X-ray scattering (SAXS) and the support of circular dichroism data. A set of HSA solutions with urea concentrations between 0.00 and 9.00 M was analyzed, and the singular value decomposition method applied to the complete SAXS data set allowed us to distinguish four different states in solution. Besides the native and unfolded forms, two intermediates I1 and I2 have been identified, and the low-resolution structures of these states were obtained by exploiting both ab initio and rigid body fitting methods. The I1 structure was characterized by only one open domain (domain I, which does not host a binding site for either of the ligands), whereas I2 presents only one closed domain (domain III). A direct comparison with the unfolding pathway of the HSA:Ibu complex (Galantini et al. Biophys. Chem. 2010, 147, 111-122) pointed out that the presence of propofol as a second ligand, located in subdomain IIIB, leads to the appearance of an intermediate with two closed domains (domains II and III), which are those that accommodate the ligands. Moreover, the equilibrium between I2 and the unfolded form is slightly shifted toward higher urea concentrations. These results suggest that the cobinding significantly hinders the unfolding process.

  12. 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

  13. Noncovalent interactions between a trinuclear monofunctional platinum complex and human serum albumin.

    PubMed

    Wang, Yanqing; Wang, Xiaoyong; Wang, Jing; Zhao, Yongmei; He, Weijiang; Guo, Zijian

    2011-12-19

    Interactions between platinum complexes and human serum albumin (HSA) play crucial roles in the metabolism, distribution, and efficacy of platinum-based anticancer drugs. Polynuclear monofunctional platinum(II) complexes represent a new class of anticancer agents that display distinct molecular characters of pharmacological action from those of cisplatin. In this study, the interaction between a trinuclear monofunctional platinum(II) complex, [Pt(3)LCl(3)](ClO(4))(3) (L = N,N,N',N',N",N"-hexakis(2-pyridylmethyl)-1,3,5-tris(aminomethyl)benzene) (1), and HSA was investigated using ultraviolet-visible spectroscopy, Fourier transform infrared spectroscopy, circular dichroism spectroscopy, fluorescence spectroscopy, molecular docking, and inductively coupled plasma mass spectrometry. The spectroscopic and thermodynamic data show that the interaction is a spontaneous process with the estimated enthalpy and entropy changes being 14.6 kJ mol(-1) and 145.5 J mol(-1) K(-1), respectively. The reactive sites of HSA to complex 1 mainly locate within its hydrophobic cavity in domain II. Noncovalent actions such as π-π stacking and hydrophobic bonding are the primary contributors to the interaction between HSA and complex 1, which is different from the scenario for cisplatin in similar conditions. The results suggest that the connection between complex 1 and HSA is reversible, and therefore the cytotoxic activity of the complex could be preserved during blood circulation.

  14. 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

    2016-01-05

    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.

  15. Immune response to acetaldehyde-human serum albumin adduct among healthy subjects related to alcohol intake.

    PubMed

    Romanazzi, Valeria; Schilirò, Tiziana; Carraro, Elisabetta; Gilli, Giorgio

    2013-09-01

    Acetaldehyde (AA) is the main metabolic product in ethanol metabolism, although it can also derive from sources of airborne pollution. As a typical aldehyde, AA is able to react with a variety of molecular targets, including DNA and protein. This property justifies the hypothesis of a immune reaction against this kind of adduct, to be studied by a seroprevalence screening approach. In this study, the correlation between drinking habits and the amount of circulating AA-human serum albumin adduct (AA-HSA) was evaluated in a group of healthy subjects, non alcohol-addicted. Daily ethanol intake (grams) was inferred for each subject using the information collected through a questionnaire, and AA-HSA antibodies (AA-HSA ab) analyses were performed using the Displacement Assay on whole blood samples. The findings showed a correlation between ethanol intake and immune response to molecular adduct. These results underscore the evaluation of AA-HSA ab amount as a suitable molecular marker for alcohol intake that can be applied in future investigations on a large scale for prevention screening.

  16. Probing the binding of fluoxetine hydrochloride to human serum albumin by multispectroscopic techniques

    NASA Astrophysics Data System (ADS)

    Katrahalli, Umesha; Jaldappagari, Seetharamappa; Kalanur, Shankara S.

    2010-01-01

    The interaction between human serum albumin (HSA) and fluoxetine hydrochloride (FLX) have been studied by using different spectroscopic techniques viz., fluorescence, UV-vis absorption, circular dichroism and FTIR under simulated physiological conditions. Fluorescence results revealed the presence of static type of quenching mechanism in the binding of FLX to HSA. The values of binding constant, K of FLX-HSA were evaluated at 289, 300 and 310 K and were found to be 1.90 × 10 3, 1.68 × 10 3 and 1.45 × 10 3 M -1, respectively. The number of binding sites, n was noticed to be almost equal to unity thereby indicating the presence of a single class of binding site for FLX on HSA. Based on the thermodynamic parameters, Δ H0 and Δ S0 nature of binding forces operating between HSA and FLX were proposed. Spectral results revealed the conformational changes in protein upon interaction. Displacement studies indicated the site I as the main binding site for FLX on HSA. The effect of common ions on the binding of FLX to HSA was also investigated.

  17. Investigation of Interaction Between Ozagrel and Human Serum Albumin by Spectroscopic and Electrochemical Methods

    NASA Astrophysics Data System (ADS)

    Li, S.; Wang, Li; Hao, J.; Wang, L.; Tong, Y.-J.; Fu, Z.-Q.; Zhang, A.-P.

    2017-01-01

    The interaction between ozagrel and human serum albumin (HSA) was investigated by fl uorescence spectroscopy, UV-Vis absorption spectroscopy, cyclic voltammetry (CV), differential pulse voltammetry (DPV), and Fourier transform infrared spectroscopy (FTIR) under simulative physiological conditions. The results of CV, DPV and fl uorescence titration revealed that ozagrel bound to HSA. The enthalpy change (ΔH) and the entropy change (ΔS) were derived to be positive values, indicating that the hydrophobic force played the main role in the binding of ozagrel with HSA. The binding distance between ozagrel and HSA was 1.75 nm. Upon binding with ozagrel, the conformation and the secondary structure of HSA molecules were changed. The percentage of α-helix and β-sheet structures decreased by 7.25% and 4.58%, respectively, while the percentage of a β-turn structure increased by 2.67%. The effect of common ions on the binding of ozagrel with HSA was also examined. This study will give an insight into the evaluation of the drug's stabi-lity during transport and its releasing effi ciency at the target site under simulative physiological conditions.

  18. Anti-coagulant rodenticide binding properties of human serum albumin: a biochromatographic approach.

    PubMed

    André, Claire; Guillaume, Yves Claude

    2004-03-05

    In this paper, the anti-coagulant rodenticide-human serum albumin (HSA) binding was investigated using a perturbation method to calculate the solute distribution isotherms. It was shown that rodenticide can bound either on the benzodiazepine HSA site with low affinity (site I) or on the warfarin HSA site with high affinity (site II). The thermodynamic parameters of this association were calculated for the two HSA binding sites. For the site II, the rodenticide-HSA association was governed enthalpically whereas for the site I, this one was driven entropically. Moreover, the role of the magnesium (Mg(2+)) and calcium (Ca(2+)) on this association was carried out. It was clearly demonstrated that the rodenticide affinity for the site I was not affected by modifying the bulk solvent surface tension whereas for the site II the association constant increased strongly with the Mg(2+) or the Ca(2+) concentration in the bulk solvent. These results showed that the rodenticide-HSA affinity and thus the rodenticide toxicological effect depends on the Mg(2+) or Ca(2+) concentration.

  19. Ethanol or/and captopril-induced precipitation and secondary conformational changes of human serum albumin

    NASA Astrophysics Data System (ADS)

    Lin, Shan-Yang; Li, Mei-Jane; Wei, Yen-Shan

    2004-11-01

    We determined the secondary structure of solid-state native human serum albumin (HSA) and its precipitates induced by ethanol, captopril, or a captopril/ethanol mixture. A transmission Fourier transform infrared (FT-IR) microspectroscopy equipped with a thermal analyzer was used. The secondary structural composition of solid-state native HSA was 54% α-helices (1655 cm -1), 22% β-turns (1679 cm -1), and 23% β-sheets (1633 cm -1). After ethanol treatment, a new peak was observed at 1690 cm -1, and the peak at 1633 cm -1 was more apparent in the HSA precipitates. The corresponding compositions consisted of 59% α-helices, 17% β-turns, and 24% β-sheets. After treatment with captopril with or without ethanol, the percentage of α-helices and β-turns decreased in both HSA precipitates, but the percentage of β-sheets increased. The temperature-dependent structural transformation from α-helices/random coils to β-sheets for the solid-state HSA samples occurred at markedly different onset temperatures. The onset temperature for native HSA was 85 °C, and that for HSA precipitates obtained from ethanol, captopril, or captopril/ethanol was 100, 48 or 57 °C, respectively. The thermal-induced structural transformation from α-helices/random coils to β-sheets implies a partial unfolding structure in these HSA samples.

  20. Mechanistic investigation of domain specific unfolding of human serum albumin and the effect of sucrose.

    PubMed

    Yadav, Rajeev; Sen, Pratik

    2013-11-01

    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.

  1. A spectroscopic study of the wavelength-dependent photoisomerizations of bilirubins bound to human serum albumin

    NASA Astrophysics Data System (ADS)

    Mazzoni, Marina; Agati, Giovanni; Pratesi, Riccardo; Persico, Maurizio

    2005-12-01

    The wavelength-dependent photoisomerizations of the asymmetric bilirubin BR-IXα and of the symmetric bilirubin-IIIα (BR-III) and mesobilirubin-XIIIα (MBR-XIII) bound to human serum albumin (HSA) in aqueous solution were analysed with the help of an exciton coupling model. The modelling was based on the absorption and circular dichroism (CD) spectra (bisignate Cotton effect). Time-dependent density functional theory (TD-DFT) of the free BR-IX molecule suggested the presence of two main bands of exciton coupling character in the blue region of the spectrum, and other weaker bands of charge transfer character at longer wavelengths. These peculiarities were taken into account to fit the photoisomerization quantum yields in the blue-green region as functions of the wavelength, obtaining the bandshape of the exciton coupling bands from the experimental CD spectra. The other excitons were extracted from the decomposition of the band resulting from the difference between the absorption spectrum and the sum (normalized-to-absorption) of the two CD excitons. We expressed photoisomerization quantum yields in terms of the sum of the contributions to photon absorption deriving from all the exciton states normalized to total absorption. For all the reversible photoprocesses of bilirubins and for the irreversible one of BR-IXα in HSA (i.e. lumirubin formation), we give reliable mean values of the individual state excitation probabilities and photoisomerization efficiencies in the pigment protein complex.

  2. Toxic effects of chrysoidine on human serum albumin: isothermal titration calorimetry and spectroscopic investigations.

    PubMed

    Sun, Haoyu; Liu, Yingxue; Li, Meng; Han, Songlin; Yang, Xudan; Liu, Rutao

    2016-03-01

    Chrysoidine is widely used in industry as a type of azo dye, and is sometimes used illegally as a food additive despite its potential toxicity. Human serum albumin (HSA) is one of the most important proteins in blood plasma and possesses major physiological functions. In the present study, the conformational and functional effects of chrysoidine on HSA were investigated by isothermal titration calorimetry (ITC), multiple spectroscopic methods, a molecular docking study and an esterase activity assay. Based on the ITC results, the binding stoichiometry of chrysoidine to HSA was estimated to be 1.5:1, and was a spontaneous process via a single hydrogen bond. The binding of chrysoidine to HSA induced dynamic quenching in fluorescence, and changes in secondary structure and in the microenvironment of the Trp-214 residue. In addition, the hydrogen bond (1.80 Å) formed between the chrysoidine molecule and the Gln-211 residue. The esterase activity of HSA decreased following the addition chrysoidine due to the change in protein structure. This study details the direct interaction between chrysoidine and HSA at the molecular level and the mechanism for toxicity as a result of the functional changes induced by HSA structural variation upon binding to chrysoidine in vitro. This study provides useful information towards detailing the transportation mechanism and toxicity of chrysoidine in vivo.

  3. Spectroscopic and molecular modeling evidence of clozapine binding to human serum albumin at subdomain IIA

    NASA Astrophysics Data System (ADS)

    Wu, Xinhu; Liu, Jianjun; Wang, Qiang; Xue, Weiwei; Yao, Xiaojun; Zhang, Yan; Jin, Jing

    2011-09-01

    Various spectroscopy and molecular docking methods were used to examine the binding of Clozapine (CLZ) to human serum albumin (HSA) in this paper. By monitoring the intrinsic fluorescence of single Trp214 residue and performing Dansylamide (DNSA) displacement measurement, the specific binding of CLZ in the vicinity of Sudlow's Site I of HSA has been clarified. An apparent distance of 27.3 Å between the Trp214 and CLZ was obtained via fluorescence resonance energy transfer (FRET) method. In addition, the changes in the secondary structure of HSA after its complexation with CLZ ligand were studied with CD spectroscopy, which indicate that CLZ does not has remarkable effect on the structure of the protein. Moreover, thermal denaturation experiment shows that the HSA-CLZ complexes are conformationally more stable. Finally, the binding details between CLZ and HSA were further confirmed by molecular docking studies, which revealed that CLZ was bound at subdomain IIA through multiple interactions, such as hydrophobic effect, van der Waals forces and hydrogen bonding.

  4. Spectroscopic and molecular modeling evidence of clozapine binding to human serum albumin at subdomain IIA.

    PubMed

    Wu, Xinhu; Liu, Jianjun; Wang, Qiang; Xue, Weiwei; Yao, Xiaojun; Zhang, Yan; Jin, Jing

    2011-09-01

    Various spectroscopy and molecular docking methods were used to examine the binding of Clozapine (CLZ) to human serum albumin (HSA) in this paper. By monitoring the intrinsic fluorescence of single Trp214 residue and performing Dansylamide (DNSA) displacement measurement, the specific binding of CLZ in the vicinity of Sudlow's Site I of HSA has been clarified. An apparent distance of 27.3 Å between the Trp214 and CLZ was obtained via fluorescence resonance energy transfer (FRET) method. In addition, the changes in the secondary structure of HSA after its complexation with CLZ ligand were studied with CD spectroscopy, which indicate that CLZ does not has remarkable effect on the structure of the protein. Moreover, thermal denaturation experiment shows that the HSA-CLZ complexes are conformationally more stable. Finally, the binding details between CLZ and HSA were further confirmed by molecular docking studies, which revealed that CLZ was bound at subdomain IIA through multiple interactions, such as hydrophobic effect, van der Waals forces and hydrogen bonding.

  5. Characterization of minor site probes for human serum albumin by high-performance affinity chromatography.

    PubMed

    Sengupta, A; Hage, D S

    1999-09-01

    This study used high-performance affinity chromatography (HPAC) and immobilized human serum albumin (HSA) columns to examine the specificity and cross-reactivity of various compounds that have been proposed as markers for the minor binding sites of HSA. These agents included acetyldigitoxin and digitoxin as probes for the digitoxin site, phenol red as a probe for the bilirubin site, and cisor trans-clomiphene as markers for the tamoxifen site. None of these probes showed any significant binding at HSA's indole-benzodiazepine site. However, phenol red did bind at the warfarin-azapropazone site of HSA, and cis/trans-clomiphene gave positive allosteric effects caused by the binding of warfarin to HSA. Digitoxin and acetyldigitoxin were found to bind to a common, unique region on HSA; cis- and trans-clomiphene also appeared to interact at a unique site, although trans-clomiphene displayed additional direct competition with phenol red. From these results it was possible to develop a model that described the general relationship between these binding regions on HSA. This information should be useful in future studies that employ HPAC for characterizing the binding of HSA to other drugs or clinical agents.

  6. 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

  7. An approach to remove albumin for the proteomic analysis of low abundance biomarkers in human serum.

    PubMed

    Ahmed, Nuzhat; Barker, Gillian; Oliva, Karen; Garfin, David; Talmadge, Kenneth; Georgiou, Harry; Quinn, Michael; Rice, Greg

    2003-10-01

    Proteomic technologies are being used to discover and identify disease-associated biomarkers. The application of these technologies in the search for potential diagnostic/prognostic biomarkers in the serum of patients has been limited by the presence of highly abundant albumin and immunoglobulins that constitute approximately 60-97% of the total serum proteins. The purpose of the study was to evaluate whether treatment of human serum with Affi-Gel Blue alone or in combination with Protein A (Aurum serum protein mini kit, Bio-Rad) before two-dimensional gel electrophoresis (2-DE) analysis removed high abundance proteins to allow the visualization of low abundant proteins. Serum samples were treated with either Affi-Gel Blue or Aurum kit and then subjected to 2-DE using 11 cm, pH 4-7 isoelectric focussing strips for the first dimension and 10% sodium dodecyl sulfate-polyacrylamide gel electrophoresis for second dimension. Protein spots were visualized using a fluorescent protein dye (SYPRO Ruby, Bio-Rad). Comparison between treatment methods showed significant removal of albumin by both Affi-Gel Blue and Aurum kit and considerable differences in the protein profile of the gels after each treatment. Direct comparison between treatments revealed twenty-eight protein spots unique to Affi-Gel Blue while only two spots were unique after Aurum kit treatment. Unique spots in Affi-Gel Blue and Aurum kit treated serum were not visualized in untreated serum. Sixteen hours of Affi-Gel Blue treatment resulted in enhanced visualization of fifty-three protein spots by two-fold, thirty-one by five-fold, twelve by ten-fold and six by twenty-fold. In parallel after Aurum kit treatment two-, five-, ten- and twenty-fold enhancements of thirty, thirteen, eight and five protein spots, respectively, were observed. The pattern of increased visualization of protein spots with both treatment methods was similar. In conclusion, treatment of serum samples with Affi-Gel Blue or Aurum kit before

  8. Adsorption of human fibrinogen and albumin onto hydrophobic and hydrophilic Ti6Al4V powder

    NASA Astrophysics Data System (ADS)

    Rodríguez-Sánchez, Jesús; Gallardo-Moreno, Amparo M.; Bruque, José M.; González-Martín, M. Luisa

    2016-07-01

    Adsorption of proteins on solid surfaces has been widely studied because of its importance in various biotechnological, medical and technical applications, such as medical implants or biosensors. One of the main problems is the adsorption-induced conformational changes because they often modify the biological activity of the proteins, which is believed to be a key factor on the subsequent cellular adhesion. The aim of this work is the study of the adsorption of human fibrinogen (Fg) and human serum albumin (HSA) onto Ti6Al4V particles, commercially available on different size, that are used to elaborate scaffolds to provide structural support to cell proliferation, promoting tissue development and bone regeneration among others. The study was done through the analysis of the adsorption isotherms and the electrical characterization of surfaces after adsorption in terms of the zeta potential (ζ). From this analysis it seems that Fg adsorbs preferentially vertically oriented (end-on) and HSA moves sequentially over the surface of the Ti6Al4V particles through dimmer formation, allowing adsorption progress over this initial bilayer. The zeta potential values of both proteins remain constant when the monolayer is formed. The study also extends the analysis of both adsorption behaviour and ζ potential characterization factors to the influence of the substrate hydrophobicity as this property can be modified for the Ti6Al4V by irradiating it with ultraviolet light (UV-C) without changes on its chemical composition [1,2]. Differences at low protein concentrations were found for both isotherms and zeta-potential values.

  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. 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.

  11. Human Serum Albumin Nanoparticles for Use in Cancer Drug Delivery: Process Optimization and In Vitro Characterization

    PubMed Central

    Lomis, Nikita; Westfall, Susan; Farahdel, Leila; Malhotra, Meenakshi; Shum-Tim, Dominique; Prakash, Satya

    2016-01-01

    Human serum albumin nanoparticles (HSA-NPs) are widely-used drug delivery systems with applications in various diseases, like cancer. For intravenous administration of HSA-NPs, the particle size, surface charge, drug loading and in vitro release kinetics are important parameters for consideration. This study focuses on the development of stable HSA-NPs containing the anti-cancer drug paclitaxel (PTX) via the emulsion-solvent evaporation method using a high-pressure homogenizer. The key parameters for the preparation of PTX-HSA-NPs are: the starting concentrations of HSA, PTX and the organic solvent, including the homogenization pressure and its number cycles, were optimized. Results indicate a size of 143.4 ± 0.7 nm and 170.2 ± 1.4 nm with a surface charge of −5.6 ± 0.8 mV and −17.4 ± 0.5 mV for HSA-NPs and PTX-HSA-NPs (0.5 mg/mL of PTX), respectively. The yield of the PTX-HSA-NPs was ~93% with an encapsulation efficiency of ~82%. To investigate the safety and effectiveness of the PTX-HSA-NPs, an in vitro drug release and cytotoxicity assay was performed on human breast cancer cell line (MCF-7). The PTX-HSA-NPs showed dose-dependent toxicity on cells of 52%, 39.3% and 22.6% with increasing concentrations of PTX at 8, 20.2 and 31.4 μg/mL, respectively. In summary, all parameters involved in HSA-NPs’ preparation, its anticancer efficacy and scale-up are outlined in this research article. PMID:28335244

  12. 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.

  13. Broadband measurements of the frequency dependence of attenuation coefficient and velocity in amniotic fluid, urine and human serum albumin solutions.

    PubMed

    Verma, Prashant K; Humphrey, Victor F; Duck, Francis A

    2005-10-01

    The frequency dependence of attenuation coefficient in amniotic fluid, urine and 4.5% and 20% human serum albumin solutions over the frequency range 5 MHz to 25 MHz was measured at both room temperature and physiological temperature using a variable path length technique. A 15 MHz (13 mm diameter) transducer was used to produce a broadband single-cycle pulse and a 4 mm diameter bilaminar polyvinylidene difluoride membrane hydrophone was used to detect the attenuated pulse. Standard time-of-flight measurement techniques were used to measure the acoustic velocity in the same fluid samples. At physiological temperature, the attenuation coefficients in amniotic fluid, urine and 4.5% and 20% human albumin solution were found to be 0.0053 f(1.65), 0.0047 f(1.67), 0.019 f(1.57) and 0.167 f(1.27) dB cm(-1), respectively, where f is in MHz. The velocities in amniotic fluid, urine and 4.5% human albumin solution at physiological temperature were found to be 1541.1 m s(-1) +/- 1.3 m s(-1), 1551.3 m s(-1) +/- 1.3 ms(-1) and 1547.3 m s(-1) +/- 1.0 m s(-1), respectively. The results provide unique data over the diagnostic and therapeutic ultrasonic frequency range that can be used as input data for theoretical models that attempt to simulate nonlinear pressure fields and temperature rises from medical ultrasonic transducers.

  14. 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

  15. Preparation and immunogenicity of tag-free recombinant human eppin

    PubMed Central

    Zhang, Jie; Ding, Xin-Liang; Bian, Zeng-Hui; Xia, Yan-Kai; Wang, Shou-Lin; Song, Ling; Wang, Xin-Ru

    2011-01-01

    Human epididymal protease inhibitor (eppin) may be effective as a male contraceptive vaccine. In a number of studies, eppin with an engineered His6-tag has been produced using prokaryotic expression systems. For production of pharmaceutical-grade proteins for human use, however, the His6-tag must be removed. This study describes a method for producing recombinant human eppin without a His6-tag. We constructed plasmid pET28a (+)-His6-tobacco etch virus (TEV)-eppin for expression in Escherichia coli. After purification and refolding, the fusion protein His6-TEV-eppin was digested with TEV protease to remove the His6-tag and was further purified by NTA-Ni2+ affinity chromatography. Using this procedure, 2 mg of eppin without a His6-tag was isolated from 1 l of culture with a purity of >95%. The immunogenicity of the eppin was characterized using male Balb/c mice. PMID:21892195

  16. [Human serum albumin modified under oxidative/halogenative stress enhances luminol-dependent chemiluminescence of human neutrophils].

    PubMed

    Mikhal'chik, E V; Smolina, N V; Astamirova, T C; Gorudko, I V; Grigor'eva, D V; Ivanov, V A; Sokolov, A V; Kostevich, V A; Cherenkevich, S N; Panasenko, O M

    2013-01-01

    It is shown that human serum albumin, previously treated with HOCl (HSA-Cl), enhances luminol-dependent chemiluminescence of neutrophils activated by phorbol-12-myristate-13-acetate (PMA). The enzyme-linked immunosorbent assay revealed that addition of HSA-Cl to neutrophils promotes exocytosis of myeloperoxidase. Inhibitor of myeloperoxidase--4-aminobenzoic acid hydrazide, without any effect on lucigenin-dependent chemiluminescence of neutrophils stimulated with PMA, effectively suppressed luminol-dependent chemiluminescence (IC50 = 20 microM) under the same conditions. The transfer of the cells from medium with HSA-Cl and myeloperoxidase to fresh medium abolished an increase in PMA-induced luminol-dependent chemiluminescence, but not the ability of neutrophils to respond to re-addition of HSA-Cl. A direct and significant (r = 0.75, p) correlation was observed between the intensity of PMA stimulated neutrophil chemiluminescence response and myeloperoxidase activity in the cell-free media after chemiluminescence measurements. These results suggest the involvement of myeloperoxidase in the increase of neutrophil PMA-stimulated chemiluminescence response in the presence of HSA-Cl. A significant positive correlation was found between myeloperoxidase activity in blood plasma of children with severe burns and the enhancing effects of albumin fraction of the same plasma on luminol-dependent chemiluminescence of PMA-stimulated donor neutrophils. These results support a hypothesis that proteins modified in reactions involving myeloperoxidase under oxidative/halogenative stress, stimulate neutrophils, leading to exocytosis of myeloperoxidase, a key element of halogenative stress, and to closing a "vicious circle" of neutrophil activation at the inflammatory site.

  17. Polyethylene glycol enhanced refolding of the recombinant human tissue transglutaminase.

    PubMed

    Ambrus, A; Fésüs, L

    2001-02-01

    Tissue transglutaminase forms cross-links between lysine and glutamine side-chains of polypeptide chains in a Ca2+-dependent reaction; its structural basis is still not clarified. In this study, we demonstrate that the refolding of the human recombinant enzyme molecule to its catalytically active form from inclusion bodies needs the presence of a helper material with higher molecular mass, but only in the initiation phase. Ca2+ and nucleotides are ascribed as affector molecules also in the early phase of structural reconstitution. Two optimal concentrations of polyethylene glycol and a relatively long time scale for the evolution of the final structure were identified. The optimized refolding procedure is reported.

  18. Long-acting recombinant coagulation factor IX albumin fusion protein (rIX-FP) in hemophilia B: results of a phase 3 trial.

    PubMed

    Santagostino, Elena; Martinowitz, Uri; Lissitchkov, Toshko; Pan-Petesch, Brigitte; Hanabusa, Hideji; Oldenburg, Johannes; Boggio, Lisa; Negrier, Claude; Pabinger, Ingrid; von Depka Prondzinski, Mario; Altisent, Carmen; Castaman, Giancarlo; Yamamoto, Koji; Álvarez-Roman, Maria-Teresa; Voigt, Christine; Blackman, Nicole; Jacobs, Iris

    2016-04-07

    A global phase 3 study evaluated the pharmacokinetics, efficacy, and safety of recombinant fusion protein linking coagulation factor IX with albumin (rIX-FP) in 63 previously treated male patients (12-61 years) with severe hemophilia B (factor IX [FIX] activity ≤2%). The study included 2 groups: group 1 patients received routine prophylaxis once every 7 days for 26 weeks, followed by either 7-, 10-, or 14-day prophylaxis regimen for a mean of 50, 38, or 51 weeks, respectively; group 2 patients received on-demand treatment of bleeding episodes for 26 weeks and then switched to a 7-day prophylaxis regimen for a mean of 45 weeks. The mean terminal half-life of rIX-FP was 102 hours, 4.3-fold longer than previous FIX treatment. Patients maintained a mean trough of 20 and 12 IU/dL FIX activity on prophylaxis with rIX-FP 40 IU/kg weekly and 75 IU/kg every 2 weeks, respectively. There was 100% reduction in median annualized spontaneous bleeding rate (AsBR) and 100% resolution of target joints when subjects switched from on-demand to prophylaxis treatment with rIX-FP (P< .0001). The median AsBR was 0.00 for all prophylaxis regimens. Overall, 98.6% of bleeding episodes were treated successfully, including 93.6% that were treated with a single injection. No patient developed an inhibitor, and no safety concerns were identified. These results indicate rIX-FP is safe and effective for preventing and treating bleeding episodes in patients with hemophilia B at dosing regimens of 40 IU/kg weekly and 75 IU/kg every 2 weeks. This trial was registered at www.clinicaltrials.gov as #NCT0101496274.

  19. Long-acting recombinant coagulation factor IX albumin fusion protein (rIX-FP) in hemophilia B: results of a phase 3 trial

    PubMed Central

    Martinowitz, Uri; Lissitchkov, Toshko; Pan-Petesch, Brigitte; Hanabusa, Hideji; Oldenburg, Johannes; Boggio, Lisa; Negrier, Claude; Pabinger, Ingrid; von Depka Prondzinski, Mario; Altisent, Carmen; Castaman, Giancarlo; Yamamoto, Koji; Álvarez-Roman, Maria-Teresa; Voigt, Christine; Blackman, Nicole; Jacobs, Iris

    2016-01-01

    A global phase 3 study evaluated the pharmacokinetics, efficacy, and safety of recombinant fusion protein linking coagulation factor IX with albumin (rIX-FP) in 63 previously treated male patients (12-61 years) with severe hemophilia B (factor IX [FIX] activity ≤2%). The study included 2 groups: group 1 patients received routine prophylaxis once every 7 days for 26 weeks, followed by either 7-, 10-, or 14-day prophylaxis regimen for a mean of 50, 38, or 51 weeks, respectively; group 2 patients received on-demand treatment of bleeding episodes for 26 weeks and then switched to a 7-day prophylaxis regimen for a mean of 45 weeks. The mean terminal half-life of rIX-FP was 102 hours, 4.3-fold longer than previous FIX treatment. Patients maintained a mean trough of 20 and 12 IU/dL FIX activity on prophylaxis with rIX-FP 40 IU/kg weekly and 75 IU/kg every 2 weeks, respectively. There was 100% reduction in median annualized spontaneous bleeding rate (AsBR) and 100% resolution of target joints when subjects switched from on-demand to prophylaxis treatment with rIX-FP (P < .0001). The median AsBR was 0.00 for all prophylaxis regimens. Overall, 98.6% of bleeding episodes were treated successfully, including 93.6% that were treated with a single injection. No patient developed an inhibitor, and no safety concerns were identified. These results indicate rIX-FP is safe and effective for preventing and treating bleeding episodes in patients with hemophilia B at dosing regimens of 40 IU/kg weekly and 75 IU/kg every 2 weeks. This trial was registered at www.clinicaltrials.gov as #NCT0101496274. PMID:26755710

  20. Granulomatous interstitial pneumonia in a miniature swine associated with repeated intravenous injections of Tc-99m human serum albumin: concise communication

    SciTech Connect

    Whinnery, J.E.; Young, J.T.

    1980-03-01

    Albumin lung-scanning agents have a proven high degree of safety, with the only contraindication to their use being allergic hypersensitivity. We have used these agents to investigate the physiologic effects of high G/sub z/ acceleratory forces on pulmonary perfusion using the miniature swine. Multiple doses of human macroaggregated albumin and human-albumin microspheres were given to a miniature swine at various levels of centrifugal acceleration over a 6-wk period. The dosages given were the same per kilogram as those used for routine clinical human studies. The animal subsequently died from a severe granulomatous interstitial pneumonia. The granulomatous lesions suggest that the pathogenesis may have involved a cell-mediated delayed hypersensitivity. This interstitial pneumonia may represent the end point in a chronic hypersensitivity response to the human-albumin lung-scanning agents.

  1. Enhanced Proteolytic Processing of Recombinant Human Coagulation Factor VIII B-Domain Variants by Recombinant Furins.

    PubMed

    Demasi, Marcos A; de S Molina, Erika; Bowman-Colin, Christian; Lojudice, Fernando H; Muras, Angelita; Sogayar, Mari C

    2016-06-01

    Recombinant human factor VIII (rFVIII) is used in replacement therapy for hemophilia A. Current research efforts are focused on bioengineering rFVIII molecules to improve its secretion efficiency and stability, limiting factors for its efficient production. However, high expression yield in mammalian cells of these rFVIII variants is generally associated with limited proteolytic processing. Non-processed single-chain polypeptides constitute non-natural FVIII molecule configurations with unpredictable toxicity and/or antigenicity. Our main objective was to demonstrate the feasibility of promoting full-proteolytic processing of an rFVIII variant retaining a portion of the B-domain, converting it into the smallest natural activatable form of rFVIII, while keeping its main advantage, i.e., improved secretion efficiency. We generated and employed a CHO-DG44 cell clone producing an rFVIII variant retaining a portion of the B-domain and the FVIII native cleavage site between Arg(1648) and Glu(1649). By bioengineering CHO-DG44 cells to express stably the recombinant human endoproteases PACE, PACE-SOL, PCSK5, PCSK6, or PCKS7, we were able to achieve complete intra- or extracellular proteolytic processing of this rFVIII variant. Additionally, our quantitative data indicated that removal of the B-domain segment by intracellular proteolytic processing does not interfere with this rFVIII variant secretion efficiency. This work also provides the first direct evidence of (1) intracellular cleavage at the Arg(1648) FVIII processing site promoted by wild-type PACE and PCSK7 and (2) proteolytic processing at the Arg(1648) FVIII processing site by PCSK6.

  2. 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.

  3. Environment sensitive fluorescent analogue of biologically active oxazoles differentially recognizes human serum albumin and bovine serum albumin: Photophysical and molecular modeling studies.

    PubMed

    Maiti, Jyotirmay; Biswas, Suman; Chaudhuri, Ankur; Chakraborty, Sandipan; Chakraborty, Sibani; Das, Ranjan

    2017-03-15

    An environment sensitive fluorophore, 4-(5-(4-(dimethylamino)phenyl)oxazol-2-yl)benzoic acid (DMOBA), that closely mimics biologically active 2,5-disubstituited oxazoles has been designed to probe two homologous serum proteins, human serum albumin (HSA) and bovine serum albumin (BSA) by means of photophysical and molecular modeling studies. This fluorescent analogue exhibits solvent polarity sensitive fluorescence due to an intramolecular charge transfer in the excited state. In comparison to water, the steady state emission spectra of DMOBA in BSA is characterized by a greater blue shift (~10nm) and smaller Stokes' shift (~5980cm(-1)) in BSA than HSA (Stokes'shift~6600cm(-1)), indicating less polar and more hydrophobic environment of the dye in the former than the latter. The dye-protein binding interactions are remarkably stronger for BSA than HSA which is evident from higher value of the association constant for the DMOBA-BSA complex (Ka~5.2×10(6)M(-1)) than the DMOBA-HSA complex (Ka~1.0×10(6)M(-1)). Fӧrster resonance energy transfer studies revealed remarkably less efficient energy transfer (8%) between the donor tryptophans in BSA and the acceptor DMOBA dye than that (30%) between the single tryptophan moiety in HSA and the dye, which is consistent with a much larger distance between the donor (tryptophan)-acceptor (dye) pair in BSA (34.5Å) than HSA (25.4Å). Site specific competitive binding assays have confirmed on the location of the dye in Sudlow's site II of BSA and in Sudlow's site I of HSA, respectively. Molecular modeling studies have shown that the fluorescent analogue is tightly packed in the binding site of BSA due to strong steric complementarity, where, binding of DMOBA to BSA is primarily dictated by the van der Waals and hydrogen bonding interactions. In contrast, in HSA the steric complementarity is less significant and binding is primarily guided by polar interactions and van der Waals interactions appear to be less significant in the

  4. Environment sensitive fluorescent analogue of biologically active oxazoles differentially recognizes human serum albumin and bovine serum albumin: Photophysical and molecular modeling studies

    NASA Astrophysics Data System (ADS)

    Maiti, Jyotirmay; Biswas, Suman; Chaudhuri, Ankur; Chakraborty, Sandipan; Chakraborty, Sibani; Das, Ranjan

    2017-03-01

    An environment sensitive fluorophore, 4-(5-(4-(dimethylamino)phenyl)oxazol-2-yl)benzoic acid (DMOBA), that closely mimics biologically active 2,5-disubstituited oxazoles has been designed to probe two homologous serum proteins, human serum albumin (HSA) and bovine serum albumin (BSA) by means of photophysical and molecular modeling studies. This fluorescent analogue exhibits solvent polarity sensitive fluorescence due to an intramolecular charge transfer in the excited state. In comparison to water, the steady state emission spectra of DMOBA in BSA is characterized by a greater blue shift ( 10 nm) and smaller Stokes' shift ( 5980 cm- 1) in BSA than HSA (Stokes'shift 6600 cm- 1), indicating less polar and more hydrophobic environment of the dye in the former than the latter. The dye-protein binding interactions are remarkably stronger for BSA than HSA which is evident from higher value of the association constant for the DMOBA-BSA complex (Ka 5.2 × 106 M- 1) than the DMOBA-HSA complex (Ka 1.0 × 106 M- 1). Fӧrster resonance energy transfer studies revealed remarkably less efficient energy transfer (8%) between the donor tryptophans in BSA and the acceptor DMOBA dye than that (30%) between the single tryptophan moiety in HSA and the dye, which is consistent with a much larger distance between the donor (tryptophan)-acceptor (dye) pair in BSA (34.5 Å) than HSA (25.4 Å). Site specific competitive binding assays have confirmed on the location of the dye in Sudlow's site II of BSA and in Sudlow's site I of HSA, respectively. Molecular modeling studies have shown that the fluorescent analogue is tightly packed in the binding site of BSA due to strong steric complementarity, where, binding of DMOBA to BSA is primarily dictated by the van der Waals and hydrogen bonding interactions. In contrast, in HSA the steric complementarity is less significant and binding is primarily guided by polar interactions and van der Waals interactions appear to be less significant in the

  5. Gold Nanorod Mediated Mild Hyperthermia and PEGylated Human Serum Albumin Drug Delivery for Cancer Therapies

    NASA Astrophysics Data System (ADS)

    Mehtala, Jonathan G.

    Photothermally active gold nanorods were used to sensitize cells to chemotherapeutic agents by producing mildly hyperthermic effects (42-43 °C). We examined the synergistic effects of GNR-mediated mild hyperthermia (MHT) on cisplatin (CP) activity against SKOV3 ovarian cancer cells. In vitro studies were performed using CP at cytostatic concentrations (5 μM) and mPEG-stabilized GNRs (lambdamax 815 nm) with near-infrared laser excitation for MHT (or external heating as a positive control), followed by 72 hours incubation at 37 °C. The amount of PEG-GNRs needed for GNR-mediated MHT was determined to be 1 μg/mL, several times lower than the loadings used in tumor tissue ablation. A cell viability assay indicated 80% enhancement in CP-mediated cytotoxicity 3 days after GNR-mediated MHT relative to the projected additive effect. A pilot in vivo study showed preliminary results that cisplatin chemotherapy can be developed in combination with low loadings of GNR-mediated MHT for localized MHT to treat tumors. Stable aqueous dispersions of citrate-stabilized gold nanorods were prepared in scalable fashion by surfactant exchange from cetyltrimethylammonium bromide (CTAB)-stabilized GNRs, using sodium polystyrenesulfonate (PSS) as a detergent. Nanoparticle tracking analysis (NTA) was used to measure the size of the Cit-GNR dispersions, which provides particle sizing resolution several times better than that of dynamic light scattering (DLS). Cit-GNRs were further functionalized with human serum albumin (HSA) and thiols and dithiocarbamates (DTCs) of varying molecular weights. The quality of the Cit-GNR dispersions allows us to address fundamental questions relating GNR stabilization to surface adsorption, including insights into the formation of the protein corona in serum-containing media. Mono-PEGylated human serum albumin was synthesized to investigate its ability to improve the bioavailability of the ability of paclitaxel (PTX), a poorly soluble drug. Matrix assisted

  6. Binding of methacycline to human serum albumin at subdomain IIA using multispectroscopic and molecular modeling methods.

    PubMed

    Dong, Chengyu; Lu, Ningning; Liu, Ying

    2013-01-01

    This study was designed to examine the interaction of methacyline (METC) with human serum albumin (HSA) by multispectroscopy and a molecular modeling method under simulative physiological conditions. The quenching mechanism was suggested to be static quenching based on fluorescence and ultraviolet-visible (UV-Vis) spectroscopy. According to the Vant' Hoff equation, the values of enthalpy (∆H) and entropy change (∆S) were calculated to be -95.29 kJ/mol and -218.13 J/mol/K, indicating that the main driving force of the interaction between HSA and METC were hydrogen bonds and van der Waals's forces. By performing displacement measurements, the specific binding of METC in the vicinity of Sudlow's site I of HSA was clarified. An apparent distance of 3.05 nm between Trp214 and METC was obtained via the fluorescence resonance energy transfer (FRET) method. Furthermore, the binding details between METC and HSA were further confirmed by molecular docking studies, which revealed that METC was bound at subdomain IIA through multiple interactions, such as hydrophobic effect, polar forces, hydrogen bonding, etc. The results of three-dimensional fluorescence and Fourier transform infrared (FTIR) spectroscopy showed that METC caused conformational and some microenvironmental changes in HSA and reduced the α-helix significantly in the range of 52.3-40.4% in HSA secondary structure. Moreover, the coexistence of metal ions such as Ca(2+), Al(3+), Fe(3+), Zn(2+), Cu(2+), Cr(3+) and Cd(2+) can decrease the binding constants of METC-HSA.

  7. Spectroscopic analysis and molecular modeling on the interaction of jatrorrhizine with human serum albumin (HSA)

    NASA Astrophysics Data System (ADS)

    Li, Junfen; Li, Jinzeng; Jiao, Yong; Dong, Chuan

    2014-01-01

    In this work, the interaction of jatrorrhizine with human serum albumin (HSA) was studied by means of UV-vis and fluorescence spectra. The intrinsic fluorescence of HSA was quenched by jatrorrhizine, which was rationalized in terms of the static quenching mechanism. The results show that jatrorrhizine can obviously bind to HSA molecules. According to fluorescence quenching calculations, the bimolecular quenching constant (kq), apparent quenching constant (KSV) at different temperatures were obtained. The binding constants K are 4059 L mol-1 and 1438 L mol-1 at 299 K and 304 K respectively, and the number of binding sites n is almost 1. The thermodynamic parameters determined by the Van't Hoff analysis of the binding constants (ΔH -12.25 kJ mol-1 and ΔS 28.17 J mol-1 K-1) clearly indicate that the electrostatic force plays a major role in the process. The efficiency of energy transfer and the distance between the donor (HSA) and the acceptor (jatrorrhizine) were calculated as 22.2% and 3.19 nm according to Föster's non-radiative energy transfer theory. In addition, synchronous fluorescence spectroscopy reveals that jatrorrhizine can influence HSA's microstructure. That is, jatrorrhizine is more vicinal to tryptophane (Trp) residue than to tyrosine (Tyr) residue and the damage site is also mainly at Trp residue. Molecular modeling result shows that jatrorrhizine-HSA complex formed not only on the basis of electrostatic forces, but also on the basis of π-π staking and hydrogen bond. The research results will offer a reference for the studies on the biological effects and action mechanism of small molecule with protein.

  8. Elucidation of the binding mechanism of coumarin derivatives with human serum albumin.

    PubMed

    Garg, Archit; Manidhar, Darla Mark; Gokara, Mahesh; Malleda, Chandramouli; Suresh Reddy, Cirandur; Subramanyam, Rajagopal

    2013-01-01

    Coumarin is a benzopyrone which is widely used as an anti-coagulant, anti-oxidant, anti-cancer and also to cure arthritis, herpes, asthma and inflammation. Here, we studied the binding of synthesized coumarin derivatives with human serum albumin (HSA) at physiological pH 7.2 by using fluorescence spectroscopy, circular dichroism spectroscopy, molecular docking and molecular dynamics simulation studies. By addition of coumarin derivatives to HSA the maximum fluorescence intensity was reduced due to quenching of intrinsic fluorescence upon binding of coumarin derivatives to HSA. The binding constant and free energy were found to be 1.957±0.01×10(5) M(-1), -7.175 Kcal M(-1) for coumarin derivative (CD) enamide; 0.837±0.01×10(5) M(-1), -6.685 Kcal M(-1) for coumarin derivative (CD) enoate, and 0.606±0.01×10(5) M(-1), -6.49 Kcal M(-1) for coumarin derivative methylprop (CDM) enamide. The CD spectroscopy showed that the protein secondary structure was partially unfolded upon binding of coumarin derivatives. Further, the molecular docking studies showed that coumarin derivatives were binding to HSA at sub-domain IB with the hydrophobic interactions and also with hydrogen bond interactions. Additionally, the molecular dynamics simulations studies contributed in understanding the stability of protein-drug complex system in the aqueous solution and the conformational changes in HSA upon binding of coumarin derivatives. This study will provide insights into designing of the new inspired coumarin derivatives as therapeutic agents against many life threatening diseases.

  9. 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.

  10. Excited triplet state photophysics of the sulphonated aluminium phthalocyanines bound to human serum albumin.

    PubMed

    Foley, M S; Beeby, A; Parker, A W; Bishop, S M; Phillips, D

    1997-03-01

    The binding of the sulphonated aluminum phthalocyanines to human serum albumin (HSA) in aqueous phosphate buffer solution at 25 degrees C has been studied by measuring the properties of the triplet excited states of these dyes. The triplet lifetimes were measured by triplet-triplet absorption flash photolysis. The triplet lifetime of the disulphonated AlS2Pc (2.5 microM) varies from 500 +/- 30 microseconds in the absence of protein to 1.100 microseconds and longer with HSA concentrations above 100 microM. Under identical conditions, the maximum triplet lifetimes of the mono-, tri- and tetrasulphonated compounds bound to HSA are shorter than those for the disulphonated species. The increase in the triplet state lifetimes is attributed to the ability of the bulk aqueous phase to interact with the sensitizer at the site of binding; the site of binding being dependent on the degree of sulphonation. For AlS2Pc and AlS3Pc at all HSA concentrations, and regardless of the degree of sulphonation, all the triplet state decay profiles follow simple pseudo-first-order kinetics. The exponential decay of the triplet phthalocyanine at all HSA concentrations is ascribed to the rapid association and dissociation of the phthalocyanine-HSA complex on the time-scales of the triplet state lifetimes. A simplified one-step binding model is utilized to describe the results. The association of AlS1Pc with HSA results in substantial quenching of the triplet state quantum yield, and a more complex model is required to analyze the results. The tetrasulphonated compound (AlS4Pc) binds to the protein at a site where it experiences some protection from the aqueous phase.

  11. Interaction between phillygenin and human serum albumin based on spectroscopic and molecular docking

    NASA Astrophysics Data System (ADS)

    Song, W.; Ao, M. Z.; Shi, Y.; Yuan, L. F.; Yuan, X. X.; Yu, L. J.

    2012-01-01

    In this paper, the interaction of human serum albumin (HSA) with phillygenin was investigated by fluorescence, circular dichroism (CD), UV-vis spectroscopic and molecular docking methods under physiological conditions. The Stern-Volmer analysis indicated that the fluorescence quenching of HSA by phillygenin resulted from static mechanism, and the binding constants were 1.71 × 10 5, 1.61 × 10 5 and 1.47 × 10 4 at 300, 305 and 310 K, respectively. The results of UV-vis spectra show that the secondary structure of the protein has been changed in the presence of phillygenin. The CD spectra showed that HSA conformation was altered by phillygenin with a major reduction of α-helix and an increase in β-sheet and random coil structures, indicating a partial protein unfolding. The distance between donor (HSA) and acceptor (phillygenin) was calculated to be 3.52 nm and the results of synchronous fluorescence spectra showed that binding of phillygenin to HSA can induce conformational changes in HSA. Molecular docking experiments found that phillygenin binds with HSA at IIIA domain of hydrophobic pocket with hydrogen bond interactions. The ionic bonds were formed with the O (4), O (5) and O (6) of phillygenin with nitrogen of ASN109, ARG186 and LEU115, respectively. The hydrogen bonds are formed between O (2) of phillygenin and SER419. In the presence of copper (II), iron (III) and alcohol, the apparent association constant KA and the number of binding sites of phillygenin on HSA were both decreased in the range of 88.84-91.97% and 16.09-18.85%, respectively. In view of the evidence presented, it is expected to enrich our knowledge of the interaction dynamics of phillygenin to the important plasma protein HSA, and it is also expected to provide important information of designs of new inspired drugs.

  12. Elucidation of the Binding Mechanism of Coumarin Derivatives with Human Serum Albumin

    PubMed Central

    Gokara, Mahesh; Malleda, Chandramouli; Suresh Reddy, Cirandur; Subramanyam, Rajagopal

    2013-01-01

    Coumarin is a benzopyrone which is widely used as an anti-coagulant, anti-oxidant, anti-cancer and also to cure arthritis, herpes, asthma and inflammation. Here, we studied the binding of synthesized coumarin derivatives with human serum albumin (HSA) at physiological pH 7.2 by using fluorescence spectroscopy, circular dichroism spectroscopy, molecular docking and molecular dynamics simulation studies. By addition of coumarin derivatives to HSA the maximum fluorescence intensity was reduced due to quenching of intrinsic fluorescence upon binding of coumarin derivatives to HSA. The binding constant and free energy were found to be 1.957±0.01×105 M−1, −7.175 Kcal M−1 for coumarin derivative (CD) enamide; 0.837±0.01×105 M−1, −6.685 Kcal M−1 for coumarin derivative (CD) enoate, and 0.606±0.01×105 M−1, −6.49 Kcal M−1 for coumarin derivative methylprop (CDM) enamide. The CD spectroscopy showed that the protein secondary structure was partially unfolded upon binding of coumarin derivatives. Further, the molecular docking studies showed that coumarin derivatives were binding to HSA at sub-domain IB with the hydrophobic interactions and also with hydrogen bond interactions. Additionally, the molecular dynamics simulations studies contributed in understanding the stability of protein-drug complex system in the aqueous solution and the conformational changes in HSA upon binding of coumarin derivatives. This study will provide insights into designing of the new inspired coumarin derivatives as therapeutic agents against many life threatening diseases. PMID:23724004

  13. Improving the reliability of human serum albumin-thiol group determination.

    PubMed

    Jovanović, Vesna B; Penezić-Romanjuk, Ana Z; Pavićević, Ivan D; Aćimović, Jelena M; Mandić, Ljuba M

    2013-08-01

    The thiol (Cys34) content of human serum albumin (HSA-SH) decreases during oxidative and carbonyl stress and, therefore, could represent a useful parameter in clinical practice. Nevertheless, the reliability of HSA-thiol determination with Ellman's method depends on the purity of isolated HSA. Determination of total serum thiols (mmol/L) and HSA-SH content (mmol -SH/mmol HSA) after HSA isolation from diabetic patient and control sera by a two-step precipitation with ammonium sulfate (AS), as well as HSA-SH contribution (%) to total serum thiols, was assessed. Purity and yield of isolated HSA were monitored spectrophotometrically and by native polyacrylamide gel electrophoresis. Precipitation of HSA from serum via a two-step method with AS produced HSA with 91.9±3.6% purity and 69.7±4.4% yield, allowing for precise (relative standard deviation of 3.2%) and reliable (comparing with total serum thiols) measurement of HSA-SH content with DTNB [5,5'-dithiobis-(2-nitrobenzoic acid)]. The content of the HSA-SH group in patients with type 2 diabetes was significantly (P<0.05) lower compared with that of the healthy cohort (0.483±0.067 vs. 0.561±0.054 mmol -SH/mmol HSA). Because the proposed method of HSA isolation is simple, time-efficient, and technically less demanding, and it also enables reliable determination of HSA-SH content, it is suitable for clinical practice.

  14. 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.

  15. (19)F NMR spectroscopic characterization of the interaction of niflumic acid with human serum albumin.

    PubMed

    Kitamura, Keisuke; Omran, Ahmed A; Takegami, Shigehiko; Tanaka, Rumi; Kitade, Tatsuya

    2007-04-01

    The interaction of a non-steroidal anti-inflammatory drug, niflumic acid (NFA), with human serum albumin (HSA) has been investigated by (19)F nuclear magnetic resonance (NMR) spectroscopy. A (19)F NMR spectrum of NFA in a buffered (pH 7.4) solution of NaCl (0.1 mol L(-1)) contained a single sharp signal of its CF(3) group 14.33 ppm from the internal reference 2,2,2-trifluoroethanol. Addition of 0.6 mmol L(-1) HSA to the NFA buffer solution caused splitting of the CF(3) signal into two broadened signals, shifted to the lower fields of 14.56 and 15.06 ppm, with an approximate intensity ratio of 1:3. Denaturation of HSA by addition of 3.0 mol L(-1) guanidine hydrochloride (GU) restored a single sharp signal of CF(3) at 14.38 ppm, indicating complete liberation of NFA from HSA as a result of its denaturation. These results suggest that the binding is reversible and occurs in at least two HSA regions. Competitive (19)F NMR experiments using warfarin, dansyl-L: -asparagine, and benzocaine (site I ligands), and L: -tryptophan and ibuprofen (site II ligands) revealed that NFA binds to site I at two different regions, Ia and Ib, in the ratio 1:3. By use of (19)F NMR with NFA as an (19)F NMR probe the nonfluorinated site I-binding drugs sulfobromophthalein and iophenoxic acid were also found to bind sites Ia and Ib, respectively. These results illustrate the usefulness and convenience of (19)F NMR for investigation of the HSA binding of both fluorinated and nonfluorinated drugs.

  16. 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.

  17. 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.

  18. Binding studies of L-3,4-dihydroxyphenylalanine with human serum albumin.

    PubMed

    Yeggoni, Daniel Pushparaju; Subramanyam, Rajagopal

    2014-12-01

    L-Dopa has been used to increase dopamine concentrations in the treatment of Parkinson's disease and dopamine-responsive dystonia. The binding interaction between L-dopa (phytochemical) and human serum albumin (HSA) under simulated physiological conditions was investigated by spectroscopic and molecular modeling methods. The results revealed that L-dopa caused fluorescence emission quenching of HSA through a static quenching procedure and the binding constant obtained was 2.3 ± 0.01 × 10(4) M(-1), which is corresponding to -5.9 kcal M(-1) of free energy at 25 °C. Interestingly, L-dopa is not binding to the α-1-acidglycoprotein, which is also a plasma protein and an acute phase protein. Furthermore, circular dichroism results confirm that in the presence of L-dopa the secondary structure of HSA is altered due to partial unfolding of the protein. Importantly, the displacement experiment with site specific probes, phenylbutazone (site I) and ibuprofen (site II), depicts that L-dopa binds particularly to site II of HSA. In addition, the molecular modeling results also confirmed that L-dopa is binding to the subdomain IIIA of HSA and is stabilized by hydrogen bonds and hydrophilic forces. Additionally, the molecular dynamic simulation studies showed that the HSA-L-dopa complex reaches an equilibration state at around 2 ns, which indicates that the HSA-L-dopa complex is very stable. These results provided valuable information of pharmacological mechanisms of L-dopa under in vivo conditions and play a pivotal role in the development of L-dopa-inspired drugs.

  19. Structural basis and anticancer properties of ruthenium-based drug complexed with human serum albumin.

    PubMed

    Zhang, Yao; Ho, Andy; Yue, Jiping; Kong, Linlin; Zhou, Zuping; Wu, Xiaoyang; Yang, Feng; Liang, Hong

    2014-10-30

    Ruthenium-based anticancer complexes have become increasingly popular for study over the last two decades. Although ruthenium complexes are currently being investigated in clinical trials, there are still some difficulties with their delivery and associated side effects. Human serum albumin (HSA)-based delivery systems are promising for improving anticancer drug targeting and reducing negative side effects. However, there have been few studies regarding the HSA delivery system for metal-based anticancer compounds and no mention of its structural mechanism. Therefore, we studied the structure and anticancer properties of the ruthenium-based compound [RuCl5(ind)](2-) in complex with HSA. The structure revealed that [RuCl5(ind)](2-) has two binding sites in HSA. In the IB subdomain, [RuCl5(ind)](2-) binds to a new sub-site by coordinating with His-146. In the IIA subdomain, ruthenium (III) of [RuCl5(ind)](2-) binds to the hydrophobic cavity and forms coordination bonds by replacing chlorine atoms with the His-242 and Lys-199 residues of HSA. Interestingly, [RuCl5(ind)](2-), together with HSA, can enhance cytotoxicity by two to five times in cancer cells but has no effect on normal cells in vitro. Compared with unbound drug, the HSA-[RuCl5(ind)](2-) complex promotes MGC-803 cell apoptosis and also has a stronger capacity for cell cycle arrest at the G2 phase in MGC-803. In conclusion, this study will guide the rational design and development of ruthenium-containing or ruthenium-centered drugs and an HSA delivery system for ruthenium-based drugs.

  20. Investigations on the effects of Cu(2+) on the structure and function of human serum albumin.

    PubMed

    Jing, Mingyang; Liu, Rutao; Yan, Wenbao; Tan, Xuejie; Chen, Yadong

    2016-03-01

    Human serum albumin (HSA) is the most prominent protein in blood plasma with important physiological functions. Although copper is an essential metal for all organisms, the massive utilization of copper has led to concerns regarding its potential health impact. To better understand the potential toxicity and toxic mechanisms of Cu(2+), it is of vital importance to characterize the interaction of Cu(2+) with HSA. The effect of Cu(2+) on the structure and function of HSA in vitro were investigated by biophysical methods including fluorescence techniques, circular dichroism (CD), time-resolved measurements, isothermal titration calorimetry (ITC), molecular simulations and esterase activity assay. Multi-spectroscopic measurements proved that Cu(2+) quenched the intrinsic fluorescence of HSA in a dynamic process accompanied by the formation of complex and alteration of secondary structure. But the Cu(2+) had minimal effect on the backbone and secondary structure of HSA at relatively low concentrations. The ITC results indicated Cu(2+) interacted with HSA spontaneously through hydrophobic forces with approximately 1 thermodynamic identical binding sites at 298 K. The esterase activity of HSA was inhibited obviously at the concentration of 8 × 10(-5) M. However, molecular simulation showed that Cu(2+) mainly interacted with the amino acid residues Asp (451) by the electrostatic force. Thus, we speculated the interaction between Cu(2+) and HSA might induce microenvironment of the active site (Arg 410). This study has provided a novel idea to explore the biological toxicity of Cu(2+) at the molecular level.

  1. 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.

  2. Tuning the serum persistence of human serum albumin domain III:diabody fusion proteins

    PubMed Central

    Kenanova, Vania E.; Olafsen, Tove; Salazar, Felix B.; Williams, Lawrence E.; Knowles, Scott; Wu, Anna M.

    2010-01-01

    The long circulation persistence of human serum albumin (HSA) is enabled by its domain III (DIII) interaction with the neonatal Fc receptor (FcRn). A protein scaffold based on HSA DIII was designed. To modify the serum half life of the scaffold, residues H535, H510, and H464 were individually mutated to alanine. HSA DIII wild type (WT) and variants were fused to the anti-carcinoembryonic antigen (CEA) T84.66 diabody (Db), radiolabeled with 124I and injected into xenografted athymic mice for serial PET/CT imaging. All proteins targeted the CEA-positive tumor. The mean residence times (MRT) of the proteins, calculated by quantifying blood activity from the PET images, were: Db-DIII WT (56.7 h), H535A (25 h), H510A (20 h), H464A (17 h), compared with Db (2.9 h). Biodistribution confirmed the order of blood clearance from slow to fast: Db-DIII WT > H535A > H510A > H464A > Db with 4.0, 2.0, 1.8, 1.6 and 0.08 %ID/g of remaining blood activity at 51 h, respectively. This study demonstrates that attenuating the DIII–FcRn interaction provides a way of controlling the pharmacokinetics of the entire Db-DIII fusion protein without compromising tumor targeting. H464 appears to be most crucial for FcRn binding (greatest reduction in MRT), followed by H510 and H535. By mutating the DIII scaffold, we can dial serum kinetics for imaging or therapy applications. PMID:20802234

  3. UW solution improved with high anti-apoptotic activity by S-nitrosated human serum albumin.

    PubMed

    Ishima, Yu; Shinagawa, Takuya; Yoneshige, Shinji; Kragh-Hansen, Ulrich; Ohya, Yuki; Inomata, Yukihiro; Kai, Toshiya; Otagiri, Masaki; Maruyama, Toru

    2013-04-01

    S-Nitrosated human serum albumin (SNO-HSA) is useful in preventing liver ischemia/reperfusion injury, and SNO-HSA should thus be able to prevent cell injury during liver transplantation. However, the potential protective effect of SNO-HSA on a combination of cold and warm ischemia, which is obligatory when performing liver transplantation, has not been examined. Therefore, we evaluated the protective effect of SNO-HSA added to University of Wisconsin (UW) solution during cold or/and warm ischemia in situ and in vitro. First, we observed that apoptotic and necrotic cell death were increased during cold and warm ischemia, respectively. SNO-HSA, which possesses anti-apoptosis activity at low NO concentrations, can inhibit cold ischemia injury both in situ and in vitro. In contrast, SNO-HSA had no significant effect on warm liver ischemia injury which, however, can be reduced by UW solution. We also demonstrated that the cellular uptake of NO from SNO-HSA can occur during cold ischemia resulting in induction of heme oxygenase-1 within 3h of cold ischemia. Our results indicate that treatment with SNO-HSA or UW solution alone is not sufficient to inhibit liver injury during a period of both cold and warm ischemia. However, a combination of SNO-HSA and UW solution can be used to prevent the two types of ischemia. SNO-HSA-added UW solution could be very useful in transplantation, because the previously imposed constraints on preservation time can be removed. This is a great advantage in a situation as the present one with increased utilization of scarce donor organs for more recipients.

  4. Investigating protein haptenation mechanisms of skin sensitisers using human serum albumin as a model protein.

    PubMed

    Aleksic, Maja; Pease, Camilla K; Basketter, David A; Panico, Maria; Morris, Howard R; Dell, Anne

    2007-06-01

    Covalent modification of skin proteins by electrophiles is a key event in the induction of skin sensitisation but not skin irritation although the exact nature of the binding mechanisms has not been determined empirically for the vast majority of sensitisers. It is also unknown whether immunologically relevant protein targets exist in the skin contributing to effecting skin sensitisation. To determine the haptenation mechanism(s) and spectra of amino acid reactivity in an intact protein for two sensitisers expected to react by different mechanisms, human serum albumin (HSA) was chosen as a model protein. The aim of this work was also to verify for selected non-sensitisers and irritants that no protein haptenation occurs even under forcing conditions. HSA was incubated with chemicals and the resulting complexes were digested with trypsin and analysed deploying matrix-assisted laser desorption/ionization mass spectrometry, reverse phase high performance liquid chromatography and nano-electrospray tandem mass spectrometry. The data confirmed that different residues (lysine, cysteine, histidine and tyrosine) are covalently modified in a highly selective and differential manner by the sensitisers 2,4-dinitro-1-chlorobenzene and phenyl salicylate. Additionally, non-sensitisers 2,4-dichloro-1-nitrobenzene, butyl paraben and benzaldehyde and irritants benzalkonium chloride and sodium dodecyl sulphate did not covalently modify HSA under any conditions. The data indicate that covalent haptenation is a prerequisite of skin sensitisation but not irritation. The data also suggest that protein modifications are targeted to certain amino acids residing in chemical microenvironments conducive to reactivity within an intact protein. Deriving such information is relevant to our understanding of antigen formation in the immunobiology of skin sensitisation and in the development of in vitro protein haptenation assays.

  5. Spectroscopic studies of the interaction of anti-coagulant rodenticide diphacinone with human serum albumin

    NASA Astrophysics Data System (ADS)

    Tang, Jianghong; Qi, Shengda; Chen, Xingguo

    2005-11-01

    The interaction of diphacinone with human serum albumin (HSA) was studied by the methods of fluorescence and Fourier transform infrared (FT-IR) spectroscopy under simulative physiological conditions. Diphacinone can strongly quench the intrinsic fluorescence of HSA by static quenching. The apparent binding constants KT at four different temperatures (291, 300, 310, and 318 K) were obtained according to Scatchard procedure. The Stern-Volmer and Scatchard plots both had an intersection at C diphacinone/C HSA≈1.2, which indicated that diphacinone binded to different binding sites on HSA. The analytical results of fluorescence data showed when C diphacinone/C HSA was lower than 1.2, the numbers of binding sites were near 1.1, and C diphacinone/C HSA was higher than 1.2, the number of binding sites was approximately 1.8. The FT-IR spectra had proved that the secondary structure of HSA changed after interacting with diphacinone in aqueous solution. The thermodynamic parameters were calculated by van't Hoff equation. The enthalpy change (Δ H0) and entropy change (Δ S0) were -14.59 kJ mol -1 and 62.49 J mol -1 K -1, respectively. The results suggested that the hydrophobic interaction might play a main role in the interaction of diphacinone with the HSA. The binding distance ( r) between diphacinone and tryptophan in HSA was obtained according to the Förster energy transfer theory. Furthermore, the study of molecular modeling indicated that diphacinone could bind to the site I of HSA and hydrophobic interaction was the major acting force, which was in agreement with the binding mode study.

  6. 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.

  7. Modulation of linoleic acid-binding properties of human serum albumin by divalent metal cations.

    PubMed

    Nemashkalova, Ekaterina L; Permyakov, Eugene A; Permyakov, Sergei E; Litus, Ekaterina A

    2017-03-16

    Human serum albumin (HSA) is an abundant multiligand carrier protein, linked to progression of Alzheimer's disease (AD). Blood HSA serves as a depot of amyloid β (Aβ) peptide. Aβ peptide-buffering properties of HSA depend on interaction with its ligands. Some of the ligands, namely, linoleic acid (LA), zinc and copper ions are involved into AD progression. To clarify the interplay between LA and metal ion binding to HSA, the dependence of LA binding to HSA on Zn(2+), Cu(2+), Mg(2+) and Ca(2+) levels and structural consequences of these interactions have been explored. Seven LA molecules are bound per HSA molecule in the absence of the metal ions. Zn(2+) binding to HSA causes a loss of one bound LA molecule, while the other metals studied exert an opposite effect (1-2 extra LA molecules are bound). In most cases, the observed effects are not related to the metal-induced changes in HSA quaternary structure. However, the Zn(2+)-induced decline in LA capacity of HSA could be due to accumulation of multimeric HSA forms. Opposite to Ca(2+)/Mg(2+)-binding, Zn(2+) or Cu(2+) association with HSA induces marked changes in its hydrophobic surface. Overall, the divalent metal ions modulate LA capacity and affinity of HSA to a different extent. LA- and Ca(2+)-binding to HSA synergistically support each other. Zn(2+) and Cu(2+) induce more pronounced changes in hydrophobic surface and quaternary structure of HSA and its LA capacity. A misbalanced metabolism of these ions in AD could modify interactions of HSA with LA, other fatty acids and hydrophobic substances, associated with AD.

  8. Reversible binding of tolmetin, zomepirac, and their glucuronide conjugates to human serum albumin and plasma.

    PubMed

    Ojingwa, J C; Spahn-Langguth, H; Benet, L Z

    1994-02-01

    Acyl glucuronides of drugs and bilirubin have been shown in the past decade to be reactive metabolites undergoing acyl migration and irreversible binding. The latter reaction has been hypothesized to be facilitated by or to proceed through the formation of a reversible complex. Furthermore, it has been suggested that the decreased binding seen in patients with compromised excretory function may be due to competition by elevated plasma concentrations of the glucuronides. In these reversible binding studies, we characterized the extent and the "site" of binding of tolmetin, zomepirac, their glucuronides and isomeric conjugates. We also examined the displacement between the parent drugs and their glucuronide conjugates using a rapid ultrafiltration method. Tolmetin exhibited three classes of binding sites with a primary association constant of 1.7 x 10(6) M-1 (Kd1 = 0.60 microM). The primary association constant of zomepirac (1.16 x 10(6) M-1, Kd1 = 0.86 microM) is similar to that of tolmetin. The beta 1 and alpha/beta 3 glucuronides of both compounds bind to a lesser extent than their parent aglycones. The isomeric glucuronide conjugates of both compounds showed much stronger binding than the beta/1 conjugates. Of the four glucuronides investigated, tolmetin glucuronide-alpha/beta 3 isomer was bound by fatty acid free human serum albumin with the highest affinity (4.6 x 10(5) M-1, Kd = 2.22 microM). Protein binding of the parent drugs and conjugates were decreased significantly at pH 5.0. In displacement studies, except for salicylate and acetylsalicylate, drugs known to bind to Sites I and II as well as the digitoxin and tamoxifen binding sites had little inhibitory effect on the binding of tolmetin, zomepirac, and their glucuronide conjugates.

  9. Binding of suprofen to human serum albumin. Role of the suprofen carboxyl group.

    PubMed

    Maruyama, T; Lin, C C; Yamasaki, K; Miyoshi, T; Imai, T; Yamasaki, M; Otagiri, M

    1993-03-09

    The binding of suprofen (SP), a non-steroidal anti-inflammatory drug of the arylpropionic acid class, and its methyl ester derivative (SPM) to human serum albumin (HSA) was studied by dialysis and spectroscopic techniques. In spite of the remarkable differences in the physicochemical properties of SP and SPM, the binding of each molecule to HSA was quantitatively very similar. Thermodynamic analysis suggests that the interaction of SP with HSA may be caused by electrostatic as well as hydrophobic forces, whereas the interactions with SPM may be explained by hydrophobic and van der Waals forces. Similarities in the difference UV absorption spectra between ligand-detergent micelle and -HSA systems indicate that the SP and SPM molecules are inserted into a hydrophobic crevice on HSA. The same studies suggest that the carboxyl group of SP interacts with a cationic sub-site which is closely associated with the SP binding site. Proton relaxation rate measurements indicate that the thiophen ring and propanoate portion of the SP molecule is the major binding site for HSA. The locations of SP and SPM binding sites were identified by using fluorescence probes which bind to a known site on HSA. The displacement data implied that SP primarily binds to Site II, while the high affinity site of SPM as well as low affinity site of SP are at the warfarin binding site in the Site I area. From binding data with chemically modified HSA derivatives, it is likely that highly reactive tyrosine (Tyr) and lysine (Lys) residues, which may be Tyr-411 and Lys-195, are specifically involved in SP binding. In contrast, these two residues are clearly separated from the SPM binding site. The binding of SP and SPM is independent of conformational changes on HSA that accompany N-B transition. There is evidence that the carboxyl group may play a crucial role in the high affinity binding processes of SP to HSA.

  10. Influence of the albumin concentration and temperature on the lysis of human erythrocytes by sodium dodecyl sulfate.

    PubMed

    Fonseca, L C; Arvelos, L R; Netto, R C M; Lins, A B; Garrote-Filho, M S; Penha-Silva, N

    2010-10-01

    The stability of human erythrocytes to sodium dodecyl sulfate (SDS) was assessed spectrophotometrically in the presence of different concentrations of bovine serum albumin (BSA) and at different temperatures (27-45 °C). The absorbance at 540 nm (A₅₄₀) was correlated with the SDS concentration by sigmoidal regression based on the Boltzmann equation. Erythrocyte stability was characterized on the basis of the SDS concentration that induces hemolysis in 50% of the cells (D₅₀). Progressive increases in the albumin concentration led to increases in the D₅₀ value. The protective effect of BSA against SDS-induced hemolysis was attributed to the binding of the surfactant to the hydrophobic binding sites of this protein. The D₅₀ values decreased sigmoidally with an increase in the temperature. This trend, which could not be explained by changes in the spectral properties of hemoglobin, maybe due to heterogeneity in the erythrocyte population.

  11. Drug binding to human serum albumin: abridged review of results obtained with high-performance liquid chromatography and circular dichroism.

    PubMed

    Ascoli, Giorgio A; Domenici, Enrico; Bertucci, Carlo

    2006-09-01

    The drug binding to plasma and tissue proteins are fundamental factors in determining the overall pharmacological activity of a drug. Human serum albumin (HSA), together with alpha1-acid glycoprotein (AGP), are the most important plasma proteins, which act as drug carriers, with drug pharmacokinetic implications, resulting in important clinical impacts for drugs that have a relatively narrow therapeutic index. This review focuses on the combination of biochromatography and circular dichroism as an effective approach for the characterization of albumin binding sites and their enantioselectivity. Furthermore, their applications to the study of changes in the binding properties of the protein arising by the reversible or covalent binding of drugs are discussed, and examples of physiological relevance reported. Perspectives of these studies reside in supporting the development of new drugs, which require miniaturization to facilitate the screening of classes of compounds for their binding to the target protein, and a deeper characterization of the mechanisms involved in the molecular recognition processes.

  12. Recombinant human fibrinogen and sulfation of the. gamma. prime chain

    SciTech Connect

    Farrell, D.H.; Huang, S.; Chung, D.W.; Davie, E.W. ); Mulvihill, E.R. )

    1991-10-01

    Human fibrinogen and the homodimeric {gamma}{prime}-chain-containing variant have been expressed in BHK cells using cDNAs coding for the {alpha},{beta}, and {gamma} (or {gamma}{prime}) chains. The fibrinogens were secreted at levels greater than 4 {mu}g (mg of total cell protein){sup {minus}1}day{sup {minus}1} and were biologically active in clotting assays. Recombinant fibrinogen containing the {gamma}' chain incorporated {sup 35}SO{sub 4} into its chains during biosynthesis, while no incorporation occurred in the protein containing the {gamma} chain. The identity of the sulfated {gamma}{prime} chain was verified by its ability to form dimers during clotting. In addition, carboxypeptidase {Upsilon} digestion of the recombinant fibrinogen containing the {gamma}{prime} chain released 96% of the {sup 35}S label from the sulfated chain, and the radioactive material was identified as tyrosine O-sulfate. These results clarify previous findings of the sulfation of tyrosine in human fibrinogen.

  13. Validation of quantitation of regional myocardial blood flow in vivo with /sup 11/C-labeled human albumin microspheres and positron emission tomography. [Dogs

    SciTech Connect

    Wilson, R.A.; Shea, M.J.; De Landsheere, C.M.; Turton, D.; Brady, F.; Deanfield, J.E.; Selwyn, A.P.

    1984-10-01

    Use of radiolabeled microspheres is a standard method to measure regional myocardial perfusion in animals. Human albumin microspheres have been given safely to patients, but positron-emitting /sup 67/Ga-labeled human albumin microspheres are characterized by an unstable radiolabel. A new labeling procedure that covalently binds /sup 11/C to human albumin microspheres via /sup 11/CH/sub 3/I was developed. Seven open-chest and two closed-chest dogs were studied. Reference and /sup 11/C-labeled human albumin microspheres (2 to 25 mCi) were both injected into the left atrium. Positron tomographic images were obtained of the myocardial distribution of the /sup 11/C-labeled microspheres. Timed arterial withdrawal was used for both reference gamma-labeled microspheres and /sup 11/C-labeled human albumin microspheres. Regional myocardial perfusion calculated by this technique correlated well with values obtained with reference microspheres over a range of 0.2 to 3.5 ml/min/g. Thus, /sup 11/C human albumin microspheres are stable radiochemically and can be used as a quantitative measure of regional myocardial perfusion.

  14. Interaction of anticancer drug clofarabine with human serum albumin and human α-1 acid glycoprotein. Spectroscopic and molecular docking approach.

    PubMed

    Ajmal, Mohammad Rehan; Nusrat, Saima; Alam, Parvez; Zaidi, Nida; Khan, Mohsin Vahid; Zaman, Masihuz; Shahein, Yasser E; Mahmoud, Mohamed H; Badr, Gamal; Khan, Rizwan Hasan

    2017-02-20

    The binding interaction between clofarabine, an important anticancer drug and two important carrier proteins found abundantly in human plasma, Human Serum Albumin (HSA) and α-1 acid glycoprotein (AAG) was investigated by spectroscopic and molecular modeling methods. The results obtained from fluorescence quenching experiments demonstrated that the fluorescence intensity of HSA and AAG is quenched by clofarabine and the static mode of fluorescence quenching is operative. UV-vis spectroscopy deciphered the formation of ground state complex between anticancer drug and the two studied proteins. Clofarabine was found to bind at 298K with both AAG and HSA with the binding constant of 8.128×10(3) and 4.120×10(3) for AAG and HSA, respectively. There is stronger interaction of clofarabine with AAG as compared to HSA. The Gibbs free energy change was found to be negative for the interaction of clofarabine with AAG and HSA indicating that the binding process is spontaneous. Binding of clofarabine with HSA and AAG induced ordered structures in both proteins and lead to molecular compaction. Clofarabine binds to HSA near to drug site II. Hydrogen bonding and hydrophobic interactions were the main bonding forces between HSA-clofarabine and AAG-clofarabine as revealed by docking results. This study suggests the importance of binding of anticancer drug to AAG spatially in the diseases like cancers where the plasma concentration of AAG increases many folds. Design of drug dosage can be adjusted accordingly to achieve optimal treatment outcome.

  15. Properties of purified recombinant human polyamine oxidase, PAOh1/SMO.

    PubMed

    Wang, Yanlin; Murray-Stewart, Tracy; Devereux, Wendy; Hacker, Amy; Frydman, Benjamin; Woster, Patrick M; Casero, Robert A

    2003-05-16

    The discovery of an inducible oxidase whose apparent substrate preference is spermine indicates that polyamine catabolism is more complex than that originally proposed. To facilitate the study of this enzyme, the purification and characterization of the recombinant human PAOh1/SMO polyamine oxidase are reported. Purified PAOh1/SMO oxidizes both spermine (K(m)=1.6 microM) and N(1)-acetylspermine (K(m)=51 microM), but does not oxidize spermidine. The purified human enzyme also does not oxidize eight representative antitumor polyamine analogues; however, specific oligamine analogues were found to be potent inhibitors of the oxidation of spermine by PAOh1/SMO. The results of these studies are consistent with the hypothesis that PAOh1/SMO represents a new addition to the polyamine metabolic pathway that may represent a new target for antineoplastic drug development.

  16. Specific absorption of human serum albumin, immunoglobulin A, and immunoglobulin G with selected strains of group A and G streptococci.

    PubMed Central

    Kronvall, G; Simmons, A; Myhre, E B; Jonsson, S

    1979-01-01

    Five gram-positive bacterial strains were selected for absorption studies of human serum samples. Strain AR1 (group A, M-type 1) and G148 (group G), with strong immunoglobulin G (IgG) binding capacities, and strain AW43 (group A, M-type 60), binding both IgA1 and IgA2, were compared with Staphylococcus aureus Cowan I and with Staphylococcus epidermidis L603. Both AR1 and G148 were capable of completely absorbing out serum IgG. In contrast, S. aureus Cowan I left a fraction unabsorbed, as expected from its known lack of IgG3 binding. Strain AW43 absorbed out all serum IgA, using a 10-microliter bacterial pellet for 20 microliter of serum. Serum IgM levels were slightly reduced by S. aureus Cowan I absorption. On the basis of the experiments, a bacterial mixture was designed consisting of S. aureus Cowan I and group A streptococcus strains AR1 and AW43, with absorption characteristics suitable for use in discriminating between early IgM and late IgG and IgA immune responses in routine serological work. A new type of bacteria-mammalian protein binding was discovered. Human serum albumin was completely absorbed out by strain G148 and to a lesser extent by strain AR1 and AW43. S. aureus Cowan I and S. epidermidis were negative. The binding capacity of G148 for albumin equalled that of Cowan I for IgG. The binding pattern of albumin to the strains was different from those of IgG, IgA, IgM, fibrinogen, haptoglobin, or aggregated beta 2-microglobulin and therefore seems to represent another type of bacterial-mammalian interaction with a specific albumin receptor on the surface of streptococci. Images PMID:383609

  17. 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

  18. Genetic recombination between human and animal parasites creates novel strains of human pathogen.

    PubMed

    Gibson, Wendy; Peacock, Lori; Ferris, Vanessa; Fischer, Katrin; Livingstone, Jennifer; Thomas, James; Bailey, Mick

    2015-03-01

    Genetic recombination between pathogens derived from humans and livestock has the potential to create novel pathogen strains, highlighted by the influenza pandemic H1N1/09, which was derived from a re-assortment of swine, avian and human influenza A viruses. Here we investigated whether genetic recombination between subspecies of the protozoan parasite, Trypanosoma brucei, from humans and animals can generate new strains of human pathogen, T. b. rhodesiense (Tbr) responsible for sleeping sickness (Human African Trypanosomiasis, HAT) in East Africa. The trait of human infectivity in Tbr is conferred by a single gene, SRA, which is potentially transferable to the animal pathogen Tbb by sexual reproduction. We tracked the inheritance of SRA in crosses of Tbr and Tbb set up by co-transmitting genetically-engineered fluorescent parental trypanosome lines through tsetse flies. SRA was readily transferred into new genetic backgrounds by sexual reproduction between Tbr and Tbb, thus creating new strains of the human pathogen, Tbr. There was no evidence of diminished growth or transmissibility of hybrid trypanosomes carrying SRA. Although expression of SRA is critical to survival of Tbr in the human host, we show that the gene exists as a single copy in a representative collection of Tbr strains. SRA was found on one homologue of chromosome IV in the majority of Tbr isolates examined, but some Ugandan Tbr had SRA on both homologues. The mobility of SRA by genetic recombination readily explains the observed genetic variability of Tbr in East Africa. We conclude that new strains of the human pathogen Tbr are being generated continuously by recombination with the much larger pool of animal-infective trypanosomes. Such novel recombinants present a risk for future outbreaks of HAT.

  19. Profiling Cys34 Adducts of Human Serum Albumin by Fixed-Step Selected Reaction Monitoring*

    PubMed Central

    Li, He; Grigoryan, Hasmik; Funk, William E.; Lu, Sixin Samantha; Rose, Sherri; Williams, Evan R.; Rappaport, Stephen M.

    2011-01-01

    A method is described for profiling putative adducts (or other unknown covalent modifications) at the Cys34 locus of human serum albumin (HSA), which represents the preferred reaction site for small electrophilic species in human serum. By comparing profiles of putative HSA-Cys34 adducts across populations of interest it is theoretically possible to explore environmental causes of degenerative diseases and cancer caused by both exogenous and endogenous chemicals. We report a novel application of selected-reaction-monitoring (SRM) mass spectrometry, termed fixed-step SRM (FS-SRM), that allows detection of essentially all HSA-Cys34 modifications over a specified range of mass increases (added masses). After tryptic digestion, HSA-Cys34 adducts are contained in the third largest peptide (T3), which contains 21 amino acids and an average mass of 2433.87 Da. The FS-SRM method does not require that exact masses of T3 adducts be known in advance but rather uses a theoretical list of T3-adduct m/z values separated by a fixed increment of 1.5. In terms of added masses, each triply charged parent ion represents a bin of ±2.3 Da between 9.1 Da and 351.1 Da. Synthetic T3 adducts were used to optimize FS-SRM and to establish screening rules based upon selected b- and y-series fragment ions. An isotopically labeled T3 adduct is added to protein digests to facilitate quantification of putative adducts. We used FS-SRM to generate putative adduct profiles from six archived specimens of HSA that had been pooled by gender, race, and smoking status. An average of 66 putative adduct hits (out of a possible 77) were detected in these samples. Putative adducts covered a wide range of concentrations, were most abundant in the mass range below 100 Da, and were more abundant in smokers than in nonsmokers. With minor modifications, the FS-SRM methodology can be applied to other nucleophilic sites and proteins. PMID:21193536

  20. A Comparative Analysis of Synonymous Codon Usage Bias Pattern in Human Albumin Superfamily

    PubMed Central

    Mirsafian, Hoda; Mat Ripen, Adiratna; Singh, Aarti; Teo, Phaik Hwan; Merican, Amir Feisal; Mohamad, Saharuddin Bin

    2014-01-01

    Synonymous codon usage bias is an inevitable phenomenon in organismic taxa across the three domains of life. Though the frequency of codon usage is not equal across species and within genome in the same species, the phenomenon is non random and is tissue-specific. Several factors such as GC content, nucleotide distribution, protein hydropathy, protein secondary structure, and translational selection are reported to contribute to codon usage preference. The synonymous codon usage patterns can be helpful in revealing the expression pattern of genes as well as the evolutionary relationship between the sequences. In this study, synonymous codon usage bias patterns were determined for the evolutionarily close proteins of albumin superfamily, namely, albumin, α-fetoprotein, afamin, and vitamin D-binding protein. Our study demonstrated that the genes of the four albumin superfamily members have low GC content and high values of effective number of codons (ENC) suggesting high expressivity of these genes and less bias in codon usage preferences. This study also provided evidence that the albumin superfamily members are not subjected to mutational selection pressure. PMID:24707212

  1. FORMATION OF HEMOGLOBIN AND ALBUMIN ADDUCTS OF BENZENE OXIDE IN MOUSE, RAT, AND HUMAN BLOOD

    EPA Science Inventory

    Little is known about the formation and disposition of benzene oxide (BO), the initial metabolite arising from oxidation of benzene by cytochrome P450. In this study, reactions of BO with hemoglobin (Hb) and albumin (Alb) were investigated in blood from B6C3F1 mice, F344 rats, ...

  2. 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.

  3. 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).

  4. Photoabsorption of acridine yellow and proflavin bound to human serum albumin studied by means of quantum mechanics/molecular dynamics.

    PubMed

    Aidas, Kęstutis; Olsen, Jógvan Magnus H; Kongsted, Jacob; Ågren, Hans

    2013-02-21

    Attempting to unravel mechanisms in optical probing of proteins, we have performed pilot calculations of two cationic chromophores-acridine yellow and proflavin-located at different binding sites within human serum albumin, including the two primary drug binding sites as well as a heme binding site. The computational scheme adopted involves classical molecular dynamics simulations of the ligands bound to the protein and subsequent linear response polarizable embedding density functional theory calculations of the excitation energies. A polarizable embedding potential consisting of point charges fitted to reproduce the electrostatic potential and isotropic atomic polarizabilities computed individually for every residue of the protein was used in the linear response calculations. Comparing the calculated aqueous solution-to-protein shifts of maximum absorption energies to available experimental data, we concluded that the cationic proflavin chromophore is likely not to bind albumin at its drug binding site 1 nor at its heme binding site. Although agreement with experimental data could only be obtained in qualitative terms, our results clearly indicate that the difference in optical response of the two probes is due to deprotonation, and not, as earlier suggested, to different binding sites. The ramifications of this finding for design of molecular probes targeting albumin or other proteins is briefly discussed.

  5. Relations between high-affinity binding sites for L-tryptophan, diazepam, salicylate and Phenol Red on human serum albumin.

    PubMed Central

    Kragh-Hansen, U

    1983-01-01

    Binding of L-tryptophan, diazepam, salicylate and Phenol Red to defatted human serum albumin was studied by ultrafiltration at pH 7.0. All ligands bind to one high-affinity binding site with association constants of the order of 10(4)-10(5)M-1. The number of secondary binding sites was found to vary from zero to five, with association constants about 10(3)M-1. Competitive binding studies with different pairs of the ligands were performed. Binding of both ligands was determined simultaneously. L-Tryptophan and diazepam were found to compete for a common high-affinity binding site on albumin. The following combinations of ligands do not bind competitively to albumin: L-tryptophan-Phenol Red, L-tryptophan-salicylate and Phenol Red-salicylate. On the other hand, high-affinity bindings of the three ligands do not take place independently but in such a way that binding of one of the ligands results in a decrease in binding of the other ligands. The decreases in binding are reciprocal and can be accounted for by introducing a coupling constant. The magnitude of the constant is dependent on the ligands being bound. In the present study, the mutual decrease in binding was more pronounced with L-tryptophan-salicylate and Phenol Red-salicylate than with L-tryptophan-Phenol Red. PMID:6847607

  6. Expression and purification of recombinant human EGFL7 protein.

    PubMed

    Picuric, Srdjan; Friedrich, Matthias; Oess, Stefanie

    2009-11-01

    The secreted epidermal growth factor-like protein 7 (EGFL7) plays an important role in angiogenesis, especially in the recruitment of endothelial and smooth muscle cells to the site of the nascent vessel and their ordered assembly into functional vasculature. However, progress in the understanding of the underlying mechanisms is to date greatly hindered by the lack of recombinant EGFL7 protein in a stable, soluble, native state, thus preventing e.g. the characterization of the proposed functional receptor as well as investigation of additional biological effects of EGFL7. So far all attempts to produce sufficient amounts of recombinant EGFL7 protein by various groups have failed. In this study we describe a procedure for the expression and purification of human EGFL7 from Sf9 cells and for the first time provide means to isolate biologically functional EGFL7 protein in sufficient quantities for its further biological characterization. We believe that the availability of EGFL7 will greatly accelerate our understanding of the precise role of EGFL7 and the underlying molecular mechanisms of EGFL7 action in the fundamentally important process of angiogenesis.

  7. “Genome-wide recombination and chromosome segregation in human oocytes and embryos reveal selection for maternal recombination rates”

    PubMed Central

    Natesan, Senthilkumar A.; Joshi, Hrishikesh A.; Cimadomo, Danilo; Griffin, Darren K.; Sage, Karen; Summers, Michael C.; Thornhill, Alan R.; Housworth, Elizabeth; Herbert, Alex D.; Rienzi, Laura; Ubaldi, Filippo M.; Handyside, Alan H.; Hoffmann, Eva R.

    2015-01-01

    Crossover recombination reshuffles genes and prevents errors in segregation that lead to extra or missing chromosomes (aneuploidy) in human eggs, a major cause of pregnancy failure and congenital disorders. Here, we generate genome-wide maps of crossovers and chromosome segregation patterns by recovering all three products of single female meioses. Genotyping > 4 million informative single-nucleotide polymorphisms (SNPs) from 23 complete meioses allowed us to map 2,032 maternal and 1,342 paternal crossovers and to infer the segregation patterns of 529 chromosome pairs. We uncover a novel reverse chromosome segregation pattern in which both homologs separate their sister chromatids at meiosis I; detect selection for higher recombination rates in the female germline by the elimination of aneuploid embryos; and report chromosomal drive against non-recombinant chromatids at meiosis II. Collectively, our findings reveal that recombination not only affects homolog segregation at meiosis I but also the fate of sister chromatids at meiosis II. PMID:25985139

  8. 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.

  9. Albumin synthesis in humans increases immediately following the administration of endotoxin.

    PubMed

    Barle, Hans; Januszkiewicz, Anna; Hållström, Lars; Essén, Pia; McNurlan, Margaret A; Garlick, Peter J; Wernerman, Jan

    2002-11-01

    In order to investigate the immediate (i.e. within 3 h) response of albumin synthesis to the administration of endotoxin, as a model of a moderate and well controlled catabolic insult, two measurements employing L-[(2)H(5)]phenylalanine were performed in 16 volunteers. One group ( n =8) received an intravenous injection of endotoxin (4 ng/kg; lot EC-6) immediately after the first measurement of albumin synthesis, whereas the other group received saline. A second measurement was initiated 1 h later. In the endotoxin group, the fractional synthesis rate of albumin was 6.9+/-0.6%/day (mean+/-S.D.) in the first measurement. In the second measurement, a significant increase was observed (9.6+/-1.2%/day; P <0.001). The corresponding values in the control group were were 6.6+/-0.6%/day and 7.0+/-0.6%/day respectively (not significant compared with first measurement and P <0.001 compared with the second measurement in the endotoxin group). The absolute synthesis rates of albumin were 148+/-35 and 201+/-49 mg x kg(-1) x day(-1) before and after endotoxin ( P <0.01). In the control group, the corresponding values were 131+/-21 and 132+/-20 mg x kg(-1) x day(-1) (not significant compared with the first measurement and P <0.01 compared with the second measurement in the endotoxin group). In conclusion, these results indicate that albumin synthesis increases in the very early phase after a catabolic insult, as represented by the administration of endotoxin.

  10. Induction of synthesis and secretion of interleukin 1 beta in the human monocytic THP-1 cells by human serum albumins modified with methylglyoxal and advanced glycation endproducts.

    PubMed

    Westwood, M E; Thornalley, P J

    1996-04-01

    Human serum albumin modified with 1-2 methylglyoxal residues per molecule of protein (MGmin-HSA) stimulated the synthesis and secretion of interleukin 1 beta (IL-1 beta) from human monocytic THP-1 cells in vitro. It was a more potent inducer of IL-1 beta synthesis than human serum albumin highly-modified with glucose-derived advanced glycation endproducts (AGE-HSA). With 20 microM ligand. IL-1 beta synthesis was (pg/10(6) cells): MGmin-HSA 484.5 +/- 50.3; AGE-HSA 30.6 +/- 2.0 (n = 3). IL-1 beta synthesis increased markedly with MGmin-HSA concentrations > 5 microM. IL-1 beta synthesis and secretion from monocytes in response to methylglyoxal-modified proteins in vivo may contribute to the development of macro- and micro-angiopathy, particularly in diabetes mellitus.

  11. COMPARISON OF MODIFICATION SITES FORMED ON HUMAN SERUM ALBUMIN AT VARIOUS STAGES OF GLYCATION

    PubMed Central

    Barnaby, Omar S.; Cerny, Ronald L.; Clarke, William; Hage, David S.

    2010-01-01

    Background Many of the complications encountered during diabetes can be linked to the non-enzymatic glycation of proteins, including human serum albumin (HSA). However, there is little information regarding how the glycation pattern of HSA changes as the total extent of glycation is varied. The goal of this study was to identify and conduct a semi-quantitative comparison of the glycation products on HSA that are produced in the presence of various levels of glycation. Methods Three glycated HSA samples were prepared in vitro by incubating physiological concentrations of HSA with 15 mmol/l glucose for 2 or 5 weeks, or with 30 mmol/l glucose for 4 weeks. These samples were then digested and examined by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) to identify the glycation products that were formed. Results It was found that the glycation pattern of HSA changed with its overall extent of total glycation. Many modifications including previously-reported primary glycation sites (e.g., K199, K281, and the N-terminus) were consistently found in the tested samples. Lysines 199 and 281, as well as arginine 428, contained the most consistently identified and abundant glycation products. Lysines 93, 276, 286, 414, 439, and 524/525, as well as the N-terminus and arginines 98, 197, and 521, were also found to be modified at various degrees of HSA glycation. Conclusions The glycation pattern of HSA was found to vary with different levels of total glycation and included modifications at the 2 major drug binding sites on this protein. This result suggests that different modified forms of HSA, both in terms of the total extent of glycation and glycation pattern, may be found at various stages of diabetes. The clinical implication of these results is that the binding of HSA to some drug may be altered at various stages of diabetes as the extent of glycation and types of modifications in this protein are varied. PMID:21034726

  12. Existence of Different Structural Intermediates on the Fibrillation Pathway of Human Serum Albumin

    PubMed Central

    Juárez, Josué; Taboada, Pablo; Mosquera, Víctor

    2009-01-01

    The fibrillation propensity of the multidomain protein human serum albumin (HSA) was analyzed under different solution conditions. The aggregation kinetics, protein conformational changes upon self-assembly, and structure of the different intermediates on the fibrillation pathway were determined by means of thioflavin T (ThT) fluorescence and Congo Red absorbance; far- and near-ultraviolet circular dichroism; tryptophan fluorescence; Fourier transform infrared spectroscopy; x-ray diffraction; and transmission electron, scanning electron, atomic force, and microscopies. HSA fibrillation extends over several days of incubation without the presence of a lag phase, except for HSA samples incubated at acidic pH and room temperature in the absence of electrolyte. The absence of a lag phase occurs if the initial aggregation is a downhill process that does not require a highly organized and unstable nucleus. The fibrillation process is accompanied by a progressive increase in the β-sheet (up to 26%) and unordered conformation at the expense of α-helical conformation, as revealed by ThT fluorescence and circular dichroism and Fourier transform infrared spectroscopies, but changes in the secondary structure contents depend on solution conditions. These changes also involve the presence of different structural intermediates in the aggregation pathway, such as oligomeric clusters (globules), bead-like structures, and ring-shaped aggregates. We suggest that fibril formation may take place through the role of association-competent oligomeric intermediates, resulting in a kinetic pathway via clustering of these oligomeric species to yield protofibrils and then fibrils. The resultant fibrils are elongated but curly, and differ in length depending on solution conditions. Under acidic conditions, circular fibrils are commonly observed if the fibrils are sufficiently flexible and long enough for the ends to find themselves regularly in close proximity to each other. These fibrils

  13. 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

  14. Study of human serum albumin-TiO(2) nanocrystalline electrodes interaction by impedance electrochemical spectroscopy.

    PubMed

    Oliva, F Y; Avalle, L B; Macagno, V A; De Pauli, C P

    2001-07-02

    The adsorption of human serum albumin (HSA) onto nanocrystalline TiO(2) electrodes was studied by electrochemical impedance spectroscopy (EIS) in function of pH and electrode potential. The characterization and physico-chemical properties of the TiO(2) electrode were investigated by scanning electron microscopy (SEM), UV-photoelectron spectroscopy (UPS), cyclic voltammetry and capacitance measurements. The impedance response of the particulate TiO(2) electrode/protein interface was fitted using an equivalent circuit model to describe the adsorption process. The adsorbed protein layer, which is formed as soon as the protein is injected into the solution and becomes in contact with the electrode, was investigated as a function of electrode potential and solution pH. The measurements were performed under pseudo-steady-state and steady-state conditions, which gave information about the different states of the system. With the pseudo-steady state measurements, it was possible to determine two rate constants of the protein adsorption process, which correspond to two different states of the protein. The shortest one was associated with the first contact between the protein and the substrate and the second relaxation time, with the protein suffering an structural rearrangement due to the interaction with the TiO(2) electrode. It was detected that at sufficiently long times (approx. 1 h, where the system was under steady state conditions), a quasi-reversible protein adsorption mechanism was established. The measurements performed as a function of frequency under steady-state conditions, an equivalent circuit with a Warburg element gave the better fitting to data taken at -0.585 V closer to the oxide flat band potential and it was associated with protein diffusion. Experimental results obtained at only one frequency as a function of potential could be fitted to a model that takes into account non-specific and probable specific protein adsorption, which renders to be

  15. [Use of recombinant Human Growth Hormone (rHGH)].

    PubMed

    Calzada-León, Raúl

    2017-01-01

    Recombinant human growth hormone, synthesized in E.coli or mammalian cells cultures, is since 1985, a useful therapeutic resource to increase growth velocity and final height. In this paper are discussed the four phases (aims, security and efficacy, utility and efficiency) indispensables to define the start of treatment, as well as the absolute, relative and metabolic indications and the transitory and permanent conditions that contraindicate its use. It is commented the way to optimize the results (simple but indispensables indications for the physician, the patients and their family). Finally it is analyzed the results of treatment in patients with growth hormone deficiency, Turner syndrome, chronic renal failure, Prader-Willi syndrome, Noonan syndrome, SHOX deficiency, intrauterine growth retardation and idiopathic short stature.

  16. Adsorption of biopolymers human serum albumin and human gamma globulin to well-defined surfaces of self-assembled monolayers

    NASA Astrophysics Data System (ADS)

    Cregger, Tricia Ann

    The tenacity with which the blood proteins Human Serum Albumin (HSA) and Human Gamma Globulin (HGG) adsorb to a surface modified with a monomolecular coating varies with the packing of the alkyl chains in the coating. The adsorption of proteins onto well-defined surfaces of self-assembled monolayers (SAMs) was studied with X-ray reflectometry (XR), neutron reflectometry (NR), optical reflectometry, and total internal reflection fluorescence (TIRF). NR and XR was used to study adsorption in the absence of flow, while optical reflectometry and TIRF were used to probe the adsorption under flow conditions. In particular, competitive adsorption measurements of binary solutions of HSA, HGG and Fibrinogen (FIB) were performed with TIRE The properties of the surface were varied by altering the alkyl chains' packing density and the chain end functionality of the SAMs. The depth profiles of protein concentration near the adsorbing surface measured by NR were dependent upon the chain packing density in the case of HSA. The concentration depth profile of HGG was unaltered by varying chain packing density. Measurements performed under flow using optical reflectometry showed a different behavior: the surface excess of adsorbed HSA was relatively independent of the surface packing, while the surface excess of HGG depended on the packing density of the SAM. The tenacity with which the proteins adsorbed to different functionalized surfaces was determined by attempting to remove the protein using a strong surfactant, sodium dodecyl sulfate (SDS). Ex situ XR measurements suggested that both HSA and HGG adsorb more tenaciously to a less densely-packed monolayer, almost independent of surface functionality. Two exceptions were a less densely-packed vinyl-terminated monolayer and a less densely-packed bromine-terminated monolayer, from which HSA could not be removed at all.

  17. Human albumin solution for patients with cirrhosis and acute on chronic liver failure: Beyond simple volume expansion

    PubMed Central

    Valerio, Christopher; Theocharidou, Eleni; Davenport, Andrew; Agarwal, Banwari

    2016-01-01

    To provide an overview of the properties of human serum albumin (HSA), and to review the evidence for the use of human albumin solution (HAS) in critical illness, sepsis and cirrhosis. A MEDLINE search was performed using the terms “human albumin”, “critical illness”, “sepsis” and “cirrhosis”. The references of retrieved articles were reviewed manually. Studies published between 1980 and 2014 were selected based on quality criteria. Data extraction was performed by all authors. HSA is the main plasma protein contributing greatly to its oncotic pressure. HSA demonstrates important binding properties for endogenous and exogenous toxins, drugs and drug metabolites that account for its anti-oxidant and anti-inflammatory properties. In disease states, hypoalbuminaemia is secondary to decreased HSA production, increased loss or transcapillary leakage into the interstitial space. HSA function can be also altered in disease with reduced albumin binding capacity and increased production of modified isoforms. HAS has been used as volume expander in critical illness, but received criticism due to cost and concerns regarding safety. More recent studies confirmed the safety of HAS, but failed to show any survival benefit compared to the cheaper crystalloid fluids, therefore limiting its use. On the contrary, in cirrhosis there is robust data to support the efficacy of HAS for the prevention of circulatory dysfunction post-large volume paracentesis and in the context of spontaneous bacterial peritonitis, and for the treatment of hepato-renal syndrome and hypervolaemic hyponatraemia. It is likely that not only the oncotic properties of HAS are beneficial in cirrhosis, but also its functional properties, as HAS replaces the dysfunctional HSA. The role of HAS as the resuscitation fluid of choice in critically ill patients with cirrhosis, beyond the established indications for HAS use, should be addressed in future studies. PMID:26981172

  18. Short-term effects of recombinant human growth hormone and feeding on gluconeogenesis in humans

    Technology Transfer Automated Retrieval System (TEKTRAN)

    After a short-term fast, lactating women have increased rates of glucose production but not gluconeogenesis (GNG) despite relative hypoinsulinemia. We explored the effects of non-insulin-dependent increase in glucose utilization and recombinant human growth hormone (rhGH) on glucose production, glyc...

  19. Explaining the highly enantiomeric photocyclodimerization of 2-anthracenecarboxylate bound to human serum albumin using time-resolved anisotropy studies.

    PubMed

    Fuentealba, Denis; Kato, Hanako; Nishijima, Masaki; Fukuhara, Gaku; Mori, Tadashi; Inoue, Yoshihisa; Bohne, Cornelia

    2013-01-09

    The mechanism for the high enantiomeric excess (ee) (80-90%) observed in the photocyclodimerization of 2-anthracenecarboxylate (AC) in the chiral binding sites of human serum albumin (HSA) was studied using fluorescence anisotropy. A long rotational correlation time of 36 ns was observed for the excited states of the ACs bound to the HSA site responsible for the high ee, suggesting that the ACs have restricted rotational mobility in this site. The ACs in this site have the same prochiral face protected by the protein, and this protection is responsible for the high ee observed. These insights provide a strategy for the rational design of supramolecular photochirogenic systems.

  20. Study on the interaction of sulforaphane with human and bovine serum albumins.

    PubMed

    Abassi, Parvane; Abassi, Farzane; Yari, Faramarz; Hashemi, Mehrdad; Nafisi, Shohreh

    2013-05-05

    Sulforaphane; [1-isothiocyanato-4-(methylsulfinyl) butane], (SFN) is an isothiocyanate derived from glucoraphanin present in cruciferous vegetables and has a variety of potential chemopreventive actions. This study was designed to examine the interaction of sulforaphane with HSA and BSA. FTIR, UV-Vis spectroscopic methods as well as molecular modeling were used to determine the drug binding mode, binding constant and the effect of drug complexation on serum albumins stability and conformation. Structural analysis showed that SFN bind HSA and BSA via polypeptide polar groups with overall binding constants of KSFN-HSA=6.54×10(4) and KSFN-BSA=8.55×10(4) M(-1). HSA and BSA conformations were altered by a major reduction of α-helix upon SFN interaction. These results suggest that serum albumins might act as carrier proteins for SFN in delivering them to target tissues.

  1. Induction of antinuclear antibodies in patients with rheumatoid arthritis receiving treatment with human recombinant interferon gamma.

    PubMed Central

    Seitz, M; Franke, M; Kirchner, H

    1988-01-01

    Of six patients with rheumatoid arthritis (RA) treated with human recombinant interferon gamma for two to eight months, three developed antinuclear antibodies (ANAs). This was accompanied by a simultaneous clinical exacerbation of the disease activity. In this study both anti-inflammatory and immunostimulatory effects of human recombinant interferon gamma in patients with RA were observed. PMID:3137901

  2. The inhibitory effect of ionizing radiation on Fc and C3 receptors on mouse and human leukocytes, and the protective potential of human albumin

    SciTech Connect

    Herrera, M.A.; Diaz-Perches, R.; Gutierrez, M.; Gamminio, E.; Liera, C.; Nieto, P.; Weiss-Steider, B. )

    1990-08-01

    The effect that ionizing radiation has in vitro on Fc and C3 receptors was evaluated at various doses and measured by means of erythrocytes coated with antibody (EA) and erythrocytes coated with antibody and complement (EAC) rosettes on human peripheral blood leukocytes (PBL) and on mouse bone marrow cells (BMC) and PBL. We found that the number of cells with either EA and EAC rosettes decreased as the radiation doses increased, and that they were almost absent when the highest doses were employed. We obtained evidence that albumin is a natural source of radio-protection for Fc and C3 receptors, and we showed that by increasing the amount of this molecule we could completely protect receptors for EA and EAC in vitro. Finally, the possible therapeutic value of the administration of human albumin to patients undergoing radiotherapy is discussed.

  3. Glycolaldehyde and maleyl conjugated human serum albumin as potential macrophage-targeting carriers for molecular imaging purposes.

    PubMed

    Gustafsson, Björn; Hedin, Ulf; Caidahl, Kenneth

    2015-01-01

    Maleylated bovine serum albumin is a known ligand for targeting macrophages and has potential as a carrier for molecular imaging purposes. We present a novel synthesis of glycolaldehyde-conjugated human serum albumin (GA-HSA) and maleylated human serum albumin (Mal-HSA). Seventeen modifications of fluorescently tagged GA-HSA and Mal-HSA molecules with different degrees of conjugation were prepared. The comparative uptake studies, using 12 of these modifications, were done in vitro on mouse monocytes/macrophages (RAW264.7), and evaluated qualitatively by confocal microscopy and quantitatively by flow cytometry. The GA modifications are taken up by the macrophages approximately 40% better than the maleyl modifications at low concentrations (≤ 3 μM), while at higher concentrations it appears that the maleyl modifications are taken up around 25-44% better than the GA-modified HSA. However, high uptake at low concentrations will be beneficial for in vivo localizing inflammation in areas with low penetration of the probe as in an atherosclerotic plaque. Further, another advantage of GA-HSA is that GA competes less than the maleyl group for the free reactive amine sites that are to be used for conjugation of metal chelating ligands (e.g. tetraazacyclododecanetetraacetic acid and triazacyclononanetriacetic acid). Metal ions such as Gd(3+) and Mn(2+) can be chelated for positive Magnetic Resonance (MR) contrast and positron emitting ions such as (64) Cu(2+) and (68) Ga(3+) for Positron Emission Tomography (PET) imaging. These are important properties, especially, when considering the MR contrast possibilities owing to the low sensitivity of the technique, and would motivate the use of GA-HSA before Mal-HSA.

  4. Numb Protects Human Renal Tubular Epithelial Cells From Bovine Serum Albumin-Induced Apoptosis Through Antagonizing CHOP/PERK Pathway.

    PubMed

    Ding, Xuebing; Ma, Mingming; Teng, Junfang; Shao, Fengmin; Wu, Erxi; Wang, Xuejing

    2016-01-01

    In recent studies, we found that Numb is involved in oxidative stress-induced apoptosis of renal proximal tubular cells; however, its function on ER stress-induced apoptosis in proteinuric kidney disease remains unknown. The objective of the present study is to explore the role of Numb in urinary albumin-induced apoptosis of human renal tubular epithelial cells (HKCs). In this study, we demonstrate that incubation of HKCs with bovine serum albumin (BSA) resulted in caspase three-dependent cell death. Numb expression was down-regulated by BSA in a time- and dose-dependent manner. Knockdown of Numb by siRNA sensitized HKCs to BSA-induced apoptosis, whereas overexpression of Numb protected HKCs from BSA-induced apoptosis. Moreover, BSA activated CHOP/PERK signaling pathway in a time- and dose-dependent manner as indicated by increased expression of CHOP, PERK, and P-PERK. Furthermore, knockdown of CHOP or PERK significantly attenuated the promoting effect of Numb on BSA-induced apoptosis, while overexpression of CHOP impaired the protective effect of Numb on BSA-induced apoptosis. Taken together, our findings demonstrate that Numb plays a protective role on BSA-induced apoptosis through inhibiting CHOP/PERK signaling pathway in human renal tubular epithelial cells. Therefore, the results from this study provides evidence that Numb is a new target of ER-associated apoptotic signaling networks and Numb may serve as a promising therapeutic target for proteinuric diseases.

  5. Investigation of the effect of mutations of rat albumin on the binding affinity to the alpha(4)beta(1) integrin antagonist, 4-[1-[3-chloro-4-[N'-(2-methylphenyl)ureido]phenylacetyl]-(4S)-fluoro-(2S)-pyrrolidine-2-yl]methoxybenzoic acid (D01-4582), using recombinant rat albumins.

    PubMed

    Ito, Takashi; Takahashi, Masayuki; Okazaki, Osamu; Sugiyama, Yuichi

    2010-08-02

    The authors reported previously rat strain differences in plasma protein binding to alpha(4)beta(1) antagonist D01-4582, resulting in a great strain difference in its pharmacokinetics (19-fold differences in the AUC). The previous study suggested that amino acid changes of V238L and/or T293I in albumin reduced the binding affinity. In order to elucidate the relative significance of these mutations, an expression system was developed to obtain recombinant rat albumins (rRSA) using Pichia pastoris, followed by a binding analysis of four rRSAs by the ultracentrifugation method. The equilibrium dissociation constant (K(d)) of wild-type rRSA was 210 nM, while K(d) of rRSA that carried both V238L and T293I mutations was 974 nM. K(d) of artificial rRSA that carried only V238L was 426 nM, and K(d) of artificial rRSA that carried only T293I was 191 nM. These results suggested that V238L would be more important in the alteration of K(d). However, since none of the single mutations were sufficient to explain the reduction of affinity, the possibility was also suggested that T293I interacted cooperatively to reduce the binding affinity of rat albumin to D01-4582. Further investigation is required to elucidate the mechanism of the possible cooperative interaction.

  6. [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

  7. Study of twenty preparations of human albumin solution which failed in quality control testing due to elevated sodium content, a poor internal quality control at manufacturing unit.

    PubMed

    Prasad, J P; Madhu, Y; Singh, Surinder; Soni, G R; Agnihotri, N; Singh, Varsha; Kumar, Pradeep; Jain, Nidhi; Prakash, Anu; Singh, Varun

    2016-11-01

    Current study is conducted in our laboratory due to failure in quality control testing of twenty batches of Human Albumin solution in which sodium content is higher than the prescribed limit. These batches are received in short duration from indigenous manufacturer and is the first incident of failure of Human albumin preparation in sodium content of manufacturer. On request of manufacturer, study is conducted to rule out the cause. Repeat testing of each out of specification batch is conducted and a trend analysis is drawn between our findings and manufacturer's results, also study of trend analysis of manufacturer for the last one year. Trend analysis data indicated towards poor consistency of batches with major shift at various time intervals in sodium content of human albumin preparation. Further analysis rule out that non-traceable quality of standard used in the internal quality control testing by manufacturer is the root cause of the problem.

  8. Production of transgenic cattle highly expressing human serum albumin in milk by phiC31 integrase-mediated gene delivery.

    PubMed

    Luo, Yan; Wang, Yongsheng; Liu, Jun; Lan, Hui; Shao, Minghao; Yu, Yuan; Quan, Fusheng; Zhang, Yong

    2015-10-01

    Transgenic cattle expressing high levels of recombinant human serum albumin (HSA) in their milk may as an alternative source for commercial production. Our objective was to produce transgenic cattle highly expressing HSA in milk by using phiC31 integrase system and somatic cell nuclear transfer (SCNT). The mammary-specific expression plasmid pIACH(-), containing the attB recognition site for phiC31 integrase, were co-transfected with integrase expression plasmid pCMVInt into bovine fetal fibroblast cells (BFFs). PhiC31 integrase-mediated integrations in genome of BFFs were screened by nested inverse PCR. After analysis of sequence of the PCR products, 46.0% (23/50) of the both attB-genome junction sites (attL and attR) were confirmed, and four pseudo attP sites were identified. The integration rates in BF3, BF11, BF19 and BF4 sites were 4.0% (2/50), 6.0% (3/50), 16.0% (8/50) and 20.0% (10/50), respectively. BF3 is located in the bovine chromosome 3 collagen alpha-3 (VI) chain isomer 2 gene, while the other three sites are located in the non-coding region. The transgenic cell lines from BF11, BF19 and BF4 sites were used as donors for SCNT. Two calves from transgenic cells BF19 were born, one died within a few hours after birth, and another calf survived healthy. PCR and Southern blot analysis revealed integration of the transgene in the genome of cloned calves. The nested reverse PCR confirmed that the integration site in cloned calves was identical to the donor cells. The western blotting assessment indicated that recombinant HSA was expressed in the milk of transgenic cattle and the expression level was about 4-8 mg/mL. The present study demonstrated that phiC31 integrase system was an efficient and safety gene delivery tool for producing HSA transgenic cattle. The production of recombinant HSA in the milk of cattle may provide a large-scale and cost-effective resource.

  9. Transport of benzo[alpha]pyrene in the dually perfused human placenta perfusion model: effect of albumin in the perfusion medium.

    PubMed

    Mathiesen, Line; Rytting, Erik; Mose, Tina; Knudsen, Lisbeth E

    2009-09-01

    Transport of benzo[alpha]pyrene (BaP) across the placenta was examined because it is a ubiquitous and highly carcinogenic substance found in tobacco smoke, polluted air and certain foods. Foetal exposure to this substance is highly relevant but is difficult to estimate. The human placenta is unique compared to other species; since it is available without major ethical obstacles, we have used the human placenta perfusion model to study transport from mother to foetus. Placentas were donated after births at Rigshospitalet in Copenhagen from pregnant mothers who signed an informed consent. BaP is lipophilic and studies using cell culture medium in 6-hr placenta perfusions showed minimal transport through the placenta. To increase the solubility of BaP in perfusion medium and to increase physiological relevance, perfusions were also performed with albumin added to the perfusion medium [2 and 30 mg/ml bovine serum albumin (BSA) and 30 mg/ml human serum albumin (HSA)]. The addition of albumin resulted in increased transfer of BaP from maternal to foetal reservoirs. The transfer was even higher in the presence of an HSA formulation containing acetyltryptophanate and caprylate, resulting in a foetal-maternal concentration (FM) ratio of 0.71 +/- 0.10 after 3 hr and 0.78 +/- 0.11 after 6 hr, whereas the FM ratio in perfusions without albumin was only 0.05 +/- 0.03 after 6 hr of perfusion. Less BaP accumulated in placental tissue in perfusions with added albumin. This shows that transplacental transport of the pro-carcinogenic substance BaP occurs, and emphasizes the importance of adding physiological concentrations of albumin when studying the transport of lipophilic substances.

  10. The Cluster [Re6Se8I6]3− Induces Low Hemolysis of Human Erythrocytes in Vitro: Protective Effect of Albumin

    PubMed Central

    Rojas-Mancilla, Edgardo; Oyarce, Alexis; Verdugo, Viviana; Zheng, Zhiping; Ramírez-Tagle, Rodrigo

    2015-01-01

    The cluster Re6Se8I63− has been shown to induce preferential cell death of a hepatic carcinoma cell line, thus becoming a promising anti-cancer drug. Whether this cluster induces acute hemolysis or if it interacts with albumin remains unclear. The effect of acute exposure of human red blood cells to different concentrations of the cluster with and without albumin is described. Red blood cells from healthy donors were isolated, diluted at 1% hematocrit and exposed to the cluster (25–150 µM) at 37 °C, under agitation. Hemolysis and morphology were analyzed at 1 and 24 h. The potential protection of 0.1% albumin was also evaluated. Exposition to therapeutic doses of the cluster did not induce acute hemolysis. Similar results were observed following 24 h of exposition, and albumin slightly reduced hemolysis levels. Furthermore, the cluster induced alteration in the morphology of red blood cells, and this was prevented by albumin. Together, these results indicate that the cluster Re6Se8I63− is not a hemolytic component and induces moderate morphological alterations of red blood cells at high doses, which are prevented by co-incubation with albumin. In conclusion, the cluster Re6Se8I63− could be intravenously administered in animals at therapeutic doses for in vivo studies. PMID:25590300

  11. Development of Diagnostic Fragment Ion Library for Glycated Peptides of Human Serum Albumin: Targeted Quantification in Prediabetic, Diabetic, and Microalbuminuria Plasma by Parallel Reaction Monitoring, SWATH, and MSE*

    PubMed Central

    Korwar, Arvind M.; Vannuruswamy, Garikapati; Jagadeeshaprasad, Mashanipalya G.; Jayaramaiah, Ramesha H.; Bhat, Shweta; Regin, Bhaskaran S.; Ramaswamy, Sureshkumar; Giri, Ashok P.; Mohan, Viswanathan; Balasubramanyam, Muthuswamy; Kulkarni, Mahesh J.

    2015-01-01

    Human serum albumin is one of the most abundant plasma proteins that readily undergoes glycation, thus glycated albumin has been suggested as an additional marker for monitoring glycemic status. Hitherto, only Amadori-modified peptides of albumin were quantified. In this study, we report the construction of fragment ion library for Amadori-modified lysine (AML), N(ε)-(carboxymethyl)lysine (CML)-, and N(ε)-(carboxyethyl)lysine (CEL)-modified peptides of the corresponding synthetically modified albumin using high resolution accurate mass spectrometry (HR/AM). The glycated peptides were manually inspected and validated for their modification. Further, the fragment ion library was used for quantification of glycated peptides of albumin in the context of diabetes. Targeted Sequential Window Acquisition of all THeoretical Mass Spectra (SWATH) analysis in pooled plasma samples of control, prediabetes, diabetes, and microalbuminuria, has led to identification and quantification of 13 glycated peptides comprised of four AML, seven CML, and two CEL modifications, representing nine lysine sites of albumin. Five lysine sites namely K549, K438, K490, K88, and K375, were observed to be highly sensitive for glycation modification as their respective m/z showed maximum fold change and had both AML and CML modifications. Thus, peptides involving these lysine sites could be potential novel markers to assess the degree of glycation in diabetes. PMID:26023067

  12. Human recombinant RNASET2: A potential anti-cancer drug.

    PubMed

    Roiz, Levava; Smirnoff, Patricia; Lewin, Iris; Shoseyov, Oded; Schwartz, Betty

    2016-01-01

    The roles of cell motility and angiogenetic processes in metastatic spread and tumor aggressiveness are well established and must be simultaneously targeted to maximize antitumor drug potency. This work evaluated the antitumorigenic capacities of human recombinant RNASET2 (hrRNASET2), a homologue of the Aspergillus niger T2RNase ACTIBIND, which has been shown to display both antitumorigenic and antiangiogenic activities. hrRNASET2 disrupted intracellular actin filament and actin-rich extracellular extrusion organization in both CT29 colon cancer and A375SM melanoma cells and induced a significant dose-dependent inhibition of A375SM cell migration. hrRNASET2 also induced full arrest of angiogenin-induced tube formation and brought to a three-fold lower relative HT29 colorectal and A375SM melanoma tumor volume, when compared to Avastin-treated animals. In parallel, mean blood vessel counts were 36.9% lower in hrRNASET2-vs. Avastin-treated mice and survival rates of hrRNASET2-treated mice were 50% at 73 days post-treatment, while the median survival time for untreated animals was 22 days. Moreover, a 60-day hrRNASET2 treatment period reduced mean A375SM lung metastasis foci counts by three-fold when compared to untreated animals. Taken together, the combined antiangiogenic and antitumorigenic capacities of hrRNASET2, seemingly arising from its direct interaction with intercellular and extracellular matrices, render it an attractive anticancer therapy candidate.

  13. Human recombinant RNASET2: A potential anti-cancer drug

    PubMed Central

    Roiz, Levava; Smirnoff, Patricia; Lewin, Iris; Shoseyov, Oded; Schwartz, Betty

    2016-01-01

    The roles of cell motility and angiogenetic processes in metastatic spread and tumor aggressiveness are well established and must be simultaneously targeted to maximize antitumor drug potency. This work evaluated the antitumorigenic capacities of human recombinant RNASET2 (hrRNASET2), a homologue of the Aspergillus niger T2RNase ACTIBIND, which has been shown to display both antitumorigenic and antiangiogenic activities. hrRNASET2 disrupted intracellular actin filament and actin-rich extracellular extrusion organization in both CT29 colon cancer and A375SM melanoma cells and induced a significant dose-dependent inhibition of A375SM cell migration. hrRNASET2 also induced full arrest of angiogenin-induced tube formation and brought to a three-fold lower relative HT29 colorectal and A375SM melanoma tumor volume, when compared to Avastin-treated animals. In parallel, mean blood vessel counts were 36.9% lower in hrRNASET2-vs. Avastin-treated mice and survival rates of hrRNASET2-treated mice were 50% at 73 days post-treatment, while the median survival time for untreated animals was 22 days. Moreover, a 60-day hrRNASET2 treatment period reduced mean A375SM lung metastasis foci counts by three-fold when compared to untreated animals. Taken together, the combined antiangiogenic and antitumorigenic capacities of hrRNASET2, seemingly arising from its direct interaction with intercellular and extracellular matrices, render it an attractive anticancer therapy candidate. PMID:27014725

  14. Recombinant methods for screening human DNA excision repair proficiency

    SciTech Connect

    Athas, W.F.

    1988-01-01

    A method for measuring DNA excision repair in response to ultraviolet radiation (UV)-induced DNA damage has been developed, validated, and field-tested in cultured human lymphocytes. The methodology is amenable to population-based screening and should facilitate future epidemiologic studies seeking to investigate associations between excision repair proficiency and cancer susceptibility. The impetus for such endeavors derives from the belief that the high incidence of skin cancer in the genetic disorder xeroderma pigmentosum (XP) primarily is a result of the reduced capacity of patients cells to repair UV-induced DNA damage. For assay, UV-irradiated non-replicating recombinant plasmid DNA harboring a chloramphenicol acetyltransferase (CAT) indicator gene is introduced into lymphocytes using DEAE-dextran short-term transfection conditions. Exposure to UV induces transcriptionally-inactivating DNA photoproducts in the plasmid DNA which inactivate CAT gene expression. Excision repair of the damaged CAT gene is monitored indirectly as a function of reactivated CAT enzyme activity following a 40 hour repair/expression incubation period.

  15. Expression and biochemical characterization of recombinant human epididymis protein 4.

    PubMed

    Hua, Ling; Liu, Yunhui; Zhen, Shuai; Wan, Deyou; Cao, Jiyue; Gao, Xin

    2014-10-01

    Whey acidic proteins (WAP) belong to a large gene family of antibacterial peptides that perform critical immune system functions. The function of human epididymis protein 4 (HE4), a 124-amino acid long polypeptide that has two whey acidic protein four-disulfide core (WFDC) domains, is not well studied. Here, a fusion gene encoding the HE4 protein fused to an IgG1 Fc domain was constructed. The recombinant HE4 protein was expressed as a secretory protein in Pichia pastoris and mammalian HEK293-F cells and was subsequently purified. Our data suggested that the HE4 protein produced by these two expression systems bound to both gram-negative and gram-positive bacteria, but demonstrated slightly inhibitory activity towards the growth of Staphylococcus aureus. Moreover, HE4 exhibited proteinase inhibitory activity towards trypsin, elastase, matrix metallopeptidase 9, and the secretory proteinases from Bacillus subtilis. The effects of glycosylation on the biochemical characterization of HE4 were also investigated. LC-ESI-MS glycosylation analysis showed that the high-mannose glycosylated form of HE4 expressed by P. pastoris has lower biological activity when compared to its complex-glycosylated form produced from HEK293-F cells. The implications of this are discussed, which may be provide theoretical basis for its important role in the development of cancer and innate immune system.

  16. Conformation and activity of recombinant human fibroblast interferon-beta.

    PubMed

    Boublik, M; Moschera, J A; Wei, C; Kung, H F

    1990-04-01

    Conformation of highly purified recombinant human fibroblast interferon-beta (rHuIFN-beta) was correlated with its biological activity. The extent of ordered secondary structure was determined by circular dichroic (CD) spectroscopy in various buffer conditions to establish conditions of protein stability and its potential for helix formation. The highest "helicity" (about 50 +/- 5% of alpha-helices) and the highest antiviral activities (4-10 x 10(7) units/mg) were found in 50% ethylene glycol, 1 M NaCl and 0.05 M Na3PO4, pH 7.2 (Buffer I); 80 mM citric acid, 20 mM Na2HPO4, pH 2.9 (Buffer II); and 25 mM NH4OAc, 125 mM NaCl, pH 5.1 (Buffer III). Both helicity and antiviral activity of the IFN-beta decrease in parallel with denaturation by urea, heat, and/or by repeated cycles of freezing and thawing. Low pH (pH 2.9 Buffer II) exhibits a distinct stabilizing effect on the structure and antiviral activity of IFN-beta against heat denaturation.

  17. Recombinant Human Factor IX Produced from Transgenic Porcine Milk

    PubMed Central

    Lee, Meng-Hwan; Lin, Yin-Shen; Tu, Ching-Fu; Yen, Chon-Ho

    2014-01-01

    Production of biopharmaceuticals from transgenic animal milk is a cost-effective method for highly complex proteins that cannot be efficiently produced using conventional systems such as microorganisms or animal cells. Yields of recombinant human factor IX (rhFIX) produced from transgenic porcine milk under the control of the bovine α-lactalbumin promoter reached 0.25 mg/mL. The rhFIX protein was purified from transgenic porcine milk using a three-column purification scheme after a precipitation step to remove casein. The purified protein had high specific activity and a low ratio of the active form (FIXa). The purified rhFIX had 11.9 γ-carboxyglutamic acid (Gla) residues/mol protein, which approached full occupancy of the 12 potential sites in the Gla domain. The rhFIX was shown to have a higher isoelectric point and lower sialic acid content than plasma-derived FIX (pdFIX). The rhFIX had the same N-glycosylation sites and phosphorylation sites as pdFIX, but had a higher specific activity. These results suggest that rhFIX produced from porcine milk is physiologically active and they support the use of transgenic animals as bioreactors for industrial scale production in milk. PMID:24955355

  18. Boundary mode lubrication of articular cartilage by recombinant human lubricin.

    PubMed

    Gleghorn, Jason P; Jones, Aled R C; Flannery, Carl R; Bonassar, Lawrence J

    2009-06-01

    Lubrication of cartilage involves a variety of physical and chemical factors, including lubricin, a synovial glycoprotein that has been shown to be a boundary lubricant. It is unclear how lubricin boundary lubricates a wide range of bearings from tissue to artificial surfaces, and if the mechanism is the same for both soluble and bound lubricin. In the current study, experiments were conducted to investigate the hypothesis that recombinant human lubricin (rh-lubricin) lubricates cartilage in a dose-dependent manner and that soluble and bound fractions of rh-lubricin both contribute to the lubrication process. An rh-lubricin dose response was observed with maximal lubrication achieved at concentrations of rh-lubricin greater than 50 microg/mL. A concentration-response variable-slope model was fit to the data, and indicated that rh-lubricin binding to cartilage was not first order. The pattern of decrease in equilibrium friction coefficient indicated that aggregation of rh-lubricin or steric arrangement may regulate boundary lubrication. rh-lubricin localized at the cartilage surface was found to lubricate a cartilage-glass interface in boundary mode, as did soluble rh-lubricin at high concentrations (150 microg/mL); however, the most effective lubrication occurred when both soluble and bound rh-lubricin were present at the interface. These findings point to two distinct mechanisms by which rh-lubricin lubricates, one mechanism involving lubricin bound to the tissue surface and the other involving lubricin in solution.

  19. The disulphide mapping, folding and characterisation of recombinant Ber e 1, an allergenic protein, and SFA8, two sulphur-rich 2S plant albumins.

    PubMed

    Alcocer, Marcos J C; Murtagh, Gareth J; Bailey, Kevin; Dumoulin, Mireille; Meseguer, Amparo Sarabia; Parker, Martin J; Archer, David B

    2002-11-15

    We have cloned and expressed genes encoding the allergenic brazil nut 2S albumin (Ber e 1) and the sunflower albumin 8 (SFA8) in the methylotrophic yeast Pichia pastoris. We show that both proteins were secreted at high levels and that the purified proteins were properly folded. We also showed that Ber e 1 is glycosylated during secretion and that the glycan does not interfere with the folding or immunoreactivity. The disulphide map of the Ber e 1 protein was experimentally established and is in agreement with the conserved disulphide structure of other members of the 2S albumin family. A model three-dimensional structure of the allergen was generated. During the expression studies and through mutation we have also shown that alteration of the sequences around the Kex2 endoproteolytic processing site in the expressed fusion protein can compromise the secretion by targeting part of the protein for possible degradation. The secreted production of these properly folded sulphur-rich plant albumins presents an opportunity to delineate the attributes that make an allergen and to facilitate the diagnosis and therapy of type I allergy.

  20. Human recombinant erythropoietin in the prevention and treatment of anemia of prematurity.

    PubMed

    Ohls, Robin K

    2002-01-01

    Human recombinant erythropoietin has been studied extensively as treatment for a variety of anemias. Since in vitro studies showed the primary etiology of the anemia of prematurity to be insufficient serum erythropoietin concentrations, clinical trials have evaluated the administration of human recombinant erythropoietin to preterm infants to treat this indication. These studies were followed by pharmacokinetic determinations in animal models and preterm infants, which revealed that preterm infants required greater doses of human recombinant erythropoietin because of a more rapid clearance and greater volume of distribution. Recent studies have focused on the administration of human recombinant erythropoietin in the first weeks of life to alleviate the anemia caused by excessive phlebotomy losses, and to prevent the anemia of prematurity. In addition, human recombinant erythropoietin has been tried clinically in a variety of neonatal populations in an attempt to decrease or eliminate transfusions. Although much information has been accumulated about the clinical use of human recombinant erythropoietin in preterm infants over the last 15 years, many questions remain unanswered. The evolution of clinical practice in the care of extremely low birthweight infants continues to affect the number of transfusions. It is likely that human recombinant erythropoietin administration in combination with instituting rigorous transfusion guidelines and decreasing phlebotomy losses will have the greatest impact in decreasing transfusion requirements in all preterm and term neonates, regardless of the etiology of their anemia.

  1. Expression of adrenomedullin in rats after spinal cord injury and intervention effect of recombinant human erythropoietin.

    PubMed

    Zhao, Liang; Jing, Yu; Qu, Lin; Meng, Xiangwei; Cao, Yang; Tan, Huibing

    2016-12-01

    The expression of adrenomedullin (ADM) in injured tissue of rat spinal cord was observed and the effect of recombinant human erythropoietin was analyzed. A total of 45 Sprague-Dawley rats were selected and divided into 3 equal groups including, a sham-operation group in which rats received an excision of vertebral plate; a spinal cord injury model group and a recombinant human erythropoietin group in which rats with spinal cord injury received a caudal vein injection of 300 units recombinant human erythropoietin after injury. Hematoxylin and eosin staining was performed to observe the spinal cord injury conditions. Immunohistochemical staining was performed to observe the expression of ADM. Pathologic changes in the group of recombinant human erythropoietin at various times were significantly less severe than those in the group of spinal cord injury model. The expression of ADM was increased particularly in the group of recombinant human erythropoietin (P<0.01). The improved Tarlov scores of the group of spinal cord injury model and the group of recombinant human erythropoietin were lower than those of the sham-operation group at 3, 6 and 9 days (P<0.01). Thus, the recombinant human erythropoietin is capable of alleviating the secondary injury of spinal cord. One of the mechanisms may be achieved by promoting the increase of ADM expression.

  2. Expression of adrenomedullin in rats after spinal cord injury and intervention effect of recombinant human erythropoietin

    PubMed Central

    Zhao, Liang; Jing, Yu; Qu, Lin; Meng, Xiangwei; Cao, Yang; Tan, Huibing

    2016-01-01

    The expression of adrenomedullin (ADM) in injured tissue of rat spinal cord was observed and the effect of recombinant human erythropoietin was analyzed. A total of 45 Sprague-Dawley rats were selected and divided into 3 equal groups including, a sham-operation group in which rats received an excision of vertebral plate; a spinal cord injury model group and a recombinant human erythropoietin group in which rats with spinal cord injury received a caudal vein injection of 300 units recombinant human erythropoietin after injury. Hematoxylin and eosin staining was performed to observe the spinal cord injury conditions. Immunohistochemical staining was performed to observe the expression of ADM. Pathologic changes in the group of recombinant human erythropoietin at various times were significantly less severe than those in the group of spinal cord injury model. The expression of ADM was increased particularly in the group of recombinant human erythropoietin (P<0.01). The improved Tarlov scores of the group of spinal cord injury model and the group of recombinant human erythropoietin were lower than those of the sham-operation group at 3, 6 and 9 days (P<0.01). Thus, the recombinant human erythropoietin is capable of alleviating the secondary injury of spinal cord. One of the mechanisms may be achieved by promoting the increase of ADM expression. PMID:28101163

  3. Analysis of recombinant human tumour necrosis factor-alpha-induced CD4 expression on human eosinophils.

    PubMed Central

    Hossain, M; Okubo, Y; Horie, S; Sekiguchi, M

    1996-01-01

    We examined the hypothesis that one of the pro-inflammatory cytokines, tumour necrosis factor-alpha (TNF-alpha), could induce expression of the adhesion molecule CD4 on human eosinophils. We further examined the effector function of CD4 and the mechanisms regulating CD4 expression. Human eosinophils were cultured with various concentrations of recombinant human TNF-alpha (rhTNF-alpha) with or without various drugs for 24 hr. After culture, eosinophils were stained for CD4 using a monoclonal antibody and then analysed by flow cytometry. Eosinophil-derived neurotoxin (EDN) release as eosinophil degranulation was examined by cross-linking of CD4 on eosinophils. The rhTNF-alpha induced CD4 expression on human eosinophils in a dose- and time-dependent fashion; rhTNF-alpha-induced CD4 expression was significantly inhibited by 10(-6) M cycloheximide, 10(-8) M dexamethasone, or 10(-6) M herbimycin A. Recombinant human interferon-gamma inhibited rhTNF-alpha-induced CD4 expression in a dose-dependent manner. However, cross-linking of CD4 on eosinophils did not evoke EDN release, suggesting that newly expressed CD4 molecules on human eosinophils do not play any role in triggering degranulation. Our data indicate that TNF-alpha-induced CD4 expression on human eosinophils is dependent on protein synthesis and may be dependent on tyrosine kinase activity. PMID:8690465

  4. A Molecular Dynamics Approach to Ligand-Receptor Interaction in the Aspirin-Human Serum Albumin Complex

    PubMed Central

    Alvarez, H. Ariel; McCarthy, Andrés N.; Grigera, J. Raúl

    2012-01-01

    In this work, we present a study of the interaction between human serum albumin (HSA) and acetylsalicylic acid (ASA, C9H8O4) by molecular dynamics simulations (MD). Starting from an experimentally resolved structure of the complex, we performed the extraction of the ligand by means of the application of an external force. After stabilization of the system, we quantified the force used to remove the ASA from its specific site of binding to HSA and calculated the mechanical nonequilibrium external work done during this process. We obtain a reasonable value for the upper boundary of the Gibbs free energy difference (an equilibrium thermodynamic potential) between the complexed and noncomplexed states. To achieve this goal, we used the finite sampling estimator of the average work, calculated from the Jarzynski Equality. To evaluate the effect of the solvent, we calculated the so-called “viscous work,” that is, the work done to move the aspirin in the same trajectory through the solvent in absence of the protein, so as to assess the relevance of its contribution to the total work. The results are in good agreement with the available experimental data for the albumin affinity constant for aspirin, obtained through quenching fluorescence methods. PMID:23251150

  5. Modulation of the reactivity of the thiol of human serum albumin and its sulfenic derivative by fatty acids

    PubMed Central

    Torres, María José; Turell, Lucía; Botti, Horacio; Antmann, Laura; Carballal, Sebastián; Ferrer-Sueta, Gerardo; Radi, Rafael; Alvarez, Beatriz

    2012-01-01

    The single cysteine residue of human serum albumin (HSA-SH) is the most abundant plasma thiol. HSA transports fatty acids (FA), a cargo that increases under conditions of diabetes, exercise or adrenergic stimulation. The stearic acid-HSA (5/1) complex reacted 6-fold faster at pH 7.4 with the disulfide 5,5′-dithiobis(2-nitrobenzoic acid) (DTNB) and 2-fold faster with hydrogen peroxide and peroxynitrite. The apparent pKa of HSA-SH decreased from 7.9 ± 0.1 to 7.4 ± 0.1. Exposure to H2O2 (2 mM, 5 min, 37 °C) yielded 0.29 ± 0.04 moles of sulfenic acid (HSA-SOH) per mole of FA-bound HSA. The reactivity of HSA-SOH with low molecular weight thiols increased ~3-fold in the presence of FA. The enhanced reactivity of the albumin thiol at neutral pH upon FA binding can be rationalized by considering that the corresponding conformational changes that increase thiol exposure both increase the availability of the thiolate due to a lower apparent pKa and also loosen steric constraints for reactions. Since situations that increase circulating FA are associated with oxidative stress, this increased reactivity of HSA-SH could assist in oxidant removal. PMID:22450170

  6. Insight into the interaction of antitubercular and anticancer compound clofazimine with human serum albumin: spectroscopy and molecular modelling.

    PubMed

    Ajmal, Mohammad Rehan; Zaidi, Nida; Alam, Parvez; Nusrat, Saima; Siddiqi, Mohd Khursheed; Badr, Gamal; Mahmoud, Mohamed H; Khan, Rizwan Hasan

    2017-01-01

    The binding of clofazimine to human serum albumin (HSA) was investigated by applying optical spectroscopy and molecular docking methods. Fluorescence quenching data revealed that clofazimine binds to protein with binding constant in the order of 10(4) M(-1), and with the increase in temperature, Stern-Volmer quenching constants gradually decreased indicating quenching mode to be static. The UV-visible spectra showed increase in absorbance upon interaction of HSA with clofazimine which further reveals formation of the drug-albumin complex. Thermodynamic parameters obtained from fluorescence data indicate that the process is exothermic and spontaneous. Forster distance (Ro) obtained from fluorescence resonance energy transfer is found to be 2.05 nm. Clofazimine impelled rise in α-helical structure in HSA as observed from far-UV CD spectra while there are minor alterations in tertiary structure of the protein. Clofazimine interacts strongly with HSA inducing secondary structure in the protein and slight alterations in protein topology as suggested by dynamic light scattering results. Moreover, docking results indicate that clofazimine binds to hydrophobic pocket near to the drug site II in HSA.

  7. The automatic use of capillary isoelectric focusing with whole column imaging detection for carbamazepine binding to human serum albumin.

    PubMed

    Maciążek-Jurczyk, Małgorzata; Pawliszyn, Janusz

    2016-08-05

    The binding of the anticonvulsant drug carbamazepine (CBZ) to human serum albumin, both without (dHSA) and in the presence of fatty acids (HSA) was studied in real time by capillary isoelectric focusing with whole column imaging detection (cIEF-WCID). Reaction mixtures at different CBZ:HSA and CBZ:dHSA molar ratios (0:1/25:1) were prepared in phosphate buffer saline (PBS) solution at a physiological pH (7.4), and incubated for 0-72h at 37°C in a water bath. Application of the cIEF-WCID method allowed for observations on the impact of increasing CBZ:serum albumin molar ratios on isoelectric point (pI) shifts, as well as changes in peak area and absorbance, which serve as evidence of structural alterations occurring in the protein in the presence of CBZ. The obtained cIEF-WCID results indicated that the dynamic process of complex formation is not dependent on incubation time. The presented work allowed for recognition of different types of interactions, as well as for the calculation of association constants that demonstrate the stability of the complex. This study was also designed to examine the possible impact of fatty acids (FAs) on protein stability and drug delivery in blood.

  8. Studies on the interactions of 3,6-diaminoacridine derivatives with human serum albumin by fluorescence spectroscopy.

    PubMed

    Gökoğlu, Elmas; Kıpçak, Fulya; Seferoğlu, Zeynel

    2014-11-01

    This study reports the preparation and investigation of the modes of binding of the two symmetric 3,6-diaminoacridine derivatives obtained from proflavine, which are 3,6-diphenoxycarbonyl aminoacridine and 3,6-diethoxycarbonyl aminoacridine to human serum albumin (HSA). The interaction of HSA with the derivatives was investigated using fluorescence quenching and ultraviolet-visible absorption spectra at pH 7.2 and different temperatures. The results suggest that the derivatives used can interact strongly with HSA and are the formation of HSA-derivative complexes and hydrophobic interactions as the predominant intermolecular forces in stabilizing for each complex. The Stern-Volmer quenching constants, binding constants, binding sites and corresponding thermodynamic parameters ΔH, ΔS and ΔG were calculated at different temperatures. The binding distance (r) ~ 3 nm between the donor (HSA) and acceptors (3,6-diethoxycarbonyl aminoacridine, 3,6-diphenoxycarbonyl aminoacridine and proflavine) was obtained according to Förster's non-radiative energy transfer theory. Moreover, the limit of detection and limit of quantification of derivatives were calculated in the presence of albumin.

  9. Probing the interaction of human serum albumin with DPPH in the absence and presence of the eight antioxidants.

    PubMed

    Li, Xiangrong; Chen, Dejun; Wang, Gongke; Lu, Yan

    2015-02-25

    Albumin represents a very abundant and important circulating antioxidant in plasma. DPPH radical is also called 2,2-diphenyl-1-picrylhydrazyl. It has been widely used for measuring the efficiency of antioxidants. In this paper, the ability of human serum albumin (HSA) to scavenge DPPH radical was investigated using UV-vis absorption spectra. The interaction between HSA and DPPH was investigated in the absence and presence of eight popular antioxidants using fluorescence spectroscopy. These results indicate the antioxidant activity of HSA against DPPH radical is similar to glutathione and the value of IC50 is 5.200×10(-5) mol L(-1). In addition, the fluorescence experiments indicate the quenching mechanism of HSA, by DPPH, is a static process. The quenching process of DPPH with HSA is easily affected by the eight antioxidants, however, they cannot change the quenching mechanism of DPPH with HSA. The binding of DPPH to HSA primarily takes place in subdomain IIA and exists two classes of binding sites with two different interaction behaviors. The decreased binding constants and the number of binding sites of DPPH with HSA by the introduction of the eight antioxidants may result from the competition of the eight antioxidants and DPPH binding to HSA. The binding of DPPH to HSA may induce the micro-environment of the lone Trp-214 from polar to slightly nonpolar.

  10. Probing the interaction of human serum albumin with DPPH in the absence and presence of the eight antioxidants

    NASA Astrophysics Data System (ADS)

    Li, Xiangrong; Chen, Dejun; Wang, Gongke; Lu, Yan

    2015-02-01

    Albumin represents a very abundant and important circulating antioxidant in plasma. DPPH radical is also called 2,2-diphenyl-1-picrylhydrazyl. It has been widely used for measuring the efficiency of antioxidants. In this paper, the ability of human serum albumin (HSA) to scavenge DPPH radical was investigated using UV-vis absorption spectra. The interaction between HSA and DPPH was investigated in the absence and presence of eight popular antioxidants using fluorescence spectroscopy. These results indicate the antioxidant activity of HSA against DPPH radical is similar to glutathione and the value of IC50 is 5.200 × 10-5 mol L-1. In addition, the fluorescence experiments indicate the quenching mechanism of HSA, by DPPH, is a static process. The quenching process of DPPH with HSA is easily affected by the eight antioxidants, however, they cannot change the quenching mechanism of DPPH with HSA. The binding of DPPH to HSA primarily takes place in subdomain IIA and exists two classes of binding sites with two different interaction behaviors. The decreased binding constants and the number of binding sites of DPPH with HSA by the introduction of the eight antioxidants may result from the competition of the eight antioxidants and DPPH binding to HSA. The binding of DPPH to HSA may induce the micro-environment of the lone Trp-214 from polar to slightly nonpolar.

  11. A molecular dynamics approach to ligand-receptor interaction in the aspirin-human serum albumin complex.

    PubMed

    Alvarez, H Ariel; McCarthy, Andrés N; Grigera, J Raúl

    2012-01-01

    In this work, we present a study of the interaction between human serum albumin (HSA) and acetylsalicylic acid (ASA, C(9)H(8)O(4)) by molecular dynamics simulations (MD). Starting from an experimentally resolved structure of the complex, we performed the extraction of the ligand by means of the application of an external force. After stabilization of the system, we quantified the force used to remove the ASA from its specific site of binding to HSA and calculated the mechanical nonequilibrium external work done during this process. We obtain a reasonable value for the upper boundary of the Gibbs free energy difference (an equilibrium thermodynamic potential) between the complexed and noncomplexed states. To achieve this goal, we used the finite sampling estimator of the average work, calculated from the Jarzynski Equality. To evaluate the effect of the solvent, we calculated the so-called "viscous work," that is, the work done to move the aspirin in the same trajectory through the solvent in absence of the protein, so as to assess the relevance of its contribution to the total work. The results are in good agreement with the available experimental data for the albumin affinity constant for aspirin, obtained through quenching fluorescence methods.

  12. Preparation of protein imprinted materials by hierarchical imprinting techniques and application in selective depletion of albumin from human serum

    PubMed Central

    Liu, Jinxiang; Deng, Qiliang; Tao, Dingyin; Yang, Kaiguang; Zhang, Lihua; Liang, Zhen; Zhang, Yukui

    2014-01-01

    Hierarchical imprinting was developed to prepare the protein imprinted materials, as the artificial antibody, for the selective depletion of HSA from the human serum proteome. Porcine serum albumin (PSA) was employed as the dummy template for the fabrication of the recognition sites. To demonstrate the advantages of the hierarchical imprinting, molecularly imprinted polymers prepared by hierarchical imprinting technique (h-MIPs) were compared with those obtained by bulk imprinting (b-MIPs), in terms of the binding capacity, adsorption kinetics, selectivity and synthesis reproducibility. The binding capacity of h-MIPs could reach 12 mg g−1. And saturation binding could be reached in less than 20 min for the h-MIPs. In the protein mixture, h-MIPs exhibit excellent selectivity for PSA, with imprinting factors as about 3.6, much higher than those for non-template proteins. For the proteomic application, the identified protein group number in serum treated by h-MIPs was increased to 422, which is 21% higher than that obtained from the original serum, meanwhile the identified protein group number for the Albumin Removal kit was only 376. The results demonstrate that protein imprinted polymers prepared by hierarchical imprinting technique, might become the artificial antibodies for the selective depletion of high abundance proteins in proteome study. PMID:24976158

  13. Preparation of protein imprinted materials by hierarchical imprinting techniques and application in selective depletion of albumin from human serum

    NASA Astrophysics Data System (ADS)

    Liu, Jinxiang; Deng, Qiliang; Tao, Dingyin; Yang, Kaiguang; Zhang, Lihua; Liang, Zhen; Zhang, Yukui

    2014-06-01

    Hierarchical imprinting was developed to prepare the protein imprinted materials, as the artificial antibody, for the selective depletion of HSA from the human serum proteome. Porcine serum albumin (PSA) was employed as the dummy template for the fabrication of the recognition sites. To demonstrate the advantages of the hierarchical imprinting, molecularly imprinted polymers prepared by hierarchical imprinting technique (h-MIPs) were compared with those obtained by bulk imprinting (b-MIPs), in terms of the binding capacity, adsorption kinetics, selectivity and synthesis reproducibility. The binding capacity of h-MIPs could reach 12 mg g-1. And saturation binding could be reached in less than 20 min for the h-MIPs. In the protein mixture, h-MIPs exhibit excellent selectivity for PSA, with imprinting factors as about 3.6, much higher than those for non-template proteins. For the proteomic application, the identified protein group number in serum treated by h-MIPs was increased to 422, which is 21% higher than that obtained from the original serum, meanwhile the identified protein group number for the Albumin Removal kit was only 376. The results demonstrate that protein imprinted polymers prepared by hierarchical imprinting technique, might become the artificial antibodies for the selective depletion of high abundance proteins in proteome study.

  14. Involvement of BDNF and NGF in the mechanism of neuroprotective effect of human recombinant erythropoietin nanoforms.

    PubMed

    Solev, I N; Balabanyan, V Yu; Volchek, I A; Elizarova, O S; Litvinova, S A; Garibova, T L; Voronina, T A

    2013-06-01

    Human recombinant erythropoietin adsorbed on poly(butyl)cyanoacrylate nanoparticles and administered intraperitoneally in a dose of 0.05 mg/kg exhibited a neuroprotective effect in experimental intracerebral posttraumatic hematomas (hemorrhagic stroke) and reduced animal mortality. Human recombinant erythropoietin, native and adsorbed on lactic and glycolic acid copolymer-based nanoparticles, exhibited no antistroke effect on this model. Analysis of reverse transcription PCR products showed that human recombinant erythropoietin adsorbed on poly(butyl)cyanoacrylate nanoparticles more than 2-fold increased the expression of BDNF and NGF neurotrophins in the rat brain frontal cortex and hippocampus.

  15. Human insulin genome sequence map, biochemical structure of insulin for recombinant DNA insulin.

    PubMed

    Chakraborty, Chiranjib; Mungantiwar, Ashish A

    2003-08-01

    Insulin is a essential molecule for type I diabetes that is marketed by very few companies. It is the first molecule, which was made by recombinant technology; but the commercialization process is very difficult. Knowledge about biochemical structure of insulin and human insulin genome sequence map is pivotal to large scale manufacturing of recombinant DNA Insulin. This paper reviews human insulin genome sequence map, the amino acid sequence of porcine insulin, crystal structure of porcine insulin, insulin monomer, aggregation surfaces of insulin, conformational variation in the insulin monomer, insulin X-ray structures for recombinant DNA technology in the synthesis of human insulin in Escherichia coli.

  16. Exploring the binding of 4-thiothymidine with human serum albumin by spectroscopy, atomic force microscopy, and molecular modeling methods.

    PubMed

    Zhang, Juling; Gu, Huaimin; Zhang, Xiaohui

    2014-01-30

    The interaction of 4-thiothymidine (S(4)TdR) with human serum albumin (HSA) was studied by equilibrium dialysis under normal physiological conditions. In this work, the mechanism of the interaction between S(4)TdR and human serum albumin (HSA) was exploited by fluorescence, UV, CD circular, and SERS spectroscopic. Fluorescence and UV spectroscopy suggest that HSA intensities are significantly decreased when adding S(4)TdR to HAS, and the quenching mechanism of the fluorescence is static. Also, the ΔG, ΔH, and ΔS values across temperature indicated that hydrophobic interaction was the predominant binding force. The CD circular results show that there is little change in the secondary structure of HSA except the environment of amino acid changes when adding S(4)TdR to HSA. The surface-enhanced Raman scattering (SERS) shows that the interaction between S(4)TdR and HSA can be achieved through different binding sites which are probably located in the II A and III A hydrophobic pockets of HSA which correspond to Sudlow's I and II binding sites. In addition, the molecular modeling displays that S(4)TdR-HSA complex is stabilized by hydrophobic forces, which result from amino acid residues. The atomic force microscopy results revealed that the single HSA molecular dimensions were larger after interaction of 4-thiothymidine. This work would be useful to understand the state of the transportation, distribution, and metabolism of the anticancer drugs in the human body, and it could provide a useful biochemistry parameter for the development of new anti-cancer drugs and research of pharmacology mechanisms.

  17. Effect of human and bovine serum albumin on kinetic chemiluminescence of Mn (III)-Tetrakis (4-sulfonatophenyl) porphyrin-luminol-hydrogen peroxide system.

    PubMed

    Kazemi, Sayed Yahya; Abedirad, Seyed Mohammad

    2012-01-01

    The present work deals with an attempt to study the effect of human and bovine serum albumin on kinetic parameters of chemiluminescence of luminol-hydrogen peroxide system catalyzed by manganese tetrasulfonatophenyl porphyrin (MnTSPP). The investigated parameters involved pseudo-first-order rise and fall rate constant for the chemiluminescence burst, maximum level intensity, time to reach maximum intensity, total light yield, and values of the intensity at maximum CL which were evaluated by nonlinear least square program KINFIT. Because of interaction of metalloporphyrin with proteins, the CL parameters are drastically affected. The systems resulted in Stern-Volmer plots with k(Q) values of 3.17 × 10(5) and 3.7 × 10(5) M(-1) in the quencher concentration range of 1.5 × 10(-6) to 1.5 × 10(-5) M for human serum albumin (HSA) and bovine serum albumin (BSA), respectively.

  18. Ligand and proton exchange dynamics in recombinant human myoglobin mutants.

    PubMed

    Lambright, D G; Balasubramanian, S; Boxer, S G

    1989-05-05

    Site-specific mutants of human myoglobin have been prepared in which lysine 45 is replaced by arginine (K45R) and aspartate 60 by glutamate (D60E), in order to examine the influence of these residues and their interaction on the dynamics of the protein. These proteins were studied by a variety of methods, including one and two-dimensional proton nuclear magnetic resonance spectroscopy, exchange kinetics for the distal and proximal histidine NH protons as a function of pH in the met cyano forms, flash photolysis of the CO forms, and ligand replacement kinetics. The electronic absorption and proton nuclear magnetic resonance spectra of the CO forms of these proteins are virtually identical, indicating that the structure of the heme pocket is unaltered by these mutations. There are, however, substantial changes in the dynamics of both CO binding and proton exchange for the mutant K45R, whereas the mutant D60E exhibits behavior indistinguishable from the reference human myoglobin. K45R has a faster CO bimolecular recombination rate and slower CO off-rate relative to the reference. The kinetics for CO binding are independent of pH (6.5 to 10) as well as ionic strength (0 to 1 M-NaCl). The exchange rate for the distal histidine NH is substantially lower for K45R than the reference, whereas the proximal histidine NH exchange rate is unaltered. The exchange behavior of the human proteins is similar to that reported for a comparison of the exchange rates for myoglobins having lysine at position 45 with sperm whale myoglobin, which has arginine at this position. This indicates that the differences in exchange rates reflects largely the Lys----Arg substitution. The lack of a simple correlation for the CO kinetics with this substitution means that these are sensitive to other factors as well. Specific kinetic models, whereby substitution of arginine for lysine at position 45 can affect ligand binding dynamics, are outlined. These experiments demonstrate that a relatively

  19. How Good Are Indirect Tests at Detecting Recombination in Human mtDNA?

    PubMed Central

    White, Daniel James; Bryant, David; Gemmell, Neil John

    2013-01-01

    Empirical proof of human mitochondrial DNA (mtDNA) recombination in somatic tissues was obtained in 2004; however, a lack of irrefutable evidence exists for recombination in human mtDNA at the population level. Our inability to demonstrate convincingly a signal of recombination in population data sets of human mtDNA sequence may be due, in part, to the ineffectiveness of current indirect tests. Previously, we tested some well-established indirect tests of recombination (linkage disequilibrium vs. distance using D′ and r2, Homoplasy Test, Pairwise Homoplasy Index, Neighborhood Similarity Score, and Max χ2) on sequence data derived from the only empirically confirmed case of human mtDNA recombination thus far and demonstrated that some methods were unable to detect recombination. Here, we assess the performance of these six well-established tests and explore what characteristics specific to human mtDNA sequence may affect their efficacy by simulating sequence under various parameters with levels of recombination (ρ) that vary around an empirically derived estimate for human mtDNA (population parameter ρ = 5.492). No test performed infallibly under any of our scenarios, and error rates varied across tests, whereas detection rates increased substantially with ρ values > 5.492. Under a model of evolution that incorporates parameters specific to human mtDNA, including rate heterogeneity, population expansion, and ρ = 5.492, successful detection rates are limited to a range of 7−70% across tests with an acceptable level of false-positive results: the neighborhood similarity score incompatibility test performed best overall under these parameters. Population growth seems to have the greatest impact on recombination detection probabilities across all models tested, likely due to its impact on sequence diversity. The implications of our findings on our current understanding of mtDNA recombination in humans are discussed. PMID:23665874

  20. Recombinant human serum amyloid A (apoSAAp) binds cholesterol and modulates cholesterol flux.

    PubMed

    Liang, J S; Sipe, J D

    1995-01-01

    During acute inflammation, the serum amyloid A (apoSAA) proteins apoSAA1 and apoSAA2 are transiently associated with high density lipoproteins (HDL) in concentrations of as much as 1000-fold more than their concentrations during homeostasis; however, their effect on HDL function is unclear. Recombinant apoSAAp, a hybrid of the closely related human apoSAA1 and apoSAA2 isoforms, was found to exhibit a high affinity for cholesterol. The adsorption of apoSAAp to polystyrene microtiter wells at physiological pH, temperature, and salt concentration was inhibited and reversed by cholesterol. ApoSAAp, to a greater extent than apoA-I, albumin, or fetal bovine serum, enhanced diffusion of cholesterol from HDL across a membrane that retained molecules > 3.5 kDa. Cholesterol from 25 nM to 125 microM inhibited binding of [3H]cholesterol to 167 nM apoSAAp. A cholesterol binding assay was developed to determine the dissociation constant for binding of [3H]cholesterol to apoSAAp; Kd = 1.7 +/- 0.3 x 10(-7) M and the maximum binding capacity (Bmax) is 1.1 +/- 0.1 mol/mol. After binding cholesterol, the apparent size of apoSAAp as determined by gel filtration on Sephacryl S-100 was increased from 12 to 23 kDa. ApoSAAp enhanced free [14C]cholesterol uptake from tissue culture medium by HepG2 cells, an effect that was dose dependent and blocked by polyclonal antibodies to human apoSAA1 and apoSAA2. ApoSAAp, unlike apoA-I, was taken up from serum-free medium by HepG2 cells and appeared to be degraded by cell-associated enzymes. Unlike peritoneal exudate cells, human HepG2 hepatoma cells do not secrete an enzyme that degrades apoSAAp. These results suggest that apoSAA can potentially serve as a transient cholesterol-binding protein.

  1. Protection against cisplatin-induced nephrotoxicity by recombinant human erythropoietin.

    PubMed

    Yalcin, Suayib; Müftüoğlu, Sevda; Cetin, Eren; Sarer, Banu; Yildirim, Berna Akkuş; Zeybek, Dilara; Orhan, Bülent

    2003-01-01

    Cisplatin (CDDP) is a potent nephrotoxin, and nephrotoxicity is its most important dose-limiting toxicity. In this study, we aimed to investigate the role of recombinant human erythropoietin (rhEPO) in the protection of cisplatin-induced nephrotoxicity and compare its efficacy with the cell-protective agent amifostine. All experiments were conducted on female Wistar albino rats. Animals were randomly assigned to four groups, each including six rats. Group A received only CDDP, group B received CDDP plus rhEPO, group C received CDDP plus amifostine, and group D received only rhEPO. At the end of 7 wk, hemoglobin (Hgb), hematocrite (Htc), blood urea nitrogen (BUN), and creatinine (Cr) levels were determined and kidneys of the rats were removed. The weights of the kidneys were measured and sent for histopathological examination. Proximal tubules from four areas of the kidney (outer cortex, inner cortex, the medullary ray, and outer stripe of outer medulla [OSOM]) were evaluated. There were statistically significant differences among the groups in terms of tubular scores, including overall renal tubular score, cortex, inner cortex, OSOM, and medullary ray tubular scores, and Htc levels. Group A rats had the worse tubular scores in all categories when compared to group D rats. When the results of groups B and C were compared, there were no differences in terms of BUN, Cr levels, and tubular scores, but the Htc level was significantly higher in group B. Group B rats had better overall and OSOM tubular scores when compared to group A. Group C also had better overall and OSOM tubular scores compared to group A. The present study showed for the first time that rhEPO plays an important role in the prevention of cisplatin-induced nephrotoxicity and it is as effective as amifostine.

  2. Supercritical fluid precipitation of recombinant human immunoglobulin from aqueous solutions.

    PubMed

    Nesta, D P; Elliott, J S; Warr, J P

    2000-02-20

    Supercritical carbon dioxide was used as an antisolvent for producing recombinant human immunoglobulin G (rIgG) particulate powders. Liquid carbon dioxide (CO(2)) was premixed with ethanol to create a single-phase, modified supercritical fluid (SCF). The modified SCF was then vigorously mixed with a pharmaceutically acceptable, aqueous formulation of rIgG, and the mixture was immediately atomized into a pressurized vessel where rapid expansion of the modified SCF extracted the aqueous phase, resulting in precipitation of the protein powder. The process was reproducible, and resulting powder products were characterized by their aqueous solubilities, and the spectroscopic profile, molecular integrity, and antigen binding activity of the individual soluble fractions. Molecular integrity was assessed via size-exclusion high-performance liquid chromatography (SEC), whereas antigen binding activity was determined using an enzyme-linked immunosorbent assay (ELISA). Attempts to characterize particle size and morphology were confounded due to the extremely deliquescent nature of the powders, causing them to absorb moisture rapidly and become gummy. Operational conditions were optimized to a point which yielded powders that were completely soluble, and had ultraviolet (UV) spectroscopic and SEC profiles indistinguishable from those of the reference standard starting solution from which the powders were derived. Antigen binding activities of the powders, however, were

  3. Myelostimulatory activity of recombinant human interleukin-2 in mice

    SciTech Connect

    Talmadge, J.E.; Schneider, M.; Keller, J.; Ruscetti, F.; Longo, D.; Pennington, R.; Bowersox, O.; Tribble, H.

    1989-05-01

    In a series of studies designed to extend our understanding of interleukin-2 (IL-2) and to study the effect of biologic response modifiers on bone marrow, we observed that administering recombinant human (rH) IL-2 to normal mice resulted in an increase in the frequency of colony-forming units-culture (CFU-C) in bone marrow. In addition, rH IL-2 was able to accelerate host recovery from cyclophosphamide (CTX)- or radiation-induced bone marrow depression and peripheral blood leukopenia. Not only can rH IL-2 accelerate, in a dose-dependent manner, the return of bone marrow, peripheral blood cellularity, and CFU-C frequency to normal levels following cytoreduction by CTX or irradiation, but it also significantly increases CFU-C frequency to greater than normal levels. Furthermore, rH IL-2 can significantly prolong survival of animals receiving a lethal dose of irradiation or CTX. Thus, multiple mechanisms are responsible for the synergistic therapeutic activity associated with rH IL-2 and CTX. rH IL-2 does not act only as an immunomodulatory agent in the presence or absence of suppressor T cells, but also accelerates host recovery from cytoreductive agents, resulting in decreased leukopenia and perhaps resistances to secondary infection. Thus, rH IL-2 plus chemotherapy may increase therapeutic activity against neoplastic disease, not only by adding immune stimulation to the direct antitumor effect of the drug but also by allowing delivery of higher, more effective doses of chemotherapy.

  4. Recombinant human erythropoietin improves neurological outcomes in very preterm infants

    PubMed Central

    Song, Juan; Sun, Huiqing; Xu, Falin; Kang, Wenqing; Gao, Liang; Guo, Jiajia; Zhang, Yanhua; Xia, Lei; Wang, Xiaoyang

    2016-01-01

    Objective To evaluate the efficacy and safety of repeated low‐dose human recombinant erythropoietin (rhEPO) in the improvement of neurological outcomes in very preterm infants. Methods A total of 800 infants of ≤32‐week gestational age who had been in an intensive care unit within 72 hours after birth were included in the trial between January 2009 and June 2013. Preterm infants were randomly assigned to receive rhEPO (500IU/kg; n = 366) or placebo (n = 377) intravenously within 72 hours after birth and then once every other day for 2 weeks. The primary outcome was death or moderate to severe neurological disability assessed at 18 months of corrected age. Results Death and moderate/severe neurological disability occurred in 91 of 338 very preterm infants (26.9%) in the placebo group and in 43 of 330 very preterm infants (13.0%) in the rhEPO treatment group (relative risk [RR] = 0.40, 95% confidence interval [CI] = 0.27–0.59, p < 0.001) at 18 months of corrected age. The rate of moderate/severe neurological disability in the rhEPO group (22 of 309, 7.1%) was significantly lower compared to the placebo group (57 of 304, 18.8%; RR = 0.32, 95% CI = 0.19–0.55, p < 0.001), and no excess adverse events were observed. Interpretation Repeated low‐dose rhEPO treatment reduced the risk of long‐term neurological disability in very preterm infants with no obvious adverse effects. Ann Neurol 2016;80:24–34 PMID:27130143

  5. S-Nitrosylation of secreted recombinant human glypican-1.

    PubMed

    Svensson, Gabriel; Mani, Katrin

    2009-12-01

    Glypican-1 is a glycosylphosphatidylinositol anchored cell surface S-nitrosylated heparan sulfate proteoglycan that is processed by nitric oxide dependent degradation of its side chains. Cell surface-bound glypican-1 becomes internalized and recycles via endosomes, where the heparan sulphate chains undergo nitric oxide and copper dependent autocleavage at N-unsubstituted glucosamines, back to the Golgi. It is not known if the S-nitrosylation occurs during biosynthesis or recycling of the protein. Here we have generated a recombinant human glypican-1 lacking the glycosylphosphatidylinositol-anchor. We find that this protein is directly secreted into the culture medium both as core protein and proteoglycan form and is not subjected to internalization and further modifications during recycling. By using SDS-PAGE, Western blotting and radiolabeling experiments we show that the glypican-1 can be S-nitrosylated. We have measured the level of S-nitrosylation in the glypican-1 core protein by biotin switch assay and find that the core protein can be S-nitrosylated in the presence of copper II ions and NO donor. Furthermore the glypican-1 proteoglycan produced in the presence of polyamine synthesis inhibitor, alpha-difluoromethylornithine, was endogenously S-nitrosylated and release of nitric oxide induced deaminative autocleavage of the HS side chains of glypican-1. We also show that the N-unsubstituted glucosamine residues are formed during biosynthesis of glypican-1 and that the content increased upon inhibition of polyamine synthesis. It cannot be excluded that endogenous glypican-1 can become further S-nitrosylated during recycling.

  6. Skeletal ligament healing using the recombinant human amelogenin protein.

    PubMed

    Hanhan, Salem; Ejzenberg, Ayala; Goren, Koby; Saba, Faris; Suki, Yarden; Sharon, Shay; Shilo, Dekel; Waxman, Jacob; Spitzer, Elad; Shahar, Ron; Atkins, Ayelet; Liebergall, Meir; Blumenfeld, Anat; Deutsch, Dan; Haze, Amir

    2016-05-01

    Injuries to ligaments are common, painful and debilitating, causing joint instability and impaired protective proprioception sensation around the joint. Healing of torn ligaments usually fails to take place, and surgical replacement or reconstruction is required. Previously, we showed that in vivo application of the recombinant human amelogenin protein (rHAM(+)) resulted in enhanced healing of the tooth-supporting tissues. The aim of this study was to evaluate whether amelogenin might also enhance repair of skeletal ligaments. The rat knee medial collateral ligament (MCL) was chosen to prove the concept. Full thickness tear was created and various concentrations of rHAM(+), dissolved in propylene glycol alginate (PGA) carrier, were applied to the transected MCL. 12 weeks after transection, the mechanical properties, structure and composition of transected ligaments treated with 0.5 μg/μl rHAM(+) were similar to the normal un-transected ligaments, and were much stronger, stiffer and organized than control ligaments, treated with PGA only. Furthermore, the proprioceptive free nerve endings, in the 0.5 μg/μl rHAM(+) treated group, were parallel to the collagen fibres similar to their arrangement in normal ligament, while in the control ligaments the free nerve endings were entrapped in the scar tissue at different directions, not parallel to the axis of the force. Four days after transection, treatment with 0.5 μg/μl rHAM(+) increased the amount of cells expressing mesenchymal stem cell markers at the injured site. In conclusion application of rHAM(+) dose dependently induced mechanical, structural and sensory healing of torn skeletal ligament. Initially the process involved recruitment and proliferation of cells expressing mesenchymal stem cell markers.

  7. Superoxide dismutase activity of the naturally occurring human serum albumin-copper complex without hydroxyl radical formation.

    PubMed

    Kato, Ryunosuke; Akiyama, Matofusa; Kawakami, Hiroyoshi; Komatsu, Teruyuki

    2014-01-01

    The superoxide radical anion (O2(.-)) is biologically toxic and contributes to the pathogenesis of various diseases. Here we describe the superoxide dismutase (SOD) activity of human serum albumin (HSA) complexed with a single Cu(II) ion at the N-terminal end (HSA-Cu complex). The structure of this naturally occurring copper-coordinated blood serum protein has been characterized by several physicochemical measurements. The O2(.-) dismutation ability of the HSA-Cu (1:1) complex is almost the same as that of the well-known SOD mimics, such as Mn(III) -tetrakis(N-methylpyridinium)porphyrin. Interestingly, the HSA-Cu complex does not induce a subsequent Fenton reaction to produce the hydroxyl radical (OH(.)), which is one of the most harmful reactive oxygen species.

  8. Binding and conformational changes of human serum albumin upon interaction with 4-aminoantipyrine studied by spectroscopic methods and cyclic voltammetry.

    PubMed

    Gowda, Jayant I; Nandibewoor, Sharanappa T

    2014-04-24

    The interactions of 4-aminoantipyrine (AAP) with human serum albumin (HSA) have been studied by UV-visible spectroscopy, fluorescence spectroscopy and cyclic voltammetry. The binding of 4-aminoantipyrine quenches the HSA fluorescence, revealing a 1:1 interaction with a binding constant of about 10(5) M(-1). The experimental results showed that AAP effectively quenched the intrinsic fluorescence of HSA via dynamic type of quenching. In addition, according to the synchronous fluorescence spectra of HSA in presence of 4-aminoantipyrine, the tryptophan residue of the proteins are most perturbed by the binding process. The number of binding sites, the binding constant, site probe study, some common metal ions effect and the thermodynamic parameters were calculated.

  9. Connecting simulated, bioanalytical, and molecular docking data on the stereoselective binding of (±)-catechin to human serum albumin.

    PubMed

    Sabela, Myalowenkosy I; Gumede, Njabulo J; Escuder-Gilabert, Laura; Martín-Biosca, Yolanda; Bisetty, Khirsna; Medina-Hernández, María-Jose; Sagrado, Salvador

    2012-02-01

    The stereoselective binding of the frequently ingested nutraceutical (±)-catechin, with demonstrated differential biological activity between enantiomers, to human serum albumin (HSA), with the largest complexation and enantioselectivity potential among the plasmatic proteins, is studied by combining simulations to optimize the experimental design, robust in vitro electrokinetic chromatographic data, and molecular docking-chiral recognition estimates. Methodological and mathematical drawbacks in previous reports on (±)-catechin-HSA are detected and eliminated. Recent and novel direct equations extracted from the classical interaction model allows advantageous univariate mathematical data treatment, providing the first evidence of quantitative (±)-catechin-HSA enantioselectivity. Also, the binding site in HSA of the enantiomers is approached, and both the experimental enantioselectivity and the main binding site information are contrasted with a molecular docking approach.

  10. [The macrophage disappearance reaction in guinea pigs sensitized with bovine gamma globulin or human scrum albumin (author's transl)].

    PubMed

    Schimke, R; Bernstein, B; Ambrosius, H

    1977-01-01

    The macrophage disappearance reaction (MDR) is a suitable test for detection of cell mediated immunity against bovine gamma globulin (BGG) and human serum albumin (HSA) in guinea pigs. The MDR is a technical simple, good manipulable, and quantifiable test. The optimal test conditions for the antigens BGC and HSA are the following: Peritoneal exudat cells (PEC) were stimulated with paraffin oil. On the 5th day after receiving oil the animals were injected with 80 microgram BGG or 30 microgram HSA i.p. 5 hours later the PEC were harvested and counted. With the MDR it is possible to detect differences with respect to degree of cell-mediated immunity. Supernatants of sensitized lymphocytes produces the MDR too.

  11. Kaempferol-human serum albumin interaction: Characterization of the induced chirality upon binding by experimental circular dichroism and TDDFT calculations

    NASA Astrophysics Data System (ADS)

    Matei, Iulia; Ionescu, Sorana; Hillebrand, Mihaela

    2012-10-01

    The experimental induced circular dichroism (ICD) and absorption spectra of the achiral flavonoid kaempferol upon binding to human serum albumin (HSA) were correlated to electronic CD and UV-vis spectra theoretically predicted by time-dependent density functional theory (TDDFT). The neutral and four anionic species of kaempferol in various conformations were considered in the calculations. The appearance of the experimental ICD signal was rationalized in terms of kaempferol binding to HSA in a distorted, chiral, rigid conformation. The comparison between the experimental and simulated spectra allowed for the identification of the kaempferol species that binds to HSA, namely the anion generated by deprotonation of the hydroxyl group in position 7. This approach constitutes a convenient method for evidencing the binding species and for determining its conformation in the binding pocket of the protein. Its main advantage over the UV-vis absorption method lays in the fact that only the bound ligand species gives an ICD signal.

  12. SERS spectroscopy of kaempferol and galangin under the interaction of human serum albumin with adsorbed silver nanoparticles.

    PubMed

    Zhang, Wei; Bai, Xueyuan; Wang, Yingping; Zhao, Bing; Zhao, Daqing; Zhao, Yu

    2012-06-15

    Raman and surface-enhanced Raman scattering (SERS) spectroscopy were employed to probe the interaction of the flavonol drugs, kaempferol and galangin, with human serum albumin (HSA). SERS spectra of both flavonol derivatives were obtained from a colloidal silver surface in physiological condition, based on the high performance of the enhanced substrate, the most enhanced modes of kaempferol and galangin were those with certain motions perpendicular to the metal surface. The SERS spectra were allowed to predict similar orientation geometry for both of the drugs on the colloidal surface with minor difference. In addition, both flavonols-HSA complexes were prepared in different concentration ratios and the orientated differences between kaempferol and galangin were investigated by SERS.

  13. SERS spectroscopy of kaempferol and galangin under the interaction of human serum albumin with adsorbed silver nanoparticles

    NASA Astrophysics Data System (ADS)

    Zhang, Wei; Bai, Xueyuan; Wang, Yingping; Zhao, Bing; Zhao, Daqing; Zhao, Yu

    Raman and surface-enhanced Raman scattering (SERS) spectroscopy were employed to probe the interaction of the flavonol drugs, kaempferol and galangin, with human serum albumin (HSA). SERS spectra of both flavonol derivatives were obtained from a colloidal silver surface in physiological condition, based on the high performance of the enhanced substrate, the most enhanced modes of kaempferol and galangin were those with certain motions perpendicular to the metal surface. The SERS spectra were allowed to predict similar orientation geometry for both of the drugs on the colloidal surface with minor difference. In addition, both flavonols-HSA complexes were prepared in different concentration ratios and the orientated differences between kaempferol and galangin were investigated by SERS.

  14. Mechanistic and conformational studies on the interaction of food dye amaranth with human serum albumin by multispectroscopic methods.

    PubMed

    Zhang, Guowen; Ma, Yadi

    2013-01-15

    The mechanism of interaction between food dye amaranth and human serum albumin (HSA) in physiological buffer (pH 7.4) was investigated by fluorescence, UV-vis absorption, circular dichroism (CD), and Fourier transform infrared (FT-IR) spectroscopy. Results obtained from analysis of fluorescence spectra indicated that amaranth had a strong ability to quench the intrinsic fluorescence of HSA through a static quenching procedure. The negative value of enthalpy change and positive value of entropy change elucidated that the binding of amaranth to HSA was driven mainly by hydrophobic and hydrogen bonding interactions. The surface hydrophobicity of HSA increased after binding with amaranth. The binding distance between HSA and amaranth was estimated to be 3.03 nm and subdomain IIA (Sudlow site I) was the primary binding site for amaranth on HSA. The results of CD and FT-IR spectra showed that binding of amaranth to HSA induced conformational changes of HSA.

  15. Effects of pH and ionic strength on the thermodynamics of human serum albumin-photosensitizer binding

    PubMed Central

    Jones, Cecil L.; Dickson, TiReJe; Hayes, Ronald; Thomas, Lana

    2013-01-01

    Fluorescence spectroscopy was used to measure the effects of pH and ionic strength on thermodynamic parameters governing the interaction of human serum albumin with zinc phthalocyanine tetrasulfonic acid. Fluorescence emission of zinc phthalocyanine increases at 686 nm with increasing concentrations of the protein. The non-linear correlation between protein concentration and emission of the photosensitizer was fitted using Chipman’s analysis to calculate the binding affinities. The standard enthalpy and entropy changes were estimated from van’t Hoff analysis of data that were acquired from temperature ramping studies. Results show that reaction is primarily driven by solution dynamics and that the change in enthalpy for the system becomes increasingly unfavorable with increasing pH and ionic strength. The effect of ionic strength on the entropy change for binding is shown to be significantly greater than the effects of pH. The interplay between entropy and enthalpy changes is demonstrated. PMID:24058218

  16. Benzo(a)pyrene-albumin adducts in humans exposed to polycyclic aromatic hydrocarbons in an industrial area of Poland.

    PubMed Central

    Kure, E H; Andreassen, A; Ovrebø, S; Grzybowska, E; Fiala, Z; Strózyk, M; Chorazy, M; Haugen, A

    1997-01-01

    OBJECTIVES: The interaction of benzo(a)pyrene with serum albumin was measured in an attempt to identify the actual exposure and to evaluate albumin adduct measurements as biomarkers for exposure monitoring. METHODS: Benzo(a)pyrene-diol-epoxide (BPDE)-albumin adducts were measured by competitive enzyme linked immunosorbent assay (ELISA) in plasma of coke oven plant workers from three plants and from people living in a highly industrialised area of Silesia in Poland. Due to the high air concentrations of polycyclic aromatic hydrocarbons (PAHs) in this area, a control group was selected from a rural non-industrialised area in Poland. Breathing zone air measurements of PAHs were collected from some of the participants. RESULTS: Coke oven plant workers and non-occupationally exposed people had similar concentrations of albumin adducts whereas the rural controls were significantly lower (2.74 fmol adducts/microgram albumin (SEM 0.124)). The mean concentration of BPDE-albumin adduct in plasma of both the occupational and the environmental groups were significantly higher in the summer samples (4.34 fmol adducts/microgram albumin (SEM 0.335) and 4.55 fmol adducts/microgram albumin (SEM 0.296), respectively) than in the winter samples (3.06 fmol adducts/microgram albumin (SEM 0.187) and 3.04 fmol adducts/microgram albumin (SEM 0.184), respectively) even though the air measurements showed higher concentrations of PAHs in the winter. The statistical analysis did not show any effects of air exposures on concentrations of BPDE-albumin adduct. CONCLUSIONS: A multiple regression analysis of the measured concentrations of BPDE-albumin adducts for all the groups, during both seasons, indicates that occupational exposures do not contribute significantly to the formation of adducts. In general, the concentrations of albumin adducts found vary within relatively small limits for the two seasons and between the various groups of participants. No extreme differences were found. PMID

  17. Chemiluminescence lateral flow immunoassay cartridge with integrated amorphous silicon photosensors array for human serum albumin detection in urine samples.

    PubMed

    Zangheri, Martina; Di Nardo, Fabio; Mirasoli, Mara; Anfossi, Laura; Nascetti, Augusto; Caputo, Domenico; De Cesare, Giampiero; Guardigli, Massimo; Baggiani, Claudio; Roda, Aldo

    2016-12-01

    A novel and disposable cartridge for chemiluminescent (CL)-lateral flow immunoassay (LFIA) with integrated amorphous silicon (a-Si:H) photosensors array was developed and applied to quantitatively detect human serum albumin (HSA) in urine samples. The presented analytical method is based on an indirect competitive immunoassay using horseradish peroxidase (HRP) as a tracer, which is detected by adding the luminol/enhancer/hydrogen peroxide CL cocktail. The system comprises an array of a-Si:H photosensors deposited on a glass substrate, on which a PDMS cartridge that houses the LFIA strip and the reagents necessary for the CL immunoassay was optically coupled to obtain an integrated analytical device controlled by a portable read-out electronics. The method is simple and fast with a detection limit of 2.5 mg L(-1) for HSA in urine and a dynamic range up to 850 mg L(-1), which is suitable for measuring physiological levels of HSA in urine samples and their variation in different diseases (micro- and macroalbuminuria). The use of CL detection allowed accurate and objective analyte quantification in a dynamic range that extends from femtomoles to picomoles. The analytical performances of this integrated device were found to be comparable with those obtained using a charge-coupled device (CCD) as a reference off-chip detector. These results demonstrate that integrating the a-Si:H photosensors array with CL-LFIA technique provides compact, sensitive and low-cost systems for CL-based bioassays with a wide range of applications for in-field and point-of-care bioanalyses. Graphical Abstract A novel integrated portable device was developed for direct quantitative detection of human serum albumin (HSA) in urine samples, exploiting a chemiluminescence lateral flow immunoassay (LFIA). The device comprises a cartridge that holds the LFIA strip and all the reagents necessary for the analysis, an array of amorphous silicon photosensors, and a custom read-out electronics.

  18. Effect of ageing of human serum albumin in vitro on surface hydrophobicity and binding sites of metronidazole

    NASA Astrophysics Data System (ADS)

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

    2011-05-01

    The fluorescence characteristic of the "alkaline-ageing" process was performed. The quenching of the aged form of human serum albumin (AHSA) fluorescence by acrylamide (Ac) was smaller than that of native HSA, in contrast to the negatively charged anion iodide quencher. The comparison of quenching of fluorescence probes ANS and DNSA bound to aged and native forms of HSA allows for the conclusion that "alkaline-ageing process" causes an increase of hydrophobicity within the binding site located in subdomain IIA. This conclusion was confirmed by the F coefficients calculated for the emission fluorescence spectra of A- and N-forms of HSA excited at 295 nm and 275 nm which show that the increase of hydrophobicity is more significant within tyrosyl than within tryptophanyl residues. The binding constants metronidazole-HSA as well as the number of the class of binding sites were determined by the use of the Scatchard and Klotz-plot analysis. Ageing of HSA causes an increase of the quenching constant determined from the Stern-Volmer equation for λex 275 nm. However ageing does not affect the K Q value for λex 295 nm. The influence of ageing of human serum albumin on its surface hydrophobicity was also studied with the use of 8-anilino-1-naphthalenesulfonic acid (ANS) as the fluorescence probe. At the ANS fluorescence excitation wavelength λex 360 nm the change in surface hydrophobicity is not observed for both N- and A-forms of HSA. The increase of surface hydrophobicity of the A-form in comparison with that of the native form at λex 295 nm indicates that within subdomain IIA an alteration of HSA conformation takes place.

  19. 76 FR 65210 - Certain Products and Pharmaceutical Compositions Containing Recombinant Human Erythropoetin...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-20

    ... From the Federal Register Online via the Government Publishing Office INTERNATIONAL TRADE COMMISSION Certain Products and Pharmaceutical Compositions Containing Recombinant Human Erythropoetin... sale within the United States after importation of certain products and pharmaceutical...

  20. Effect of human serum albumin on the kinetics of 4-methylumbelliferyl-β-D-N-N'-N″ Triacetylchitotrioside hydrolysis catalyzed by hen egg white lysozyme.

    PubMed

    Calderon, Cristian; Abuin, Elsa; Lissi, Eduardo; Montecinos, Rodrigo

    2011-08-01

    The effect of human serum albumin (HSA) addition on the rate of hydrolysis of the synthetic substrate 4-methylumbelliferyl-β-D-N-N'-N″ triacetylchitotrioside ((NAG)(3)-MUF) catalyzed by hen egg white lysozyme has been measured in aqueous solution (citrate buffer 50 mM pH = 5.2 at 37 °C). The presence of HSA leads to a decrease in the rate of the process. The reaction follows a Michaelis-Menten mechanism under all the conditions employed. The catalytic rate constant decreases tenfold when the albumin concentration increases, while the Michaelis constant remains almost constant in the albumin concentration range employed. Ultracentrifugation experiments indicate that the main origin of the observed variation in the kinetic behavior is related to the existence of an HSA-lysozyme interaction. Interestingly, the dependence of the catalytic rate constant with albumin concentration parallels the decrease of the free enzyme concentration. We interpret these results in terms of the presence in the system of two enzyme populations; namely, the HSA associated enzyme which does not react and the free enzyme reacting as in the absence of albumin. Other factors such as association of the substrate to albumin or macromolecular crowding effects due to the presence of albumin are discarded. Theoretical modeling of the structure of the HSA-lysozyme complex shows that the Glu35 and Asp52 residues located in the active site of lysozyme are oriented toward the HSA surface. This conformation will inactivate lysozyme molecules bound to HSA.

  1. A novel exendin-4 human serum albumin fusion protein, E2HSA, with an extended half-life and good glucoregulatory effect in healthy rhesus monkeys

    SciTech Connect

    Zhang, Ling; Wang, Lin; Meng, Zhiyun; Gan, Hui; Gu, Ruolan; Wu, Zhuona; Gao, Lei; Zhu, Xiaoxia; Sun, Wenzhong; Li, Jian; Zheng, Ying; Dou, Guifang

    2014-03-07

    Highlights: • E2HSA has an extended half-life and good plasma stability. • E2HSA could improve glucose-dependent insulin secretion. • E2HSA has excellent glucoregulatory effects in vivo. • E2HSA could potentially be used as a new long-acting GLP-1 receptor agonist for type 2 diabetes management. - Abstract: Glucagon-like peptide-1 (GLP-1) has attracted considerable research interest in terms of the treatment of type 2 diabetes due to their multiple glucoregulatory functions. However, the short half-life, rapid inactivation by dipeptidyl peptidase-IV (DPP-IV) and excretion, limits the therapeutic potential of the native incretin hormone. Therefore, efforts are being made to develop the long-acting incretin mimetics via modifying its structure. Here we report a novel recombinant exendin-4 human serum albumin fusion protein E2HSA with HSA molecule extends their circulatory half-life in vivo while still retaining exendin-4 biological activity and therapeutic properties. In vitro comparisons of E2HSA and exendin-4 showed similar insulinotropic activity on rat pancreatic islets and GLP-1R-dependent biological activity on RIN-m5F cells, although E2HSA was less potent than exendin-4. E2HSA had a terminal elimation half-life of approximate 54 h in healthy rhesus monkeys. Furthermore, E2HSA could reduce postprandial glucose excursion and control fasting glucose level, dose-dependent suppress food intake. Improvement in glucose-dependent insulin secretion and control serum glucose excursions were observed during hyperglycemic clamp test (18 h) and oral glucose tolerance test (42 h) respectively. Thus the improved physiological characterization of E2HSA make it a new potent anti-diabetic drug for type 2 diabetes therapy.

  2. Probing the molecular interaction of triazole fungicides with human serum albumin by multispectroscopic techniques and molecular modeling.

    PubMed

    Zhang, Jing; Zhuang, Shulin; Tong, Changlun; Liu, Weiping

    2013-07-31

    Triazole fungicides, one category of broad-spectrum fungicides, are widely applied in agriculture and medicine. The extensive use leads to many residues and casts potential detrimental effects on aquatic ecosystems and human health. After exposure of the human body, triazole fungicides may penetrate into the bloodstream and interact with plasma proteins. Whether they could have an impact on the structure and function of proteins is still poorly understood. By using multispectroscopic techniques and molecular modeling, the interaction of several typical triazole fungicides with human serum albumin (HSA), the major plasma protein, was investigated. The steady-state and time-resolved fluorescence spectra manifested that static type, due to complex formation, was the dominant mechanism for fluorescence quenching. Structurally related binding modes speculated by thermodynamic parameters agreed with the prediction of molecular modeling. For triadimefon, hydrogen bonding with Arg-218 and Arg-222 played an important role, whereas for imazalil, myclobutanil, and penconazole, the binding process was mainly contributed by hydrophobic and electrostatic interactions. Via alterations in three-dimensional fluorescence and circular dichroism spectral properties, it was concluded that triazoles could induce slight conformational and some microenvironmental changes of HSA. It is anticipated that these data can provide some information for possible toxicity risk of triazole fungicides to human health and be helpful in reinforcing the supervision of food safety.

  3. Mechanism of binding of the radiosensitizers metronidazole and misonidazole (RO-07-0582) to bovine and human serum albumin: a proton NMR study

    SciTech Connect

    Sulkowska, A.; Lubas, B.; Wilczok, T.

    1981-01-01

    High-resolution proton NMR spectra of the radiosensitizer metronidazole and its derivative misonidazole (RO-07-0582) were measured in D/sub 2/O at resonance frequency 60 MHz and interpreted in the aliphatic and aromatic regions. The linewidths of the NMR peaks attributed to individual fragments of nitroimidazole molecules were then analyzed in the presence of bovine and human serum albumin. With increasing concentration of serum albumin, a selectively larger broadening of the lines attributable to the protons of the aliphatic moieties than of those of the imidazole rings was observed for both compounds. This broadening for misonidazole strongly depends on the ionic strength of the solution. The results indicate a specific immobilization of the molecules of both radiosensitizers during their interaction with serum albumin and the involvement of the aliphatic chains of misonidazole and metronidazole as the primary binding sites.

  4. Factors influencing recombination frequency and distribution in a human meiotic crossover hotspot.

    PubMed

    Jeffreys, Alec J; Neumann, Rita

    2005-08-01

    Little is known about the factors that influence the frequency and distribution of meiotic recombination events within human crossover hotspots. We now describe the detailed analysis of sperm recombination in the NID1 hotspot. Like the neighbouring MS32 hotspot, the NID1 hotspot is associated with a minisatellite, suggesting that hotspots predispose DNA to tandem repetition. Unlike MS32, crossover resolution breakpoints in NID1 avoid the minisatellite, producing a cold spot within the hotspot. This avoidance may be related to the palindromic nature of the minisatellite interfering with the generation and/or processing of recombination intermediates. The NID1 hotspot also contains a single nucleotide polymorphism (SNP) close to the centre, which appears to directly influence the frequency of crossover initiation. Quantitative gene conversion assays show that this SNP affects the frequency of gene conversion and crossover to a very similar extent, providing evidence that conversions and crossovers are triggered by the same recombination initiating events. The recombination-suppressing allele is over-transmitted to recombinant progeny, and provides the most dramatic example to date of recombination-mediated meiotic drive, of a magnitude sufficient to virtually guarantee that the recombination suppressor will eventually replace the more active allele in human populations.

  5. Transmission distortion affecting human noncrossover but not crossover recombination: a hidden source of meiotic drive.

    PubMed

    Odenthal-Hesse, Linda; Berg, Ingrid L; Veselis, Amelia; Jeffreys, Alec J; May, Celia A

    2014-02-01

    Meiotic recombination ensures the correct segregation of homologous chromosomes during gamete formation and contributes to DNA diversity through both large-scale reciprocal crossovers and very localised gene conversion events, also known as noncrossovers. Considerable progress has been made in understanding factors such as PRDM9 and SNP variants that influence the initiation of recombination at human hotspots but very little is known about factors acting downstream. To address this, we simultaneously analysed both types of recombinant molecule in sperm DNA at six highly active hotspots, and looked for disparity in the transmission of allelic variants indicative of any cis-acting influences. At two of the hotspots we identified a novel form of biased transmission that was exclusive to the noncrossover class of recombinant, and which presumably arises through differences between crossovers and noncrossovers in heteroduplex formation and biased mismatch repair. This form of biased gene conversion is not predicted to influence hotspot activity as previously noted for SNPs that affect recombination initiation, but does constitute a powerful and previously undetected source of recombination-driven meiotic drive that by extrapolation may affect thousands of recombination hotspots throughout the human genome. Intriguingly, at both of the hotspots described here, this drive favours strong (G/C) over weak (A/T) base pairs as might be predicted from the well-established correlations between high GC content and recombination activity in mammalian genomes.

  6. Production of recombinant human antithrombin by Pichia pastoris.

    PubMed

    Kuwae, Shinobu; Ohyama, Masao; Ohya, Tomoshi; Ohi, Hideyuki; Kobayashi, Kaoru

    2005-03-01

    This paper deals with the production of recombinant human antithrombin (rAT) by the methylotrophic yeast Pichia pastoris. In preliminary methanol-limited fed-batch fermentation, the rAT concentration reached 324 mg/l at 192 h of cultivation, but the specific heparin cofactor (HC) activity of rAT in the culture supernatant was 10% of that of plasma-derived antithrombin (pAT). To improve the specific HC activity of rAT, effort was first focused on the optimization of culture pH and media composition, resulting in protection of rAT against pH-dependent instability and proteolytic degradation. However, even in the optimized methanol-limited fed-batch fermentation, the specific HC activity of rAT in the culture supernatant was still 20% that of pAT. To investigate the unknown mechanisms involved in the decreased specific HC activity of rAT, the culture supernatant of mock-transfected cells was prepared by methanol-limited fed-batch fermentation. When pAT was added to this supernatant, a rapid decrease in HC activity was observed; the residual HC activity was 26% after 24 h of incubation at 25 degrees C. The loss of pAT activity was prevented by addition of a formaldehyde scavenger, amino urea, to the supernatant. In addition, alcohol oxidase activity was observed in the supernatant, resulting in the accumulation of formaldehyde in the culture broth. These results suggest that the formaldehyde produced by methanol oxidation in the culture broth of P. pastoris might decrease the HC activity of rAT during fermentation. Replacing the methanol with glycerol as the carbon source improved the specific HC activity of rAT from 20% to above 40% of that of pAT. In the glycerol-limited fed-batch fermentation, rAT is expressed at 100 mg/l under the control of the truncated mutated AOX2 promoter.

  7. CHO expressed recombinant human lactoferrin as an adjuvant for BCG.

    PubMed

    Hwang, Shen-An; Kruzel, Marian L; Actor, Jeffrey K

    2015-12-01

    Lactoferrin (LF), an iron binding protein with immune modulatory activities, has adjuvant activity to enhance vaccine efficacy. Tuberculosis (TB) is a pulmonary disease caused by the pathogen Mycobacterium tuberculosis (MTB). Progressive TB disease is clinically defined by damaging pulmonary pathology, a result of inflammation due to immune reactivity. The current vaccine for TB, an attenuated strain of Mycobacterium bovis, Bacillus Calmette Guerin (BCG), has only limited efficacy to prevent adult pulmonary TB. This study examines a Chinese hamster ovary (CHO) expressed recombinant human LF (rHLF) to boost efficacy of the BCG vaccine and delay early pathology post infectious challenge. C57BL/6 mice were immunized with BCG, or BCG admixed with either rHLF or bovine LF (bLF; internal control), or remained unvaccinated. Mice were then aerosol challenged with Erdman MTB. All vaccinated mice demonstrated decreased organ bacterial load up to 19 weeks post infection compared with non-vaccinated controls. Furthermore, mice receiving bLF or rHLF supplemented BCG vaccines showed a modest decrease in lung pathology developed over time, compared to the BCG vaccine alone. While mice vaccinated with BCG/rHLF demonstrated increased general lung inflammation at day 7, it occurred without noticeable increase in pro-inflammatory cytokines. At later times, decreased pathology in the rHLF groups correlated with decreased inflammatory cytokines. Splenic recall to BCG antigens showed BCG/rHLF vaccination increased production of IFN-γ, IL-6, and GM-CSF compared to naïve, BCG, and BCG/bLF groups. Analysis of T cell stimulating functions of bone marrow derived macrophages and dendritic cells treated with BCG/bLF or BCG/rHLF showed decreases in IL-10 production when co-cultured with sensitized CD4 and CD8 T cells, compared to those cultured with macrophages/dendritic cells treated with BCG without LF. These results indicate that addition of rHLF to the BCG vaccine can modulate development

  8. Probing the binding sites of antibiotic drugs doxorubicin and N-(trifluoroacetyl) doxorubicin with human and bovine serum albumins.

    PubMed

    Agudelo, Daniel; Bourassa, Philippe; Bruneau, Julie; Bérubé, Gervais; Asselin, Eric; Tajmir-Riahi, Heidar-Ali

    2012-01-01

    We located the binding sites of doxorubicin (DOX) and N-(trifluoroacetyl) doxorubicin (FDOX) with bovine serum albumin (BSA) and human serum albumins (HSA) at physiological conditions, using constant protein concentration and various drug contents. FTIR, CD and fluorescence spectroscopic methods as well as molecular modeling were used to analyse drug binding sites, the binding constant and the effect of drug complexation on BSA and HSA stability and conformations. Structural analysis showed that doxorubicin and N-(trifluoroacetyl) doxorubicin bind strongly to BSA and HSA via hydrophilic and hydrophobic contacts with overall binding constants of K(DOX-BSA) = 7.8 (± 0.7) × 10(3) M(-1), K(FDOX-BSA) = 4.8 (± 0.5)× 10(3) M(-1) and K(DOX-HSA) = 1.1 (± 0.3)× 10(4) M(-1), K(FDOX-HSA) = 8.3 (± 0.6)× 10(3) M(-1). The number of bound drug molecules per protein is 1.5 (DOX-BSA), 1.3 (FDOX-BSA) 1.5 (DOX-HSA), 0.9 (FDOX-HSA) in these drug-protein complexes. Docking studies showed the participation of several amino acids in drug-protein complexation, which stabilized by H-bonding systems. The order of drug-protein binding is DOX-HSA > FDOX-HSA > DOX-BSA > FDOX>BSA. Drug complexation alters protein conformation by a major reduction of α-helix from 63% (free BSA) to 47-44% (drug-complex) and 57% (free HSA) to 51-40% (drug-complex) inducing a partial protein destabilization. Doxorubicin and its derivative can be transported by BSA and HSA in vitro.

  9. Incorporation of lapatinib into human serum albumin nanoparticles with enhanced anti-tumor effects in HER2-positive breast cancer.

    PubMed

    Wan, Xu; Zheng, Xiaoyao; Pang, Xiaoying; Zhang, Zheming; Zhang, Qizhi

    2015-12-01

    Lapatinib, a selective small-molecule dual-tyrosine kinase inhibitor of HER2 and EGFR, is effective in HER2-positive patients with advanced metastatic breast cancer. However, its low and variable oral absorption, large required daily dose and serious gastrointestinal side effects all limit its clinical use. Intravenous administration offers a good option to overcome these disadvantages. However, the poor solubility of lapatinib in water and organic solvents causes lapatinib to fail in a common injectable preparation. Considering lapatinib's high albumin binding ability (>99%), in this study, we developed human serum albumin nanoparticles loaded with lapatinib (LHNPs) by Nab technology for intravenous administration and investigated its efficacy against HER2-positive breast cancer. Raman shift, X-ray diffraction and X-ray photoelectron spectroscopy studies demonstrated that lapatinib was successfully incorporated into nanoparticles, and LHNPs exhibited good stability and sustained-release effect in vitro. LHNPs could be effectively taken up by SKBr3 cells in a concentration- and time-dependent manner, and the uptake was mediated by energy-dependent endocytosis, which involved clathrin-dependent pinocytosis. Furthermore, in vitro and in vivo data indicated that LHNPs presented the strong ability to induce apoptosis and superior anti-tumor efficacy in tumor-bearing mice to the commercial tablet Tykerb through the inhibition of HER2 phosphorylation. Subchronic toxicity assays indicated that LHNPs had no hepatic or kidney toxicity. With mature technology for industrial production and enhanced therapeutic effects, LHNPs are likely to have great potential as a safe therapeutic candidate against HER2-positive breast cancer in the clinic.

  10. Artificial restriction DNA cutters to promote homologous recombination in human cells.

    PubMed

    Katada, Hitoshi; Komiyama, Makoto

    2011-02-01

    Homologous recombination is almost the only way to modify the genome in a predetermined fashion, despite its quite low frequency in mammalian cells. It has been already reported that the frequency of this biological process can be notably increased by inducing a double strand break (DSB) at target site. This article presents completely chemistry-based artificial restriction DNA cutter (ARCUT) for the promotion of homologous recombination in human cells. This cutter is composed of Ce(IV)/EDTA complex (molecular scissors) and two strands of peptide nucleic acid (PNA), and contains no proteins. Its scission site in the genome is determined simply by Watson-Crick rule so that ARCUT for desired homologous recombination is easily and straightforwardly designed and synthesized. The site-specificity of the scission is high enough to cut human genome at one target site. The DSB induced by this cutter is satisfactorily recognized by the repair system in human cells and promotes the targeted homologous recombination.

  11. Spectroscopic analysis of the impact of oxidative stress on the structure of human serum albumin (HSA) in terms of its binding properties

    NASA Astrophysics Data System (ADS)

    Maciążek-Jurczyk, M.; Sułkowska, A.

    2015-02-01

    Oxygen metabolism has an important role in the pathogenesis of rheumatoid arthritis (RA). Reactive oxygen species (ROS) are produced in the course of cellular oxidative phosphorylation and by activated phagocytic cells during oxidative bursts, exceed the physiological buffering capacity and result in oxidative stress. ROS result in oxidation of serum albumin, which causes a number of structural changes in the spatial structure, may influence the binding and cause significant drug interactions, particularly in polytherapy. During the oxidation modification of amino acid residues, particularly cysteine and methionine may occur. The aim of the study was to investigate the influence of oxidative stress on human serum albumin (HSA) structure and evaluate of possible alterations in the binding of the drug to oxidized human serum albumin (oHSA). HSA was oxidized by a chloramine-T (CT). CT reacts rapidly with sulfhydryl groups and at pH 7.4 the reaction was monitored by spectroscopic techniques. Modification of free thiol group in the Cys residue in HSA was quantitatively determined by the use of Ellman's reagent. Changes of albumin conformation were examined by comparison of modified (oHSA) and nonmodified human serum albumin (HSA) absorption spectra, emission spectra, red-edge shift (REES) and synchronous spectroscopy. Studies of absorption spectra indicated that changes in the value of absorbance associated with spectral changes in the region of 200-250 nm involve structural alterations in peptide backbone conformation. Synchronous fluorescence spectroscopy technique confirmed changes of position of tryptophanyl and tyrosyl residues fluorescent band caused by CT. Moreover analysis of REES effect allowed to observe structural changes caused by CT in the region of the hydrophobic pocket containing the tryptophanyl residue. Effect of oxidative stress on binding of anti-rheumatic drugs, sulfasalazine (SSZ) and sulindac (SLD) in the high and low affinity binding sites was

  12. Noninvasive Imaging of Myocardial Inflammation in Myocarditis using 68Ga-tagged Mannosylated Human Serum Albumin Positron Emission Tomography

    PubMed Central

    Lee, Seung-Pyo; Im, Hyung-Jun; Kang, Shinae; Chung, Seock-Jin; Cho, Ye Seul; Kang, Hyejeong; Park, Ho Seon; Hwang, Do-Won; Park, Jun-Bean; Paeng, Jin-Chul; Cheon, Gi-Jeong; Lee, Yun-Sang; Jeong, Jae Min; Kim, Yong-Jin

    2017-01-01

    The diagnosis of myocarditis traditionally relies on invasive endomyocardial biopsy but none of the imaging studies so far are specific for infiltration of the inflammatory cells itself. We synthesized 68Ga-2-(p-isothiocyanatobenzyl)-1,4,7-triazacyclononane-1,4,7-triacetic acid (NOTA) mannosylated human serum albumin (MSA) by conjugating human serum