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Sample records for active peptides derived

  1. Anticoagulant activity of original synthetic peptide derivatives.

    PubMed

    Drozd, N N; Tolstenkov, A S; Makarov, V A; Miphtakhova, N T; Voyushina, T L; Sergeev, M E

    2008-01-01

    Original synthetic peptide derivatives exhibit anticoagulant activity in vitro and in vivo. They delayed fibrin clot formation from human blood plasma in tests for the intrinsic coagulation pathway (activated partial thromboplastin time) and final stage of plasma coagulation (thrombin time) and inhibited amidolytic activity of thrombin. We determined the minimum effective dose of the most active compound providing a 2-fold lengthening of blood clotting time (activated partial thromboplastin time test and thrombin time test), which persisted for 2-3 h. PMID:19024001

  2. Antimicrobial and Immunomodulatory Activities of PR-39 Derived Peptides

    PubMed Central

    Veldhuizen, Edwin J. A.; Schneider, Viktoria A. F.; Agustiandari, Herfita; van Dijk, Albert; Tjeerdsma-van Bokhoven, Johanna L. M.; Bikker, Floris J.; Haagsman, Henk P.

    2014-01-01

    The porcine cathelicidin PR-39 is a host defence peptide that plays a pivotal role in the innate immune defence of the pig against infections. Besides direct antimicrobial activity, it is involved in immunomodulation, wound healing and several other biological processes. In this study, the antimicrobial- and immunomodulatory activity of PR-39, and N- and C-terminal derivatives of PR-39 were tested. PR-39 exhibited an unexpected broad antimicrobial spectrum including several Gram positive strains such as Bacillus globigii and Enterococcus faecalis. Of organisms tested, only Staphylococcus aureus was insensitive to PR-39. Truncation of PR-39 down to 15 (N-terminal) amino acids did not lead to major loss of activity, while peptides corresponding to the C-terminal part of PR-39 were hampered in their antimicrobial activity. However, shorter peptides were all much more sensitive to inhibition by salt. Active peptides induced ATP leakage and loss of membrane potential in Bacillus globigii and Escherichia coli, indicating a lytic mechanism of action for these peptides. Finally, only the mature peptide was able to induce IL-8 production in porcine macrophages, but some shorter peptides also had an effect on TNF-α production showing differential regulation of cytokine induction by PR-39 derived peptides. None of the active peptides showed high cytotoxicity highlighting the potential of these peptides for use as an alternative to antibiotics. PMID:24755622

  3. Biologically active insulin-derived peptides.

    PubMed

    Fawcett, Janet

    2014-06-01

    Insulin has many actions within cells many of which are dependent on the cell type. For example, insulin stimulates glucose uptake in adipose tissue and skeletal muscle but not in liver. In liver glucose influx will increase as insulin stimulates the phosphorylation of glucose and eventual storage in the form of glycogen. Insulin also increases glucose oxidation, decreases glucose production, decreases lipolysis, increases protein synthesis and inhibits protein degradation in addition to others. Many actions have been related to insulin binding to its receptor and subsequent phosphorylation cascades, but insulin action on protein degradation has been shown to be linked to insulin degradation, specifically insulin degradation by the insulin-degrading enzyme (IDE). This activity has been shown to be due to an interaction of IDE with the proteasome, which is responsible for degradation of ubiquitin-tagged proteins. Smaller fragments of insulin that are produced by the action of IDE that do not bind to the insulin receptor show a small effect on protein degradation and a modest effect on mitogenesis. These small fragments do however inhibit lipolysis in a similar manner to insulin. If fragments are larger and can bind to the receptor they have been shown to increase glucose oxidation. Studies show that fragments of the insulin molecule have cellular activity, and that the varied actions of insulin are not completely controlled by insulin binding to the insulin receptor, even though the mechanisms may not be mutually exclusive. PMID:24559166

  4. Bactericidal Activity of Mammalian Cathelicidin-Derived Peptides

    PubMed Central

    Travis, Sue M.; Anderson, Norma N.; Forsyth, William R.; Espiritu, Cesar; Conway, Barbara D.; Greenberg, E. P.; McCray, Paul B.; Lehrer, Robert I.; Welsh, Michael J.; Tack, Brian F.

    2000-01-01

    Endogenous antimicrobial peptides of the cathelicidin family contribute to innate immunity. The emergence of widespread antibiotic resistance in many commonly encountered bacteria requires the search for new bactericidal agents with therapeutic potential. Solid-phase synthesis was employed to prepare linear antimicrobial peptides found in cathelicidins of five mammals: human (FALL39/LL37), rabbit (CAP18), mouse (mCRAMP), rat (rCRAMP), and sheep (SMAP29 and SMAP34). These peptides were tested at ionic strengths of 25 and 175 mM against Pseudomonas aeruginosa, Escherichia coli, Staphylococcus aureus, and methicillin-resistant Staphylococcus aureus. Each peptide manifested activity against P. aeruginosa irrespective of the NaCl concentration. CAP18 and SMAP29 were the most effective peptides of the group against all test organisms under both low- and high-salt conditions. Select peptides of 15 to 21 residues, modeled on CAP18 (37 residues), retained activity against the gram-negative bacteria and methicillin-sensitive S. aureus, although the bactericidal activity was reduced compared to that of the parent peptide. In accordance with the behavior of the parent molecule, the truncated peptides adopted an α-helical structure in the presence of trifluoroethanol or lipopolysaccharide. The relationship between the bactericidal activity and several physiochemical properties of the cathelicidins was examined. The activities of the full-length peptides correlated positively with a predicted gradient of hydrophobicity along the peptide backbone and with net positive charge; they correlated inversely with relative abundance of anionic residues. The salt-resistant, antimicrobial properties of CAP18 and SMAP29 suggest that these peptides or congeneric structures have potential for the treatment of bacterial infections in normal and immunocompromised persons and individuals with cystic fibrosis. PMID:10768969

  5. Bactericidal activity of mammalian cathelicidin-derived peptides.

    PubMed

    Travis, S M; Anderson, N N; Forsyth, W R; Espiritu, C; Conway, B D; Greenberg, E P; McCray, P B; Lehrer, R I; Welsh, M J; Tack, B F

    2000-05-01

    Endogenous antimicrobial peptides of the cathelicidin family contribute to innate immunity. The emergence of widespread antibiotic resistance in many commonly encountered bacteria requires the search for new bactericidal agents with therapeutic potential. Solid-phase synthesis was employed to prepare linear antimicrobial peptides found in cathelicidins of five mammals: human (FALL39/LL37), rabbit (CAP18), mouse (mCRAMP), rat (rCRAMP), and sheep (SMAP29 and SMAP34). These peptides were tested at ionic strengths of 25 and 175 mM against Pseudomonas aeruginosa, Escherichia coli, Staphylococcus aureus, and methicillin-resistant Staphylococcus aureus. Each peptide manifested activity against P. aeruginosa irrespective of the NaCl concentration. CAP18 and SMAP29 were the most effective peptides of the group against all test organisms under both low- and high-salt conditions. Select peptides of 15 to 21 residues, modeled on CAP18 (37 residues), retained activity against the gram-negative bacteria and methicillin-sensitive S. aureus, although the bactericidal activity was reduced compared to that of the parent peptide. In accordance with the behavior of the parent molecule, the truncated peptides adopted an alpha-helical structure in the presence of trifluoroethanol or lipopolysaccharide. The relationship between the bactericidal activity and several physiochemical properties of the cathelicidins was examined. The activities of the full-length peptides correlated positively with a predicted gradient of hydrophobicity along the peptide backbone and with net positive charge; they correlated inversely with relative abundance of anionic residues. The salt-resistant, antimicrobial properties of CAP18 and SMAP29 suggest that these peptides or congeneric structures have potential for the treatment of bacterial infections in normal and immunocompromised persons and individuals with cystic fibrosis. PMID:10768969

  6. Antioxidant activities of a peptide derived from chicken dark meat.

    PubMed

    Fukada, Yoko; Mizutani, Saki; Nomura, Sarika; Hara, Wakana; Matsui, Riko; Nagai, Kumiko; Murakami, Yuki; Washio, Nanami; Ikemoto, Narumi; Terashima, Masaaki

    2016-05-01

    Antioxidant activities against hypochlorite ions and peroxyl radicals of a chicken dark meat hydrolysate digested with pepsin were examined with the myoglobin method based on the structure change of myoglobin due to redox reaction with reactive oxygen species (ROS). A peptide that showed strong antioxidant activity against the peroxyl radical was isolated from the hydrolysate using HPLC equipped with a hydrophobic-interacting column. The sequence of the first five amino acid residues of the peptide was determined as YASGR (Tyr-Ala-Ser-Gly-Arg), and this sequence matched with the amino acid residues 143-147 of chicken β-actin (GenBank: CAA25004.1). The synthetic peptide YASGR showed very high antioxidant activity against the peroxyl radical. Antioxidant activities of the free amino acids, confirmed that the tyrosine residue of this peptide was possibly responsible for antioxidant activity. PMID:27407214

  7. Nonopiate active proenkephalin-derived peptides are secreted by T helper cells.

    PubMed

    Roth, K A; Lorenz, R G; Unanue, R A; Weaver, C T

    1989-10-01

    Recent investigations have shown that the neuroendocrine and immune systems profoundly affect each other. In part, these interactions occur via common chemical messengers and receptors. One possible shared chemical messenger is the opioid precursor preproenkephalin, for which high concentrations of messenger RNA are present in brain, adrenal, and activated T helper cells. Because the biologic action of most peptide messengers depends on the posttranslational processing of the precursor, we have examined T helper cell lines for the production of proenkephalin-derived peptides. These peptides were characterized by multiple radioimmunoassays, gel filtration chromatography, and opiate radioreceptor assays. We found that activated T helper cells secrete significant concentrations of high-molecular-weight, opiate-inactive peptides, which are distinct from the proenkephalin-derived peptides of the neuroendocrine system. These studies clearly indicate cell-specific processing of proenkephalin, and suggest that the T helper cell-secreted products may have nonopiate receptor-mediated actions. PMID:2529160

  8. Molecular Design, Structural Analysis and Antifungal Activity of Derivatives of Peptide CGA-N46.

    PubMed

    Li, Rui-Fang; Lu, Zhi-Fang; Sun, Ya-Nan; Chen, Shi-Hua; Yi, Yan-Jie; Zhang, Hui-Ru; Yang, Shuo-Ye; Yu, Guang-Hai; Huang, Liang; Li, Chao-Nan

    2016-09-01

    Chromogranin A (CGA)-N46, a derived peptide of human chromogranin A, has antifungal activity. To further research the active domain of CGA-N46, a series of derivatives were designed by successively deleting amino acid from both terminus of CGA-N46, and the amino acid sequence of each derivative was analyzed by bioinformatic software. Based on the predicted physicochemical properties of the peptides, including half-life time in mammalian reticulocytes (in vitro), yeast (in vivo) and E. coli (in vivo), instability index, aliphatic index and grand average of hydropathicity (GRAVY), the secondary structure, net charge, the distribution of hydrophobic residues and hydrophilic residues, the final derivatives CGA-N15, CGA-N16, CGA-N12 and CGA-N8 were synthesized by solid-phase peptide synthesis. The results of bioinformatic analysis showed that CGA-N46 and its derivatives were α-helix, neutral or weak positive charge, hydrophilic, and CGA-N12 and CGA-N8 were more stable than the other derivatives. The results of circular dichroism confirmed that CGA-N46 and its derived peptides displayed α-helical structure in an aqueous solution and 30 mM sodium dodecylsulfate, but α-helical contents decreased in hydrophobic lipid vesicles. CGA-N15, CGA-N16, CGA-N12 and CGA-N8 had higher antifungal activities than their mother peptide CGA-N46. Among of the derived peptides, CGA-N12 showed the least hemolytic activity. In conclusion, we have successfully identified the active domain of CGA-N46 with strong antifungal activity and weak hemolytic activity, which provides the possibility to develop a new class of antibiotics. PMID:27165480

  9. Immunomodulatory and Anti-Inflammatory Activities of Chicken Cathelicidin-2 Derived Peptides.

    PubMed

    van Dijk, Albert; van Eldik, Mandy; Veldhuizen, Edwin J A; Tjeerdsma-van Bokhoven, Hanne L M; de Zoete, Marcel R; Bikker, Floris J; Haagsman, Henk P

    2016-01-01

    Host Defence Peptides and derived peptides are promising classes of antimicrobial and immunomodulatory lead compounds. For this purpose we examined whether chicken cathelicidin-2 (CATH-2)-derived peptides modulate the function and inflammatory response of avian immune cells. Using a chicken macrophage cell line (HD11) we found that full-length CATH-2 dose-dependently induced transcription of chemokines CXCLi2/IL-8, MCP-3 and CCLi4/RANTES, but not of pro-inflammatory cytokine IL-1β. In addition, CATH-2 efficiently inhibited IL-1β and nitric oxide production by HD11 cells induced by different sources of lipopolysaccharides (LPS). N-terminal truncated CATH-2 derived peptides maintained the capacity to selectively induce chemokine transcription, but despite their high LPS affinity several analogs lacked LPS-neutralizing capacity. Substitution of phenylalanine residues by tryptophan introduced endotoxin neutralization capacity in inactive truncated CATH-2 derived peptides. In contrast, amino acid substitution of phenylalanine by tyrosine abrogated endotoxin neutralization activity of CATH-2 analogs. These findings support a pivotal role for aromatic residues in peptide-mediated endotoxin neutralization by CATH-2 analogs and were shown to be independent of LPS affinity. The capacity to modulate chemokine production and dampen endotoxin-induced pro-inflammatory responses in chicken immune cells implicates that small CATH-2 based peptides could serve as leads for the design of CATH-2 based immunomodulatory anti-infectives. PMID:26848845

  10. Immunomodulatory and Anti-Inflammatory Activities of Chicken Cathelicidin-2 Derived Peptides

    PubMed Central

    van Dijk, Albert; van Eldik, Mandy; Veldhuizen, Edwin J. A.; Tjeerdsma-van Bokhoven, Hanne L. M.; de Zoete, Marcel R.; Bikker, Floris J.; Haagsman, Henk P.

    2016-01-01

    Host Defence Peptides and derived peptides are promising classes of antimicrobial and immunomodulatory lead compounds. For this purpose we examined whether chicken cathelicidin-2 (CATH-2)-derived peptides modulate the function and inflammatory response of avian immune cells. Using a chicken macrophage cell line (HD11) we found that full-length CATH-2 dose-dependently induced transcription of chemokines CXCLi2/IL-8, MCP-3 and CCLi4/RANTES, but not of pro-inflammatory cytokine IL-1β. In addition, CATH-2 efficiently inhibited IL-1β and nitric oxide production by HD11 cells induced by different sources of lipopolysaccharides (LPS). N-terminal truncated CATH-2 derived peptides maintained the capacity to selectively induce chemokine transcription, but despite their high LPS affinity several analogs lacked LPS-neutralizing capacity. Substitution of phenylalanine residues by tryptophan introduced endotoxin neutralization capacity in inactive truncated CATH-2 derived peptides. In contrast, amino acid substitution of phenylalanine by tyrosine abrogated endotoxin neutralization activity of CATH-2 analogs. These findings support a pivotal role for aromatic residues in peptide-mediated endotoxin neutralization by CATH-2 analogs and were shown to be independent of LPS affinity. The capacity to modulate chemokine production and dampen endotoxin-induced pro-inflammatory responses in chicken immune cells implicates that small CATH-2 based peptides could serve as leads for the design of CATH-2 based immunomodulatory anti-infectives. PMID:26848845

  11. Activity Prediction and Molecular Mechanism of Bovine Blood Derived Angiotensin I-Converting Enzyme Inhibitory Peptides

    PubMed Central

    Zhang, Ting; Nie, Shaoping; Liu, Boqun; Yu, Yiding; Zhang, Yan; Liu, Jingbo

    2015-01-01

    Development of angiotensin I-converting enzyme (ACE, EC 3.4.15.1) inhibitory peptides from food protein is under extensive research as alternative for the prevention of hypertension. However, it is difficult to identify peptides released from food sources. To accelerate the progress of peptide identification, a three layer back propagation neural network model was established to predict the ACE-inhibitory activity of pentapeptides derived from bovine hemoglobin by simulated enzyme digestion. The pentapeptide WTQRF has the best predicted value with experimental IC50 23.93 μM. The potential molecular mechanism of the WTQRF / ACE interaction was investigated by flexible docking. PMID:25768442

  12. Reactive Center Loop (RCL) Peptides Derived from Serpins Display Independent Coagulation and Immune Modulating Activities.

    PubMed

    Ambadapadi, Sriram; Munuswamy-Ramanujam, Ganesh; Zheng, Donghang; Sullivan, Colin; Dai, Erbin; Morshed, Sufi; McFadden, Baron; Feldman, Emily; Pinard, Melissa; McKenna, Robert; Tibbetts, Scott; Lucas, Alexandra

    2016-02-01

    Serpins regulate coagulation and inflammation, binding serine proteases in suicide-inhibitory complexes. Target proteases cleave the serpin reactive center loop scissile P1-P1' bond, resulting in serpin-protease suicide-inhibitory complexes. This inhibition requires a near full-length serpin sequence. Myxomavirus Serp-1 inhibits thrombolytic and thrombotic proteases, whereas mammalian neuroserpin (NSP) inhibits only thrombolytic proteases. Both serpins markedly reduce arterial inflammation and plaque in rodent models after single dose infusion. In contrast, Serp-1 but not NSP improves survival in a lethal murine gammaherpesvirus68 (MHV68) infection in interferon γ-receptor-deficient mice (IFNγR(-/-)). Serp-1 has also been successfully tested in a Phase 2a clinical trial. We postulated that proteolytic cleavage of the reactive center loop produces active peptide derivatives with expanded function. Eight peptides encompassing predicted protease cleavage sites for Serp-1 and NSP were synthesized and tested for inhibitory function in vitro and in vivo. In engrafted aorta, selected peptides containing Arg or Arg-Asn, not Arg-Met, with a 0 or +1 charge, significantly reduced plaque. Conversely, S-6 a hydrophobic peptide of NSP, lacking Arg or Arg-Asn with -4 charge, induced early thrombosis and mortality. S-1 and S-6 also significantly reduced CD11b(+) monocyte counts in mouse splenocytes. S-1 peptide had increased efficacy in plasminogen activator inhibitor-1 serpin-deficient transplants. Plaque reduction correlated with mononuclear cell activation. In a separate study, Serp-1 peptide S-7 improved survival in the MHV68 vasculitis model, whereas an inverse S-7 peptide was inactive. Reactive center peptides derived from Serp-1 and NSP with suitable charge and hydrophobicity have the potential to extend immunomodulatory functions of serpins. PMID:26620556

  13. Analysis of the antimicrobial activities of a chemokine-derived peptide (CDAP-4) on Pseudomonas aeruginosa

    SciTech Connect

    Martinez-Becerra, Francisco; Dominguez-Ramirez, Lenin; Mendoza-Hernandez, Guillermo; Lopez-Vidal, Yolanda; Soldevila, Gloria . E-mail: garciaze@servidor.unam.mx

    2007-04-06

    Chemokines are key molecules involved in the control of leukocyte trafficking. Recently, a novel function as antimicrobial proteins has been described. CCL13 is the only member of the MCP chemokine subfamily displaying antimicrobial activity. To determine Key residues involved in its antimicrobial activity, CCL13 derived peptides were synthesized and tested against several bacterial strains, including Pseudomonas aeruginosa. One of these peptides, corresponding to the C-terminal region of CCL13 (CDAP-4) displayed good antimicrobial activity. Electron microscopy studies revealed remarkable morphological changes after CDAP-4 treatment. By computer modeling, CDAP-4 in {alpha} helical configuration generated a positive electrostatic potential that extended beyond the surface of the molecule. This feature is similar to other antimicrobial peptides. Altogether, these findings indicate that the antimicrobial activity was displayed by CCL13 resides to some extent at the C-terminal region. Furthermore, CDAP-4 could be considered a good antimicrobial candidate with a potential use against pathogens including P. aeruginosa.

  14. Anticancer activity of a synthetic peptide derived from harmoniasin, an antibacterial peptide from the ladybug Harmonia axyridis.

    PubMed

    Kim, In-Woo; Lee, Joon Ha; Kwon, Young-Nam; Yun, Eun-Young; Nam, Sung-Hee; Ahn, Mi-Young; Kang, Dong-Chul; Hwang, Jae Sam

    2013-08-01

    Harmoniasin is a defensin-like antimicrobial peptide identified from the ladybug Harmonia axyridis. Among the synthetic homodimer peptide analogues derived from harmoniasin, HaA4 has been found to have antibacterial activity without hemolytic activity. In this study, we investigated whether HaA4 has anticancer activity against human leukemia cell lines such as U937 and Jurkat cells. HaA4 manifested cytotoxicity and decreased the cell viability of U937 and Jurkat cells in MTS assay and LDH release assay. We found that HaA4 induced apoptotic and necrotic cell death of the leukemia cells using flow cytometric analysis, acridine orange/ethidium bromide staining and nucleosomal fragmentation of genomic DNA. Activation of caspase-7 and -9 and fragmentation of poly (ADP-ribose) polymerase was detected in the HaA4-treated leukemia cells, suggesting induction of a caspase-dependent apoptosis pathway by HaA4. Caspase-dependent apoptosis was further confirmed by reversal of the HaA4-induced viability reduction by treatment of Z-VAD-FMK, a pan-caspase inhibitor. In conclusion, HaA4 caused necrosis and caspase-dependent apoptosis in both U937 and Jurkat leukemia cells, which suggests potential utility of HaA4 as a cancer therapeutic agent. PMID:23732481

  15. The anti-cancer activity of a cationic anti-microbial peptide derived from monomers of polyhydroxyalkanoate.

    PubMed

    O'Connor, Stephen; Szwej, Emilia; Nikodinovic-Runic, Jasmina; O'Connor, Aisling; Byrne, Annette T; Devocelle, Marc; O'Donovan, Norma; Gallagher, William M; Babu, Ramesh; Kenny, Shane T; Zinn, Manfred; Zulian, Qun Ren; O'Connor, Kevin E

    2013-04-01

    The biodegradable polymer medium chain length polyhydroxyalkanoate (mclPHA), produced by Pseudomonas putida CA-3, was depolymerised and the predominant monomer (R)-3-hydroxydecanoic acid (R10) purified. R10 was conjugated to a d-peptide DP18 and its derivatives. All peptides conjugated with R10 exhibited greater anti-cancer activity compared to the unconjugated peptides. Unconjugated and conjugated peptides were cytocidal for cancer cells. Conjugation of R10 to peptides was essential for enhanced anti-proliferation activity, as unconjugated mixes did not result in enhancement of anti-cancer activity. The conjugation of R10 resulted in more rapid uptake of peptides into HeLa and MiaPaCa cells compared to unconjugated peptide. Both unconjugated and R10 conjugated peptides localized to the mitochondria of HeLa and MiaPaCa cells and induced apoptosis. Peptide conjugated with a terminally hydroxylated decanoic acid (ω-hydroxydecanoic acid) exhibited 3.3 and 6.3 fold higher IC(50) values compared to R10 conjugated peptide indicating a role for the position of the hydroxyl moiety in enhancement of anti-cancer activity. Conjugation of decanoic acid (C10) to peptides resulted in similar or higher IC(50) values compared to R10 conjugates but C10 conjugates did not exhibit any cancer selectivity. Combination studies showed that R10DP18L exhibited synergy with cisplatin, gemcitabine, and taxotere with IC(50) values in the nanomolar range. PMID:23343631

  16. Antibacterial activity of lactoferrin and a pepsin-derived lactoferrin peptide fragment.

    PubMed Central

    Yamauchi, K; Tomita, M; Giehl, T J; Ellison, R T

    1993-01-01

    Although the antimicrobial activity of lactoferrin has been well described, its mechanism of action has been poorly characterized. Recent work has indicated that in addition to binding iron, human lactoferrin damages the outer membrane of gram-negative bacteria. In this study, we determined whether bovine lactoferrin and a pepsin-derived bovine lactoferrin peptide (lactoferricin) fragment have similar activities. We found that both 20 microM bovine lactoferrin and 20 microM lactoferricin release intrinsically labeled [3H]lipopolysaccharide ([3H]LPS) from three bacterial strains, Escherichia coli CL99 1-2, Salmonella typhimurium SL696, and Salmonella montevideo SL5222. Under most conditions, more LPS is released by the peptide fragment than by whole bovine lactoferrin. In the presence of either lactoferrin or lactoferricin there is increased killing of E. coli CL99 1-2 by lysozyme. Like human lactoferrin, bovine lactoferrin and lactoferricin have the ability to bind to free intrinsically labeled [3H]LPS molecules. In addition to these effects, whereas bovine lactoferrin was at most bacteriostatic, lactoferricin demonstrated consistent bactericidal activity against gram-negative bacteria. This bactericidal effect is modulated by the cations Ca2+, Mg2+, and Fe3+ but is independent of the osmolarity of the medium. Transmission electron microscopy of bacterial cells exposed to lactoferricin show the immediate development of electron-dense "membrane blisters." These experiments offer evidence that bovine lactoferrin and lactoferricin damage the outer membrane of gram-negative bacteria. Moreover, the peptide fragment lactoferricin has direct bactericidal activity. As lactoferrin is exposed to proteolytic factors in vivo which could cleave the lactoferricin fragment, the effects of this peptide are of both mechanistic and physiologic relevance. Images PMID:8423097

  17. Synthesis and Antiproliferative Activity Evaluation of the Disulfide-Containing Cyclic Peptide Thiochondrilline C and Derivatives.

    PubMed

    Vippila, Mohana Rao; Ly, Phuong Kim; Cuny, Gregory D

    2015-10-23

    Thiochondrilline C (4) was previously isolated from Verrucisispora sp. and reported to have moderate cytotoxicity against human lung adenocarcinoma cells. Herein, we report the synthesis of thiochondrilline C by N-terminal peptide extension, oxidative disulfide bond formation, and heterocycle installation as key steps. Antiproliferative activities for the prepared natural product and several derivatives against the NCI 60 cancer cell line panel are also described. Derivative 22 was identified as a moderately potent antiproliferative agent (50% growth inhibition (GI50) = 0.2-12.2 μM) with leukemia (average GI50 = 1.8 ± 0.1 μM) and colon (average GI50 = 2.4 ± 0.3 μM) cells being most sensitive. PMID:26444379

  18. Anti-biofilm activity of ultrashort cinnamic acid peptide derivatives against medical device-related pathogens.

    PubMed

    Laverty, Garry; McCloskey, Alice P; Gorman, Sean P; Gilmore, Brendan F

    2015-10-01

    The threat of antimicrobial resistance has placed increasing emphasis on the development of innovative approaches to eradicate multidrug-resistant pathogens. Biofilm-forming microorganisms, for example, Staphylococcus epidermidis and Staphylococcus aureus, are responsible for increased incidence of biomaterial infection, extended hospital stays and patient morbidity and mortality. This paper highlights the potential of ultrashort tetra-peptide conjugated to hydrophobic cinnamic acid derivatives. These peptidomimetic molecules demonstrate selective and highly potent activity against resistant biofilm forms of Gram-positive medical device-related pathogens. 3-(4-Hydroxyphenyl)propionic)-Orn-Orn-Trp-Trp-NH2 displays particular promise with minimum biofilm eradication concentration (MBEC) values of 125 µg/ml against methicillin sensitive (ATCC 29213) and resistant (ATCC 43300) S. aureus and activity shown against biofilm forms of Escherichia coli (MBEC: 1000 µg/ml). Kill kinetics confirms complete eradication of established 24-h biofilms at MBEC with 6-h exposure. Reduced cell cytotoxicity, relative to Gram-positive pathogens, was proven via tissue culture (HaCaT) and haemolysis assays (equine erythrocytes). Existing in nature as part of the immune response, antimicrobial peptides display great promise for exploitation by the pharmaceutical industry in order to increase the library of available therapeutic molecules. Ultrashort variants are particularly promising for translation as clinical therapeutics as they are more cost-effective, easier to synthesise and can be tailored to specific functional requirements based on the primary sequence allowing factors such as spectrum of activity to be varied. PMID:26310860

  19. Antimicrobial Activity of Novel Synthetic Peptides Derived from Indolicidin and Ranalexin against Streptococcus pneumoniae

    PubMed Central

    Jindal, Hassan Mahmood; Le, Cheng Foh; Mohd Yusof, Mohd Yasim; Velayuthan, Rukumani Devi; Lee, Vannajan Sanghiran; Zain, Sharifuddin Md; Isa, Diyana Mohd; Sekaran, Shamala Devi

    2015-01-01

    Antimicrobial peptides (AMPs) represent promising alternatives to conventional antibiotics in order to defeat multidrug-resistant bacteria such as Streptococcus pneumoniae. In this study, thirteen antimicrobial peptides were designed based on two natural peptides indolicidin and ranalexin. Our results revealed that four hybrid peptides RN7-IN10, RN7-IN9, RN7-IN8, and RN7-IN6 possess potent antibacterial activity against 30 pneumococcal clinical isolates (MIC 7.81-15.62µg/ml). These four hybrid peptides also showed broad spectrum antibacterial activity (7.81µg/ml) against S. aureus, methicillin resistant S. aureus (MRSA), and E. coli. Furthermore, the time killing assay results showed that the hybrid peptides were able to eliminate S. pneumoniae within less than one hour which is faster than the standard drugs erythromycin and ceftriaxone. The cytotoxic effects of peptides were tested against human erythrocytes, WRL-68 normal liver cell line, and NL-20 normal lung cell line. The results revealed that none of the thirteen peptides have cytotoxic or hemolytic effects at their MIC values. The in silico molecular docking study was carried out to investigate the binding properties of peptides with three pneumococcal virulent targets by Autodock Vina. RN7IN6 showed a strong affinity to target proteins; autolysin, pneumolysin, and pneumococcal surface protein A (PspA) based on rigid docking studies. Our results suggest that the hybrid peptides could be suitable candidates for antibacterial drug development. PMID:26046345

  20. Factors affecting antimicrobial activity of MUC7 12-mer, a human salivary mucin-derived peptide

    PubMed Central

    Wei, Guo-Xian; Campagna, Alexander N; Bobek, Libuse A

    2007-01-01

    Background MUC7 12-mer (RKSYKCLHKRCR), a cationic antimicrobial peptide derived from the human low-molecular-weight salivary mucin MUC7, possesses potent antimicrobial activity in vitro. In order to evaluate the potential therapeutic application of the MUC7 12-mer, we examined the effects of mono- and divalent cations, EDTA, pH, and temperature on its antimicrobial activity. Methods Minimal Inhibitory Concentrations (MICs) were determined using a liquid growth inhibition assay in 96-well microtiter plates. MUC7 12-mer was added at concentrations of 1.56–50 μM. MICs were determined at three endpoints: MIC-0, MIC-1, and MIC-2 (the lowest drug concentration showing 10%, 25% and 50% of growth, respectively). To examine the effect of salts or EDTA, a checkerboard microdilution technique was used. Fractional inhibitory concentration index (FICi) was calculated on the basis of MIC-0. The viability of microbial cells treated with MUC7 12-mer in the presence of sodium or potassium was also determined by killing assay or flow cytometry. Results The MICs of MUC7 12-mer against organisms tested ranged from 6.25–50 μM. For C. albicans, antagonism (FICi 4.5) was observed for the combination of MUC7 12-mer and calcium; however, there was synergism (FICi 0.22) between MUC7 12-mer and EDTA, and the synergism was retained in the presence of calcium at its physiological concentration (1–2 mM). No antagonism but additivity or indifference (FICi 0.55–2.5) was observed for the combination of MUC7 12-mer and each K+, Na+, Mg2+, or Zn2+. MUC7 12-mer peptide (at 25 μM) also exerted killing activity in the presence of NaCl, (up to 25 mM for C. albicans and up to 150 mM for E. coli, a physiological concentration of sodium in the oral cavity and serum, respectively) and retained candidacidal activity in the presence of KCl (up to 40 mM). The peptide exhibited higher inhibitory activity against C. albicans at pH 7, 8, and 9 than at pH 5 and 6, and temperature up to 60°C did not

  1. New Milk Protein-Derived Peptides with Potential Antimicrobial Activity: An Approach Based on Bioinformatic Studies

    PubMed Central

    Dziuba, Bartłomiej; Dziuba, Marta

    2014-01-01

    New peptides with potential antimicrobial activity, encrypted in milk protein sequences, were searched for with the use of bioinformatic tools. The major milk proteins were hydrolyzed in silico by 28 enzymes. The obtained peptides were characterized by the following parameters: molecular weight, isoelectric point, composition and number of amino acid residues, net charge at pH 7.0, aliphatic index, instability index, Boman index, and GRAVY index, and compared with those calculated for known 416 antimicrobial peptides including 59 antimicrobial peptides (AMPs) from milk proteins listed in the BIOPEP database. A simple analysis of physico-chemical properties and the values of biological activity indicators were insufficient to select potentially antimicrobial peptides released in silico from milk proteins by proteolytic enzymes. The final selection was made based on the results of multidimensional statistical analysis such as support vector machines (SVM), random forest (RF), artificial neural networks (ANN) and discriminant analysis (DA) available in the Collection of Anti-Microbial Peptides (CAMP database). Eleven new peptides with potential antimicrobial activity were selected from all peptides released during in silico proteolysis of milk proteins. PMID:25141106

  2. Antibacterial Activity of Synthetic Peptides Derived from Lactoferricin against Escherichia coli ATCC 25922 and Enterococcus faecalis ATCC 29212

    PubMed Central

    León-Calvijo, María A.; Leal-Castro, Aura L.; Almanzar-Reina, Giovanni A.; Rosas-Pérez, Jaiver E.; García-Castañeda, Javier E.; Rivera-Monroy, Zuly J.

    2015-01-01

    Peptides derived from human and bovine lactoferricin were designed, synthesized, purified, and characterized using RP-HPLC and MALDI-TOF-MS. Specific changes in the sequences were designed as (i) the incorporation of unnatural amino acids in the sequence, the (ii) reduction or (iii) elongation of the peptide chain length, and (iv) synthesis of molecules with different number of branches containing the same sequence. For each peptide, the antibacterial activity against Escherichia coli ATCC 25922 and Enterococcus faecalis ATCC 29212 was evaluated. Our results showed that Peptides I.2 (RWQWRWQWR) and I.4 ((RRWQWR)4K2Ahx2C2) exhibit bigger or similar activity against E. coli (MIC 4–33 μM) and E. faecalis (MIC 10–33 μM) when they were compared with lactoferricin protein (LF) and some of its derivate peptides as II.1 (FKCRRWQWRMKKLGA) and IV.1 (FKCRRWQWRMKKLGAPSITCVRRAE). It should be pointed out that Peptides I.2 and I.4, containing the RWQWR motif, are short and easy to synthesize; our results demonstrate that it is possible to design and obtain synthetic peptides that exhibit enhanced antibacterial activity using a methodology that is fast and low-cost and that allows obtaining products with a high degree of purity and high yield. PMID:25815317

  3. Antibacterial activity of synthetic peptides derived from lactoferricin against Escherichia coli ATCC 25922 and Enterococcus faecalis ATCC 29212.

    PubMed

    León-Calvijo, María A; Leal-Castro, Aura L; Almanzar-Reina, Giovanni A; Rosas-Pérez, Jaiver E; García-Castañeda, Javier E; Rivera-Monroy, Zuly J

    2015-01-01

    Peptides derived from human and bovine lactoferricin were designed, synthesized, purified, and characterized using RP-HPLC and MALDI-TOF-MS. Specific changes in the sequences were designed as (i) the incorporation of unnatural amino acids in the sequence, the (ii) reduction or (iii) elongation of the peptide chain length, and (iv) synthesis of molecules with different number of branches containing the same sequence. For each peptide, the antibacterial activity against Escherichia coli ATCC 25922 and Enterococcus faecalis ATCC 29212 was evaluated. Our results showed that Peptides I.2 (RWQWRWQWR) and I.4 ((RRWQWR)4K2Ahx2C2) exhibit bigger or similar activity against E. coli (MIC 4-33 μM) and E. faecalis (MIC 10-33 μM) when they were compared with lactoferricin protein (LF) and some of its derivate peptides as II.1 (FKCRRWQWRMKKLGA) and IV.1 (FKCRRWQWRMKKLGAPSITCVRRAE). It should be pointed out that Peptides I.2 and I.4, containing the RWQWR motif, are short and easy to synthesize; our results demonstrate that it is possible to design and obtain synthetic peptides that exhibit enhanced antibacterial activity using a methodology that is fast and low-cost and that allows obtaining products with a high degree of purity and high yield. PMID:25815317

  4. A polyalanine peptide derived from polar fish with anti-infectious activities

    NASA Astrophysics Data System (ADS)

    Cardoso, Marlon H.; Ribeiro, Suzana M.; Nolasco, Diego O.; de La Fuente-Núñez, César; Felício, Mário R.; Gonçalves, Sónia; Matos, Carolina O.; Liao, Luciano M.; Santos, Nuno C.; Hancock, Robert E. W.; Franco, Octávio L.; Migliolo, Ludovico

    2016-02-01

    Due to the growing concern about antibiotic-resistant microbial infections, increasing support has been given to new drug discovery programs. A promising alternative to counter bacterial infections includes the antimicrobial peptides (AMPs), which have emerged as model molecules for rational design strategies. Here we focused on the study of Pa-MAP 1.9, a rationally designed AMP derived from the polar fish Pleuronectes americanus. Pa-MAP 1.9 was active against Gram-negative planktonic bacteria and biofilms, without being cytotoxic to mammalian cells. By using AFM, leakage assays, CD spectroscopy and in silico tools, we found that Pa-MAP 1.9 may be acting both on intracellular targets and on the bacterial surface, also being more efficient at interacting with anionic LUVs mimicking Gram-negative bacterial surface, where this peptide adopts α-helical conformations, than cholesterol-enriched LUVs mimicking mammalian cells. Thus, as bacteria present varied physiological features that favor antibiotic-resistance, Pa-MAP 1.9 could be a promising candidate in the development of tools against infections caused by pathogenic bacteria.

  5. A polyalanine peptide derived from polar fish with anti-infectious activities

    PubMed Central

    Cardoso, Marlon H.; Ribeiro, Suzana M.; Nolasco, Diego O.; de la Fuente-Núñez, César; Felício, Mário R.; Gonçalves, Sónia; Matos, Carolina O.; Liao, Luciano M.; Santos, Nuno C.; Hancock, Robert E. W.; Franco, Octávio L.; Migliolo, Ludovico

    2016-01-01

    Due to the growing concern about antibiotic-resistant microbial infections, increasing support has been given to new drug discovery programs. A promising alternative to counter bacterial infections includes the antimicrobial peptides (AMPs), which have emerged as model molecules for rational design strategies. Here we focused on the study of Pa-MAP 1.9, a rationally designed AMP derived from the polar fish Pleuronectes americanus. Pa-MAP 1.9 was active against Gram-negative planktonic bacteria and biofilms, without being cytotoxic to mammalian cells. By using AFM, leakage assays, CD spectroscopy and in silico tools, we found that Pa-MAP 1.9 may be acting both on intracellular targets and on the bacterial surface, also being more efficient at interacting with anionic LUVs mimicking Gram-negative bacterial surface, where this peptide adopts α-helical conformations, than cholesterol-enriched LUVs mimicking mammalian cells. Thus, as bacteria present varied physiological features that favor antibiotic-resistance, Pa-MAP 1.9 could be a promising candidate in the development of tools against infections caused by pathogenic bacteria. PMID:26916401

  6. Intracellular protein delivery activity of peptides derived from insulin-like growth factor binding proteins 3 and 5

    SciTech Connect

    Goda, Natsuko; Tenno, Takeshi; Inomata, Kosuke; Shirakawa, Masahiro; Tanaka, Toshiki; Hiroaki, Hidekazu

    2008-08-01

    Insulin-like growth factor binding proteins (IGFBPs) have various IGF-independent cellular activities, including receptor-independent cellular uptake followed by transcriptional regulation, although mechanisms of cellular entry remain unclear. Herein, we focused on their receptor-independent cellular entry mechanism in terms of protein transduction domain (PTD) activity, which is an emerging technique useful for clinical applications. The peptides of 18 amino acid residues derived from IGFBP-3 and IGFBP-5, which involve heparin-binding regions, mediated cellular delivery of an exogenous protein into NIH3T3 and HeLa cells. Relative protein delivery activities of IGFBP-3/5-derived peptides were approximately 20-150% compared to that of the HIV-Tat peptide, a potent PTD. Heparin inhibited the uptake of the fusion proteins with IGFBP-3 and IGFBP-5, indicating that the delivery pathway is heparin-dependent endocytosis, similar to that of HIV-Tat. The delivery of GST fused to HIV-Tat was competed by either IGFBP-3 or IGFBP-5-derived synthetic peptides. Therefore, the entry pathways of the three PTDs are shared. Our data has shown a new approach for designing protein delivery systems using IGFBP-3/5 derived peptides based on the molecular mechanisms of IGF-independent activities of IGFBPs.

  7. Multiple biological activities for two peptides derived from the nerve growth factor precursor

    SciTech Connect

    Dicou, Eleni . E-mail: dicou@ipmc.cnrs.fr

    2006-09-01

    ProNGF can be cleaved proteolytically at dibasic residues and liberates two other peptides beside NGF, LIP1 a 29 amino acid (aa) peptide and LIP2 a 38 aa peptide. These peptides were found present in the rat intestine and shown to induce rapid phosphorylation of the Trk receptor in cell lines. The present study describes several novel biological properties for these peptides. They exert an anti-proliferative effect on the mitogenic activity of estrogen and IGF in MCF-7 cells. They protect against in vivo induction of excitotoxic lesions by the glutamatergic analogue ibotenate injected into the developing mouse brain and against in vitro NMDA-induced cell death in primary neuronal cultures. They bind to murine microglial cells and induce phosphorylation of Akt. These results suggest a role for LIP1 and LIP2 in cell survival.

  8. Solution structures, dynamics, and ice growth inhibitory activity of peptide fragments derived from an antarctic yeast protein.

    PubMed

    Shah, Syed Hussinien H; Kar, Rajiv K; Asmawi, Azren A; Rahman, Mohd Basyaruddin A; Murad, Abdul Munir A; Mahadi, Nor M; Basri, Mahiran; Rahman, Raja Noor Zaliha A; Salleh, Abu B; Chatterjee, Subhrangsu; Tejo, Bimo A; Bhunia, Anirban

    2012-01-01

    Exotic functions of antifreeze proteins (AFP) and antifreeze glycopeptides (AFGP) have recently been attracted with much interest to develop them as commercial products. AFPs and AFGPs inhibit ice crystal growth by lowering the water freezing point without changing the water melting point. Our group isolated the Antarctic yeast Glaciozyma antarctica that expresses antifreeze protein to assist it in its survival mechanism at sub-zero temperatures. The protein is unique and novel, indicated by its low sequence homology compared to those of other AFPs. We explore the structure-function relationship of G. antarctica AFP using various approaches ranging from protein structure prediction, peptide design and antifreeze activity assays, nuclear magnetic resonance (NMR) studies and molecular dynamics simulation. The predicted secondary structure of G. antarctica AFP shows several α-helices, assumed to be responsible for its antifreeze activity. We designed several peptide fragments derived from the amino acid sequences of α-helical regions of the parent AFP and they also showed substantial antifreeze activities, below that of the original AFP. The relationship between peptide structure and activity was explored by NMR spectroscopy and molecular dynamics simulation. NMR results show that the antifreeze activity of the peptides correlates with their helicity and geometrical straightforwardness. Furthermore, molecular dynamics simulation also suggests that the activity of the designed peptides can be explained in terms of the structural rigidity/flexibility, i.e., the most active peptide demonstrates higher structural stability, lower flexibility than that of the other peptides with lower activities, and of lower rigidity. This report represents the first detailed report of downsizing a yeast AFP into its peptide fragments with measurable antifreeze activities. PMID:23209600

  9. A cactus-derived toxin-like cystine knot Peptide with selective antimicrobial activity.

    PubMed

    Aboye, Teshome L; Strömstedt, Adam A; Gunasekera, Sunithi; Bruhn, Jan G; El-Seedi, Hesham; Rosengren, K Johan; Göransson, Ulf

    2015-05-01

    Naturally occurring cystine knot peptides show a wide range of biological activity, and as they have inherent stability they represent potential scaffolds for peptide-based drug design and biomolecular engineering. Here we report the discovery, sequencing, chemical synthesis, three-dimensional solution structure determination and bioactivity of the first cystine knot peptide from Cactaceae (cactus) family: Ep-AMP1 from Echinopsis pachanoi. The structure of Ep-AMP1 (35 amino acids) conforms to that of the inhibitor cystine knot (or knottin) family but represents a novel diverse sequence; its activity was more than 500 times higher against bacterial than against eukaryotic cells. Rapid bactericidal action and liposome leakage implicate membrane permeabilisation as the mechanism of action. Sequence homology places Ec-AMP1 in the plant C6-type of antimicrobial peptides, but the three dimensional structure is highly similar to that of a spider neurotoxin. PMID:25821084

  10. Anticancer Activity of the Antimicrobial Peptide Scolopendrasin VII Derived from the Centipede, Scolopendra subspinipes mutilans.

    PubMed

    Lee, Joon Ha; Kim, In-Woo; Kim, Sang-Hee; Kim, Mi-Ae; Yun, Eun-Young; Nam, Sung-Hee; Ahn, Mi-Young; Kang, Dongchul; Hwang, Jae Sam

    2015-08-01

    Previously, we performed de novo RNA sequencing of Scolopendra subspinipes mutilans using high-throughput sequencing technology and identified several antimicrobial peptide candidates. Among them, a cationic antimicrobial peptide, scolopendrasin VII, was selected based on its physicochemical properties, such as length, charge, and isoelectric point. Here, we assessed the anticancer activities of scolopendrasin VII against U937 and Jurkat leukemia cell lines. The results showed that scolopendrasin VII decreased the viability of the leukemia cells in MTS assays. Furthermore, flow cytometric analysis and acridine orange/ethidium bromide staining revealed that scolopendrasin VII induced necrosis in the leukemia cells. Scolopendrasin VII-induced necrosis was mediated by specific interaction with phosphatidylserine, which is enriched in the membrane of cancer cells. Taken together, these data indicated that scolopendrasin VII induced necrotic cell death in leukemia cells, probably through interaction with phosphatidylserine. The results provide a useful anticancer peptide candidate and an efficient strategy for new anticancer peptide development. PMID:25907065

  11. A preliminary study on the antibacterial mechanism of Tegillarca granosa hemoglobin by derived peptides and peroxidase activity.

    PubMed

    Bao, Yongbo; Wang, Juanjuan; Li, Chenghua; Li, Peifen; Wang, Sufang; Lin, Zhihua

    2016-04-01

    The blood clam, Tegillarca granosa, is one of the few bivalve molluscs containing hemoglobin (Hb). In the present study, we purified two types of T. granosa hemoglobin, Tg-HbI and Tg-HbII, using size exclusion chromatography and measured their antibacterial and peroxidase activities. We also tested antibacterial activities of peptides prepared by trypsin digestion of purified Tg-Hb and reversed-phase high-performance liquid chromatography purification. Purified Tg-HbI and Tg-HbII showed antibacterial activity against Escherichia coli, Pseudomonas putida, Bacillus subtilis, and Bacillus firmus, with differences in minimal inhibitory concentrations (MICs), but lacked antibacterial activity against Vibrio alginolyticus, Vibrio parahaemolyticus, Vibrio harveyi and Staphylococcus aureus. In contrast, 7 Tg-Hb derived peptides exhibited varying degrees of antibacterial activity against V. alginolyticus (MICs: 12-200 μg/ml), V. parahaemolyticus (11-100 μg/ml) and V. harveyi (1-200 μg/ml). The antibacterial activity of Hb derived peptides was confirmed by fluorescence microscopy. In addition, peroxidase activity was detected in Tg-HbI and Tg-HbII. The results indicated that in addition to functioning as a respiratory protein T. granosa hemoglobins likely play a role in host antibacterial defense probably via a peroxidase activity of native molecules and some internal peptides released from the proteins. PMID:26876330

  12. Dipeptidyl-peptidase IV inhibitory activity of peptides derived from tuna cooking juice hydrolysates.

    PubMed

    Huang, Shih-Li; Jao, Chia-Ling; Ho, Kit-Pan; Hsu, Kuo-Chiang

    2012-05-01

    The in vitro DPP-IV inhibitory activity of isolated peptides from of tuna cooking juice hydrolyzed by Protease XXIII (PR) and orientase (OR) was determined. The results showed that the peptide fractions with the molecular weight over 1,422 Da possessed the greatest DPP-IV inhibitory activity. The amino acid sequences of the three peptides isolated from PR and OR hydrolysates were identified by MALDI-TOF/TOF MS/MS, and they were Pro-Gly-Val-Gly-Gly-Pro-Leu-Gly-Pro-Ile-Gly-Pro-Cys-Tyr-Glu (1412.7 Da), Cys-Ala-Tyr-Gln-Trp-Gln-Arg-Pro-Val-Asp-Arg-Ile-Arg (1690.8 Da) and Pro-Ala-Cys-Gly-Gly-Phe-Try-Ile-Ser-Gly-Arg-Pro-Gly (1304.6 Da), while they showed the dose-dependent inhibition effect of DPP-IV with IC(50) values of 116.1, 78.0 and 96.4 μM, respectively. In vitro simulated gastrointestinal digestion retained or even improved the DPP-IV inhibitory activities of the three peptides. The results suggest that tuna cooking juice would be a good precursor of DPP-IV inhibitor, and the DPP-IV inhibitory peptides can successfully passed through the digestive tract. PMID:22450467

  13. Recent Research in Antihypertensive Activity of Food Protein-derived Hydrolyzates and Peptides.

    PubMed

    Saleh, Ahmed S M; Zhang, Qing; Shen, Qun

    2016-04-01

    Year to year obesity prevalence, reduced physical activities, bad habits/or stressful lifestyle, and other environmental and physiological impacts lead to increase in diseases such as coronary heart disease, stroke, cancer, diabetes, and hypertension worldwide. Hypertension is considered as one of the most common serious chronic diseases; however, discovery of medications with high efficacy and without side effects for treatment of patients remains a challenge for scientists. Recent trends in functional foods have evidenced that food bioactive proteins play a major role in the concepts of illness and curing; therefore, nutritionists, biomedical scientists, and food scientists are working together to develop improved systems for the discovery of peptides with increased potency and therapeutic benefits. This review presents a recent research carried out to date for the purpose of isolation and identification of bioactive hydrolyzates and peptides with angiotensin I converting enzyme inhibitory activity and antihypertensive effect from animal, marine, microbial, and plant food proteins. Effects of food processing and hydrolyzation conditions as well as some other impacts on formation, activity, and stability of these hydrolyzates and peptides are also presented. PMID:25036695

  14. CAP37-derived antimicrobial peptides have in vitro antiviral activity against adenovirus and herpes simplex virus type 1

    PubMed Central

    Gordon, Y. Jerold; Romanowski, Eric G.; Shanks, Robert M. Q.; Yates, Kathleen A.; Hinsley, Heather; Pereira, H. Anne

    2009-01-01

    Purpose The antiviral activity of an established antibacterial CAP37 domain and its extracellular mechanism of action were investigated. Methods CAP37-derived peptides modified to assess the importance of disulfide bonds were evaluated in cytotoxicity, and antiviral assays (direct time kill, dose-dependency and TOTO-1) for adenovirus (Ad) and herpes simplex virus type 1 (HSV-1). Results Variable virus, adenovirus serotype-dependant, and dose-dependent inhibition were demonstrated without cytotoxicity. For Peptide A (CAP3720-44), TOTO-1 dye uptake was demonstrated for Ad5 and HSV-1. Conclusions Unlike the antibacterial activity of this CAP37 domain, its antiviral activity is not fully dependent upon disulfide bond formation. Viral inhibition appears to result, in part, from disruption of the envelope and/or capsid. PMID:19274533

  15. Oral activity of a nature-derived cyclic peptide for the treatment of multiple sclerosis

    PubMed Central

    Thell, Kathrin; Hellinger, Roland; Sahin, Emine; Michenthaler, Paul; Gold-Binder, Markus; Haider, Thomas; Kuttke, Mario; Liutkevičiūtė, Zita; Göransson, Ulf; Gründemann, Carsten; Schabbauer, Gernot; Gruber, Christian W.

    2016-01-01

    Multiple sclerosis (MS) is the most common autoimmune disease affecting the central nervous system. It is characterized by auto-reactive T cells that induce demyelination and neuronal degradation. Treatment options are still limited and several MS medications need to be administered by parenteral application but are modestly effective. Oral active drugs such as fingolimod have been weighed down by safety concerns. Consequently, there is a demand for novel, especially orally active therapeutics. Nature offers an abundance of compounds for drug discovery. Recently, the circular plant peptide kalata B1 was shown to silence T-cell proliferation in vitro in an IL-2–dependent mechanism. Owing to this promising effect, we aimed to determine in vivo activity of the cyclotide [T20K]kalata B1 using the MS mouse model experimental autoimmune encephalomyelitis (EAE). Treatment of mice with the cyclotide resulted in a significant delay and diminished symptoms of EAE by oral administration. Cyclotide application substantially impeded disease progression and did not exhibit adverse effects. Inhibition of lymphocyte proliferation and the reduction of proinflammatory cytokines, in particular IL-2, distinguish the cyclotide from other marketed drugs. Considering their stable structural topology and oral activity, cyclotides are candidates as peptide therapeutics for pharmaceutical drug development for treatment of T-cell-mediated disorders. PMID:27035952

  16. Cationic Antimicrobial Peptides Derived from Crocodylus siamensis Leukocyte Extract, Revealing Anticancer Activity and Apoptotic Induction on Human Cervical Cancer Cells.

    PubMed

    Theansungnoen, Tinnakorn; Maijaroen, Surachai; Jangpromma, Nisachon; Yaraksa, Nualyai; Daduang, Sakda; Temsiripong, Theeranan; Daduang, Jureerut; Klaynongsruang, Sompong

    2016-06-01

    Known antimicrobial peptides KT2 and RT2 as well as the novel RP9 derived from the leukocyte extract of the freshwater crocodile (Crocodylus siamensis) were used to evaluate the ability in killing human cervical cancer cells. RP9 in the extract was purified by a combination of anion exchange column and reversed-phase HPLC, and its sequence was analyzed by mass spectrometry. The novel peptide could inhibit Gram-negative Vibrio cholerae (clinical isolation) and Gram-positive Bacillus pumilus TISTR 905, and its MIC values were 61.2 µM. From scanning electron microscopy, the peptide was seen to affect bacterial surfaces directly. KT2 and RT2, which are designed antimicrobial peptides using the C. siamensis Leucrocin I template, as well as RP9 were chemically synthesized for investigation of anticancer activity. By Sulforhodamine B colorimetric assay, these antimicrobial peptides could inhibit both HeLa and CaSki cancer cell lines. The IC50 values of KT2 and RT2 for HeLa and CaSki cells showed 28.7-53.4 and 17.3-30.8 µM, while those of RP9 were 126.2 and 168.3 µM, respectively. Additionally, the best candidate peptides KT2 and RT2 were used to determine the apoptotic induction on cancer cells by human apoptosis array assay. As a result, KT2 and RT2 were observed to induce apoptotic cell death in HeLa cells. Therefore, these results indicate that KT2 and RT2 with antimicrobial activity have a highly potent ability to kill human cervical cancer cells. PMID:27129462

  17. Effects of active immunisation with myelin basic protein and myelin-derived altered peptide ligand on pain hypersensitivity and neuroinflammation.

    PubMed

    Perera, Chamini J; Lees, Justin G; Duffy, Samuel S; Makker, Preet G S; Fivelman, Brett; Apostolopoulos, Vasso; Moalem-Taylor, Gila

    2015-09-15

    Neuropathic pain is a debilitating condition in multiple sclerosis and experimental autoimmune encephalomyelitis (EAE). Specific myelin basic protein (MBP) peptides are encephalitogenic, and myelin-derived altered peptide ligands (APLs) are capable of preventing and ameliorating EAE. We investigated the effects of active immunisation with a weakly encephalitogenic epitope of MBP (MBP87-99) and its mutant APL (Cyclo-87-99[A(91),A(96)]MBP87-99) on pain hypersensitivity and neuroinflammation in Lewis rats. MBP-treated rats exhibited significant mechanical and thermal pain hypersensitivity associated with infiltration of T cells, MHC class II expression and microglia activation in the spinal cord, without developing clinical signs of paralysis. Co-immunisation with APL significantly decreased pain hypersensitivity and neuroinflammation emphasising the important role of neuroimmune crosstalk in neuropathic pain. PMID:26298325

  18. Food-derived immunomodulatory peptides.

    PubMed

    Santiago-López, Lourdes; Hernández-Mendoza, Adrián; Vallejo-Cordoba, Belinda; Mata-Haro, Verónica; González-Córdova, Aarón F

    2016-08-01

    Food proteins contain specific amino acid sequences within their structures that may positively impact bodily functions and have multiple immunomodulatory effects. The functional properties of these specific sequences, also referred to as bioactive peptides, are revealed only after the degradation of native proteins during digestion processes. Currently, milk proteins have been the most explored source of bioactive peptides, which presents an interesting opportunity for the dairy industry. However, plant- and animal-derived proteins have also been shown to be important sources of bioactive peptides. This review summarizes the in vitro and in vivo evidence of the role of various food proteins as sources of immunomodulatory peptides and discusses the possible pathways involving these properties. © 2016 Society of Chemical Industry. PMID:26940008

  19. Chebulin: Terminalia chebula Retz. fruit-derived peptide with angiotensin-I-converting enzyme inhibitory activity.

    PubMed

    Sornwatana, Thakorn; Bangphoomi, Kunan; Roytrakul, Sittiruk; Wetprasit, Nuanchawee; Choowongkomon, Kiattawee; Ratanapo, Sunanta

    2015-01-01

    Angiotensin-I-converting enzyme (ACE) plays an important role in blood pressure regulation. In this study, an ACE-hexapeptide inhibitor (Asp-Glu-Asn-Ser-Lys-Phe) designated as chebulin was produced from the fruit protein of Terminalia chebula Retz. by pepsin digestion, ultrafiltrated through a 3 KDa cut-off membrane, a reverse-phase high-performance liquid chromatography, and nano-liquid chromatography tandem mass spectrometry analysis. Chebulin was found to inhibit ACE in a noncompetitive manner, as supported by the structural model. It bounds to ACE by the hydrogen bond, hydrophobic and ionic interactions via the interactions of C-terminal Phe (Phe-6), and N-terminal residues (Asp-1 and Glu-2) with the amino acid residues on noncatalytic sites of the ACE. The results showed that chebulin derived from fruits of T. chebula Retz. is a potential ACE-peptide inhibitor that could be used as a functional food additive for the prevention of hypertension and as an alternative to ACE inhibitor drug. PMID:25410725

  20. Bax-derived membrane-active peptides act as potent and direct inducers of apoptosis in cancer cells

    PubMed Central

    Valero, Juan Garcia; Sancey, Lucie; Kucharczak, Jérôme; Guillemin, Yannis; Gimenez, Diana; Prudent, Julien; Gillet, Germain; Salgado, Jesús; Coll, Jean-Luc; Aouacheria, Abdel

    2011-01-01

    SUMMARY Although many cancer cells are primed for apoptosis, they usually develop resistance to cell death at multiple levels. Permeabilization of the outer mitochondrial membrane, which is mediated by proapoptotic Bcl-2 family members like Bax, is considered as a point-of-no-return for initiating apoptotic cell death. This crucial role has placed Bcl-2 family proteins as recurrent targets for anticancer drug development. Here, we propose and demonstrate a new concept based on using minimal active version of Bax to induce cell death independently of endogenous Bcl-2 proteins. We show that membrane-active segments of Bax can directly induce the release of mitochondria-residing apoptogenic factors and commit tumor cells promptly and irreversibly to caspase-dependent apoptosis. On this basis, we designed a peptide encompassing part of the Bax pore-forming domain, able to target mitochondria, induce cytochrome c release and trigger caspase-dependent apoptosis. Moreover, this Bax-derived poropeptide produced effective tumor regression after peritumoral injection in a nude mouse xenograft model. Thus, peptides derived from proteins evolutionary functionalized to form pores in the mitochondrial outer membrane represent novel templates for anticancer agents. PMID:21245196

  1. DEFINITIVE ROLE FOR NATRIURETIC PEPTIDE RECEPTOR-C IN MEDIATING THE VASORELAXANT ACTIVITY OF C-TYPE NATRIURETIC PEPTIDE AND ENDOTHELIUM-DERIVED HYPERPOLARISING FACTOR

    PubMed Central

    Villar, Inmaculada C.; Panayiotou, Catherine M.; Sheraz, Adil; Madhani, Melanie; Scotland, Ramona S.; Nobles, Muriel; Kemp-Harper, Barbara; Ahluwalia, Amrita; Hobbs, Adrian J.

    2012-01-01

    Objective C-type natriuretic peptide (CNP) has recently been suggested to represent an endothelium-derived hyperpolarizing factor (EDHF) in the mammalian resistance vasculature, important in the regulation of local blood flow and systemic blood pressure. Additionally, this peptide has been shown to protect against ischaemia-reperfusion injury and inhibits leukocyte and platelet activation. Herein, we use a novel, selective natriuretic peptide receptor-C (NPR-C) antagonist (M372049) to highlight the pivotal contribution of CNP/NPR-C signalling in the EDHF-dependent regulation of vascular tone and investigate the mechanism(s) underlying the release and biological activity of CNP and EDHF. Methods In vitro pharmacological investigation was conducted in rat (Sprague-Dawley) aorta and mesenteric resistance arteries. Relaxant responses to CNP, atrial natriuretic peptide (ANP), the nitric oxide donor spermine-NONOate (SPER-NO) and the endothelium-dependent vasodilator, acetylcholine (ACh) were examined in the absence and presence of M372049 or inhibitor cocktails shown previously to block endothelium-dependent dilatation in the resistance vasculature. RT-PCR was employed to characterize the expression of NPR subtypes in the vessels studied. Results M372049 produced concentration-dependent inhibition of the vasorelaxant activity of CNP in rat isolated mesenteric resistance arteries but not aorta; in contrast, M372049 did not affect relaxations to ANP or SPER-NO in either vessel. M372049 or ouabain alone produced small, significant inhibition of EDHF-dependent relaxations in mesenteric arteries and in combination acted synergistically to abolish such responses. A combination of M372049 with established inhibitors of EDHF-dependent relaxation revealed that multiple, distinct pathways coordinate the bioactivity of EDHF in the resistance vasculature, and that CNP/NPR-C signalling represents a major component. Conclusions These data substantiate CNP/NPR-C signalling as a

  2. TFP5, a peptide derived from p35, a Cdk5 neuronal activator, rescues cortical neurons from glucose toxicity.

    PubMed

    Binukumar, B K; Zheng, Ya-Li; Shukla, Varsha; Amin, Niranjana D; Grant, Philip; Pant, Harish C

    2014-01-01

    Multiple lines of evidence link the incidence of diabetes to the development of Alzheimer's disease (AD). Patients with diabetes have a 50 to 75% increased risk of developing AD. Cyclin dependent kinase 5 (Cdk5) is a serine/threonine protein kinase, which forms active complexes with p35 or p39, found principally in neurons and in pancreatic β cells. Recent studies suggest that Cdk5 hyperactivity is a possible link between neuropathology seen in AD and diabetes. Previously, we identified P5, a truncated 24-aa peptide derived from the Cdk5 activator p35, later modified as TFP5, so as to penetrate the blood-brain barrier after intraperitoneal injections in AD model mice. This treatment inhibited abnormal Cdk5 hyperactivity and significantly rescued AD pathology in these mice. The present study explores the potential of TFP5 peptide to rescue high glucose (HG)-mediated toxicity in rat embryonic cortical neurons. HG exposure leads to Cdk5-p25 hyperactivity and oxidative stress marked by increased reactive oxygen species production, and decreased glutathione levels and superoxide dismutase activity. It also induces hyperphosphorylation of tau, neuroinflammation as evident from the increased expression of inflammatory cytokines like TNF-α, IL-1β, and IL-6, and apoptosis. Pretreatment of cortical neurons with TFP5 before HG exposure inhibited Cdk5-p25 hyperactivity and significantly attenuated oxidative stress by decreasing reactive oxygen species levels, while increasing superoxide dismutase activity and glutathione. Tau hyperphosphorylation, inflammation, and apoptosis induced by HG were also considerably reduced by pretreatment with TFP5. These results suggest that TFP5 peptide may be a novel candidate for type 2 diabetes therapy. PMID:24326517

  3. Supra-molecular assembly of a lumican-derived peptide amphiphile enhances its collagen-stimulating activity.

    PubMed

    Walter, Merlin N M; Dehsorkhi, Ashkan; Hamley, Ian W; Connon, Che J

    2016-02-01

    C16-YEALRVANEVTLN, a peptide amphiphile (PA) incorporating a biologically active amino acid sequence found in lumican, has been examined for its influence upon collagen synthesis by human corneal fibroblasts in vitro, and the roles of supra-molecular assembly and activin receptor-like kinase ALK receptor signaling in this effect were assessed. Cell viability was monitored using the Alamar blue assay, and collagen synthesis was assessed using Sirius red. The role of ALK signaling was studied by receptor inhibition. Cultured human corneal fibroblasts synthesized significantly greater amounts of collagen in the presence of the PA over both 7-day and 21-day periods. The aggregation of the PA to form nanotapes resulted in a notable enhancement in this activity, with an approximately two-fold increase in collagen production per cell. This increase was reduced by the addition of an ALK inhibitor. The data presented reveal a stimulatory effect upon collagen synthesis by the primary cells of the corneal stroma, and demonstrate a direct influence of supra-molecular assembly of the PA upon the cellular response observed. The effects of PA upon fibroblasts were dependent upon ALK receptor function. These findings elucidate the role of self-assembled nanostructures in the biological activity of peptide amphiphiles, and support the potential use of a self-assembling lumican derived PA as a novel biomaterial, intended to promote collagen deposition for wound repair and tissue engineering purposes. PMID:26626506

  4. Casocidin-I: a casein-alpha s2 derived peptide exhibits antibacterial activity.

    PubMed

    Zucht, H D; Raida, M; Adermann, K; Mägert, H J; Forssmann, W G

    1995-09-25

    Here we report the isolation and characterization of an antibacterial peptide from bovine milk inhibiting the growth of Escherichia coli, and Staphylococcus carnosus. The primary structure of the peptide was revealed as a 39-amino-acid-containing fragment of bovine alpha s2-casein (position 165-203) by means of Edman amino acid sequencing and mass spectrometry. Since human milk does not contain any casein-alpha s2, these findings could explain the different influence of human and bovine milk on the gastrointestinal flora of the suckling. PMID:7556666

  5. Design and analysis of structure-activity relationship of novel antimicrobial peptides derived from the conserved sequence of cecropin.

    PubMed

    Hao, Gang; Shi, Yong-Hui; Han, Jing-Hui; Li, Qi-Hui; Tang, Ya-Li; Le, Guo-Wei

    2008-03-01

    We have de novo designed four antimicrobial peptides AMP-A/B/C/D, the 51-residues peptides, which are based on the conserved sequence of cecropin. In the present study, the four peptides were chemically synthesized and their activities assayed. Their secondary structure, amphipathic property, electric field distribution and transmembrane domain were subsequently predicted by bioinformatics tools. Finally, the structure-activity relationship was analyzed from the results of activity experiments and prediction. The results of activity experiments indicated that AMP-B/C/D clearly possessed excellent broad-spectrum activity against bacteria, whereas AMP-A was almost inactive against most of the bacterial strains tested. AMP-B/C/D showed more potent activity against Gram-positive bacteria than against Gram-negative bacteria. By utilizing bioinformatics analysis tools, we found that the secondary structure of the four cation peptides was mainly alpha-helix, and the result of CD spectrum also displayed that all the peptides had considerable alpha-helix in the presence of either 50% TFE or SDS micelles. AMP-C showed much better activity than other peptides against most of the bacteria tested, owing to its remarkable cation property and the amphipathic character of its N-terminal. The study of structure-activity relationship of the designed peptides confirmed that amphipathic structure and high net positive charge were prerequisites for maintaining their activities. PMID:17929330

  6. Antimicrobial Peptide CMA3 Derived from the CA-MA Hybrid Peptide: Antibacterial and Anti-inflammatory Activities with Low Cytotoxicity and Mechanism of Action in Escherichia coli

    PubMed Central

    Lee, Jong-kook; Seo, Chang Ho; Luchian, Tudor

    2015-01-01

    CA-MA is a hybrid antimicrobial peptide (AMP) derived from two naturally occurring AMPs, cecropin A and magainin 2. CA-MA shows strong antimicrobial activity against Gram-negative and Gram-positive bacteria but also exhibits cytotoxicity toward mammalian cells. Our objective was to identify CA-MA analogues with reduced cytotoxicity by systematic replacement of amino acids with positively charged R groups (His and Lys), aliphatic R groups (Leu), or polar R groups (Glu). Among the CA-MA analogues studied (CMA1 to -6), CMA3 showed the strongest antimicrobial activity, including against drug-resistant Escherichia coli and Pseudomonas aeruginosa strains isolated from hospital patients. CMA3 appeared to act by inducing pore formation (toroidal model) in the bacterial membrane. In cytotoxicity assays, CMA3 showed little cytotoxicity toward human red blood cells (hRBCs) or HaCaT cells. Additionally, no fluorescence was released from small or giant unilamellar vesicles exposed to 60 μM CMA3 for 80 s, whereas fluorescence was released within 35 s upon exposure to CA-MA. CMA3 also exerted strong lipopolysaccharide (LPS)-neutralizing activity in RAW 264.7 cells, and BALB/c mice exposed to LPS after infection by Escherichia coli showed improved survival after administration of one 0.5-mg/kg of body weight or 1-mg/kg dose of CMA3. Finally, in a mouse model of septic shock, CMA3 reduced the levels of proinflammatory factors, including both nitric oxide and white blood cells, and correspondingly reduced lung tissue damage. This study suggests that CMA3 is an antimicrobial/antiendotoxin peptide that could serve as the basis for the development of anti-inflammatory and/or antimicrobial agents with low cytotoxicity. PMID:26552969

  7. Anti-microbial, anti-biofilm activities and cell selectivity of the NRC-16 peptide derived from witch flounder, Glyptocephalus cynoglossus.

    PubMed

    Gopal, Ramamourthy; Lee, Jun Ho; Kim, Young Gwon; Kim, Myeong-Sun; Seo, Chang Ho; Park, Yoonkyung

    2013-06-01

    Previous studies had identified novel antimicrobial peptides derived from witch flounder. In this work, we extended the search for the activity of peptide that showed antibacterial activity on clinically isolated bacterial cells and bacterial biofilm. Pseudomonas aeruginosa was obtained from otitis media and cholelithiasis patients, while Staphylococcus aureus was isolated from otitis media patients. We found that synthetic peptide NRC-16 displays antimicrobial activity and is not sensitive to salt during its bactericidal activity. Interestingly, this peptide also led to significant inhibition of biofilm formation at a concentration of 4-16 μM. NRC-16 peptide is able to block biofilm formation at concentrations just above its minimum inhibitory concentration while conventional antibiotics did not inhibit the biofilm formation except ciprofloxacin and piperacillin. It did not cause significant lysis of human RBC, and is not cytotoxic to HaCaT cells and RAW264.7 cells, thereby indicating its selective antimicrobial activity. In addition, the peptide's binding and permeation activities were assessed by tryptophan fluorescence, calcein leakage and circular dichroism using model mammalian membranes composed of phosphatidylcholine (PC), PC/cholesterol (CH) and PC/sphingomyelin (SM). These experiments confirmed that NRC-16 does not interact with any of the liposomes but the control peptide melittin did. Taken together, we found that NRC-16 has potent antimicrobial and antibiofilm activities with less cytotoxicity, and thus can be considered for treatment of microbial infection in the future. PMID:23760014

  8. Elastin-derived peptides enhance melanoma growth in vivo by upregulating the activation of Mcol-A (MMP-1) collagenase

    PubMed Central

    Devy, J; Duca, L; Cantarelli, B; Joseph-Pietras, D; Scandolera, A; Rusciani, A; Parent, L; Thevenard, J; Pasco, S Brassart; Tarpin, M; Martiny, L; Debelle, L

    2010-01-01

    Background: Elastin peptides possess several biological activities and in vitro data suggest they could be involved in the early phase of melanoma growth. Methods: Using diverse in vitro and in vivo techniques (cell proliferation, invasion and migration assays, zymography, western blots, collagen degradation assay, reverse transcription PCR, melanoma allographs and immunohistochemistry), we analysed the effect of elastin-derived peptides (EDPs) on B16F1 melanoma growth and invasion, as well as on the proteolytic systems involved. Results: We found that EDPs dramatically promote in vivo tumour development of B16F1 melanoma, as well as their in vitro migration and invasion. The inhibition of serine proteases and matrix metalloproteinases (MMPs) activities, by aprotinin and galardin, respectively, demonstrated that these enzymes were involved in these processes. However, we found that EDPs did not increase urokinase-type plasminogen activator, tissue-type plasminogen activator or MMP-2 expression and/or activation, neither in vitro nor in vivo. Nevertheless, we observed a strong increase of pro-MMP-9 secretion in EDPs-treated tumours and, more importantly, an increase in the expression and activation of the murine counterpart of MMP-1, named murine collagenase-A (Mcol-A). Moreover, we show that plasminogen system inhibition decreases collagen degradation by this enzyme. Finally, the use of a specific blocking antibody against Mcol-A abolished EDP-induced B16F1 invasion in vitro, showing that this MMP was directly involved in this process. Conclusion: Our data show that in vivo, EDPs are involved in melanoma growth and invasion and reinforced the concept of elastin fragmentation as a predictive factor. PMID:20959825

  9. Release of C-type natriuretic peptide accounts for the biological activity of endothelium-derived hyperpolarizing factor

    PubMed Central

    Chauhan, Sharmila D.; Nilsson, Holger; Ahluwalia, Amrita; Hobbs, Adrian J.

    2003-01-01

    Endothelial cells in most vascular beds release a factor that hyperpolarizes the underlying smooth muscle, produces vasodilatation, and plays a fundamental role in the regulation of local blood flow and systemic blood pressure. The identity of this endothelium-derived hyperpolarizing factor (EDHF), which is neither NO nor prostacyclin, remains obscure. Herein, we demonstrate that in mesenteric resistance arteries, release of C-type natriuretic peptide (CNP) accounts for the biological activity of EDHF. Both produce identical smooth muscle hyperpolarizations that are attenuated in the presence of high [K+], the Gi G protein (Gi) inhibitor pertussis toxin, the G protein-gated inwardly rectifying K+ channel inhibitor tertiapin, and a combination of Ba2+ (inwardly rectifying K+ channel blocker) plus ouabain (Na+/K+-ATPase inhibitor). Responses to EDHF and CNP are unaffected by the natriuretic peptide receptor (NPR)-A/B antagonist HS-142-1, but mimicked by the selective NPR-C agonist, cANF4–23. EDHF-dependent relaxation is concomitant with liberation of endothelial CNP; in the presence of the myoendothelial gap-junction inhibitor 18α-glycyrrhetinic acid or after endothelial denudation, CNP release and EDHF responses are profoundly suppressed. These data demonstrate that acetylcholine-evoked release of endothelial CNP activates NPR-C on vascular smooth muscle that via a Gi coupling promotes Ba2+/ouabain-sensitive hyperpolarization. Thus, we have revealed the identity of EDHF and established a pivotal role for endothelial-derived CNP in the regulation of vascular tone and blood flow. PMID:12552127

  10. Natural and synthetic peptides with antifungal activity.

    PubMed

    Ciociola, Tecla; Giovati, Laura; Conti, Stefania; Magliani, Walter; Santinoli, Claudia; Polonelli, Luciano

    2016-08-01

    In recent years, the increase of invasive fungal infections and the emergence of antifungal resistance stressed the need for new antifungal drugs. Peptides have shown to be good candidates for the development of alternative antimicrobial agents through high-throughput screening, and subsequent optimization according to a rational approach. This review presents a brief overview on antifungal natural peptides of different sources (animals, plants, micro-organisms), peptide fragments derived by proteolytic cleavage of precursor physiological proteins (cryptides), synthetic unnatural peptides and peptide derivatives. Antifungal peptides are schematically reported based on their structure, antifungal spectrum and reported effects. Natural or synthetic peptides and their modified derivatives may represent the basis for new compounds active against fungal infections. PMID:27502155

  11. Structure–activity relationships of the human prothrombin kringle-2 peptide derivative NSA9: anti-proliferative activity and cellular internalization

    PubMed Central

    Hwang, Hyun Sook; Kim, Dong Won; Kim, Soung Soo

    2006-01-01

    The human prothrombin kringle-2 protein inhibits angiogenesis and LLC (Lewis lung carcinoma) growth and metastasis in mice. Additionally, the NSA9 peptide (NSAVQLVEN) derived from human prothrombin kringle-2 has been reported to inhibit the proliferation of BCE (bovine capillary endothelial) cells and CAM (chorioallantoic membrane) angiogenesis. In the present study, we examined the structure–activity relationships of the NSA9 peptide in inhibiting the proliferation of endothelial cells lines e.g. BCE and HUVE (human umbilical vein endothelial). N- or C-terminal truncated derivatives and reverse sequence analogues of NSA9 were prepared and their anti-proliferative activities were assessed using the MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide] assay. This cell proliferation assay demonstrated that both the N-terminal region and sequence orientation of NSA9 are important for inhibiting the proliferation of endothelial cells. In particular 2 C-terminal truncation derivatives of NSA9 [NSA7 (NSAVQLV) and NSA8 (NSAVQLVE)] inhibited cellular proliferation to a greater extent than did NSA9. The heptapeptide NSA7, was found to be more potent than NSA9 in inhibiting CAM angiogenesis, and tubular formation and migration of HUVE cells. In addition NSA9, NSA8 and NSA7 peptides exhibited considerable inhibitory effects on the proliferation of tumour cells such as B16F10 (murine melanoma), LLC and L929 (murine fibroblast). Also, cellular internalization studies demonstrated that NSA7 was internalized into both endothelial and tumour cells more easily than was NSA9. In conclusion, these results suggest that NSA7, residing within the full sequence of NSA9, contains the required sequence for anti-proliferative activity and cellular internalization. PMID:16390327

  12. Synthesis, characterization, and biological activity of poly(arginine)-derived cancer-targeting peptides in HepG2 liver cancer cells.

    PubMed

    Joseph, Stesha C; Blackman, Brittany A; Kelly, Megan L; Phillips, Mariana; Beaury, Michael W; Martinez, Ivonne; Parronchi, Christopher J; Bitsaktsis, Constantine; Blake, Allan D; Sabatino, David

    2014-09-01

    The solid-phase synthesis, structural characterization, and biological evaluation of a small library of cancer-targeting peptides have been determined in HepG2 hepatoblastoma cells. These peptides are based on the highly specific Pep42 motif, which has been shown to target the glucose-regulated protein 78 receptors overexpressed and exclusively localized on the cell surface of tumors. In this study, Pep42 was designed to contain varying lengths (3-12) of poly(arginine) sequences to assess their influence on peptide structure and biology. Peptides were effectively synthesized by 9-fluorenylmethoxycarbonyl-based solid-phase peptide synthesis, in which the use of a poly(ethylene glycol) resin provided good yields (14-46%) and crude purities >95% as analyzed by liquid chromatography-mass spectrometry. Peptide structure and biophysical properties were investigated using circular dichroism spectroscopy. Interestingly, peptides displayed secondary structures that were contingent on solvent and length of the poly(arginine) sequences. Peptides exhibited helical and turn conformations, while retaining significant thermal stability. Structure-activity relationship studies conducted by flow cytometry and confocal microscopy revealed that the poly(arginine) derived Pep42 sequences maintained glucose-regulated protein 78 binding on HepG2 cells while exhibiting cell translocation activity that was contingent on the length of the poly(arginine) strand. In single dose (0.15 mM) and dose-response (0-1.5 mM) cell viability assays, peptides were found to be nontoxic in human HepG2 liver cancer cells, illustrating their potential as safe cancer-targeting delivery agents. PMID:24931620

  13. Structure-Activity Analysis of the Dermcidin-derived Peptide DCD-1L, an Anionic Antimicrobial Peptide Present in Human Sweat*

    PubMed Central

    Paulmann, Maren; Arnold, Thomas; Linke, Dirk; Özdirekcan, Suat; Kopp, Annika; Gutsmann, Thomas; Kalbacher, Hubert; Wanke, Ines; Schuenemann, Verena J.; Habeck, Michael; Bürck, Jochen; Ulrich, Anne S.; Schittek, Birgit

    2012-01-01

    Dermcidin encodes the anionic amphiphilic peptide DCD-1L, which displays a broad spectrum of antimicrobial activity under conditions resembling those in human sweat. Here, we have investigated its mode of antimicrobial activity. We found that DCD-1L interacts preferentially with negatively charged bacterial phospholipids with a helix axis that is aligned flat on a lipid bilayer surface. Upon interaction with lipid bilayers DCD-1L forms oligomeric complexes that are stabilized by Zn2+. DCD-1L is able to form ion channels in the bacterial membrane, and we propose that Zn2+-induced self-assembly of DCD-1L upon interaction with bacterial lipid bilayers is a prerequisite for ion channel formation. These data allow us for the first time to propose a molecular model for the antimicrobial mechanism of a naturally processed human anionic peptide that is active under the harsh conditions present in human sweat. PMID:22262861

  14. Brain RVD-haemopressin, a haemoglobin-derived peptide, inhibits bombesin-induced central activation of adrenomedullary outflow in the rat

    PubMed Central

    Tanaka, Kenjiro; Shimizu, Takahiro; Yanagita, Toshihiko; Nemoto, Takayuki; Nakamura, Kumiko; Taniuchi, Keisuke; Dimitriadis, Fotios; Yokotani, Kunihiko; Saito, Motoaki

    2014-01-01

    BACKGROUND AND PURPOSE Haemopressin and RVD-haemopressin, derived from the haemoglobin α-chain, are bioactive peptides found in brain and are ligands for cannabinoid CB1 receptors. Activation of brain CB1 receptors inhibited the secretion of adrenal catecholamines (noradrenaline and adrenaline) induced by i.c.v. bombesin in the rat. Here, we investigated the effects of two haemoglobin-derived peptides on this bombesin-induced response EXPERIMENTAL APPROACH Anaesthetised male Wistar rats were pretreated with either haemoglobin-derived peptide, given i.c.v., 30 min before i.c.v. bombesin and plasma catecholamines were subsequently measured electrochemically after HPLC. Direct effects of bombesin on secretion of adrenal catecholamines were examined using bovine adrenal chromaffin cells. Furthermore, activation of haemoglobin α-positive spinally projecting neurons in the rat hypothalamic paraventricular nucleus (PVN, a regulatory centre of central adrenomedullary outflow) after i.c.v. bombesin was assessed by immunohistochemical techniques. KEY RESULTS Bombesin given i.c.v. dose-dependently elevated plasma catecholamines whereas incubation with bombesin had no effect on spontaneous and nicotine-induced secretion of catecholamines from chromaffin cells. The bombesin-induced increase in catecholamines was inhibited by pretreatment with i.c.v. RVD-haemopressin (CB1 receptor agonist) but not after pretreatment with haemopressin (CB1 receptor inverse agonist). Bombesin activated haemoglobin α-positive spinally projecting neurons in the PVN. CONCLUSIONS AND IMPLICATIONS The haemoglobin-derived peptide RVD-haemopressin in the brain plays an inhibitory role in bombesin-induced activation of central adrenomedullary outflow via brain CB1 receptors in the rat. These findings provide basic information for the therapeutic use of haemoglobin-derived peptides in the modulation of central adrenomedullary outflow. PMID:24138638

  15. Antimicrobial activity, improved cell selectivity and mode of action of short PMAP-36-derived peptides against bacteria and Candida.

    PubMed

    Lyu, Yinfeng; Yang, Yang; Lyu, Xiting; Dong, Na; Shan, Anshan

    2016-01-01

    Antimicrobial peptides (AMPs) have recently attracted a great deal of attention as promising antibiotic candidates, but some obstacles such as toxicity and high synthesis cost must be addressed before developing them further. For developing short peptides with improved cell selectivity, we designed a series of modified PMAP-36 analogues. Antimicrobial assays showed that decreasing chain length in a certain range retained the high antimicrobial activity of the parental peptide and reduced hemolysis. The 18-mer peptide RI18 exhibited excellent antimicrobial activity against both bacteria and fungi, and its hemolytic activity was observably lower than PMAP-36 and melittin. The selectivity indexes of RI18 against bacteria and fungi were improved approximately 19-fold and 108-fold, respectively, compared to PMAP-36. In addition, serum did not affect the antibacterial activity of RI18 against E. coli but inhibited the antifungal efficiency against C. albicans. Flow cytometry and electron microscopy observation revealed that RI18 killed microbial cells primarily by damaging membrane integrity, leading to whole cell lysis. Taken together, these results suggest that RI18 has potential for further therapeutic research against frequently-encountered bacteria and fungi. Meanwhile, modification of AMPs is a promising strategy for developing novel antimicrobials to overcome drug-resistance. PMID:27251456

  16. Antimicrobial activity, improved cell selectivity and mode of action of short PMAP-36-derived peptides against bacteria and Candida

    PubMed Central

    Lyu, Yinfeng; Yang, Yang; Lyu, Xiting; Dong, Na; Shan, Anshan

    2016-01-01

    Antimicrobial peptides (AMPs) have recently attracted a great deal of attention as promising antibiotic candidates, but some obstacles such as toxicity and high synthesis cost must be addressed before developing them further. For developing short peptides with improved cell selectivity, we designed a series of modified PMAP-36 analogues. Antimicrobial assays showed that decreasing chain length in a certain range retained the high antimicrobial activity of the parental peptide and reduced hemolysis. The 18-mer peptide RI18 exhibited excellent antimicrobial activity against both bacteria and fungi, and its hemolytic activity was observably lower than PMAP-36 and melittin. The selectivity indexes of RI18 against bacteria and fungi were improved approximately 19-fold and 108-fold, respectively, compared to PMAP-36. In addition, serum did not affect the antibacterial activity of RI18 against E. coli but inhibited the antifungal efficiency against C. albicans. Flow cytometry and electron microscopy observation revealed that RI18 killed microbial cells primarily by damaging membrane integrity, leading to whole cell lysis. Taken together, these results suggest that RI18 has potential for further therapeutic research against frequently-encountered bacteria and fungi. Meanwhile, modification of AMPs is a promising strategy for developing novel antimicrobials to overcome drug-resistance. PMID:27251456

  17. Binding stability of peptides derived from 1ALA residue and 7GLY residues to sites near active center of fluctuating papain

    NASA Astrophysics Data System (ADS)

    Nishiyama, Katsuhiko

    2012-05-01

    We investigated the binding stability of peptides derived from 1ALA residue and 7GLY residues to sites near active center of fluctuating papain via molecular dynamics and docking simulations. Replacing GLY residue in 8GLY with ALA residue had a positive effect on binding stability to the sites in some cases although the replacing had a negative effect on it in other cases. Furthermore the replacing had a negative effect on the chance of binding to the sites. Residue in peptide should be replaced on the basis of systematic exploration of its position.

  18. A new recombinant pituitary adenylate cyclase-activating peptide-derived peptide efficiently promotes glucose uptake and glucose-dependent insulin secretion.

    PubMed

    Ma, Yi; Luo, Tianjie; Xu, Wenna; Ye, Zulu; Hong, An

    2012-11-01

    The recombinant peptide, DBAYL, a promising therapeutic peptide for type 2 diabetes, is a new, potent, and highly selective agonist for VPAC2 generated through site-directed mutagenesis based on sequence alignments of pituitary adenylate cyclase-activating peptide (PACAP), vasoactive intestinal peptide (VIP), and related analogs. The recombinant DBAYL was used to evaluate its effect and mechanism in blood glucose metabolism and utilization. As much as 28.9 mg recombinant DBAYL peptide with purity over 98% can be obtained from 1 l of Luria-Bertani medium culture by the method established in this study and the prepared DBAYL with four mutations (N10Q, V18L, N29Q, and M added to the N-terminal) were much more stable than BAY55-9837. The half-life of recombinant DBAYL was about 25 folds compared with that of BAY55-9837 in vitro. The bioactivity assay of DBAYL showed that it displaced [(125)I]PACAP38 and [(125)I]VIP from VPAC2 with a half-maximal inhibitory concentration of 48.4 ± 6.9 and 47.1 ± 4.9 nM, respectively, which were significantly lower than that of BAY55-9837, one established VPAC2 agonists. DBAYL enhances the cAMP accumulation in CHO cells expressing human VPAC2 with a half-maximal stimulatory concentration (EC(50)) of 0.68 nM, whereas the receptor potency of DBAYL at human VPAC1 (EC(50) of 737 nM) was only 1/1083 of that at human VPAC2, and DBAYL had no activity toward human PAC1 receptor. Western blot analysis of the key proteins of insulin receptor signaling pathway: insulin receptor substrate 1 (IRS-1) and glucose transporter 4 (GLUT4) indicated that the DBAYL could significantly induce the insulin-stimulated IRS-1 and GLUT4 expression more efficiently than BAY55-9837 and VIP in adipocytes. Compared with BAY55-9837 and PACAP38, the recombinant peptide DBAYL can more efficiently promote insulin release and decrease plasma glucose level in Institute of Cancer Research (ICR) mice. These results suggested that DBAYL could efficiently improve glucose

  19. Antibiotic activity and structural analysis of the scorpion-derived antimicrobial peptide IsCT and its analogs.

    PubMed

    Lee, Kyungik; Shin, Song Yub; Kim, Kyoungho; Lim, Shin Saeng; Hahm, Kyung-Soo; Kim, Yangmee

    2004-10-15

    IsCT is a non-cell-selective antimicrobial peptide isolated from the scorpion Opisthacanthus madagascariensis that has potent cytolytic activity against both mammalian and bacterial cells. To investigate the structure-activity relationships of IsCT and to design novel peptide antibiotics with bacterial cell selectivity, we synthesized several analogs of IsCT and determined their three-dimensional structures in solution by 2D-NMR spectroscopy. IsCT has a linear alpha-helical structure from Gly3 to Phe13, and [K7]-IsCT has a linear alpha-helical structure from Leu2 to Phe13. [K7, P8, K11]-IsCT, which has a bend in its middle region, exhibited the highest antibacterial activity without hemolytic activity, suggesting that its proline-induced bend is an important determinant of this selectivity. Tryptophan fluorescence showed that the high selectivity of [K7, P8, K11]-IsCT toward bacterial cells is closely correlated with its highly selective interaction with negatively charged phospholipids. Its potent activity against antibiotic-resistant bacteria suggests that [K7, P8, K11]-IsCT may serve as a promising lead candidate in the development of new peptide antibiotics. PMID:15369808

  20. Antibacterial activity of peptides derived from the C-terminal region of a hemolytic lectin, CEL-III, from the marine invertebrate Cucumaria echinata.

    PubMed

    Hatakeyama, Tomomitsu; Suenaga, Tomoko; Eto, Seiichiro; Niidome, Takuro; Aoyagi, Haruhiko

    2004-01-01

    Several synthetic peptides derived from the C-terminal domain sequence of a hemolytic lectin, CEL-III, were examined as to their action on bacteria and artificial lipid membranes. Peptide P332 (KGVIFAKASVSVKVTASLSK-NH(2)), corresponding to the sequence from residue 332, exhibited strong antibacterial activity toward Gram-positive bacteria. Replacement of each Lys in P332 by Ala markedly decreased the activity. However, when all Lys were replaced by Arg, the antibacterial activity increased, indicating the importance of positively charged residues at these positions. Replacement of Val by Leu also led to higher antibacterial activity, especially toward Gram-negative bacteria. The antibacterial activity of these peptides was correlated with their membrane-permeabilizing activity toward the bacterial inner membrane and artificial lipid vesicles, indicating that the antibacterial action is due to perturbation of bacterial cell membranes, leading to enhancement of their permeability. These results also suggest that the hydrophobic region of CEL-III, from which P332 and its analogs were derived, may play some role in the interaction with target cell membranes to trigger hemolysis. PMID:14999010

  1. Comparative analysis of biological activities of Der p I-derived peptides on Fc epsilon receptor-bearing cells from Dermatophagoides pteronyssinus-sensitive patients.

    PubMed

    Jeannin, P; Pestel, J; Bossus, M; Lassalle, P; Tartar, A; Tonnel, A B

    1993-04-01

    The ability of four uncoupled synthetic peptides (p52-71, p117-133, p176-187, p188-199) derived from Der p I, a major allergen from the house dust mite Dermatophagoides pteronyssinus (Dpt) to stimulate Fc epsilon R+ cells from Dpt-sensitive patients was comparatively analysed. Each free peptide may specifically stimulate basophils (Fc epsilon RI+ cells) and platelets (Fc epsilon RII+ cells) from patients with significant levels of anti-Der p I IgE antibodies; p52-71 and p117-133 appear the best cell stimulation inducers. Both concentration-dependent biological activities of Der p I-peptide on Fc epsilon R+ cells are enhanced by coupling peptide to a carrier (as human serum albumin). Interestingly each Der p I-sensitive patient tested presents an individual pattern of response to peptide. Thus, from our results it appears that different Der p I sequences could be involved in the immune response to Der p I. PMID:7682161

  2. Comparative analysis of biological activities of Der p I-derived peptides on Fc epsilon receptor-bearing cells from Dermatophagoides pteronyssinus-sensitive patients.

    PubMed Central

    Jeannin, P; Pestel, J; Bossus, M; Lassalle, P; Tartar, A; Tonnel, A B

    1993-01-01

    The ability of four uncoupled synthetic peptides (p52-71, p117-133, p176-187, p188-199) derived from Der p I, a major allergen from the house dust mite Dermatophagoides pteronyssinus (Dpt) to stimulate Fc epsilon R+ cells from Dpt-sensitive patients was comparatively analysed. Each free peptide may specifically stimulate basophils (Fc epsilon RI+ cells) and platelets (Fc epsilon RII+ cells) from patients with significant levels of anti-Der p I IgE antibodies; p52-71 and p117-133 appear the best cell stimulation inducers. Both concentration-dependent biological activities of Der p I-peptide on Fc epsilon R+ cells are enhanced by coupling peptide to a carrier (as human serum albumin). Interestingly each Der p I-sensitive patient tested presents an individual pattern of response to peptide. Thus, from our results it appears that different Der p I sequences could be involved in the immune response to Der p I. PMID:7682161

  3. Mechanism of antifungal activity of antimicrobial peptide APP, a cell-penetrating peptide derivative, against Candida albicans: intracellular DNA binding and cell cycle arrest.

    PubMed

    Li, Lirong; Sun, Jin; Xia, Shufang; Tian, Xu; Cheserek, Maureen Jepkorir; Le, Guowei

    2016-04-01

    We investigated the antifungal properties and anti-candidal mechanism of antimicrobial peptide APP. The minimum inhibitory concentration of APP was 8 μM against Candida albicans and Aspeogillus flavus, the concentration against Saccharomyces cerevisiae and Cryptococcus neoformans was 16 μM, while 32 μM inhibited Aspergilla niger and Trichopyton rubrum. APP caused slight depolarization (12.32 ± 0.87%) of the membrane potential of intact C. albicans cells when it exerted its anti-candidal activity and only caused 21.52 ± 0.48% C. albicans cell membrane damage. APP interacted with cell wall membrane, caused potassium efflux and nucleotide leakage. However, confocal fluorescence microscopy experiment and flow cytometry confirmed that FITC-labeled APP penetrated C. albicans cell membrane with 52.31 ± 1.88% cell-penetrating efficiency and accumulated in the cytoplasm. Then, APP interact with C. albicans genomic DNA and completely suppressed DNA migration above weight ratio (peptide/DNA) of 2, and significantly arrested cell cycles during the S-phase (S-phase cell population was 27.09 ± 0.73%, p < 0.05) after penetrating the cell membrane. Results indicated that APP kills C. albicans for efficient cell-penetrating efficiency, strong DNA-binding affinity and significant physiological changes inducing S-phase arrest in intracellular environment. PMID:26743655

  4. Enhanced anti-tumor activity of trichosanthin after combination with a human-derived cell-penetrating peptide, and a possible mechanism of activity.

    PubMed

    Lu, Ye-Zhou; Li, Peng-Fei; Li, Yan-Zhong; Luo, Fan; Guo, Chao; Lin, Bin; Cao, Xue-Wei; Zhao, Jian; Wang, Fu-Jun

    2016-07-01

    Trichosanthin (TCS), a type I ribosome-inactivating protein (RIP-I) and renowned Chinese traditional medicine, displays a broad spectrum of biological and pharmacological properties. Particularly, its anti-tumor activity has received a great deal of attention. However, the cellular mechanism for TCS uptake varies with different tumor cell lines, leading to discrepancies in its reported ability to penetrate cells. In this study, HBD, a human derived cell-penetrating peptide (CPP), was used to improve the delivery of TCS into several types of tumor cells, including HeLa cells. Recombinant TCS (rTCS) with or without the fused HBD peptide was expressed in Escherichia coli cells and successfully purified by Ni-NTA affinity chromatography. The cellular uptake efficiency of FITC-labelled-rTCS-HBD was observed in HeLa cells and compared with the uptake efficiency of non-HBD conjugated rTCS under the same conditions using laser confocal microscopy. Moreover, the IC50 value of rTCS-HBD in the tested tumor cells was much lower than that of rTCS, indicating that HBD could efficiently deliver the rTCS into tumor cells. When compared with rTCS, rTCS-HBD induced higher rates of apoptosis in HeLa cells as analyzed by flow cytometry. Furthermore, the apoptotic events observed in HeLa cells incubated with HBD-fused rTCS included activation of Caspase-9, decrease in the Bcl-2/Bax ratio, and cleavage of PARP. These results strongly suggest the participation of mitochondria in apoptosis. This report illustrates one possible method for achieving the efficient transport of TCS into cells using a CPP as a vector, and increases the likelihood that TCS can be used in the clinic. PMID:27050721

  5. A 24-Residue Peptide (p5), Derived from p35, the Cdk5 Neuronal Activator, Specifically Inhibits Cdk5-p25 Hyperactivity and Tau Hyperphosphorylation*

    PubMed Central

    Zheng, Ya-Li; Amin, Niranjana D.; Hu, Ya-Fang; Rudrabhatla, Parvathi; Shukla, Varsha; Kanungo, Jyotshnabala; Kesavapany, Sashi; Grant, Philip; Albers, Wayne; Pant, Harish C.

    2010-01-01

    The activity of Cdk5-p35 is tightly regulated in the developing and mature nervous system. Stress-induced cleavage of the activator p35 to p25 and a p10 N-terminal domain induces deregulated Cdk5 hyperactivity and perikaryal aggregations of hyperphosphorylated Tau and neurofilaments, pathogenic hallmarks in neurodegenerative diseases, such as Alzheimer disease and amyotrophic lateral sclerosis, respectively. Previously, we identified a 125-residue truncated fragment of p35 called CIP that effectively and specifically inhibited Cdk5-p25 activity and Tau hyperphosphorylation induced by Aβ peptides in vitro, in HEK293 cells, and in neuronal cells. Although these results offer a possible therapeutic approach to those neurodegenerative diseases assumed to derive from Cdk5-p25 hyperactivity and/or Aβ induced pathology, CIP is too large for successful therapeutic regimens. To identify a smaller, more effective peptide, in this study we prepared a 24-residue peptide, p5, spanning CIP residues Lys245–Ala277. p5 more effectively inhibited Cdk5-p25 activity than did CIP in vitro. In neuron cells, p5 inhibited deregulated Cdk5-p25 activity but had no effect on the activity of endogenous Cdk5-p35 or on any related endogenous cyclin-dependent kinases in HEK293 cells. Specificity of p5 inhibition in cortical neurons may depend on the p10 domain in p35, which is absent in p25. Furthermore, we have demonstrated that p5 reduced Aβ(1–42)-induced Tau hyperphosphorylation and apoptosis in cortical neurons. These results suggest that p5 peptide may be a unique and useful candidate for therapeutic studies of certain neurodegenerative diseases. PMID:20720012

  6. Adiponectin-derived active peptide ADP355 exerts anti-inflammatory and anti-fibrotic activities in thioacetamide-induced liver injury.

    PubMed

    Wang, Huafeng; Zhang, Huan; Zhang, Zimu; Huang, Biao; Cheng, Xixi; Wang, Dan; la Gahu, Zha; Xue, Zhenyi; Da, Yurong; Li, Daiqing; Yao, Zhi; Gao, Fei; Xu, Aimin; Zhang, Rongxin

    2016-01-01

    Adiponectin is an adipocyte-derived circulating protein with beneficial effects on injured livers. Adiponectin-deficient (adipo(-/-)) mice develop enhanced liver fibrosis, suggesting that adiponectin could be a therapeutic target for liver injury. In the present study, we investigated the protective role of ADP355, an adiponectin-based active short peptide, in thioacetamide (TAA)-induced acute injury and chronic liver fibrosis in mice. ADP355 remarkably reduced TAA-induced necroinflammation and liver fibrosis. ADP355 treatment increased liver glycogen, decreased serum alanine transaminase and alkaline phosphatase activity, and promoted body weight gain, hyper-proliferation and hypo-apoptosis. In addition, ADP355 administration suppressed the TAA-induced activation of hepatic stellate cells and macrophages in the liver. These were associated with the inactivation of TGF-β1/SMAD2 signaling and the promotion of AMPK and STAT3 signaling. Sensitivity of adipo(-/-) mice to chronic liver injury was decreased with ADP355. In conclusion, ADP355 could mimic adiponectin's action and may be suitable for the preclinical or clinical therapy of chronic liver injury. PMID:26777428

  7. Adiponectin-derived active peptide ADP355 exerts anti-inflammatory and anti-fibrotic activities in thioacetamide-induced liver injury

    PubMed Central

    Wang, Huafeng; Zhang, Huan; Zhang, Zimu; Huang, Biao; Cheng, Xixi; Wang, Dan; la Gahu, Zha; Xue, Zhenyi; Da, Yurong; Li, Daiqing; Yao, Zhi; Gao, Fei; Xu, Aimin; Zhang, Rongxin

    2016-01-01

    Adiponectin is an adipocyte-derived circulating protein with beneficial effects on injured livers. Adiponectin-deficient (adipo(−/−)) mice develop enhanced liver fibrosis, suggesting that adiponectin could be a therapeutic target for liver injury. In the present study, we investigated the protective role of ADP355, an adiponectin-based active short peptide, in thioacetamide (TAA)-induced acute injury and chronic liver fibrosis in mice. ADP355 remarkably reduced TAA-induced necroinflammation and liver fibrosis. ADP355 treatment increased liver glycogen, decreased serum alanine transaminase and alkaline phosphatase activity, and promoted body weight gain, hyper-proliferation and hypo-apoptosis. In addition, ADP355 administration suppressed the TAA-induced activation of hepatic stellate cells and macrophages in the liver. These were associated with the inactivation of TGF-β1/SMAD2 signaling and the promotion of AMPK and STAT3 signaling. Sensitivity of adipo(−/−) mice to chronic liver injury was decreased with ADP355. In conclusion, ADP355 could mimic adiponectin’s action and may be suitable for the preclinical or clinical therapy of chronic liver injury. PMID:26777428

  8. New antibacterial peptide derived from bovine hemoglobin.

    PubMed

    Daoud, Rachid; Dubois, Veronique; Bors-Dodita, Loredana; Nedjar-Arroume, Naima; Krier, Francois; Chihib, Nour-Eddine; Mary, Patrice; Kouach, Mostafa; Briand, Gilbert; Guillochon, Didier

    2005-05-01

    Peptic digestion of bovine hemoglobin at low degree of hydrolysis yields an intermediate peptide fraction exhibiting antibacterial activity against Micrococcus luteus A270, Listeria innocua, Escherichia coli and Salmonella enteritidis after separation by reversed-phase HPLC. From this fraction a pure peptide was isolated and analyzed by matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) and electrospray ionization tandem mass spectrometry (ESI-MS/MS). This peptide correspond to the 107-136 fragment of the alpha chain of bovine hemoglobin. The minimum inhibitory concentrations (MIC) towards the four strains and its hemolytic activity towards bovine erythrocytes were determined. A MIC of 38 microM was reported against L. innocua and 76 microM for other various bacterial species. This peptide had no hemolytic activity up to 380 microM concentration. PMID:15808900

  9. Laminin-111-derived peptides and cancer

    PubMed Central

    Kikkawa, Yamato; Hozumi, Kentaro; Katagiri, Fumihiko; Nomizu, Motoyoshi; Kleinman, Hynda K.; Koblinski, Jennifer E.

    2013-01-01

    Laminin-111 is a large trimeric basement membrane glycoprotein with many active sites. In particular, four peptides active in tumor malignancy studies have been identified in laminin-111 using a systematic peptide screening method followed by various assays. Two of the peptides (IKVAV and AG73) are found on the α1 chain, one (YIGSR) of the β1 chain and one (C16) on the γ1 chain. The four peptides have distinct activities and receptors. Since three of the peptides (IKVAV, AG73 and C16) strongly promote tumor growth, this may explain the potent effects laminin-111 has on malignant cells. The peptide, YIGSR, decreases tumor growth and experimental metastasis via a 32/67 kD receptor while IKVAV increases tumor growth, angiogenesis and protease activity via integrin receptors. AG73 increases tumor growth and metastases via syndecan receptors. C16 increases tumor growth and angiogenesis via integrins. Identification of such sites on laminin-111 will have use in defining strategies to develop therapeutics for cancer. PMID:23263633

  10. Synthesis, antibacterial activity, and biological evaluation of formyl hydroxyamino derivatives as novel potent peptide deformylase inhibitors against drug-resistant bacteria.

    PubMed

    Yang, Shouning; Shi, Wei; Xing, Dong; Zhao, Zheng; Lv, Fengping; Yang, Liping; Yang, Yushe; Hu, Wenhao

    2014-10-30

    Peptide deformylase (PDF) has been identified as a promising target for novel antibacterial agents. In this study, a series of novel formyl hydroxyamino derivatives were designed and synthesized as PDF inhibitors and their antibacterial activities were evaluated. Among the potent PDF inhibitors (1o, 1q, 1o', 1q', and 1x), in vivo studies showed that compound 1q possesses mild toxicity, a good pharmacokinetic profile and protective effects. The good in vivo efficacy and low toxicity suggest that this class of compounds has potential for development and use in future antibacterial drugs. PMID:25151577

  11. Apoptosis Activation in Human Lung Cancer Cell Lines by a Novel Synthetic Peptide Derived from Conus californicus Venom

    PubMed Central

    Oroz-Parra, Irasema; Navarro, Mario; Cervantes-Luevano, Karla E.; Álvarez-Delgado, Carolina; Salvesen, Guy; Sanchez-Campos, Liliana N.; Licea-Navarro, Alexei F.

    2016-01-01

    Lung cancer is one of the most common types of cancer in men and women and a leading cause of death worldwide resulting in more than one million deaths per year. The venom of marine snails Conus contains up to 200 pharmacologically active compounds that target several receptors in the cell membrane. Due to their diversity and specific binding properties, Conus toxins hold great potential as source of new drugs against cancer. We analyzed the cytotoxic effect of a 17-amino acid synthetic peptide (s-cal14.1a) that is based on a native toxin (cal14.1a) isolated from the sea snail Conus californicus. Cytotoxicity studies in four lung cancer cell lines were complemented with measurement of gene expression of apoptosis-related proteins Bcl-2, BAX and the pro-survival proteins NFκB-1 and COX-2, as well as quantification of caspase activity. Our results showed that H1299 and H1437 cell lines treated with s-call4.1a had decreased cell viability, activated caspases, and reduced expression of the pro-survival protein NFκB-1. To our knowledge, this is the first report describing activation of apoptosis in human lung cancer cell lines by s-cal14.1a and we offer insight into the possible mechanism of action. PMID:26861394

  12. Apoptosis Activation in Human Lung Cancer Cell Lines by a Novel Synthetic Peptide Derived from Conus californicus Venom.

    PubMed

    Oroz-Parra, Irasema; Navarro, Mario; Cervantes-Luevano, Karla E; Álvarez-Delgado, Carolina; Salvesen, Guy; Sanchez-Campos, Liliana N; Licea-Navarro, Alexei F

    2016-02-01

    Lung cancer is one of the most common types of cancer in men and women and a leading cause of death worldwide resulting in more than one million deaths per year. The venom of marine snails Conus contains up to 200 pharmacologically active compounds that target several receptors in the cell membrane. Due to their diversity and specific binding properties, Conus toxins hold great potential as source of new drugs against cancer. We analyzed the cytotoxic effect of a 17-amino acid synthetic peptide (s-cal14.1a) that is based on a native toxin (cal14.1a) isolated from the sea snail Conus californicus. Cytotoxicity studies in four lung cancer cell lines were complemented with measurement of gene expression of apoptosis-related proteins Bcl-2, BAX and the pro-survival proteins NFκB-1 and COX-2, as well as quantification of caspase activity. Our results showed that H1299 and H1437 cell lines treated with s-call4.1a had decreased cell viability, activated caspases, and reduced expression of the pro-survival protein NFκB-1. To our knowledge, this is the first report describing activation of apoptosis in human lung cancer cell lines by s-cal14.1a and we offer insight into the possible mechanism of action. PMID:26861394

  13. Concepts for Biologically Active Peptides

    PubMed Central

    Kastin, Abba J.; Pan, Weihong

    2012-01-01

    Here we review a unique aspect of CNS research on biologically active peptides that started against a background of prevalent dogmas but ended by exerting considerable influence on the field. During the course of refuting some doctrines, we introduced several concepts that were unconventional and paradigm-shifting at the time. We showed that (1) hypothalamic peptides can act ‘up’ on the brain as well as ‘down’ on the pituitary, (2) peripheral peptides can affect the brain, (3) peptides can cross the blood-brain barrier, (4) the actions of peptides can persist longer than their half-lives in blood, (5) perinatal administration of peptides can exert actions persisting into adulthood, (6) a single peptide can have more than one action, (7) dose-response relationships of peptides need not be linear, (8) the brain produces antiopiate as well as opiate peptides, (9) there is a selective high affinity endogenous peptide ligand for the mu-opiate receptor, (10) a peptide’s name does not restrict its effects, and (11) astrocytes assume an active role in response to metabolic disturbance and hyperleptinemia. The evolving questions in our laboratories reflect the diligent effort of the neuropeptide community to identify the roles of peptides in the CNS. The next decade is expected to see greater progress in the following areas: (a) interactions of peptides with other molecules in the CNS; (b) peptide involvement in cell-cell interactions; and (c) peptides in neuropsychiatric, autoimmune, and neurodegenerative diseases. The development of peptidomics and gene silencing approaches will expedite the formation of many new concepts in a new era. PMID:20726835

  14. Potent and rapid antigonococcal activity of the venom peptide BmKn2 and its derivatives against different Maldi biotype of multidrug-resistant Neisseria gonorrhoeae.

    PubMed

    Arpornsuwan, Teerakul; Buasakul, Brisana; Jaresitthikunchai, Janthima; Roytrakul, Sittiruk

    2014-03-01

    The emergence of multidrug-resistant strains of Neisseria gonorrhoeae constitutes a serious threat to public health and necessitates the discovery of new types of antimicrobial agents. Among the 18 clinical isolates of N. gonorrhoeae with susceptible to spectinomycin, ceftriaxone and cefixime, 14 isolates were resistance to penicillin, tetracycline and ciprofloxacin, while 2 isolates were susceptible to tetracycline and another was penicillin intermediate isolate. Significant differences between laboratory strain and multidrug resistant strains were revealed by means of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry profiling and bioinformatics examination using the MALDI BioTyper software. However, Maldi Biotyper was not successfully separated ciprofloxacin-penicillin resistance and ciprofloxacin-tetracycline resistance from ciprofloxacin-penicillin-tetracycline resistant N. gonorrhoeae isolates. BmKn2 is a basic, alpha-helical peptide with no disulfide-bridge venom peptides that was first isolated from Buthus martensii Kasch. A panel of BmKn2 scorpion venom peptide and its derivatives of varying length and characteristics were synthesized chemically and evaluated for their ability to inhibit the growth of clinical N. gonorrhoeae isolates. Synthetic BmKn2 displayed potent activity against 18 clinical isolates of N. gonorrhoeae with MIC50 values of 6.9-27.6 μM. BmKn2 exerted its antibacterial activity via a bactericidal mechanism. Cyclic BmKn1 did not show antigonococcal activity. Decreasing the cationicity and helix percentage at the C-terminus of BmKn2 reduced the potency against N. gonorrhoeae. Taken together, the BmKn1 peptide can be developed as a topical therapeutic agent for treating multidrug-resistant strains of N. gonorrhoeae infections. PMID:24184420

  15. N-terminal modification of VEGF-A C terminus-derived peptides delineates structural features involved in neuropilin-1 binding and functional activity.

    PubMed

    Jia, Haiyan; Aqil, Rehan; Cheng, Lili; Chapman, Chris; Shaikh, Shaheda; Jarvis, Ashley; Chan, A W Edith; Hartzoulakis, Basil; Evans, Ian M; Frolov, Antonina; Martin, John; Frankel, Paul; Djordevic, Snezana; Zachary, Ian C; Selwood, David L

    2014-05-26

    The interaction between VEGF-A and its neuropilin (NRP) receptors mediates a number of important biological effects. NRP1 and the related molecule NRP2 are widely expressed on multiple tumour types and throughout the tumour vasculature, and are emerging as critical molecules required for the progression of angiogenic diseases. Given the increasing evidence supporting a role for NRP1 in tumour development, there is growing interest in developing inhibitors of NRP1 interactions with VEGF and its other ligands. In order to probe the interaction we synthesised a number of exon 7- and 8-derived bicyclic peptides with N-terminal lipophilic groups and found a simple N-octanoyl derivative (EG00086) to be the most potent and functionally active. Detailed modelling studies indicated that new intramolecular hydrogen bonds were formed, stabilising the structure and possibly contributing to the potency. Removal of a salt bridge between D142 and R164 implicated in VEGF-A binding to neuropilin-1 had a minor effect on potency. Isothermal calorimetry was used to assess binding of EG00086 to NRP1 and NRP2, and the stability of the peptide in serum and in vivo was investigated. EG00086 is a potent blocker of VEGF-promoted cellular adhesion to extracellular matrices, and phosphorylation of p130Cas contributes to this effect. PMID:24771685

  16. PFR peptide, one of the antimicrobial peptides identified from the derivatives of lactoferrin, induces necrosis in leukemia cells

    PubMed Central

    Lu, Yan; Zhang, Teng-Fei; Shi, Yue; Zhou, Han-Wei; Chen, Qi; Wei, Bu-Yun; Wang, Xi; Yang, Tian-Xin; Chinn, Y. Eugene; Kang, Jian; Fu, Cai-Yun

    2016-01-01

    LF11-322 (PFWRIRIRR-NH2) (PFR peptide), a nine amino acid-residue peptide fragment derived from human lactoferricin, possesses potent cytotoxicity against bacteria. We report here the discovery and characterization of its antitumor activity in leukemia cells. PFR peptide inhibited the proliferation of MEL and HL-60 leukemia cells by inducing cell death in the absence of the classical features of apoptosis, including chromatin condensation, Annexin V staining, Caspase activation and increase of abundance of pro-apoptotic proteins. Instead, necrotic cell death as evidenced by increasing intracellular PI staining and LDH release, inducing membrane disruption and up-regulating intracellular calcium level, was observed following PFR peptide treatment. In addition to necrotic cell death, PFR peptide also induced G0/G1 cell cycle arrest. Moreover, PFR peptide exhibited favorable antitumor activity and tolerability in vivo. These findings thus provide a new clue of antimicrobial peptides as a potential novel therapy for leukemia. PMID:26860588

  17. Membrane damage as first and DNA as the secondary target for anti-candidal activity of antimicrobial peptide P7 derived from cell-penetrating peptide ppTG20 against Candida albicans.

    PubMed

    Li, Lirong; Song, Fengxia; Sun, Jin; Tian, Xu; Xia, Shufang; Le, Guowei

    2016-06-01

    P7, a peptide analogue derived from cell-penetrating peptide ppTG20, possesses antibacterial and antitumor activities without significant hemolytic activity. In this study, we investigated the antifungal effect of P7 and its anti-Candida acting mode in Candida albicans. P7 displayed antifungal activity against the reference C. albicans (MIC = 4 μM), Aspergilla niger (MIC = 32 μM), Aspergillus flavus (MIC = 8 μM), and Trichopyton rubrum (MIC = 16 μM). The effect of P7 on the C. albicans cell membrane was examined by investigating the calcein leakage from fungal membrane models made of egg yolk l-phosphatidylcholine/ergosterol (10 : 1, w/w) liposomes. P7 showed potent leakage effects against fungal liposomes similar to Melittin-treated cells. C. albicans protoplast regeneration assay demonstrated that P7 interacted with the C. albicans plasma membrane. Flow cytometry of the plasma membrane potential and integrity of C. albicans showed that P7 caused 60.9 ± 1.8% depolarization of the membrane potential of intact C. albicans cells and caused 58.1 ± 3.2% C. albicans cell membrane damage. Confocal laser scanning microscopy demonstrated that part of FITC-P7 accumulated in the cytoplasm. DNA retardation analysis was also performed, which showed that P7 interacted with C. albicans genomic DNA after penetrating the cell membrane, completely inhibiting the migration of genomic DNA above the weight ratio (peptide : DNA) of 6. Our results indicated that the plasma membrane was the primary target, and DNA was the secondary intracellular target of the mode of action of P7 against C. albicans. Copyright © 2016 European Peptide Society and John Wiley & Sons, Ltd. PMID:27197902

  18. Functional evaluation of fluorescein-labeled derivatives of a peptide inhibitor of the EGF receptor dimerization.

    PubMed

    Toyama, Kei; Mizuguchi, Takaaki; Nomura, Wataru; Tamamura, Hirokazu

    2016-08-15

    A cyclic decapeptide (1, ), which acts on the extracellular region of the EGF receptor, preventing it from dimerizing, has been developed. Peptide 2, which was labeled with fluorescein at the N-terminus of peptide 1, was synthesized based on structure-activity relationship studies. Peptide 2 essentially retained the inhibitory activity of peptide 1 against the receptor autophosphorylation. Confocal microscopy studies revealed that in carcinoma cells, the fluorescence of peptide 2 was localized inside some vesicles. Treatment of intact cells by peptide 1 in combination with peptide 2 decreased the fluorescence intensity significantly compared to treatment with only peptide 2. These results indicate that peptide 2 competes with peptide 1 for binding to the cellular surface. Six derivatives of peptide 2, in which constituent amino acids, with the exception of two cysteines and proline were randomized, were synthesized and used to treat the cells. Peptides 6 and 9 showed the highest fluorescence intensity in cells. From the results of the EGF receptor autophosphorylation assay, these two derivatives were proven to have higher inhibitory activity than peptide 2, which would therefore be a useful delivery peptide and fluorescent probe to find new inhibitors against the EGF receptor. Peptides 6 and 9 are promising leads for EGF receptor inhibitors. PMID:27283787

  19. Biologically Active and Antimicrobial Peptides from Plants

    PubMed Central

    Salas, Carlos E.; Badillo-Corona, Jesus A.; Ramírez-Sotelo, Guadalupe; Oliver-Salvador, Carmen

    2015-01-01

    Bioactive peptides are part of an innate response elicited by most living forms. In plants, they are produced ubiquitously in roots, seeds, flowers, stems, and leaves, highlighting their physiological importance. While most of the bioactive peptides produced in plants possess microbicide properties, there is evidence that they are also involved in cellular signaling. Structurally, there is an overall similarity when comparing them with those derived from animal or insect sources. The biological action of bioactive peptides initiates with the binding to the target membrane followed in most cases by membrane permeabilization and rupture. Here we present an overview of what is currently known about bioactive peptides from plants, focusing on their antimicrobial activity and their role in the plant signaling network and offering perspectives on their potential application. PMID:25815307

  20. Antimicrobial activity of polycationic peptides.

    PubMed

    Giacometti, A; Cirioni, O; Barchiesi, F; Del Prete, M S; Scalise, G

    1999-11-01

    The in vitro activity of six polycationic peptides, buforin II, cecropin P1, indolicidin, magainin II, nisin, and ranalexin, were evaluated against several clinical isolates of gram-positive and gram-negative aerobic bacteria, yeasts, Pneumocystis carinii and Cryptosporidium parvum, by using microbroth dilution methods. The peptides exhibited different antibacterial activities and rapid time-dependent killing. The gram-negative organisms were more susceptible to buforin II and cecropin P1, whereas buforin II and ranalexin were the most active compounds against the gram-positive strains. Similarly, ranalexin showed the highest activity against Candida spp., whereas magainin II exerted the highest anticryptococcal activity. Finally, the peptides showed high anti-Pneumocystis activity, whereas no compound had strong inhibitory effect on C. parvum. PMID:10612440

  1. ACTIVITY-DEPENDENT NEUROPROTECTIVE PROTEIN–DERIVED PEPTIDE, NAP, PREVENTING ALCOHOL-INDUCED APOPTOSIS IN FETAL BRAIN OF C57BL/6 MOUSE

    PubMed Central

    SARI, Y.

    2012-01-01

    Possible prevention of the effects of prenatal alcohol exposure has been investigated using peptides that were previously shown to be involved in neuroprotection both in vitro and in vivo. I focused in this study on investigating the neuro-protective effects of one of these peptides with regard to the determination of the downstream signaling pathways involved in neuroprotection. This peptide with the sequence NAPVSIPQ, known as NAP, a fragment of activity-dependent neuroprotective protein, demonstrated a potent protective effect against oxidative stress associated with alcohol exposure. On embryonic day 7 (E7), weight-matched C57BL/6 pregnant females were assigned the following groups: (1) Ethanol liquid diet group (ALC) 25% (4.49%, v/v) ethano-derived calories, (2) Pair-fed (PF) control group (3) Chow control group, (4) treatment groups with alcohol alongside i.p. injections of d-NAP (ALC/d-NAP, 20 or 30 μg/20 g body weight), (5) PF/d-NAP control group. On E13, fetal brains were collected and assayed for TdT-mediated dUTP nick end labeling (TUNEL) staining, caspase-3 colorimetric assay and ELISA for cytochrome c detection. My results show that NAP significantly prevented alcohol-induced weight reduction of the fetal brain. Apoptosis was determined by TUNEL staining; NAP administration significantly prevented alcohol-induced increases in TUNEL-positive cells in primordium cingulate cortex and basal ganglia eminence. The investigation of downstream signaling pathways involving NAP neuroprotection revealed that this peptide significantly prevented alcohol-induced increase in the concentrations of caspase-3 in E13 fetal brains. Moreover, ELISA for cytochrome c shows that NAP significantly prevented both alcohol-induced increases in the level of cytosolic cytochrome c and alcohol-induced decreases in the level of mitochondrial cytochrome c. These data provide an understanding of NAP intracellular target, and the downstream mechanisms of action that will pave a path

  2. Antiviral active peptide from oyster

    NASA Astrophysics Data System (ADS)

    Zeng, Mingyong; Cui, Wenxuan; Zhao, Yuanhui; Liu, Zunying; Dong, Shiyuan; Guo, Yao

    2008-08-01

    An active peptide against herpes virus was isolated from the enzymic hydrolysate of oyster ( Crassostrea gigas) and purified with the definite direction hydrolysis technique in the order of alcalase and bromelin. The hydrolysate was fractioned into four ranges of molecular weight (>10 kDa, 10 5 kDa, 5 1 kDa and <1 kDa) using ultrafiltration membranes and dialysis. The fraction of 10 5 kDa was purified using consecutive chromatographic methods including DEAE Sephadex A-25 column, Sephadex G-25 column, and high performance liquid chromatogram (HPLC) by activity-guided isolation. The antiviral effect of the obtained peptide on herpetic virus was investigated in Vero cells by observing cytopathic effect (CPE). The result shows that the peptide has high inhibitory activity on herpetic virus.

  3. In vitro and in vivo antiangiogenic activity of a novel deca-peptide derived from human tissue-type plasminogen activator kringle 2

    SciTech Connect

    Su, Li; Xu, Xun; Zhao, Hui; Gu, Qing; Zou, Haidong

    2010-06-11

    A synthetic deca-peptide corresponding to the amino acid sequence Arg{sup 54}-Trp{sup 63} of human tissue-type plasminogen activator (t-PA) kringle 2 domain, named TKII-10, is produced and tested for its ability to inhibit endothelial cell proliferation, migration, tube formation in vitro, and angiogenesis in vivo. At the same time, another peptide TKII-10S composed of the same 10 amino acids as TKII-10, but in a different sequence, is also produced and tested. The results show that TKII-10 potently inhibits VEGF-stimulated endothelial cell migration and tube formation in a dose-dependent, as well as sequence-dependent, manner in vitro while it is inactive in inhibiting endothelial cell proliferation. Furthermore, TKII-10 potently inhibits angiogenesis in chick chorioallantoic membrane and mouse cornea. The middle four amino acids DGDA in their sequence play an important role in TKII-10 angiogenesis inhibition{sub .} These results suggest that TKII-10 is a novel angiogenesis inhibitor that may serve as a prototype for antiangiogenic drug development.

  4. Antimycobacterial activity of peptide conjugate of pyridopyrimidine derivative against Mycobacterium tuberculosis in a series of in vitro and in vivo models.

    PubMed

    Horváti, Kata; Bacsa, Bernadett; Szabó, Nóra; Fodor, Kinga; Balka, Gyula; Rusvai, Miklós; Kiss, Éva; Mező, Gábor; Grolmusz, Vince; Vértessy, Beáta; Hudecz, Ferenc; Bősze, Szilvia

    2015-06-01

    New pyridopyrimidine derivatives were defined using a novel HTS in silico docking method (FRIGATE). The target protein was a dUTPase enzyme (EC 3.6.1.23; Rv2697) which plays a key role in nucleotide biosynthesis of Mycobacterium tuberculosis (Mtb). Top hit molecules were assayed in vitro for their antimycobacterial effect on Mtb H37Rv culture. In order to enhance the cellular uptake rate, the TB820 compound was conjugated to a peptid-based carrier and a nanoparticle type delivery system (polylactide-co-glycolide, PLGA) was applied. The conjugate had relevance to in vitro antitubercular activity with low in vitro and in vivo toxicity. In a Mtb H37Rv infected guinea pig model the in vivo efficacy of orally administrated PLGA encapsulated compound was proven: animals maintained a constant weight gain and no external clinical signs of tuberculosis were observed. All tissue homogenates from lung, liver and kidney were found negative for Mtb, and diagnostic autopsy showed that no significant malformations on the tissues occurred. PMID:25728610

  5. A novel antimicrobial peptide derived from modified N-terminal domain of bovine lactoferrin: design, synthesis, activity against multidrug-resistant bacteria and Candida.

    PubMed

    Mishra, Biswajit; Leishangthem, Geeta Devi; Gill, Kamaldeep; Singh, Abhay K; Das, Swagata; Singh, Kusum; Xess, Immaculata; Dinda, Amit; Kapil, Arti; Patro, Ishan K; Dey, Sharmistha

    2013-02-01

    Lactoferrin (LF) is believed to contribute to the host's defense against microbial infections. This work focuses on the antibacterial and antifungal activities of a designed peptide, L10 (WFRKQLKW) by modifying the first eight N-terminal residues of bovine LF by selective homologous substitution of amino acids on the basis of hydrophobicity, L10 has shown potent antibacterial and antifungal properties against clinically isolated extended spectrum beta lactamases (ESBL), producing gram-negative bacteria as well as Candida strains with minimal inhibitory concentrations (MIC) ranging from 1 to 8 μg/mL and 6.5 μg/mL, respectively. The peptide was found to be least hemolytic at a concentration of 800 μg/mL. Interaction with lipopolysaccharide (LPS) and lipid A (LA) suggests that the peptide targets the membrane of gram-negative bacteria. The membrane interactive nature of the peptide, both antibacterial and antifungal, was further confirmed by visual observations employing electron microscopy. Further analyses, by means of propidium iodide based flow cytometry, also supported the membrane permeabilization of Candida cells. The peptide was also found to possess anti-inflammatory properties, by virtue of its ability to inhibit cyclooxygenase-2 (COX-2). L10 therefore emerges as a potential therapeutic remedial solution for infections caused by ESBL positive, gram-negative bacteria and multidrug-resistant (MDR) fungal strains, on account of its multifunctional activities. This study may open up new approach to develop and design novel antimicrobials. PMID:23026014

  6. Activity and Structural Comparisons of Solution Associating and Monomeric Channel-Forming Peptides Derived from the Glycine Receptor M2 Segment

    PubMed Central

    Cook, Gabriel A.; Prakash, Om; Zhang, Ke; Shank, Lalida P.; Takeguchi, Wade A.; Robbins, Ashley; Gong, Yu-Xi; Iwamoto, Takeo; Schultz, Bruce D.; Tomich, John M.

    2004-01-01

    A number of channel-forming peptides derived from the second transmembrane (TM) segment (M2) of the glycine receptor α1 subunit (M2GlyR), including the 22-residue sequence NK4-M2GlyR p22 wild type (WT) (KKKKPARVGLGITTVLTMTTQS), induce anion permeation across epithelial cell monolayers. In vitro assays suggest that this peptide or related sequences might function as a candidate for ion channel replacement therapy in treating channelopathies such as cystic fibrosis (CF). The wild-type sequence forms soluble associations in water that diminish its efficacy. Introduction of a single substitution S22W at the C-terminus, NK4-M2GlyR p22 S22W, eliminates the formation of higher molecular weight associations in solution. The S22W peptide also reduces the concentration of peptide required for half-maximal anion transport induced across Madin-Darby canine kidney cells (MDCK) monolayers. A combination of 2D double quantum filtered correlation spectroscopy (DQF-COSY), total correlation spectroscopy (TOCSY), nuclear Overhauser effect spectroscopy (NOESY), and rotating frame nuclear Overhauser effect spectroscopy (ROESY) data were recorded for both the associating WT and nonassociating S22W peptides and used to compare the primary structures and to assign the secondary structures. High-resolution structural studies were recorded in the solvent system (40% 2,2,2-Trifluoroethanol (TFE)/water), which gave the largest structural difference between the two peptides. Nuclear Overhauser effect crosspeak intensity provided interproton distances and the torsion angles were measured by spin-spin coupling constants. These constraints were put into the DYANA modeling program to generate a group of structures. These studies yielded energy-minimized structures for this mixed solvent environment. Structure for both peptides is confined to the 15-residue transmembrane segments. The energy-minimized structure for the WT peptide shows a partially helical extended structure. The S22W peptide

  7. Encapsulation of bioactive whey peptides in soy lecithin-derived nanoliposomes: Influence of peptide molecular weight.

    PubMed

    Mohan, Aishwarya; McClements, David Julian; Udenigwe, Chibuike C

    2016-12-15

    Encapsulation of peptides can be used to enhance their stability, delivery and bioavailability. This study focused on the effect of the molecular weight range of whey peptides on their encapsulation within soy lecithin-derived nanoliposomes. Peptide molecular weight did not have a major impact on encapsulation efficiency or liposome size. However, it influenced peptide distribution amongst the surface, core, and bilayer regions of the liposomes, as determined by electrical charge (ζ-potential) and FTIR analysis. The liposome ζ-potential depended on peptide molecular weight, suggesting that the peptide charged groups were in different locations relative to the liposome surfaces. FTIR analysis indicated that the least hydrophobic peptide fractions interacted more strongly with choline on the liposome surfaces. The results suggested that the peptides were unequally distributed within the liposomes, even at the same encapsulation efficiency. These findings are important for designing delivery systems for commercial production of encapsulated peptides with improved functional attributes. PMID:27451165

  8. Structure-activity relationships of alphaIIb 313-320 derived peptide inhibitors of human platelet aggregation.

    PubMed

    Stanica, Ruxandra Maria; Benaki, Dimitra; Rodis, Foteini I; Mikros, Emmanuel; Tsoukatos, Dimokritos; Tselepis, Alexandros; Tsikaris, Vasilios

    2008-11-01

    The alphaIIbbeta3 receptor, which is the most abundant receptor on the surface of platelets, can interact with a variety of adhesive proteins including fibrinogen, fibronectin and the von Willebrand factor. Fibrinogen binding on alphaIIbbeta3 is an event essential for platelet aggregation and thrombus formation. Mapping of the fibrinogen-binding domains on alphaIIb subunit suggested the sequence 313-332 as a possible binding site. This region was restricted to sequence alphaIIb 313-320 (Y313MESRADR320) using synthetic octapeptides overlapping by six residues. The YMESRADR octapeptide inhibits ADP-stimulated human platelets aggregation and binds to immobilized fibrinogen. In this study, we used the Ala scanning methodology within the sequence 313-320 aiming to evaluate the contribution of each amino acid in inhibiting platelet aggregation. It was found that the substitution of Y313, M314, E315 or S316 by A does not affect the activity of the parent octapeptide. The-RADR-motif seems to be the most essential for the biological activity of the alphaIIb 313-320 site. The conformational analysis of the YAESRADR, YMESAADR and YMESRAAR analogs by using NMR spectroscopy and distance geometry calculations revealed significant differences in their conformational states in DMSO-d6. PMID:18646252

  9. Marine algae-derived bioactive peptides for human nutrition and health.

    PubMed

    Fan, Xiaodan; Bai, Lu; Zhu, Liang; Yang, Li; Zhang, Xuewu

    2014-09-24

    Within the parent protein molecule, most peptides are inactive, and they are released with biofunctionalities after enzymatic hydrolysis. Marine algae have high protein content, up to 47% of the dry weight, depending on the season and the species. Recently, there is an increasing interest in using marine algae protein as a source of bioactive peptides due to their health promotion and disease therapy potentials. This review presents an overview of marine algae-derived bioactive peptides and especially highlights some key issues, such as in silico proteolysis and quantitative structure-activity relationship studies, in vivo fate of bioactive peptides, and novel technologies in bioactive peptides studies and production. PMID:25179496

  10. Molecular imaging probes derived from natural peptides.

    PubMed

    Charron, C L; Hickey, J L; Nsiama, T K; Cruickshank, D R; Turnbull, W L; Luyt, L G

    2016-06-01

    Covering: up to the end of 2015.Peptides are naturally occurring compounds that play an important role in all living systems and are responsible for a range of essential functions. Peptide receptors have been implicated in disease states such as oncology, metabolic disorders and cardiovascular disease. Therefore, natural peptides have been exploited as diagnostic and therapeutic agents due to the unique target specificity for their endogenous receptors. This review discusses a variety of natural peptides highlighting their discovery, endogenous receptors, as well as their derivatization to create molecular imaging agents, with an emphasis on the design of radiolabelled peptides. This review also highlights methods for discovering new and novel peptides when knowledge of specific targets and endogenous ligands are not available. PMID:26911790

  11. Antimicrobial peptide scolopendrasin VII, derived from the centipede Scolopendra subspinipes mutilans, stimulates macrophage chemotaxis via formyl peptide receptor 1.

    PubMed

    Park, Yoo Jung; Lee, Ha Young; Jung, Young Su; Park, Joon Seong; Hwang, Jae Sam; Bae, Yoe-Sik

    2015-08-01

    In this study, we report that one of the antimicrobial peptides scolopendrasin VII, derived from Scolopendra subspinipes mutilans, stimulates actin polymerization and the subsequent chemotactic migration of macrophages through the activation of ERK and protein kinase B (Akt) activity. The scolopendrasin VII-induced chemotactic migration of macrophages is inhibited by the formyl peptide receptor 1 (FPR1) antagonist cyclosporine H. We also found that scolopendrasin VII stimulate the chemotactic migration of FPR1-transfected RBL-2H3 cells, but not that of vector-transfected cells; moreover, scolopendrasin VII directly binds to FPR1. Our findings therefore suggest that the antimicrobial peptide scolopendrasin VII, derived from Scolopendra subspinipes mutilans, stimulates macrophages, resulting in chemotactic migration via FPR1 signaling, and the peptide can be useful in the study of FPR1-related biological responses. PMID:26129676

  12. Peptide TFP5/TP5 derived from Cdk5 activator P35 provides neuroprotection in the MPTP model of Parkinson's disease.

    PubMed

    Binukumar, B K; Shukla, Varsha; Amin, Niranjana D; Grant, Philip; Bhaskar, M; Skuntz, Susan; Steiner, Joseph; Pant, Harish C

    2015-12-01

    Parkinson's disease (PD) is a chronic neurodegenerative disorder characterized by the loss of dopamine neurons in the substantia nigra, decreased striatal dopamine levels, and consequent extrapyramidal motor dysfunction. Recent evidence indicates that cyclin-dependent kinase 5 (Cdk5) is inappropriately activated in several neurodegenerative conditions, including PD. To date, strategies to specifically inhibit Cdk5 hyperactivity have not been successful without affecting normal Cdk5 activity. Previously we reported that TFP5 peptide has neuroprotective effects in animal models of Alzheimer's disease. Here we show that TFP5/TP5 selective inhibition of Cdk5/p25 hyperactivation in vivo and in vitro rescues nigrostriatal dopaminergic neurodegeneration induced by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP/MPP+) in a mouse model of PD. TP5 peptide treatment also blocked dopamine depletion in the striatum and improved gait dysfunction after MPTP administration. The neuroprotective effect of TFP5/TP5 peptide is also associated with marked reduction in neuroinflammation and apoptosis. Here we show selective inhibition of Cdk5/p25 -hyperactivation by TFP5/TP5 peptide, which identifies the kinase as a potential therapeutic target to reduce neurodegeneration in Parkinson's disease. PMID:26399293

  13. Enhancing actions of peptides derived from the γ-chain of fetal human hemoglobin on the immunostimulant activities of monophosphoryl lipid A.

    PubMed

    Ulmer, Artur J; Kaconis, Yani; Heinbockel, Lena; Correa, Wilmar; Alexander, Christian; Rietschel, Ernst Th; Mach, Jean-Pierre; Gorczynski, Reginald M; Heini, Adrian; Rössle, Manfred; Richter, Walter; Gutsmann, Thomas; Brandenburg, Klaus

    2016-04-01

    Hemoglobin and its structures have been described since the 1990s to enhance a variety of biological activities of endotoxins (LPS) in a dose-dependent manner. To investigate the interaction processes in more detail, the system was extended by studying the interactions of newly designed peptides from the γ-chain of human hemoglobin with the adjuvant monophosphoryl lipid A (MPLA), a partial structure of lipid A lacking its 1-phosphate. It was found that some selected Hbg peptides, in particular two synthetic substructures designated Hbg32 and Hbg35, considerably increased the bioactivity of MPLA, which alone was only a weak activator of immune cells. These findings hold true for human mononuclar cells, monocytes and T lymphocytes. To understand the mechanisms of action in more detail, biophysical techniques were applied. These showed a peptide-induced change of the MPLA aggregate structure from multilamellar into a non-lamellar, probably inverted, cubic structure. Concomitantly, the peptides incorporated into the tightly packed MPLA aggregates into smaller units down to monomers. The fragmentation of the aggregates was an endothermic process, differing from a complex formation but rather typical for a catalytic reaction. PMID:26921253

  14. Peptide TFP5/TP5 derived from Cdk5 activator P35 provides neuroprotection in the MPTP model of Parkinson’s disease

    PubMed Central

    Binukumar, BK.; Shukla, Varsha; Amin, Niranjana D.; Grant, Philip; Bhaskar, M.; Skuntz, Susan; Steiner, Joseph; Pant, Harish C.

    2015-01-01

    Parkinson’s disease (PD) is a chronic neurodegenerative disorder characterized by the loss of dopamine neurons in the substantia nigra, decreased striatal dopamine levels, and consequent extrapyramidal motor dysfunction. Recent evidence indicates that cyclin-dependent kinase 5 (Cdk5) is inappropriately activated in several neurodegenerative conditions, including PD. To date, strategies to specifically inhibit Cdk5 hyperactivity have not been successful without affecting normal Cdk5 activity. Previously we reported that TFP5 peptide has neuroprotective effects in animal models of Alzheimer’s disease. Here we show that TFP5/TP5 selective inhibition of Cdk5/p25 hyperactivation in vivo and in vitro rescues nigrostriatal dopaminergic neurodegeneration induced by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP/MPP+) in a mouse model of PD. TP5 peptide treatment also blocked dopamine depletion in the striatum and improved gait dysfunction after MPTP administration. The neuroprotective effect of TFP5/TP5 peptide is also associated with marked reduction in neuroinflammation and apoptosis. Here we show selective inhibition of Cdk5/p25 ­hyperactivation by TFP5/TP5 peptide, which identifies the kinase as a potential therapeutic target to reduce neurodegeneration in Parkinson’s disease. PMID:26399293

  15. Recovery of casein-derived peptides with in vitro inhibitory activity of angiotensin converting enzyme (ACE) using aqueous two-phase systems.

    PubMed

    de Souza, Evaldo Cardozo; Coimbra, Jane Sélia Dos Reis; de Oliveira, Eduardo Basílio; Bonomo, Renata Cristina Ferreira

    2014-10-22

    Peptides inhibiting the activity of angiotensin converting enzyme (ACE) were obtained by trypsin-catalyzed hydrolysis of bovine milk casein, performed at 37°C, during 1, 2, 5, 8 and 24h. Results of in vitro inhibitory activity ranged between 13.4% and 78.5%. The highest ACE inhibitory activity was evidenced for hydrolysates obtained after 2h of reaction. Aqueous two-phase systems (ATPS) formed by polyethylene glycol of 1500gmol(-1) (PEG 1500)+sodium phosphate or potassium phosphates were produced and evaluated, in terms of partition coefficients (K) and extraction yields (y), to recovery the casein hydrolysates at room temperature. In ATPS containing sodium phosphate, the peptides showed a slightly greater affinity toward the bottom salt-rich phase (0.1≤K≤0.9; 5.7%≤y≤47%). In the case of ATPS containing potassium phosphates, these molecules showed substantially greater affinity toward the top polymer-rich phase (137≤K≤266; y≥99%). These results point out extraction using PEG 1500/potassium phosphate ATPS is an efficient technique to recover casein hydrolysates containing ACE inhibitors peptides. Outlined data will be helpful in integrating such unit operation to larger scale processes. PMID:25464099

  16. The effects of shortening lactoferrin derived peptides against tumour cells, bacteria and normal human cells.

    PubMed

    Yang, Nannan; Strøm, Morten B; Mekonnen, Seble M; Svendsen, John S; Rekdal, Oystein

    2004-01-01

    A number of shortened derivatives of the lactoferrin model peptide L12, PAWRKAFRWAKRMLKKAA, were designed in order to elucidate the structural basis for antitumour activity of lactoferrin derivatives. Three tumour cell lines were included in the study and toxicity determined by measuring lysis of human red blood cells and fibroblasts. The results demonstrated a strong correlation between antitumour activity and net positive charge, in which a net charge close to +7 was essential for a high antitumour activity. In order to increase the antitumour activity of the shortest peptide with a net charge less than +7, the hydrophobicity had to be increased by adding a bulky Trp residue. None of the peptides were haemolytic, but toxicity against fibroblasts was observed. However, modifications of the peptides had a higher effect on reducing fibroblast toxicity than antitumour activity and thereby resulted in peptides displaying an almost 7-fold selectivity for tumour cells compared with fibroblasts. The antimicrobial activity against the Gram-negative bacteria Escherichia coil and the Gram-positive bacteria Staphylococcus aureus was also included in order to compare the structural requirements for antitumour activity with those required for a high antimicrobial activity. The results showed that most of the peptides were highly active against both bacterial strains. Less modification by shortening the peptide sequences was tolerated for maintaining a high antitumour activity and selectivity compared with antimicrobial activity. The order of the amino acid residues and thereby the conformation of the peptides was highly essential for antitumour activity, whereas the antimicrobial activity was hardly influenced by changes in this parameter. Thus, in addition to a certain net positive charge and hydrophobicity, the ability to adopt an amphipathic conformation was a more critical structural parameter for antitumour activity than for antimicrobial activity, and implied that a

  17. Chromogranin A and Derived Peptides in Health and Disease

    PubMed Central

    Loh, Y. Peng; Cheng, Yong; Mahata, Sushil K.; Corti, Angelo; Tota, Bruno

    2012-01-01

    Chromogranin A (CgA) is a member of the granins, a family of acidic proteins found in abundance in (neuro)endocrine cells (e.g. in chromaffin cells) and in some tumors. Like other granins, CgA has a granulogenic role in secretory granule biogenesis and is stored in these organelles. CgA is partially processed differentially in various cell types to yield biologically active peptides, such as vasostatin, pancreastatin, catestatin and serpinins. In this review we describe the roles of CgA and several of its derived peptides. CgA, which is elevated in the blood of cancer patients, inhibits angiogenesis and exerts protective effects on the endothelial barrier function in tumors, thus affecting response to chemotherapy. Recent studies indicate that the serpinins promote cell survival and myocardial contractility and relaxation. Other peptides such as pancreastatin was found to have significant effects on inhibition of glucose stimulated insulin secretion and glucose up-take, induction of glycogenolysis in hepatocytes and inhibition of lipogenesis. In contrast, catestatin has opposite effects to that of pancreastatin in glucose metabolism and lipogenesis. Catestatin appears to also play a significant role in cardiac function, blood pressure regulation, and mutations in the catestatin domain of the CgA gene are associated with hypertension in humans. PMID:22388654

  18. Solid Phase Synthesis and Application of Labeled Peptide Derivatives: Probes of Receptor-Opioid Peptide Interactions

    PubMed Central

    Aldrich, Jane V.; Kumar, Vivek; Dattachowdhury, Bhaswati; Peck, Angela M.; Wang, Xin; Murray, Thomas F.

    2009-01-01

    Solid phase synthetic methodology has been developed in our laboratory to incorporate an affinity label (a reactive functionality such as isothiocyanate or bromoacetamide) into peptides (Leelasvatanakij, L. and Aldrich, J. V. (2000) J. Peptide Res. 56, 80), and we have used this synthetic strategy to prepare affinity label derivatives of a variety of opioid peptides. To date side reactions have been detected only in two cases, both involving intramolecular cyclization. We have identified several peptide-based affinity labels for δ opioid receptors that exhibit wash-resistant inhibition of binding to these receptors and are valuable pharmacological tools to study opioid receptors. Even in cases where the peptide derivatives do not bind covalently to their target receptor, studying their binding has revealed subtle differences in receptor interactions with particular opioid peptide residues, especially Phe residues in the N-terminal “message” sequences. Solid phase synthetic methodology for the incorporation of other labels (e.g. biotin) into the C-terminus of peptides has also been developed in our laboratory (Kumar, V. and Aldrich, J. V. (2003) Org. Lett. 5, 613). These two synthetic approaches have been combined to prepare peptides containing multiple labels that can be used as tools to study peptide ligand-receptor interactions. These solid phase synthetic methodologies are versatile strategies that are applicable to the preparation of labeled peptides for a variety of targets in addition to opioid receptors. PMID:19956785

  19. A peptide (P2) derived from the variable heavy chain of an anti-P-selectin monoclonal antibody (LYP20) inhibits leucocyte adhesion to thrombin-activated platelets and endothelial cells.

    PubMed

    Murphy, Joseph F; McGregor, John L

    2003-02-01

    P-selectin, a member of the selectin family of adhesion molecules, is present in endothelial Weibel-Palade bodies and platelet alpha-granules, and is rapidly expressed on their surface upon activation, resulting in leucocyte adhesion. LYP20 is a functional monoclonal antibody previously generated in our laboratory that binds with high affinity and specificity directed against P-selectin. This binding is largely imparted by the specific sequence of amino acids present on the hypervariable portions of the IgG chains. We now show that a peptide derived from the heavy chain of mAb LYP20 dose dependently inhibits the adhesion of poly morphonuclear cells to resting and thrombin-activated endothelial cells (EC) and platelets. The scrambled form of this peptide, identical in amino acid composition to the authentic peptide but with altered sequence, was not inhibitory at corresponding concentrations. Binding studies revealed that this peptide also dose dependently bound to both resting and thrombin-activated EC and platelets. Our results may prove useful for the development of new therapeutic inhibitors to modulate leucocyte interactions in inflammatory disorders. PMID:12588346

  20. Marine Peptides and Their Anti-Infective Activities

    PubMed Central

    Kang, Hee Kyoung; Seo, Chang Ho; Park, Yoonkyung

    2015-01-01

    Marine bioresources are a valuable source of bioactive compounds with industrial and nutraceutical potential. Numerous clinical trials evaluating novel chemotherapeutic agents derived from marine sources have revealed novel mechanisms of action. Recently, marine-derived bioactive peptides have attracted attention owing to their numerous beneficial effects. Moreover, several studies have reported that marine peptides exhibit various anti-infective activities, such as antimicrobial, antifungal, antimalarial, antiprotozoal, anti-tuberculosis, and antiviral activities. In the last several decades, studies of marine plants, animals, and microbes have revealed tremendous number of structurally diverse and bioactive secondary metabolites. However, the treatments available for many infectious diseases caused by bacteria, fungi, and viruses are limited. Thus, the identification of novel antimicrobial peptides should be continued, and all possible strategies should be explored. In this review, we will present the structures and anti-infective activity of peptides isolated from marine sources (sponges, algae, bacteria, fungi and fish) from 2006 to the present. PMID:25603351

  1. Peptides of the constant region of antibodies display fungicidal activity.

    PubMed

    Polonelli, Luciano; Ciociola, Tecla; Magliani, Walter; Zanello, Pier Paolo; D'Adda, Tiziana; Galati, Serena; De Bernardis, Flavia; Arancia, Silvia; Gabrielli, Elena; Pericolini, Eva; Vecchiarelli, Anna; Arruda, Denise C; Pinto, Marcia R; Travassos, Luiz R; Pertinhez, Thelma A; Spisni, Alberto; Conti, Stefania

    2012-01-01

    Synthetic peptides with sequences identical to fragments of the constant region of different classes (IgG, IgM, IgA) of antibodies (Fc-peptides) exerted a fungicidal activity in vitro against pathogenic yeasts, such as Candida albicans, Candida glabrata, Cryptococcus neoformans, and Malassezia furfur, including caspofungin and triazole resistant strains. Alanine-substituted derivatives of fungicidal Fc-peptides, tested to evaluate the critical role of each residue, displayed unaltered, increased or decreased candidacidal activity in vitro. An Fc-peptide, included in all human IgGs, displayed a therapeutic effect against experimental mucosal and systemic candidiasis in mouse models. It is intriguing to hypothesize that some Fc-peptides may influence the antifungal immune response and constitute the basis for devising new antifungal agents. PMID:22470523

  2. Decreased outer membrane permeability protects mycobacteria from killing by ubiquitin-derived peptides.

    PubMed

    Purdy, Georgiana E; Niederweis, Michael; Russell, David G

    2009-09-01

    Ubiquitin-derived peptides are bactericidal in vitro and contribute to the mycobactericidal activity of the lysosome. To further define interactions of ubiquitin-derived peptides with mycobacteria, we screened for mutants with increased resistance to the bactericidal activity of the synthetic ubiquitin-derived peptide Ub2. The four Ub2-resistant Mycobacterium smegmatis mutants were also resistant to the bactericidal action of other antimicrobial peptides and macrophages. Two mutants were in the mspA gene encoding the main M. smegmatis porin. Using a translocation-deficient MspA point mutant, we showed that susceptibility of M. smegmatis to Ub2 was independent of MspA channel activity. Instead, the M. smegmatis Ub2-resistant mutants shared a common phenotype of decreased cell wall permeability compared with wild-type bacteria. Expression of mspA rendered Mycobacterium tuberculosis CDC1551 more susceptible both to ubiquitin-derived peptides in vitro and to lysosomal killing in macrophages. Finally, biochemical assays designed to assess membrane integrity indicated that Ub2 treatment impairs membrane function of M. smegmatis and M. tuberculosis cells. The M. smegmatis Ub2-resistant mutants were more resistant than wild-type M. smegmatis to this damage. We conclude that Ub2 targets mycobacterial membranes and that reduced membrane permeability provides mycobacteria intrinsic resistance against antimicrobial compounds including bactericidal ubiquitin-derived peptides. PMID:19682257

  3. Saturation mutagenesis of selected residues of the α-peptide of the lantibiotic lacticin 3147 yields a derivative with enhanced antimicrobial activity

    PubMed Central

    Field, Des; Molloy, Evelyn M; Iancu, Catalin; Draper, Lorraine A; O' Connor, Paula M; Cotter, Paul D; Hill, Colin; Ross, R Paul

    2013-01-01

    Summary The lantibiotic lacticin 3147 consists of two ribosomally synthesized and post-translationally modified antimicrobial peptides, Ltnα and Ltnβ, which act synergistically against a wide range of Gram-positive microorganisms. We performed saturation mutagenesis of specific residues of Ltnα to determine their functional importance. The results establish that Ltnα is more tolerant to change than previously suggested by alanine scanning mutagenesis. One substitution, LtnαH23S, was identified which improved the specific activity of lacticin 3147 against one pathogenic strain, Staphylococcus aureus NCDO1499. This represents the first occasion upon which the activity of a two peptide lantibiotic has been enhanced through bioengineering. Funding Information Work in the authors' laboratory is supported by the Irish Government under the National Development Plan; by the Irish Research Council for Science Engineering and Technology (IRCSET); by Enterprise Ireland; and by Science Foundation Ireland (SFI), through the Alimentary Pharmabiotic Centre (APC) at University College Cork, Ireland, which is supported by the SFI-funded Centre for Science, Engineering and Technology (SFI-CSET) and provided P.D.C., C.H and R.P.R. with SFI Principal Investigator funding. PMID:23433070

  4. Stability and cytotoxicity of angiotensin-I-converting enzyme inhibitory peptides derived from bovine casein*

    PubMed Central

    Wu, Wei; Yu, Pan-pan; Zhang, Feng-yang; Che, Hong-xia; Jiang, Zhan-mei

    2014-01-01

    This study investigated the effect of heat treatment combined with acid and alkali on the angiotensin-I-converting enzyme (ACE) inhibitory activity of peptides derived from bovine casein. The free amino group content, color, and cytotoxicity of the peptides were measured under different conditions. When heated at 100 °C in the pH range from 9.0 to 12.0, ACE inhibitory activity was reduced and the appearance of the peptides was significantly darkened. After thermal treatment in the presence of acid and alkali, the free amino group content of ACE inhibitory peptides decreased markedly. High temperature and prolonged heating also resulted in the loss of ACE inhibitory activity, the loss of free amino groups, and the darker coloration of bovine casein-derived peptides. However, ACE inhibitory peptides, within a concentration range of from 0.01 to 0.2 mg/ml, showed no cytotoxicity to Caco-2 and ECV-304 cell lines after heat treatment. This indicated that high temperature and alkaline heat treatment impaired the stability of bovine casein-derived ACE inhibitory peptides. PMID:24510707

  5. A peptide derived from phage display library exhibits anti-tumor activity by targeting GRP78 in gastric cancer multidrug resistance cells.

    PubMed

    Kang, Jianqin; Zhao, Guohong; Lin, Tao; Tang, Shanhong; Xu, Guanghui; Hu, Sijun; Bi, Qian; Guo, Changcun; Sun, Li; Han, Shuang; Xu, Qian; Nie, Yongzhan; Wang, Biaoluo; Liang, Shuhui; Ding, Jie; Wu, Kaichun

    2013-10-10

    Multidrug resistance (MDR) remains a significant challenge to the clinical treatment of gastric cancer (GC). In the present study, using a phage display approach combined with MTT assays, we screened a specific peptide GMBP1 (Gastric cancer MDR cell-specific binding peptide), ETAPLSTMLSPY, which could bind to the surface of GC MDR cells specifically and reverse their MDR phenotypes. Immunocytochemical staining showed that the potential receptor of GMBP1 was located at the membrane and cytoplasm of MDR cells. In vitro and in vivo drug sensitivity assays, FACS analysis and Western blotting confirmed that GMBP1 was able to re-sensitize MDR cells to chemical drugs. Western blotting and proteomic approaches were used to screen the receptor of GMBP1, and GRP78, a MDR-related protein, was identified as a receptor of GMBP1. This result was further supported by immunofluoresence microscopy and Western blot. Additionally, Western blotting demonstrated that pre-incubation of GMBP1 in MDR cells greatly diminished MDR1, Bcl-2 and GRP78 expression but increased the expression of Bax, whereas downregulation of GRP78, function as a receptor and directly target for GMBP1, only inhibited MDR1 expression. Our findings suggest that GMBP1 could re-sensitize GC MDR cells to a variety of chemotherapeutic agents and this role might be mediated partly through down-regulating GRP78 expression and then inhibiting MDR1 expression. These findings indicate that peptide GMBP1 likely recognizes a novel GRP78 receptor and mediates cellular activities associated with the MDR phenotype, which provides new insight into research on the management of MDR in gastric cancer cells. PMID:23792224

  6. Review: Production and functionality of active peptides from milk.

    PubMed

    Muro Urista, C; Álvarez Fernández, R; Riera Rodriguez, F; Arana Cuenca, A; Téllez Jurado, A

    2011-08-01

    In recent years, research on the production of active peptides obtained from milk and their potential functionality has grown, to a great extent. Bioactive peptides have been defined as specific protein fragments that have a positive impact on body functions or conditions, and they may ultimately have an influence on health. Individual proteins of casein or milk-derived products such as cheese and yogurt have been used as a protein source to study the isolation and activity of peptides with several applications. Currently, the milk whey waste obtained in the production of cheese also represents a protein source from which active peptides could be isolated with potential industrial applications. The active properties of milk peptides and the results found with regard to their physiological effects have led to the classification of peptides as belonging to the group of ingredients of protein nature, appropriate for use in functional foods or pharmaceutical formulations. In this study, the main peptides obtained from milk protein and the past research studies about its production and biological activities will be explained. Second, an analysis will be made on the methods to determinate the biological activities, the separation of bioactive peptides and its structure identification. All of these form the base required to obtain synthetic peptides. Finally, we explain the experimental animal and human trials done in the past years. Nevertheless, more research is required on the design and implementation of equipment for the industrial production and separation of peptides. In addition, different authors suggest that more emphasis should therefore be given to preclinical studies, proving that results are consistent and that effects are demonstrated repeatedly by several research human groups. PMID:21917640

  7. [Progress on parasiticidal activity of anitimicrobial peptides].

    PubMed

    Liu, Ze-hua; Zhao, Jun-long

    2014-10-01

    Antimicrobial peptides are a kind of gene encoded, ribosome synthesized, small molecular polypeptides that have high efficiency, wide antibacterial spectrum, and low immunogenicity. Many studies have indicated that antimicrobial peptides can inhibit the growth of parasites or even kill them. This paper reviews the research progress on parasiticidal activity of the antimicrobial peptides in recent years, and presents the problems in the research. PMID:25726604

  8. Bioavailability of milk protein-derived bioactive peptides: a glycaemic management perspective.

    PubMed

    Horner, Katy; Drummond, Elaine; Brennan, Lorraine

    2016-06-01

    Milk protein-derived peptides have been reported to have potential benefits for reducing the risk of type 2 diabetes. However, what the active components are and whether intact peptides exert this bioactivity has received little investigation in human subjects. Furthermore, potentially useful bioactive peptides can be limited by low bioavailability. Various peptides have been identified in the gastrointestinal tract and bloodstream after milk-protein ingestion, providing valuable insights into their potential bioavailability. However, these studies are currently limited and the structure and sequence of milk peptides exerting bioactivity for glycaemic management has received little investigation in human subjects. The present article reviews the bioavailability of milk protein-derived peptides in human studies to date, and examines the evidence on milk proteins and glycaemic management, including potential mechanisms of action. Areas in need of advancement are identified. Only by establishing the bioavailability of milk protein-derived peptides, the active components and the mechanistic pathways involved can the benefits of milk proteins for the prevention or management of type 2 diabetes be fully realised in future. PMID:27109024

  9. Assessment of RNA carrier function in peptide amphiphiles derived from the HIV fusion peptide.

    PubMed

    Pratumyot, Yaowalak; Torres, Oscar B; Bong, Dennis

    2016-05-01

    A small library of amphiphilic peptides has been evaluated for duplex RNA carrier function into A549 cells. We studied peptides in which a C-terminal 7-residue cationic domain is attached to a neutral/hydrophobic 23-residue domain that is based on the viral fusion peptide of HIV. We also examined peptides in which the cationic charge was evenly distributed throughout the peptide. Strikingly, subtle sequence variations in the hydrophobic domain that do not alter net hydrophobicity result in wide variation in RNA uptake. Additionally, cyclic cystine variants are much less active as RNA carriers than their open-chain cysteine analogs. With regard to electrostatic effects, we find that lysine is less effective than arginine in facilitating uptake, and that even distribution of cationic residues throughout the peptide sequence results in especially effective RNA carrier function. Overall, minor changes in peptide hydrophobicity, flexibility and charge distribution can significantly alter carrier function. We hypothesize this is due to altered properties of the peptide-RNA assembly rather than peptide secondary structure. PMID:26988874

  10. Identification of glypican-3-derived long peptides activating both CD8+ and CD4+ T cells; prolonged overall survival in cancer patients with Th cell response

    PubMed Central

    Sayem, Mohammad A.; Tomita, Yusuke; Yuno, Akira; Hirayama, Masatoshi; Irie, Atsushi; Tsukamoto, Hirotake; Senju, Satoru; Yuba, Eiji; Yoshikawa, Toshiaki; Kono, Kenji; Nakatsura, Tetsuya; Nishimura, Yasuharu

    2016-01-01

    In a recent phase I clinical trial, a vaccine consisting of glypican-3 (GPC3)-derived CTL epitopes was found to be safe and induced measurable immune and clinical responses in patients with hepatocellular carcinoma (HCC). The aim of this study was to identify GPC3-derived long peptides (GPC3-LPs) carrying promiscuous HLA class II-restricted T helper (Th) cell epitopes. Using a computer algorithm, we predicted GPC3-LPs that can bind to promiscuous HLA class II molecules. Their antigenicity for induction of specific CD4+ T cells in healthy donors or patients with HCC, before and after vaccination with GPC3-SPs, was proven by IFNγ enzyme-linked immunospot assays. Natural processing of these epitopes was confirmed by the immune response of helper T cells to dendritic cells (DCs) loaded with GPC3 proteins. Cross-presentation capacity was assessed in vitro using human DCs and LPs encapsulated in liposomes and in vivo in HLA-A2 transgenic mice (Tgm). All five LPs could induce Th1 cells and were presented by several frequently occurring HLA class II molecules in vitro. Four of them were likely to be naturally processed. One of the LPs encapsulated in liposomes was well cross-presented in vitro; it cross-primed CTLs in HLA-A2 Tgm. LP-specific and HLA class II-restricted CD4+ T-cell responses were observed in 14 of 20 HCC patients vaccinated with GPC3-SPs. Repeated vaccinations enhanced GPC3-LP-specific responses in 8 of 13 patients with HCC. Moreover, the presence of the specific Th cell was correlated with prolonged overall survival (OS). GPC3-LPs can be useful for cancer immunotherapy. PMID:26942076

  11. Peptiderive server: derive peptide inhibitors from protein-protein interactions.

    PubMed

    Sedan, Yuval; Marcu, Orly; Lyskov, Sergey; Schueler-Furman, Ora

    2016-07-01

    The Rosetta Peptiderive protocol identifies, in a given structure of a protein-protein interaction, the linear polypeptide segment suggested to contribute most to binding energy. Interactions that feature a 'hot segment', a linear peptide with significant binding energy compared to that of the complex, may be amenable for inhibition and the peptide sequence and structure derived from the interaction provide a starting point for rational drug design. Here we present a web server for Peptiderive, which is incorporated within the ROSIE web interface for Rosetta protocols. A new feature of the protocol also evaluates whether derived peptides are good candidates for cyclization. Fast computation times and clear visualization allow users to quickly assess the interaction of interest. The Peptiderive server is available for free use at http://rosie.rosettacommons.org/peptiderive. PMID:27141963

  12. Smac-Derived Aza-Peptide As an Aminopeptidase-Resistant XIAP BIR3 Antagonist.

    PubMed

    Elsawy, Mohamed A; Tikhonova, Irina G; Martin, Lorraine; Walker, Brian

    2015-01-01

    The peptidic nature of anti-IAPs N-terminus Smac-derived peptides precludes their utilization as potential therapeutic anticancer agents. Recent advances in the development of novel Smacderived peptidomimetics and non-peptidic molecules with improved anti-IAPs activity and resistance to proteolytic cleavage have been reported and led to a number of candidates that are currently in clinical trials including LCL-161, SM-406/AT-406, GDC-0512/GDC-0917, and birinapant. As an attempt to improve the proteolytic stability of Smac peptides, we developed the Aza-peptide AzaAla- Val-Pro-Phe-Tyr-NH2 (2). Unlike unmodified peptide Ala-Val-Pro-Phe-Tyr-NH2 (1), analogue (2) exhibited resistance towards proteolytic cleavage by two aminopeptidases; LAP and DPP-IV, while retaining its IAP inhibitory activity. This was due to the altered planar geometry of the P1 residue side chain. Our findings showed that using aza-isosteres of bioactive peptide sequences imbue the residue with imperviousness to proteolysis; underscoring a potential approach for developing a new generation of Smac-derived Aza-peptidomimetics. PMID:26282728

  13. Small Peptides Derived from Penetratin as Antibacterial Agents.

    PubMed

    Parravicini, Oscar; Somlai, Csaba; Andujar, Sebastián A; Garro, Adriana D; Lima, Beatriz; Tapia, Alejandro; Feresin, Gabriela; Perczel, Andras; Tóth, Gabor; Cascales, Javier López; Rodríguez, Ana M; Enriz, Ricardo D

    2016-04-01

    The synthesis, in vitro evaluation and conformational study of several small-size peptides acting as antibacterial agents are reported. Among the compounds evaluated, the peptides Arg-Gln-Ile-Lys-Ile-Trp-Arg-Arg-Met-Lys-Trp-Lys-Lys-NH2 , Arg-Gln-Ile-Lys-Ile-Arg-Arg-Met-Lys-Trp-Arg-NH2 , and Arg-Gln-Ile-Trp-Trp-Trp-Trp-Gln-Arg-NH2 exhibited significant antibacterial activity. These were found to be very active antibacterial compounds, considering their small molecular size. In order to better understand the antibacterial activity obtained for these peptides, an exhaustive conformational analysis was performed, using both theoretical calculations and experimental measurements. Molecular dynamics simulations using two different media (water and trifluoroethanol/water) were employed. The results of these theoretical calculations were corroborated by experimental circular dichroism measurements. A brief discussion on the possible mechanism of action of these peptides at molecular level is also presented. Some of the peptides reported here constitute very interesting structures to be used as starting compounds for the design of new small-size peptides possessing antibacterial activity. PMID:26972341

  14. Anti-candidal activity of a novel peptide derived from human chromogranin A and its mechanism of action against Candida krusei

    PubMed Central

    LI, RUI-FANG; YAN, XIAO-HUI; LU, YAN-BO; LU, YA-LI; ZHANG, HUI-RU; CHEN, SHI-HUA; LIU, SHUAI; LU, ZHI-FANG

    2015-01-01

    Candida species (Candida spp.) are important fungal pathogens, which cause numerous clinical diseases associated with significant mortality and morbidity in healthcare settings. In our previous study, we identified a recombinant peptide, chromogranin A (CGA)-N46, corresponding to the N-terminal Pro31-Gln76 sequence of human CGA, that exhibited antifungal activity against Candida albicans. The present study investigated the antifungal activity of CGA-N46, and its underlying mechanism, against numerous Candida spp. CGA-N46 inhibited the growth of all of the tested Candida spp., of which Candida krusei exhibited the greatest sensitivity. CGA-N46 was able to disrupt the stability of the phospholipid monolayer without damaging the integrity and permeability of the outer membrane of C. krusei cells, and induced cytoplasm vacuolization and mitochondrial damage. In addition, treatment of C. krusei with CGA-N46 was associated with decreased levels of intracellular reactive oxygen species, a reduction in the mitochondrial membrane potential, and DNA synthesis inhibition. The results of the present study suggested that CGA-N46 was able to pass through the cell membrane of Candida spp. by temporarily destabilizing the phospholipid membrane, which in turn led to mitochondrial dysfunction and inhibition of DNA synthesis. Therefore, CGA-N46 may be considered a novel antifungal compound for the treatment of patients with C. krusei infections. PMID:26640548

  15. Milk-derived proteins and peptides in clinical trials.

    PubMed

    Artym, Jolanta; Zimecki, Michał

    2013-01-01

    Clinical trials are reviewed, involving proteins and peptides derived from milk (predominantly bovine), with the exception of lactoferrin, which will be the subject of another article. The most explored milk fraction is α-lactalbumin (LA), which is often applied with glycomacropeptide (GMP) - a casein degradation product. These milk constituents are used in health-promoting infant and adult formulae as well as in a modified form (HAMLET) to treat cancer. Lactoperoxidase (LCP) is used as an additive to mouth hygiene products and as a salivary substitute. Casein derivatives are applied, in addition, in the dry mouth syndrome. On the other hand, casein hydrolysates, containing active tripeptides, found application in hypertension and in type 2 diabetes. Lysozyme is routinely used for food conservation and in pharmaceutical products. It was successfully used in premature infants with concomitant diseases to improve health parameters. When used as prophylaxis in patients with scheduled surgery, it significantly reduced the incidence of hepatitis resulting from blood transfusion. Lysozyme was also used in infected children as an antimicrobial agent showing synergistic effects in combination with different antibiotics. Proline-rich polypeptide (PRP) was introduced to therapy of Alzheimer's disease patients. The therapeutic value of PRP was proved in several clinical trials and supported by studies on its mechanism of action. Concentrated immunoglobulin preparations from colostrum and milk of hyperimmunized cows showed efficacy in prevention of infections by bacteria, viruses and protozoa. A nutrition formula with milk-derived TGF-β2 (Modulen IBD®) found application in treatment of pediatric Crohn's disease. In conclusion, the preparations containing milk-derived products are safe and effective measures in prevention and treatment of infections as well as autoimmune and neoplastic diseases. PMID:24018446

  16. SIKVAV, a Laminin α1-Derived Peptide, Interacts with Integrins and Increases Protease Activity of a Human Salivary Gland Adenoid Cystic Carcinoma Cell Line through the ERK 1/2 Signaling Pathway

    PubMed Central

    Freitas, Vanessa M.; Vilas-Boas, Vanessa F.; Pimenta, Daniel C.; Loureiro, Vania; Juliano, Maria A.; Carvalho, Márcia R.; Pinheiro, João J.V.; Camargo, Antonio C.M.; Moriscot, Anselmo S.; Hoffman, Matthew P.; Jaeger, Ruy G.

    2007-01-01

    Adenoid cystic carcinoma is a frequently occurring malignant salivary gland neoplasm. We studied the induction of protease activity by the laminin-derived peptide, SIKVAV, in cells (CAC2) derived from this neoplasm. Laminin α1 and matrix metalloproteinases (MMPs) 2 and 9 were immunolocalized in adenoid cystic carcinoma cells in vivo and in vitro. CAC2 cells cultured on SIKVAV showed a dose-dependent increase of MMP9 as detected by zymography and colocalization of α3 and α6 integrins. Small interfering RNA (siRNA) knockdown of integrin expression in CAC2 cells resulted in decreased adhesion to the peptide. SIKVAV affinity chromatography and immunoblot analysis showed that α3, α6, and β1 integrins were eluted from the SIKVAV column, which was confirmed by mass spectrometry and a solid-phase binding assay. Small interfering RNA experiments also showed that these integrins, through extracellular signal-regulated kinase (ERK) 1/2 signaling, regulate MMP secretion induced by SIKVAV in CAC2 cells. We propose that SIKVAV increases protease activity of a human salivary gland adenoid cystic carcinoma cell line through α3β1 and α6β1 integrins and the ERK 1/2 signaling pathway. PMID:17591960

  17. DMP1-derived peptides promote remineralization of human dentin.

    PubMed

    Padovano, J D; Ravindran, S; Snee, P T; Ramachandran, A; Bedran-Russo, A K; George, A

    2015-04-01

    Remineralization of dentin during dental caries is of considerable clinical interest. Dentin matrix protein 1 (DMP1) is a non-collagenous calcium-binding protein that plays a critical role in biomineralization. In the present study, we tested if peptides derived from DMP1 can be used for dentin remineralization. Peptide pA (pA, MW = 1.726 kDa) and peptide pB (pB, MW = 2.185), containing common collagen-binding domains and unique calcium-binding domains, were synthesized by solid-phase chemistry. An extreme caries lesion scenario was created by collagenase digestion, and the biomineral-nucleating potential of these peptides was ascertained when coated on collagenase-treated dentin matrix and control, native human dentin matrix under physiological levels of calcium and phosphate. Scanning electron microscopy analysis suggests that peptide pB was an effective nucleator when compared with pA. However, a 1:4 ratio of pA to pB was determined to be ideal for dentin remineralization, based on hydroxyapatite (HA) morphology and calcium/phosphorus ratios. Interestingly, HA was nucleated on collagenase-challenged dentin with as little as 20 min of 1:4 peptide incubation. Electron diffraction confirmed the presence of large HA crystals that produced a diffraction pattern indicative of a rod-like crystal structure. These findings suggest that DMP1-derived peptides may be useful to modulate mineral deposition and subsequent formation of HA when exposed to physiological concentrations of calcium and phosphate. PMID:25694469

  18. Novel dual agonist peptide analogues derived from dogfish glucagon show promising in vitro insulin releasing actions and antihyperglycaemic activity in mice.

    PubMed

    O'Harte, F P M; Ng, M T; Lynch, A M; Conlon, J M; Flatt, P R

    2016-08-15

    The antidiabetic potential of thirteen novel dogfish glucagon derived analogues were assessed in vitro and in acute in vivo studies. Stable peptide analogues enhanced insulin secretion from BRIN-BD11 β-cells (p < 0.001) and reduced acute glycaemic responses following intraperitoneal glucose (25 nmol/kg) in healthy NIH Swiss mice (p < 0.05-p<0.001). The in vitro insulinotropic actions of [S2a]dogfish glucagon, [S2a]dogfish glucagon-exendin-4(31-39) and [S2a]dogfish glucagon-Lys(30)-γ-glutamyl-PAL, were blocked (p < 0.05-p<0.001) by the specific GLP-1 and glucagon receptor antagonists, exendin-4(9-39) and (desHis(1)Pro(4)Glu(9))glucagon amide but not by (Pro(3))GIP, indicating lack of GIP receptor involvement. These analogues dose-dependently stimulated cAMP production in GLP-1 and glucagon (p < 0.05-p<0.001) but not GIP-receptor transfected cells. They improved acute glycaemic and insulinotropic responses in high-fat fed diabetic mice and in wild-type C57BL/6J and GIPR-KO mice (p < 0.05-p<0.001), but not GLP-1R-KO mice, confirming action on GLP-1 but not GIP receptors. Overall, dogfish glucagon analogues have potential for diabetes therapy, exerting beneficial metabolic effects via GLP-1 and glucagon receptors. PMID:27179756

  19. Photoperiod Regulates vgf-Derived Peptide Processing in Siberian Hamsters

    PubMed Central

    Noli, Barbara; Brancia, Carla; Pilleri, Roberta; D’Amato, Filomena; Messana, Irene; Manconi, Barbara; Ebling, Francis J. P.; Ferri, Gian-Luca; Cocco, Cristina

    2015-01-01

    VGF mRNA is induced in specific hypothalamic areas of the Siberian hamster upon exposure to short photoperiods, which is associated with a seasonal decrease in appetite and weight loss. Processing of VGF generates multiple bioactive peptides, so the objective of this study was to determine the profile of the VGF-derived peptides in the brain, pituitary and plasma from Siberian hamsters, and to establish whether differential processing might occur in the short day lean state versus long day fat. Antisera against short sequences at the C- or N- termini of proVGF, as well as against NERP-1, TPGH and TLQP peptides, were used for analyses of tissues, and both immunohistochemistry and enzyme linked immunosorbent assay (ELISA) coupled with high-performance liquid (HPLC) or gel chromatography were carried out. VGF peptide immunoreactivity was found within cortex cholinergic perikarya, in multiple hypothalamic nuclei, including those containing vasopressin, and in pituitary gonadotrophs. ELISA revealed that exposure to short day photoperiod led to a down-regulation of VGF immunoreactivity in the cortex, and a less pronounced decrease in the hypothalamus and pituitary, while the plasma VGF levels were not affected by the photoperiod. HPLC and gel chromatography both confirmed the presence of multiple VGF-derived peptides in these tissues, while gel chromatography showed the presence of the VGF precursor in all tissues tested except for the cortex. These observations are consistent with the view that VGF-derived peptides have pleiotropic actions related to changing photoperiod, possibly by regulating cholinergic systems in the cortex, vasopressin hypothalamic pathways, and the reproductive axis. PMID:26555143

  20. LL-37-Derived Peptides Eradicate Multidrug-Resistant Staphylococcus aureus from Thermally Wounded Human Skin Equivalents

    PubMed Central

    de Breij, Anna; Chan, Heelam; van Dissel, Jaap T.; Drijfhout, Jan W.; Hiemstra, Pieter S.; El Ghalbzouri, Abdoelwaheb; Nibbering, Peter H.

    2014-01-01

    Burn wound infections are often difficult to treat due to the presence of multidrug-resistant bacterial strains and biofilms. Currently, mupirocin is used to eradicate methicillin-resistant Staphylococcus aureus (MRSA) from colonized persons; however, mupirocin resistance is also emerging. Since we consider antimicrobial peptides to be promising candidates for the development of novel anti-infective agents, we studied the antibacterial activities of a set of synthetic peptides against different strains of S. aureus, including mupirocin-resistant MRSA strains. The peptides were derived from P60.4Ac, a peptide based on the human cathelicidin LL-37. The results showed that peptide 10 (P10) was the only peptide more efficient than P60.4Ac, which is better than LL-37, in killing MRSA strain LUH14616. All three peptides displayed good antibiofilm activities. However, both P10 and P60.4Ac were more efficient than LL-37 in eliminating biofilm-associated bacteria. No toxic effects of these three peptides on human epidermal models were detected, as observed morphologically and by staining for mitochondrial activity. In addition, P60.4Ac and P10, but not LL-37, eradicated MRSA LUH14616 and the mupirocin-resistant MRSA strain LUH15051 from thermally wounded human skin equivalents (HSE). Interestingly, P60.4Ac and P10, but not mupirocin, eradicated LUH15051 from the HSEs. None of the peptides affected the excretion of interleukin 8 (IL-8) by thermally wounded HSEs upon MRSA exposure. In conclusion, the synthetic peptides P60.4Ac and P10 appear to be attractive candidates for the development of novel local therapies to treat patients with burn wounds infected with multidrug-resistant bacteria. PMID:24841266

  1. LL-37-derived peptides eradicate multidrug-resistant Staphylococcus aureus from thermally wounded human skin equivalents.

    PubMed

    Haisma, Elisabeth M; de Breij, Anna; Chan, Heelam; van Dissel, Jaap T; Drijfhout, Jan W; Hiemstra, Pieter S; El Ghalbzouri, Abdoelwaheb; Nibbering, Peter H

    2014-08-01

    Burn wound infections are often difficult to treat due to the presence of multidrug-resistant bacterial strains and biofilms. Currently, mupirocin is used to eradicate methicillin-resistant Staphylococcus aureus (MRSA) from colonized persons; however, mupirocin resistance is also emerging. Since we consider antimicrobial peptides to be promising candidates for the development of novel anti-infective agents, we studied the antibacterial activities of a set of synthetic peptides against different strains of S. aureus, including mupirocin-resistant MRSA strains. The peptides were derived from P60.4Ac, a peptide based on the human cathelicidin LL-37. The results showed that peptide 10 (P10) was the only peptide more efficient than P60.4Ac, which is better than LL-37, in killing MRSA strain LUH14616. All three peptides displayed good antibiofilm activities. However, both P10 and P60.4Ac were more efficient than LL-37 in eliminating biofilm-associated bacteria. No toxic effects of these three peptides on human epidermal models were detected, as observed morphologically and by staining for mitochondrial activity. In addition, P60.4Ac and P10, but not LL-37, eradicated MRSA LUH14616 and the mupirocin-resistant MRSA strain LUH15051 from thermally wounded human skin equivalents (HSE). Interestingly, P60.4Ac and P10, but not mupirocin, eradicated LUH15051 from the HSEs. None of the peptides affected the excretion of interleukin 8 (IL-8) by thermally wounded HSEs upon MRSA exposure. In conclusion, the synthetic peptides P60.4Ac and P10 appear to be attractive candidates for the development of novel local therapies to treat patients with burn wounds infected with multidrug-resistant bacteria. PMID:24841266

  2. Food Derived Bioactive Peptides and Intestinal Barrier Function

    PubMed Central

    Martínez-Augustin, Olga; Rivero-Gutiérrez, Belén; Mascaraque, Cristina; Sánchez de Medina, Fermín

    2014-01-01

    A wide range of food-derived bioactive peptides have been shown to exert health-promoting actions and are therefore considered functional foods or nutraceuticals. Some of these actions are related to the maintenance, reinforcement or repairment of the intestinal barrier function (IBF) whose role is to selectively allow the absorption of water, nutrients and ions while preventing the influx of microorganisms from the intestinal lumen. Alterations in the IBF have been related to many disorders, such as inflammatory bowel disease or metabolic syndrome. Components of IBF are the intestinal epithelium, the mucus layer, secretory immunoglobulin A and cells of the innate and adaptive immune systems. Here we review the effects of food derived bioactive peptides on these IBF components. In vitro and in vivo effects, both in healthy and disease states, have been reviewed. Although limited, the available information indicates a potential for food-derived peptides to modify IBF and to contribute to disease treatment, but further research is needed to better isolate responsible peptides, and to help define their mode of action. PMID:25501338

  3. Influence of metallocene substitution on the antibacterial activity of multivalent peptide conjugates.

    PubMed

    Hoffknecht, Barbara C; Prochnow, Pascal; Bandow, Julia E; Metzler-Nolte, Nils

    2016-07-01

    Peptide dendrimers and derivatisation of peptides with metallocenes showed promising results in the search for new antibacterial agents. The two concepts are combined in this work leading to multivalent, metallocene-containing peptide derivates. These new peptides were synthesised utilising microwave assisted, copper(I) catalyzed alkyne-azide cycloaddition (CuAAC, "click" chemistry). Twelve new peptide conjugates, containing either a ferrocenoyl group or a ruthenocenoyl group on so-called ultrashort (i.e. < 5 amino acids) peptides, and ranging from monovalent to trivalent conjugates, were synthesised and their antibacterial activity was investigated by minimal inhibitory concentration (MIC) assays on five different bacterial strains. The antibacterial activity was compared to the same peptide conjugates without metallocenes. The resulting MIC values showed a significant enhancement of the antibacterial activity of these peptide conjugates against Gram-positive bacteria by the metallocenoyl groups. Additionally, the compounds with two metallocenoyl groups presented the best antibacterial activities overall. PMID:26988572

  4. Cyclolinopeptides, cyclic peptides from flaxseed with osteoclast differentiation inhibitory activity.

    PubMed

    Kaneda, Toshio; Yoshida, Haruka; Nakajima, Yuki; Toishi, Minako; Nugroho, Alfarius Eko; Morita, Hiroshi

    2016-04-01

    Flaxseed (Linum usitatissimum seed) is widely used in food and natural health products. In our search for osteoclast differentiation inhibitors, some cyclic peptides isolated from flaxseed, known as the cyclolinopeptides, were discovered to have osteoclast differentiation inhibition activity. The osteoclast differentiation inhibition activity of cyclolinopeptides A-I (1-9) and their related derivatives (10-14) are described herein. Cyclolinopeptides F, H and I (6, 8 and 9), in particular, showed potent osteoclast differentiation inhibition activity. PMID:26923696

  5. Human lactoferricin derived di-peptides deploying loop structures induce apoptosis specifically in cancer cells through targeting membranous phosphatidylserine.

    PubMed

    Riedl, Sabrina; Leber, Regina; Rinner, Beate; Schaider, Helmut; Lohner, Karl; Zweytick, Dagmar

    2015-11-01

    Host defense-derived peptides have emerged as a novel strategy for the development of alternative anticancer therapies. In this study we report on characteristic features of human lactoferricin (hLFcin) derivatives which facilitate specific killing of cancer cells of melanoma, glioblastoma and rhabdomyosarcoma compared with non-specific derivatives and the synthetic peptide RW-AH. Changes in amino acid sequence of hLFcin providing 9-11 amino acids stretched derivatives LF11-316, -318 and -322 only yielded low antitumor activity. However, the addition of the repeat (di-peptide) and the retro-repeat (di-retro-peptide) sequences highly improved cancer cell toxicity up to 100% at 20 μM peptide concentration. Compared to the complete parent sequence hLFcin the derivatives showed toxicity on the melanoma cell line A375 increased by 10-fold and on the glioblastoma cell line U-87mg by 2-3-fold. Reduced killing velocity, apoptotic blebbing, activation of caspase 3/7 and formation of apoptotic DNA fragments proved that the active and cancer selective peptides, e.g. R-DIM-P-LF11-322, trigger apoptosis, whereas highly active, though non-selective peptides, such as DIM-LF11-318 and RW-AH seem to kill rapidly via necrosis inducing membrane lyses. Structural studies revealed specific toxicity on cancer cells by peptide derivatives with loop structures, whereas non-specific peptides comprised α-helical structures without loop. Model studies with the cancer membrane mimic phosphatidylserine (PS) gave strong evidence that PS only exposed by cancer cells is an important target for specific hLFcin derivatives. Other negatively charged membrane exposed molecules as sialic acid, heparan and chondroitin sulfate were shown to have minor impact on peptide activity. PMID:26239537

  6. Milk derived bioactive peptides and their impact on human health - A review.

    PubMed

    Mohanty, D P; Mohapatra, S; Misra, S; Sahu, P S

    2016-09-01

    Milk-derived bioactive peptides have been identified as potential ingredients of health-promoting functional foods. These bioactive peptides are targeted at diet-related chronic diseases especially the non-communicable diseases viz., obesity, cardiovascular diseases and diabetes. Peptides derived from the milk of cow, goat, sheep, buffalo and camel exert multifunctional properties, including anti-microbial, immune modulatory, anti-oxidant, inhibitory effect on enzymes, anti-thrombotic, and antagonistic activities against various toxic agents. Majority of those regulate immunological, gastrointestinal, hormonal and neurological responses, thereby playing a vital role in the prevention of cancer, osteoporosis, hypertension and other disorders as discussed in this review. For the commercial production of such novel bioactive peptides large scale technologies based on membrane separation and ion exchange chromatography methods have been developed. Separation and identification of those peptides and their pharmacodynamic parameters are necessary to transfer their potent functional properties into food applications. The present review summarizes the preliminary classes of bioactive milk-derived peptides along with their physiological functions, general characteristics and potential applications in health-care. PMID:27579006

  7. Antidepressant-like effect of food-derived pyroglutamyl peptides in mice.

    PubMed

    Yamamoto, Yukako; Mizushige, Takafumi; Mori, Yukiha; Shimmura, Yuki; Fukutomi, Ruuta; Kanamoto, Ryuhei; Ohinata, Kousaku

    2015-06-01

    The N-terminal glutamine residue, exposed by enzymatic cleavage of precursor proteins, is known to be modified to a pyroglutamyl residue with a cyclic structure in not only endogenous but also food-derived peptides. We investigated the effects of wheat-derived pyroglutamyl peptides on emotional behaviors. Pyroglutamyl leucine (pyroGlu-Leu, pEL) and pyroglutamyl glutaminyl leucine (pyroGlu-Gln-Leu, pEQL) exhibited antidepressant-like activity in the tail suspension and forced swim tests in mice. pEQL exhibited more potent antidepressant-like activity than pEL after i.p. and i.c.v. administration. pEQL exhibited antidepressant-like activity at a lower dose than Gln-Gln-Leu, suggesting that pyroglutamyl peptide had more potent activity. To examine whether pyroglutamyl peptides increased hippocampus neurogenesis, associated with the effects of antidepressants, we measured 5-bromo-2'-deoxyuridine (BrdU) incorporation. pEL and pEQL increased BrdU-positive cells in the dentate gyrus of the hippocampus. Intriguingly, pEL did not increase hippocampal mRNA and protein expression of brain-derived neurotrophic factor (BDNF), which is a factor associated with both neuropoietic and antidepressive effects. Thus, pyroglutamyl peptides may enhance hippocampal neurogenesis via a pathway independent of BDNF. We also confirmed that pEL and pEQL were produced in the subtilisin digest of major wheat proteins, glutenin and gliadin, after heat treatment. pEL and pEQL are the first peptides derived from wheat proteins to be shown to exhibit an antidepressant-like activity. PMID:25957094

  8. Effect of spacer length and type on the biological activity of peptide-polysaccharide matrices.

    PubMed

    Kumai, Jun; Hozumi, Kentaro; Yamada, Yuji; Katagiri, Fumihiko; Kikkawa, Yamato; Nomizu, Motoyoshi

    2016-11-01

    Peptide-polysaccharide matrices can mimic extracellular matrix structure and function and are useful for tissue and cell engineering. The spacer between the peptide and the polysaccharide is important for both peptide conformation and the interaction between the peptide and receptors. Here, the effect of a spacer on the biological activity of peptide-polysaccharide matrices using various lengths of spacers consisting of glycine, β-alanine, and ε-aminocaproic acid has been examined. Active laminin-derived peptides, including a syndecan-binding peptide (AG73: RKRLQVQLSIRT), an integrin αvβ3-binding peptide (A99a: ALRGDN), and an integrin α6β1-binding peptide (A2G10: SYWYRIEASRTG), were used as the peptide ligands and chitosan was used as a polysaccharide matrix. The spacers did not influence the biological activity of the AG73-chitosan matrix. In contrast, the integrin-binding peptide-chitosan matrices showed spacer-dependent activity. Hydrophobic spacers enhanced the cell attachment activity of the A99a-chitosan matrix. A four-glycine spacer showed the strongest effect for the biological activity of the A2G10-chitosan matrix. These results suggested that spacer-optimization for each peptide is important for designing effective peptide-polysaccharide matrices. © 2015 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 106: 512-520, 2016. PMID:26588050

  9. Peptides derived from CXCL8 based on in silico analysis inhibit CXCL8 interactions with its receptor CXCR1

    NASA Astrophysics Data System (ADS)

    Jiang, Shinn-Jong; Liou, Je-Wen; Chang, Chun-Chun; Chung, Yi; Lin, Lee-Fong; Hsu, Hao-Jen

    2015-12-01

    Chemokine CXCL8 is crucial for regulation of inflammatory and immune responses via activating its cognate receptor CXCR1. In this study, molecular docking and binding free energy calculations were combined to predict the initial binding event of CXCL8 to CXCR1 for peptide drug design. The simulations reveal that in the initial binding, the N-loop of CXCL8 interacts with the N-terminus of CXCR1, which is dominated by electrostatic interactions. The derived peptides from the binding region of CXCL8 are synthesized for further confirmation. Surface plasmon resonance analyses indicate that the CXCL8 derived peptide with 14 residues is able to bind to the receptor CXCR1 derived peptide with equilibrium KD of 252 μM while the peptide encompassing a CXCL8 K15A mutation hardly binds to CXCR1 derived peptide (KD = 1553 μM). The cell experiments show that the designed peptide inhibits CXCL8-induced and LPS-activated monocytes adhesion and transmigration. However, when the peptides were mutated on two lysine residues (K15 and K20), the inhibition effects were greatly reduced indicating these two amino acids are key residues for the initial binding of CXCL8 to CXCR1. This study demonstrates that in silico prediction based functional peptide design can be effective for developing anti-inflammation drugs.

  10. Peptides derived from CXCL8 based on in silico analysis inhibit CXCL8 interactions with its receptor CXCR1.

    PubMed

    Jiang, Shinn-Jong; Liou, Je-Wen; Chang, Chun-Chun; Chung, Yi; Lin, Lee-Fong; Hsu, Hao-Jen

    2015-01-01

    Chemokine CXCL8 is crucial for regulation of inflammatory and immune responses via activating its cognate receptor CXCR1. In this study, molecular docking and binding free energy calculations were combined to predict the initial binding event of CXCL8 to CXCR1 for peptide drug design. The simulations reveal that in the initial binding, the N-loop of CXCL8 interacts with the N-terminus of CXCR1, which is dominated by electrostatic interactions. The derived peptides from the binding region of CXCL8 are synthesized for further confirmation. Surface plasmon resonance analyses indicate that the CXCL8 derived peptide with 14 residues is able to bind to the receptor CXCR1 derived peptide with equilibrium KD of 252 μM while the peptide encompassing a CXCL8 K15A mutation hardly binds to CXCR1 derived peptide (KD = 1553 μM). The cell experiments show that the designed peptide inhibits CXCL8-induced and LPS-activated monocytes adhesion and transmigration. However, when the peptides were mutated on two lysine residues (K15 and K20), the inhibition effects were greatly reduced indicating these two amino acids are key residues for the initial binding of CXCL8 to CXCR1. This study demonstrates that in silico prediction based functional peptide design can be effective for developing anti-inflammation drugs. PMID:26689258

  11. Peptides derived from CXCL8 based on in silico analysis inhibit CXCL8 interactions with its receptor CXCR1

    PubMed Central

    Jiang, Shinn-Jong; Liou, Je-Wen; Chang, Chun-Chun; Chung, Yi; Lin, Lee-Fong; Hsu, Hao-Jen

    2015-01-01

    Chemokine CXCL8 is crucial for regulation of inflammatory and immune responses via activating its cognate receptor CXCR1. In this study, molecular docking and binding free energy calculations were combined to predict the initial binding event of CXCL8 to CXCR1 for peptide drug design. The simulations reveal that in the initial binding, the N-loop of CXCL8 interacts with the N-terminus of CXCR1, which is dominated by electrostatic interactions. The derived peptides from the binding region of CXCL8 are synthesized for further confirmation. Surface plasmon resonance analyses indicate that the CXCL8 derived peptide with 14 residues is able to bind to the receptor CXCR1 derived peptide with equilibrium KD of 252 μM while the peptide encompassing a CXCL8 K15A mutation hardly binds to CXCR1 derived peptide (KD = 1553 μM). The cell experiments show that the designed peptide inhibits CXCL8-induced and LPS-activated monocytes adhesion and transmigration. However, when the peptides were mutated on two lysine residues (K15 and K20), the inhibition effects were greatly reduced indicating these two amino acids are key residues for the initial binding of CXCL8 to CXCR1. This study demonstrates that in silico prediction based functional peptide design can be effective for developing anti-inflammation drugs. PMID:26689258

  12. Peptide-decorated chitosan derivatives enhance fibroblast adhesion and proliferation in wound healing.

    PubMed

    Patrulea, V; Hirt-Burri, N; Jeannerat, A; Applegate, L A; Ostafe, V; Jordan, O; Borchard, G

    2016-05-20

    RGD peptide sequences are known to regulate cellular activities by interacting with α5β1, αvβ5 and αvβ3 integrin, which contributes to the wound healing process. In this study, RGDC peptide was immobilized onto chitosan derivative 1,6-diaminohexane-O-carboxymethyl-N,N,N-trimethyl chitosan (DAH-CMTMC) to display RGDC-promoting adhesion for enhanced wound healing. The efficiency of N-methylation, O-carboxymethylation and spacer grafting was quantitatively and qualitatively analyzed by (1)H NMR and FTIR, yielding 0.38 degree of substitution for N-methylation and >0.85 for O-carboxymethylation. The glass transition temperatures for chitosan derivatives were also studied. Peptide immobilization was achieved through sulfhydryl groups using sulfosuccinimidyl (4-iodoacetyl)amino-benzoate (sulfo-SIAB method). RGDC immobilized peptide onto DAH-CMTMC was found to be about 15.3 μg/mg of chitosan derivative by amino acid analysis (AAA). The significant increase of human dermal fibroblast (HDF) viability in vitro over 7 days suggests that RGDC-functionalized chitosan may lead to enhanced wound healing (viability >140%). Moreover, bio-adhesion and proliferation assays confirmed that coatings of RGDC-functionalized chitosan derivatives exhibit in vitro wound healing properties by enhancing fibroblast proliferation and adhesion. These results showed that RGDC peptide-functionalized chitosan provides an optimal environment for fibroblast adhesion and proliferation. PMID:26917381

  13. Chemokine-Derived Peptides: Novel Antimicrobial and Antineoplasic Agents.

    PubMed

    Valdivia-Silva, Julio; Medina-Tamayo, Jaciel; Garcia-Zepeda, Eduardo A

    2015-01-01

    Chemokines are a burgeoning family of chemotactic cytokines displaying a broad array of functions such as regulation of homeostatic leukocyte traffic and development, as well as activating the innate immune system. Their role in controlling early and late inflammatory stages is now well recognized. An improper balance either in chemokine synthesis or chemokine receptor expression contributes to various pathological disorders making chemokines and their receptors a useful therapeutic target. Research in this area is progressing rapidly, and development of novel agents based on chemokine/ chemokine receptors antagonist functions are emerging as attractive alternative drugs. Some of these novel agents include generation of chemokine-derived peptides (CDP) with potential agonist and antagonist effects on inflammation, cancer and against bacterial infections. CDP have been generated mainly from N- and C-terminus chemokine sequences with subsequent modifications such as truncations or elongations. In this review, we present a glimpse of the different pharmacological actions reported for CDP and our current understanding regarding the potential use of CDP alone or as part of the novel therapies proposed in the treatment of microbial infections and cancer. PMID:26062132

  14. Chemokine-Derived Peptides: Novel Antimicrobial and Antineoplasic Agents

    PubMed Central

    Valdivia-Silva, Julio; Medina-Tamayo, Jaciel; Garcia-Zepeda, Eduardo A.

    2015-01-01

    Chemokines are a burgeoning family of chemotactic cytokines displaying a broad array of functions such as regulation of homeostatic leukocyte traffic and development, as well as activating the innate immune system. Their role in controlling early and late inflammatory stages is now well recognized. An improper balance either in chemokine synthesis or chemokine receptor expression contributes to various pathological disorders making chemokines and their receptors a useful therapeutic target. Research in this area is progressing rapidly, and development of novel agents based on chemokine/chemokine receptors antagonist functions are emerging as attractive alternative drugs. Some of these novel agents include generation of chemokine-derived peptides (CDP) with potential agonist and antagonist effects on inflammation, cancer and against bacterial infections. CDP have been generated mainly from N- and C-terminus chemokine sequences with subsequent modifications such as truncations or elongations. In this review, we present a glimpse of the different pharmacological actions reported for CDP and our current understanding regarding the potential use of CDP alone or as part of the novel therapies proposed in the treatment of microbial infections and cancer. PMID:26062132

  15. Synthetic RGD peptides derived from the adhesive domains of snake-venom proteins: evaluation as inhibitors of platelet aggregation.

    PubMed Central

    Lu, X; Deadman, J J; Williams, J A; Kakkar, V V; Rahman, S

    1993-01-01

    Synthetic peptides based on the RGD domains of the potent platelet aggregation inhibitors kistrin and dendroaspin were generated. The 13-amino-acid peptides were synthesized as dicysteinyl linear and disulphide cyclic forms. In platelet-aggregation studies, the cyclic peptides showed 3-fold better inhibition than their linear equivalents and approx. 100-fold greater potency than synthetic linear RGDS peptides derived from fibronectin. An amino acid substitution, Asp10-->Ala, in the kistrin-based peptide gave a 4-fold decrease in potency in the linear peptide, but produced a 2-fold elevation in the inhibitory activity of the cyclic form, generating a peptide of potency comparable with that of the parent protein. PMID:8250845

  16. Antimicrobial properties of two novel peptides derived from Theobroma cacao osmotin.

    PubMed

    Falcao, Loeni L; Silva-Werneck, Joseilde O; Ramos, Alessandra de R; Martins, Natalia F; Bresso, Emmanuel; Rodrigues, Magali A; Bemquerer, Marcelo P; Marcellino, Lucilia H

    2016-05-01

    The osmotin proteins of several plants display antifungal activity, which can play an important role in plant defense against diseases. Thus, this protein can be useful as a source for biotechnological strategies aiming to combat fungal diseases. In this work, we analyzed the antifungal activity of a cacao osmotin-like protein (TcOsm1) and of two osmotin-derived synthetic peptides with antimicrobial features, differing by five amino acids residues at the N-terminus. Antimicrobial tests showed that TcOsm1 expressed in Escherichia coli inhibits the growth of Moniliophthora perniciosa mycelium and Pichia pastoris X-33 in vitro. The TcOsm1-derived peptides, named Osm-pepA (H-RRLDRGGVWNLNVNPGTTGARVWARTK-NH2), located at R23-K49, and Osm-pepB (H-GGVWNLNVNPGTTGARVWARTK-NH2), located at G28-K49, inhibited growth of yeasts (Saccharomyces cerevisiae S288C and Pichia pastoris X-33) and spore germination of the phytopathogenic fungi Fusarium f. sp. glycines and Colletotrichum gossypi. Osm-pepA was more efficient than Osm-pepB for S. cerevisiae (MIC=40μM and MIC=127μM, respectively), as well as for P. pastoris (MIC=20μM and MIC=127μM, respectively). Furthermore, the peptides presented a biphasic performance, promoting S. cerevisiae growth in doses around 5μM and inhibiting it at higher doses. The structural model for these peptides showed that the five amino acids residues, RRLDR at Osm-pepA N-terminus, significantly affect the tertiary structure, indicating that this structure is important for the peptide antimicrobial potency. This is the first report of development of antimicrobial peptides from T. cacao. Taken together, the results indicate that the cacao osmotin and its derived peptides, herein studied, are good candidates for developing biotechnological tools aiming to control phytopathogenic fungi. PMID:26996966

  17. Identification of an HLA-A2-Restricted Epitope Peptide Derived from Hypoxia-Inducible Protein 2 (HIG2)

    PubMed Central

    Yoshimura, Sachiko; Tsunoda, Takuya; Osawa, Ryuji; Harada, Makiko; Watanabe, Tomohisa; Hikichi, Tetsuro; Katsuda, Masahiro; Miyazawa, Motoki; Tani, Masaji; Iwahashi, Makoto; Takeda, Kazuyoshi; Katagiri, Toyomasa; Nakamura, Yusuke; Yamaue, Hiroki

    2014-01-01

    We herein report the identification of an HLA-A2 supertype-restricted epitope peptide derived from hypoxia-inducible protein 2 (HIG2), which is known to be a diagnostic marker and a potential therapeutic target for renal cell carcinoma. Among several candidate peptides predicted by the HLA-binding prediction algorithm, HIG2-9-4 peptide (VLNLYLLGV) was able to effectively induce peptide-specific cytotoxic T lymphocytes (CTLs). The established HIG2-9-4 peptide-specific CTL clone produced interferon-γ (IFN-γ) in response to HIG2-9-4 peptide-pulsed HLA-A*02:01-positive cells, as well as to cells in which HLA-A*02:01 and HIG2 were exogenously introduced. Moreover, the HIG2-9-4 peptide-specific CTL clone exerted cytotoxic activity against HIG2-expressing HLA-A*02:01-positive renal cancer cells, thus suggesting that the HIG2-9-4 peptide is naturally presented on HLA-A*02:01 of HIG-2-expressing cancer cells and is recognized by CTLs. Furthermore, we found that the HIG2-9-4 peptide could also induce CTLs under HLA-A*02:06 restriction. Taken together, these findings indicate that the HIG2-9-4 peptide is a novel HLA-A2 supertype-restricted epitope peptide that could be useful for peptide-based immunotherapy against cancer cells with HIG2 expression. PMID:24416375

  18. Transepithelial transport of milk derived bioactive peptide VLPVPQK.

    PubMed

    Vij, Rishika; Reddi, Srinu; Kapila, Suman; Kapila, Rajeev

    2016-01-01

    The transepithelial transport of an antioxidative and ACE inhibitory peptide, VLPVPQK (named peptide C) derived from casein hydrolysates was investigated along with extensively studied opioid peptide β-casomorphin using a human intestinal cell (Caco-2) monolayer. The susceptibility to the brush-border peptidases and route of transepithelial transport were observed to be the primary factors influencing the transport of these peptides. The apical to basal transport mechanism was studied using bradykinin as control as it shows resistance to cellular peptidases and its route of transepithelial transport had been established. VLPVPQK and BCM 5 were hydrolyzed by cellular peptidases while bradykinin was found intact. The transport of VLPVPQK (1.0%) was found to be relatively much higher than BCM 5 (0.03%) and bradykinin (0.1%). Interestingly the effect of some inhibitors on the transport of VLPVPQK suggested involvement of PepT1 like transporters/SOPT2 while BCM 5, its hydrolytic product and bradykinin were suggested to be transported mainly via the intracellular transcytosis pathway. PMID:26213026

  19. Peptides from the scorpion Vaejovis punctatus with broad antimicrobial activity.

    PubMed

    Ramírez-Carreto, Santos; Jiménez-Vargas, Juana María; Rivas-Santiago, Bruno; Corzo, Gerardo; Possani, Lourival D; Becerril, Baltazar; Ortiz, Ernesto

    2015-11-01

    The antimicrobial potential of two new non-disulfide bound peptides, named VpAmp1.0 (LPFFLLSLIPSAISAIKKI, amidated) and VpAmp2.0 (FWGFLGKLAMKAVPSLIGGNKSSSK) is here reported. These are 19- and 25-aminoacid-long peptides with +2 and +4 net charges, respectively. Their sequences correspond to the predicted mature regions from longer precursors, putatively encoded by cDNAs derived from the venom glands of the Mexican scorpion Vaejovis punctatus. Both peptides were chemically synthesized and assayed against a variety of microorganisms, including pathogenic strains from clinical isolates and strains resistant to conventional antibiotics. Two shorter variants, named VpAmp1.1 (FFLLSLIPSAISAIKKI, amidated) and VpAmp2.1 (FWGFLGKLAMKAVPSLIGGNKK), were also synthesized and tested. The antimicrobial assays revealed that the four synthetic peptides effectively inhibit the growth of both Gram-positive (Staphylococcus aureus and Streptococcus agalactiaea) and Gram-negative (Escherichia coli and Pseudomonas aeruginosa) bacteria, with MICs in the range of 2.5-24.0 μM; yeasts (Candida albicans and Candida glabrata) with MICs of 3.1-50.0 μM; and two clinically isolated strains of Mycobacterium tuberculosis-including a multi-drug resistant one- with MICs in the range of 4.8-30.5 μM. A comparison between the activities of the original peptides and their derivatives gives insight into the structural/functional role of their distinctive residues. PMID:26352292

  20. Angiotensin I Converting Enzyme Inhibitory Peptides Derived from Phycobiliproteins of Dulse Palmaria palmata

    PubMed Central

    Furuta, Tomoe; Miyabe, Yoshikatsu; Yasui, Hajime; Kinoshita, Yasunori; Kishimura, Hideki

    2016-01-01

    We examined the inhibitory activity of angiotensin I converting enzyme (ACE) in protein hydrolysates from dulse, Palmaria palmata. The proteins extracted from dulse were mainly composed of phycoerythrin (PE) followed by phycocyanin (PC) and allophycocyanin (APC). The dulse proteins showed slight ACE inhibitory activity, whereas the inhibitory activity was extremely enhanced by thermolysin hydrolysis. The ACE inhibitory activity of hydrolysates was hardly affected by additional pepsin, trypsin and chymotrypsin treatments. Nine ACE inhibitory peptides (YRD, AGGEY, VYRT, VDHY, IKGHY, LKNPG, LDY, LRY, FEQDWAS) were isolated from the hydrolysates by reversed-phase high-performance liquid chromatography (HPLC), and it was demonstrated that the synthetic peptide LRY (IC50: 0.044 μmol) has remarkably high ACE inhibitory activity. Then, we investigated the structural properties of dulse phycobiliproteins to discuss the origin of dulse ACE inhibitory peptides. Each dulse phycobiliprotein possesses α-subunit (Mw: 17,477–17,638) and β-subunit (Mw: 17,455–18,407). The sequences of YRD, AGGEY, VYRT, VDHY, LKNPG and LDY were detected in the primary structure of PE α-subunit, and the LDY also exists in the APC α- and β-subunits. In addition, the LRY sequence was found in the β-subunits of PE, PC and APC. From these results, it was suggested that the dulse ACE inhibitory peptides were derived from phycobiliproteins, especially PE. To make sure the deduction, we carried out additional experiment by using recombinant PE. We expressed the recombinant α- and β-subunits of PE (rPEα and rPEβ, respectively), and then prepared their peptides by thermolysin hydrolysis. As a result, these peptides showed high ACE inhibitory activities (rPEα: 94.4%; rPEβ: 87.0%). Therefore, we concluded that the original proteins of dulse ACE inhibitory peptides were phycobiliproteins. PMID:26861357

  1. Angiotensin I Converting Enzyme Inhibitory Peptides Derived from Phycobiliproteins of Dulse Palmaria palmata.

    PubMed

    Furuta, Tomoe; Miyabe, Yoshikatsu; Yasui, Hajime; Kinoshita, Yasunori; Kishimura, Hideki

    2016-02-01

    We examined the inhibitory activity of angiotensin I converting enzyme (ACE) in protein hydrolysates from dulse, Palmaria palmata. The proteins extracted from dulse were mainly composed of phycoerythrin (PE) followed by phycocyanin (PC) and allophycocyanin (APC). The dulse proteins showed slight ACE inhibitory activity, whereas the inhibitory activity was extremely enhanced by thermolysin hydrolysis. The ACE inhibitory activity of hydrolysates was hardly affected by additional pepsin, trypsin and chymotrypsin treatments. Nine ACE inhibitory peptides (YRD, AGGEY, VYRT, VDHY, IKGHY, LKNPG, LDY, LRY, FEQDWAS) were isolated from the hydrolysates by reversed-phase high-performance liquid chromatography (HPLC), and it was demonstrated that the synthetic peptide LRY (IC50: 0.044 μmol) has remarkably high ACE inhibitory activity. Then, we investigated the structural properties of dulse phycobiliproteins to discuss the origin of dulse ACE inhibitory peptides. Each dulse phycobiliprotein possesses α-subunit (Mw: 17,477-17,638) and β-subunit (Mw: 17,455-18,407). The sequences of YRD, AGGEY, VYRT, VDHY, LKNPG and LDY were detected in the primary structure of PE α-subunit, and the LDY also exists in the APC α- and β-subunits. In addition, the LRY sequence was found in the β-subunits of PE, PC and APC. From these results, it was suggested that the dulse ACE inhibitory peptides were derived from phycobiliproteins, especially PE. To make sure the deduction, we carried out additional experiment by using recombinant PE. We expressed the recombinant α- and β-subunits of PE (rPEα and rPEβ, respectively), and then prepared their peptides by thermolysin hydrolysis. As a result, these peptides showed high ACE inhibitory activities (rPEα: 94.4%; rPEβ: 87.0%). Therefore, we concluded that the original proteins of dulse ACE inhibitory peptides were phycobiliproteins. PMID:26861357

  2. Dipeptidyl Peptidase IV-Inhibitory Peptides Derived from Silver Carp (Hypophthalmichthys molitrix Val.) Proteins.

    PubMed

    Zhang, Ying; Chen, Ran; Chen, Xiling; Zeng, Zhu; Ma, Huiqin; Chen, Shangwu

    2016-02-01

    The dipeptidyl peptidase IV (DPP-IV)-inhibitory bioactivity of silver carp protein (SCP) hydrolysates were investigated, and their containing efficacious DPP-IV-inhibitory peptides were explored by in silico hydrolysis analysis, peptide separation combined with liquid chromatography-tandem mass spectrometry (LC-MS/MS) identification, and chemical synthesis. SCP hydrolysates generated by six proteases all showed efficient DPP-IV-inhibitory activities, and Neutrase-generated hydrolysates had the greatest DPP-IV inhibition (IC50 of 1.12 mg/mL). In silico Neutrase hydrolysis revealed hundreds of fragments released from myosin, actin, and collagen of SCPs, which include different Pro-motif peptides but only three reported peptidic DPP-IV inhibitors with moderate or weak bioactivity. In addition, three new DPP-IV-inhibitory peptides were identified using LC-MS/MS; in particular, LPIIDI and APGPAGP showed high DPP-IV-inhibitory activity with IC50 of 105.44 and 229.14 μM, respectively, and behaved in competitive/non-competitive mixed-type DPP-IV inhibition mode. The results indicate that the SCP-derived DPP-IV-inhibitory peptides could be potential functional ingredients in the diabetic diet. PMID:26758401

  3. β-casein-derived peptides, produced by bacteria, stimulate cancer cell invasion and motility

    PubMed Central

    Oliveira, Maria José; Van Damme, Jozef; Lauwaet, Tineke; De Corte, Veerle; De Bruyne, Georges; Verschraegen, Gerda; Vaneechoutte, Mario; Goethals, Marc; Ahmadian, Mohammad Reza; Müller, Oliver; Vandekerckhove, Joël; Mareel, Marc; Leroy, Ancy

    2003-01-01

    In colon cancer, enteric bacteria and dietary factors are major determinants of the microenvironment but their effect on cellular invasion is not known. We therefore incubated human HCT-8/E11 colon cancer cells with bacteria or bacterial conditioned medium on top of collagen type I gels. Listeria monocytogenes stimulate cellular invasion through the formation of a soluble motility-promoting factor, identified as a 13mer β-casein-derived peptide (HKEMPFPKYPVEP). The peptide is formed through the combined action of Mpl, a Listeria thermolysin-like metalloprotease, and a collagen-associated trypsin-like serine protease. The 13mer peptide was also formed by tumour biopsies isolated from colon cancer patients and incubated with a β-casein source. The pro- invasive 13mer peptide-signalling pathway implicates activation of Cdc42 and inactivation of RhoA, linked to each other through the serine/threonine p21- activated kinase 1. Since both changes are necessary but not sufficient, another pathway might branch upstream of Cdc42 at phosphatidylinositol 3-kinase. Delta opioid receptor (δOR) is a candidate receptor for the 13mer peptide since naloxone, an δOR antagonist, blocks both δOR serine phosphorylation and 13mer peptide-mediated invasion. PMID:14609961

  4. F2L, a peptide derived from heme-binding protein, inhibits formyl peptide receptor-mediated signaling

    SciTech Connect

    Lee, Ha Young; Lee, Sun Young; Shin, Eun Ha; Kim, Sang Doo; Kim, Jung Mo; Lee, Mi-Sook; Ryu, Sung Ho; Bae, Yoe-Sik . E-mail: yoesik@donga.ac.kr

    2007-08-10

    F2L is an acetylated amino-terminal peptide derived from the cleavage of the human heme-binding protein. Very recently, F2L was identified as an endogenous chemoattractant peptide acting specifically through formyl peptide receptor-like (FPRL)2. In the present study, we report that F2L stimulates chemotactic migration in human neutrophils. However, F2L inhibits formyl peptide receptor (FPR) and FPRL1 activities, resulting in the complete inhibition of intracellular calcium increases, and superoxide generation induced by N-formyl-Met-Leu-Phe, MMK-1, or Trp-Lys-Tyr-Met-Val-D-Met (WKYMVm) in human neutrophils. In terms of the inhibitory role of F2L on FPR- and FPRL-mediated signaling, we found that F2L competitively inhibits the binding of {sup 125}I-WKYMVm to its specific receptors, FPR and FPRL1. F2L is the first endogenous molecule that inhibits FPR- and FPRL1-mediated signaling, and is expected to be useful in the study of FPR and FPRL1 signaling and in the development of drugs to treat diseases involving the FPR family of receptors.

  5. [Biologically Active Peptides of King Crab Hepatopancreas].

    PubMed

    Bogdanov, V V; Berezin, B B; Il'ina, A P; Yamskova, V P; Yamskov, I A

    2015-01-01

    Substances of a peptide nature isolated from the hepatopancreas of the king crab Paralithodes camtschaticus exhibited physicochemical properties and membranotropic and specific activities similar to those of membranotropic homeostatic tissue-specific bioregulators previously found in different mammalian and plant tissues. Their biological effect on vertebrate tissues was demonstrated on a model of roller organotypic cultivation of Pleurodeles waltl newt liver tissue. PMID:26353409

  6. Applications of Convertible Isonitriles in the Ligation and Macrocyclization of Multicomponent Reaction-Derived Peptides and Depsipeptides.

    PubMed

    Wessjohann, Ludger A; Morejón, Micjel C; Ojeda, Gerardo M; Rhoden, Cristiano R B; Rivera, Daniel G

    2016-08-01

    Peptide ligation and macrocyclization are among the most relevant approaches in the field of peptide chemistry. Whereas a variety of strategies relying on coupling reagents and native chemical ligation are available, there is a continuous need for efficient peptide ligation and cyclization methods. Herein we report on the utilization of convertible isonitriles as effective synthetic tools for the ligation and macrocyclization of peptides arising from isocyanide-based multicomponent reactions. The strategy relies on the use of convertible isonitriles-derived from Fukuyama amines-and peptide carboxylic acids in Ugi and Passerini reactions to afford N-alkylated peptides and depsipeptides, respectively, followed by conversion of the C-terminal amide onto either N-peptidoacyl indoles or pyrroles. Such activated peptides proved efficient in the ligation to peptidic, lipidic and fluorescently labeled amines and in macrocyclization protocols. As a result, a wide set of N-substituted peptides (with methyl, glycosyl and amino acids as N-substituents), cyclic N-methylated peptides and a depsipeptide were produced in good yields using conditions that involve either classical heating or microwave irradiation. This report improves the repertoire of peptide covalent modification methods by exploiting the synthetic potential of multicomponent reactions and convertible isonitriles. PMID:27390908

  7. Purification of a novel nitric oxide inhibitory peptide derived from enzymatic hydrolysates of Mytilus coruscus.

    PubMed

    Kim, Eun-Kyung; Kim, Yon-Suk; Hwang, Jin-Woo; Kang, Seo Hee; Choi, Dong-Kug; Lee, Kwang-Ho; Lee, Jung Suck; Moon, Sang-Ho; Jeon, Byong-Tae; Park, Pyo-Jam

    2013-06-01

    Shellfish contain significant levels of high quality protein and are therefore a potential source for biofunctional high-value peptides. To purify a novel anti-inflammatory peptide from Mytilus coruscus (M. coruscus), we applied enzymatic hydrolysis and tangential flow filtration (TFF) and investigated its nitric oxide inhibitory property. To prepare the peptide, eight proteases were employed for enzymatic hydrolysis. Flavouzyme hydrolysates, which showed clearly superior nitric oxide inhibitory activity on lipopolysaccharide (LPS)-stimulated RAW264.7, were further purified using a TFF system and consecutive chromatographic methods. Finally, a novel anti-inflammatory peptide composed of 10 amino acid residues was obtained, and the sequence was identified as Gly-Val-Ser-Leu-Leu-Gln-Gln-Phe-Phe-Leu at N-terminal position. The peptide from M. coruscus effectively inhibited nitric oxide production on macrophage cells. This is the first report of an anti-inflammatory peptide derived from the hydrolysates of M. coruscus. PMID:23500953

  8. Purification and identification of lipolysis-stimulating peptides derived from enzymatic hydrolysis of soy protein.

    PubMed

    Tsou, May-June; Kao, Fuh-Juin; Lu, Hsi-Chi; Kao, Hao-Chun; Chiang, Wen-Dee

    2013-06-01

    The aim of this study was to purify and identify lipolysis-stimulating peptides derived from Flavourzyme®-soy protein isolate (SPI) hydrolysate (F-SPIH). Glycerol release was employed as a marker for lipolysis in 3T3-L1 adipocytes. A higher glycerol release represents a better lipolysis-stimulating activity. The peptide fraction with highest glycerol release obtained from F-SPIH fractionated by sequential ultrafiltration membranes was further purified using gel filtration chromatography and two steps of reverse-phase high-performance liquid chromatography. The peptides were identified using liquid chromatography-tandem mass spectrometry (LC/MS/MS). Three lipolysis-stimulating peptides were obtained, and the amino acid sequences were ILL, LLL and VHVV, respectively. The in vitro effect of gastrointestinal proteases on lipolysis-stimulating activity of synthetic ILL, LLL and VHVV, respectively, was also investigated. The result suggested that the gastrointestinal protease did not affect lipolysis-stimulating activity of the three novel peptides, which reveals their potential to act as anti-obesity ingredients. PMID:23411267

  9. FKBPL and Peptide Derivatives: Novel Biological Agents That Inhibit Angiogenesis by a CD44-Dependent Mechanism

    PubMed Central

    Valentine, Andrea; O’Rourke, Martin; Yakkundi, Anita; Worthington, Jenny; Hookham, Michelle; Bicknell, Roy; McCarthy, Helen O.; McClelland, Keeva; McCallum, Lynn; Dyer, Hayder; McKeen, Hayley; Waugh, David; Roberts, Jennifer; McGregor, Joanne; Cotton, Graham; James, Iain; Harrison, Timothy; Hirst, David G.; Robson, Tracy

    2011-01-01

    Purpose Anti-angiogenic therapies can be an important adjunct to the management of many malignancies. Here we investigated a novel protein, FKBPL, and peptide derivative for their anti-angiogenic activity and mechanism of action. Experimental Design Recombinant FKBPL (rFKBPL) and its peptide derivative were assessed in a range of human microvascular endothelial cell (HMEC-1) assays in vitro. Their ability to inhibit proliferation, migration and Matrigel dependent tubule formation was determined. They were further evaluated in an ex-vivo rat model of neo-vascularisation and in two in vivo mouse models of angiogenesis; the sponge implantation and the intra-vital microscopy models. Anti-tumor efficacy was determined in two human tumor xenograft models grown in SCID mice. Finally, the dependence of peptide on CD44 was determined using a CD44 targeted siRNA approach or in cell lines of differing CD44 status. Results rFKBPL inhibited endothelial cell migration, tubule formation and microvessel formation in vitro and in vivo. The region responsible for FKBPL’s anti-angiogenic activity was identified and a 24 amino acid peptide (AD-01) spanning this sequence was synthesised. It was potently anti-angiogenic and inhibited growth in two human tumor xenograft models (DU145 and MDA-231) when administered systemically, either on its own, or in combination with docetaxel. The anti-angiogenic activity of FKBPL and AD-01 was dependent on the cell surface receptor CD44 and signalling downstream of this receptor promoted an anti-migratory phenotype. Conclusion FKBPL and its peptide derivative AD-01 have potent anti-angiogenic activity. Thus, these agents offer the potential of an attractive new approach to anti-angiogenic therapy. PMID:21364036

  10. Identification and Molecular Characterization of Molluskin, a Histone-H2A-Derived Antimicrobial Peptide from Molluscs

    PubMed Central

    Sathyan, Naveen; Philip, Rosamma; Chaithanya, E. R.; Anil Kumar, P. R.

    2012-01-01

    Antimicrobial peptides are humoral innate immune components of molluscs that provide protection against pathogenic microorganisms. Among these, histone-H2A-derived antimicrobial peptides are known to actively participate in host defense responses of molluscs. Present study deals with identification of putative antimicrobial sequences from the histone-H2A of back-water oyster Crassostrea madrasensis, rock oyster Saccostrea cucullata, grey clam Meretrix casta, fig shell Ficus gracilis, and ribbon bullia Bullia vittata. A 75 bp fragment encoding 25 amino acid residues was amplified from cDNA of these five bivalves and was named “Molluskin.” The 25 amino acid peptide exhibited high similarity to previously reported histone-H2A-derived AMPs from invertebrates indicating the presence of an antimicrobial sequence motif. Physicochemical properties of the peptides are in agreement with the characteristic features of antimicrobial peptides, indicating their potential role in innate immunity of molluscs.

  11. An overview of antifungal peptides derived from insect.

    PubMed

    Faruck, Mohammad Omer; Yusof, Faridah; Chowdhury, Silvia

    2016-06-01

    Fungi are not classified as plants or animals. They resemble plants in many ways but do not produce chlorophyll or make their own food photosynthetically like plants. Fungi are useful for the production of beer, bread, medicine, etc. More complex than viruses or bacteria; fungi can be destructive human pathogens responsible for various diseases in humans. Most people have a strong natural immunity against fungal infection. However, fungi can cause diseases when this immunity breaks down. In the last few years, fungal infection has increased strikingly and has been accompanied by a rise in the number of deaths of cancer patients, transplant recipients, and acquired immunodeficiency syndrome (AIDS) patients owing to fungal infections. The growth rate of fungi is very slow and quite difficult to identify. A series of molecules with antifungal activity against different strains of fungi have been found in insects, which can be of great importance to tackle human diseases. Insects secrete such compounds, which can be peptides, as a part of their immune defense reactions. Active antifungal peptides developed by insects to rapidly eliminate infectious pathogens are considered a component of the defense munitions. This review focuses on naturally occurring antifungal peptides from insects and their challenges to be used as armaments against human diseases. PMID:26093218

  12. Peptides derived from the dependence receptor ALK are proapoptotic for ALK-positive tumors

    PubMed Central

    Aubry, A; Galiacy, S; Ceccato, L; Marchand, C; Tricoire, C; Lopez, F; Bremner, R; Racaud-Sultan, C; Monsarrat, B; Malecaze, F; Allouche, M

    2015-01-01

    ALK is a receptor tyrosine kinase with an oncogenic role in various types of human malignancies. Despite constitutive activation of the kinase through gene alterations, such as chromosomal translocation, gene amplification or mutation, treatments with kinase inhibitors invariably lead to the development of resistance. Aiming to develop new tools for ALK targeting, we took advantage of our previous demonstration identifying ALK as a dependence receptor, implying that in the absence of ligand the kinase-inactive ALK triggers or enhances apoptosis. Here, we synthesized peptides mimicking the proapoptotic domain of ALK and investigated their biological effects on tumor cells. We found that an ALK-derived peptide of 36 amino acids (P36) was cytotoxic for ALK-positive anaplastic large-cell lymphoma and neuroblastoma cell lines. In contrast, ALK-negative tumor cells and normal peripheral blood mononuclear cells were insensitive to P36. The cytotoxic effect was due to caspase-dependent apoptosis and required N-myristoylation of the peptide. Two P36-derived shorter peptides as well as a cyclic peptide also induced apoptosis. Surface plasmon resonance and mass spectrometry analysis of P36-interacting proteins from two responsive cell lines, Cost lymphoma and SH-SY5Y neuroblastoma, uncovered partners that could involve p53-dependent signaling and pre-mRNA splicing. Furthermore, siRNA-mediated knockdown of p53 rescued these cells from P36-induced apoptosis. Finally, we observed that a treatment combining P36 with the ALK-specific inhibitor crizotinib resulted in additive cytotoxicity. Therefore, ALK-derived peptides could represent a novel targeted therapy for ALK-positive tumors. PMID:25950466

  13. Biologically and diagenetically derived peptide modifications in moa collagens.

    PubMed

    Cleland, Timothy P; Schroeter, Elena R; Schweitzer, Mary H

    2015-06-01

    The modifications that occur on proteins in natural environments over time are not well studied, yet characterizing them is vital to correctly interpret sequence data recovered from fossils. The recently extinct moa (Dinornithidae) is an excellent candidate for investigating the preservation of proteins, their post-translational modifications (PTMs) and diagenetic alterations during degradation. Moa protein extracts were analysed using mass spectrometry, and peptides from collagen I, collagen II and collagen V were identified. We also identified biologically derived PTMs (i.e. methylation, di-methylation, alkylation, hydroxylation, fucosylation) on amino acids at locations consistent with extant proteins. In addition to these in vivo modifications, we detected novel modifications that are probably diagenetically derived. These include loss of hydroxylation/glutamic semialdehyde, carboxymethyllysine and peptide backbone cleavage, as well as previously noted deamidation. Moa collagen sequences and modifications provide a baseline by which to evaluate proteomic studies of other fossils, and a framework for defining the molecular relationship of moa to other closely related taxa. PMID:25972464

  14. Biologically and diagenetically derived peptide modifications in moa collagens

    PubMed Central

    Cleland, Timothy P.; Schroeter, Elena R.; Schweitzer, Mary H.

    2015-01-01

    The modifications that occur on proteins in natural environments over time are not well studied, yet characterizing them is vital to correctly interpret sequence data recovered from fossils. The recently extinct moa (Dinornithidae) is an excellent candidate for investigating the preservation of proteins, their post-translational modifications (PTMs) and diagenetic alterations during degradation. Moa protein extracts were analysed using mass spectrometry, and peptides from collagen I, collagen II and collagen V were identified. We also identified biologically derived PTMs (i.e. methylation, di-methylation, alkylation, hydroxylation, fucosylation) on amino acids at locations consistent with extant proteins. In addition to these in vivo modifications, we detected novel modifications that are probably diagenetically derived. These include loss of hydroxylation/glutamic semialdehyde, carboxymethyllysine and peptide backbone cleavage, as well as previously noted deamidation. Moa collagen sequences and modifications provide a baseline by which to evaluate proteomic studies of other fossils, and a framework for defining the molecular relationship of moa to other closely related taxa. PMID:25972464

  15. The potential of food protein-derived anti-inflammatory peptides against various chronic inflammatory diseases.

    PubMed

    Majumder, Kaustav; Mine, Yoshinori; Wu, Jianping

    2016-05-01

    Inflammation is considered as one of the major causes for the initiation of various chronic diseases such as asthma, cancer, cardiovascular disease, diabetes, obesity, inflammatory bowel disease, osteoporosis and neurological diseases like Parkinson's disease. Increasing scientific evidence has delineated that inflammatory markers such as TNF-α, IL-1, IL-6, IL-8 and CRP and different transcription factors such as NF-κB and STAT are the major key factors that regulate these inflammatory diseases. Food protein-derived bioactive peptides have been shown to exhibit anti-inflammatory activity by inhibiting or reducing the expression of these inflammatory biomarkers and/or by modulating the activity of these transcription factors. This review aims to discuss various molecular targets and underlying mechanisms of food protein-derived anti-inflammatory peptides and to explore their potential against various chronic inflammatory diseases. © 2015 Society of Chemical Industry. PMID:26711001

  16. Peptides and proteins with antimicrobial activity

    PubMed Central

    Coutinho, Henrique Douglas Melo; Lôbo, Katiuscia Menezes; Bezerra, Denise Aline Casimiro; Lôbo, Inalzuir

    2008-01-01

    The increase of microbial resistance to antibiotics has led to a continuing search for newer and more effective drugs. Antimicrobial peptides are generally found in animals, plants, and microorganisms and are of great interest to medicine, pharmacology, and the food industry. These peptides are capable of inhibiting pathogenic microorganisms. They can attack parasites, while causing little or no harm to the host cells. The defensins are peptides found in granules in the polymorphonuclear neutrophils (PMNs) and are responsible for the defense of the organism. Several animal defensins, like dermaseptin, antileukoprotease, protegrin, and others, have had their activities and efficacy tested and been shown to be effective against bacteria, fungi, and protists; there are also specific defensins from invertebrates, e.g., drosomycin and heliomicin; from plants, e.g., the types A and B; and the bacteriocins, e.g., acrocin, marcescin, etc. The aim of the present work was to compile a comprehensive bibliographic review of the diverse potentially antimicrobial peptides in an effort to systematize the current knowledge on these substances as a contribution for further researches. The currently available bibliography does not give a holistic approach on this subject. The present work intends to show that the mechanism of defense represented by defensins is promising from the perspective of its application in the treatment of infectious diseases in human, animals and plants. PMID:21264153

  17. Peptide Bacteriocins--Structure Activity Relationships.

    PubMed

    Etayash, Hashem; Azmi, Sarfuddin; Dangeti, Ramana; Kaur, Kamaljit

    2015-01-01

    With the growing concerns in the scientific and health communities over increasing levels of antibiotic resistance, antimicrobial peptide bacteriocins have emerged as promising alternatives to conventional small molecule antibiotics. A substantial attention has recently focused on the utilization of bacteriocins in food preservation and health safety. Despite the fact that a large number of bacteriocins have been reported, only a few have been fully characterized and structurally elucidated. Since knowledge of the molecular structure is a key for understanding the mechanism of action and therapeutic effects of peptide, we centered our focus in this review on the structure-activity relationships of bacteriocins with a particular focus in seven bacteriocins, namely, nisin, microcin J25, microcin B17, microcin C, leucocin A, sakacin P, and pediocin PA-1. Significant structural changes responsible for the altered activity of the recent bacteriocin analogues are discussed here. PMID:26265354

  18. A CCL chemokine-derived peptide (CDIP-2) exerts anti-inflammatory activity via CCR1, CCR2 and CCR3 chemokine receptors: Implications as a potential therapeutic treatment of asthma.

    PubMed

    Méndez-Enríquez, E; Medina-Tamayo, J; Soldevila, G; Fortoul, T I; Anton, B; Flores-Romo, L; García-Zepeda, E A

    2014-05-01

    Allergic asthma is a chronic inflammatory disease characterized by the accumulation of eosinophils, Th2 cells and mononuclear cells in the airways, leading to changes in lung architecture and subsequently reduced respiratory function. We have previously demonstrated that CDIP-2, a chemokine derived peptide, reduced in vitro chemotaxis and decreased cellular infiltration in a murine model of allergic airway inflammation. However, the mechanisms involved in this process have not been identified yet. Now, we found that CDIP-2 reduces chemokine-mediated functions via interactions with CCR1, CCR2 and CCR3. Moreover, using bone marrow-derived eosinophils, we demonstrated that CDIP-2 modifies the calcium fluxes induced by CCL11 and down-modulated CCR3 expression. Finally, CDIP-2 treatment in a murine model of OVA-induced allergic airway inflammation reduced leukocyte recruitment and decreases production of cytokines. These data suggest that chemokine-derived peptides represent new therapeutic tools to generate more effective antiinflammatory drugs. PMID:24560857

  19. K1K8: an Hp1404-derived antibacterial peptide.

    PubMed

    Li, Zhongjie; Liu, Gaomin; Meng, Lanxia; Yu, Weiwei; Xu, Xiaobo; Li, Wenxin; Wu, Yingliang; Cao, Zhijian

    2016-06-01

    As an alternative class of antimicrobial agents used to overcome drug-resistant infections, antimicrobial peptides (AMPs) have recently gained significant attention. In this study, we designed an improved antimicrobial peptide, K1K8, based on the molecular template of Hp1404. Compared to the wild-type Hp1404, K1K8 showed an improved antibacterial spectrum in vitro, a lower hemolytic activity, and an enhanced serum stability. Importantly, K1K8 also decreased methicillin-resistant Staphylococcus aureus (MRSA) bacterial counts in the wounded region in a mouse skin infection model. Interestingly, K1K8 did not induce bacterial resistance or non-specific immune response reactions. Moreover, the peptide killed bacterial cells mainly by disrupting the bacterial membrane. In summary, K1K8 has the potential to be used as an improved anti-infection agent for topical use, which opens an avenue that potential anti-infection drugs may be designed and developed from the molecular templates of AMPs. PMID:26952110

  20. Antibody-independent identification of bovine milk-derived peptides in breast-milk.

    PubMed

    Picariello, Gianluca; Addeo, Francesco; Ferranti, Pasquale; Nocerino, Rita; Paparo, Lorella; Passariello, Annalisa; Dallas, David C; Robinson, Randall C; Barile, Daniela; Canani, Roberto Berni

    2016-08-10

    Exclusively breast-fed infants can exhibit clear signs of IgE or non IgE-mediated cow's milk allergy. However, the definite characterization of dietary cow's milk proteins (CMP) that survive the maternal digestive tract to be absorbed into the bloodstream and secreted into breast milk remains missing. Herein, we aimed at assessing possible CMP-derived peptides in breast milk. Using high performance liquid chromatography (HPLC)-high resolution mass spectrometry (MS), we compared the peptide fraction of breast milk from 12 donors, among which 6 drank a cup of milk daily and 6 were on a strict dairy-free diet. We identified two bovine β-lactoglobulin (β-Lg, 2 out 6 samples) and one αs1-casein (1 out 6 samples) fragments in breast milk from mothers receiving a cup of bovine milk daily. These CMP-derived fragments, namely β-Lg (f42-54), (f42-57) and αs1-casein (f180-197), were absent in milk from mothers on dairy-free diet. In contrast, neither intact nor hydrolyzed β-Lg was detected by western blot and competitive ELISA in any breast milk sample. Eight additional bovine milk-derived peptides identified by software-assisted MS were most likely false positive. The results of this study demonstrate that CMP-derived peptides rather than intact CMP may sensitize or elicit allergic responses in the neonate through mother's milk. Immunologically active peptides from the maternal diet could be involved in priming the newborn's immune system, driving a tolerogenic response. PMID:27396729

  1. Fragmentation efficiencies of peptide ions following low energy collisional activation

    NASA Astrophysics Data System (ADS)

    Summerfield, Scott G.; Gaskell, Simon J.

    1997-11-01

    Low energy fragmentations of protonated peptides in the gas phase are generally attributed to charge-directed processes. The extent and location of peptide backbone fragmentation is accordingly influenced by the extent to which charge is sequestered on amino acid side-chains. We describe systematic studies of the efficiencies of decomposition of peptide ions to assess in particular the influence of the presence of basic amino acid residues and of the protonation state. In a set of analogues containing two arginine, two histidine or two lysine residues, the extent of fragmentation of [M + 2H]2+ ions decreases with increased basicity, reflecting decreased backbone protonation. The collisionally activated dissociation of multiply protonated melittin ions shows an increase in fragmentation efficiency with higher charge state (using activation conditions which are similar for each charge state). For a single charge state, acetylation of primary amine groups increases fragmentation efficiency, consistent with the reduction in basicity of lysine side-chains. Conversion of arginine residues to the less basic dimethylpyrimidylornithine, however, decreases fragmentation efficiency, suggesting more effective sequestering of ionizing protons; the effect may be attributable to a disfavouring of proton-bridged structures but this hypothesis requires further study. Preliminary data for the decompositions of [M- 2H]2- ions derived from peptides containing two acidic residues suggest that the sequestration of charge away from the backbone is again detrimental to efficient fragmentation. Apparently diagnostic cleavages adjacent to aspartic acid residues are observed.

  2. Catalytic Activities Of [GADV]-Peptides

    NASA Astrophysics Data System (ADS)

    Oba, Takae; Fukushima, Jun; Maruyama, Masako; Iwamoto, Ryoko; Ikehara, Kenji

    2005-10-01

    We have previously postulated a novel hypothesis for the origin of life, assuming that life on the earth originated from “[GADV]-protein world”, not from the “RNA world” (see Ikehara's review, 2002). The [GADV]-protein world is constituted from peptides and proteins with random sequences of four amino acids (glycine [G], alanine [A], aspartic acid [D] and valine [V]), which accumulated by pseudo-replication of the [GADV]-proteins. To obtain evidence for the hypothesis, we produced [GADV]-peptides by repeated heat-drying of the amino acids for 30 cycles ([GADV]-P30) and examined whether the peptides have some catalytic activities or not. From the results, it was found that the [GADV]-P30 can hydrolyze several kinds of chemical bonds in molecules, such as umbelliferyl-β-D-galactoside, glycine-p-nitroanilide and bovine serum albumin. This suggests that [GADV]-P30 could play an important role in the accumulation of [GADV]-proteins through pseudo-replication, leading to the emergence of life. We further show that [GADV]-octapaptides with random sequences, but containing no cyclic compounds as diketepiperazines, have catalytic activity, hydrolyzing peptide bonds in a natural protein, bovine serum albumin. The catalytic activity of the octapeptides was much higher than the [GADV]-P30 produced through repeated heat-drying treatments. These results also support the [GADV]-protein-world hypothesis of the origin of life (see Ikehara's review, 2002). Possible steps for the emergence of life on the primitive earth are presented.

  3. Biological activity of Tat (47-58) peptide on human pathogenic fungi

    SciTech Connect

    Jung, Hyun Jun; Park, Yoonkyung; Hahm, Kyung-Soo; Lee, Dong Gun . E-mail: dglee222@knu.ac.kr

    2006-06-23

    Tat (47-58) peptide, a positively charged Arginine-rich peptide derived from HIV-1 regulatory protein Tat, is known for a peptidic delivery factor as a cell-penetrating peptide on mammalian cells. In this study, antifungal effect and its mode of action of Tat peptide were investigated on fungal cells. The results indicate that Tat peptide exhibits antifungal activity against pathogenic fungal cells without hemolytic effect on human erythrocytes. To understand the mechanism(s) of Tat peptide, the cellular distribution of the peptide was investigated. Tat peptide internalized in the fungal cells without any damage to cell membrane when examined using an artificial liposome (PC/cholesterol; 10:1, w/w). Moreover, flow cytometry analysis exhibited the uptake of Tat peptide by energy- and salt-independent pathway, and confocal scanning microscopy displayed that this peptide accumulated in the nucleus of fungal cells rapidly without any impediment by time or temperature, which generally influence on the viral infections. After penetration into the nuclear, the peptide affected the process of cell cycle of Candida albicans through the arrest at G1 phase.

  4. Dendritic-Tumor Fusion Cells Derived Heat Shock Protein70-Peptide Complex Has Enhanced Immunogenicity

    PubMed Central

    Chen, Jun; Liu, Yunyan; Luo, Wen

    2015-01-01

    Tumor-derived heat shock protein70-peptide complexes (HSP70.PC-Tu) have shown great promise in tumor immunotherapy due to numerous advantages. However, large-scale phase III clinical trials showed that the limited immunogenicity remained to be enhanced. In previous research, we demonstrated that heat shock protein 70-peptide complexes (HSP70.PC-Fc) derived from dendritic cell (DC)-tumor fusions exhibit enhanced immunogenicity compared with HSP70.PCs from tumor cells. However, the DCs used in our previous research were obtained from healthy donors and not from the patient population. In order to promote the clinical application of these complexes, HSP70.PC-Fc was prepared from patient-derived DC fused directly with patient-derived tumor cells in the current study. Our results showed that compared with HSP70.PC-Tu, HSP70.PC-Fc elicited much more powerful immune responses against the tumor from which the HSP70 was derived, including enhanced T cell activation, and CTL responses that were shown to be antigen specific and HLA restricted. Our results further indicated that the enhanced immunogenicity is related to the activation of CD4+ T cells and increased association with other heat shock proteins, such as HSP90. Therefore, the current study confirms the enhanced immunogenicity of HSP70.PC derived from DC-tumor fusions and may provide direct evidence promoting their future clinical use. PMID:25961716

  5. Dermcidin-Derived Peptides Show a Different Mode of Action than the Cathelicidin LL-37 against Staphylococcus aureus▿

    PubMed Central

    Senyürek, Ilknur; Paulmann, Maren; Sinnberg, Tobias; Kalbacher, Hubert; Deeg, Martin; Gutsmann, Thomas; Hermes, Marina; Kohler, Thomas; Götz, Fritz; Wolz, Christiane; Peschel, Andreas; Schittek, Birgit

    2009-01-01

    Dermcidin (DCD) is an antimicrobial peptide which is constitutively expressed in eccrine sweat glands. By postsecretory proteolytic processing in sweat, the DCD protein gives rise to anionic and cationic DCD peptides with a broad spectrum of antimicrobial activity. Many antimicrobial peptides induce membrane permeabilization as part of their killing mechanism, which is accompanied by a loss of the bacterial membrane potential. In this study we show that there is a time-dependent bactericidal activity of anionic and cationic DCD-derived peptides which is followed by bacterial membrane depolarization. However, DCD-derived peptides do not induce pore formation in the membranes of gram-negative and gram-positive bacteria. This is in contrast to the mode of action of the cathelicidin LL-37. Interestingly, LL-37 as well as DCD-derived peptides inhibit bacterial macromolecular synthesis, especially RNA and protein synthesis, without binding to microbial DNA or RNA. Binding studies with components of the cell envelope of gram-positive and gram-negative bacteria and with model membranes indicated that DCD-derived peptides bind to the bacterial envelope but show only a weak binding to lipopolysaccharide (LPS) from gram-negative bacteria or to peptidoglycan, lipoteichoic acid, and wall teichoic acid, isolated from Staphylococcus aureus. In contrast, LL-37 binds strongly in a dose-dependent fashion to these components. Altogether, these data indicate that the mode of action of DCD-derived peptides is different from that of the cathelicidin LL-37 and that components of the bacterial cell envelope play a role in the antimicrobial activity of DCD. PMID:19364862

  6. Antiendotoxin activity of cationic peptide antimicrobial agents.

    PubMed Central

    Gough, M; Hancock, R E; Kelly, N M

    1996-01-01

    The endotoxin from gram-negative bacteria consists of a molecule lipopolysaccharide (LPS) which can be shed by bacteria during antimicrobial therapy. A resulting syndrome, endotoxic shock, is a leading cause of death in the developed world. Thus, there is great interest in the development of antimicrobial agents which can reverse rather than promote sepsis, especially given the recent disappointing clinical performance of antiendotoxin therapies. We describe here two small cationic peptides, MBI-27 and MBI-28, which have both antiendotoxic and antibacterial activities in vitro and in vivo in animal models. We had previously demonstrated that these peptides bind to LPS with an affinity equivalent to that of polymyxin B. Consistent with this, the peptides blocked the ability of LPS and intact cells to induce the endotoxic shock mediator, tumor necrosis factor (TNF), upon incubation with the RAW 264.7 murine macrophage cell line. MBI-28 was equivalent to polymyxin B in its ability to block LPS induction of TNF by this cell line, even when added 60 min after the TNF stimulus. Furthermore, MBI-28 offered significant protection in a galactosamine-sensitized mouse model of lethal endotoxic shock. This protection correlated with the ability of MBI-28 to reduce LPS-induced circulating TNF by nearly 90% in this mouse model. Both MBI-27 and MBI-28 demonstrated antibacterial activity against gram-negative bacteria in vitro and in vivo against Pseudomonas aeruginosa infections in neutropenic mice. PMID:8945527

  7. [The Qualitative Analysis of the Amide Derivative of HLDF-6 Peptide and Its Metabolites with the Use of Tritium- and Deuterium-Labeled Derivatives].

    PubMed

    Zolotarev, A; Dadayan, A K; Kost, N V; Voevodina, M E; Sokolov, O Y; Kozik, V S; Shram, S I; Azev, V N; Bocharov, E V; Bogachouk, A P; Lipkin, V M; Myasoedov, N F

    2015-01-01

    The goal of the study was to elaborate the pharmacokinetics methods of the amide derivative of peptide HLDF-6 (TGENHR-NH2) and its range of nootropic and neuroprotective activity is wide. The hexapeptide 41TGENHR46 is a fragment of the HDLF differentiation factor. It forms the basis for the development of preventive and therapeutic preparations for treating cerebrovascular and neurodegenerative conditions. Pharmacokinetic and molecular mechanisms of the action of the HLDF-6 peptide were studied using tritium- and deuterium-labeled derivatives of this peptide, produced with the use of the high-temperature solid-state catalytic isotope exchange reaction (HSCIE). This reaction was employed to produce the tritium-labeled peptide [3H]TGENHR-NH2 with a molar radioactivity of 230 Ci/mmol and the deuterium-labeled peptide [2H]TGENHR-NH2 with an average deuterium incorporation equal to 10.5 atoms. It was shown by the NMR spectroscopy that the isotope label distribution over the labeled peptide's molecule was uniform, which allowed qualitative analysis ofboth the peptide itself and its fragments in the organism's tissues to be conducted. The newly developed pharmacokinetics method makes it possible to avoid almost completely losses of the peptides under study due to biodegradation during the analysis of tissues. These labeled peptides were used in mice, rats and rabbits to study the pharmacokinetics of the peptide and to calculate the values of its principal pharmacokinetic parameters. Characteristics of its pharmacokinetic profile in the blood were obtained, the hypothesis of pharmacokinetics linearity tested, its metabolism analyzed and its bioavailability value, 34%, calculated. It has been shown that the studied TGENHR-NH2 peptide shows high resistance to hydrolysis in the blood plasma, with dipeptidyl aminopeptidases making the largest contribution to its hydrolysis. PMID:27125017

  8. Experimental and Computational Investigation of the Effect of Hydrophobicity on Aggregation and Osteoinductive Potential of BMP-2-Derived Peptide in a Hydrogel Matrix

    PubMed Central

    Moeinzadeh, Seyedsina; Barati, Danial; Sarvestani, Samaneh K.; Karimi, Tahereh

    2015-01-01

    An attractive approach to reduce the undesired side effects of bone morphogenetic proteins (BMPs) in regenerative medicine is to use osteoinductive peptide sequences derived from BMPs. Although the structure and function of BMPs have been studied extensively, there is limited data on structure and activity of BMP-derived peptides immobilized in hydrogels. The objective of this work was to investigate the effect of concentration and hydrophobicity of the BMP-2 peptide, corresponding to residues 73–92 of the knuckle epitope of BMP-2 protein, on peptide aggregation and osteogenic differentiation of human mesenchymal stem cells encapsulated in a polyethylene glycol (PEG) hydrogel. The peptide hydrophobicity was varied by capping PEG chain ends with short lactide segments. The BMP-2 peptide with a positive index of hydrophobicity had a critical micelle concentration (CMC) and formed aggregates in aqueous solution. Based on simulation results, there was a slight increase in the concentration of free peptide in solution with 1000-fold increase in peptide concentration. The dose-osteogenic response curve of the BMP-2 peptide was in the 0.0005–0.005 mM range, and osteoinductive potential of the BMP-2 peptide was significantly less than that of BMP-2 protein even at 1000-fold higher concentrations, which was attributed to peptide aggregation. Further, the peptide or PEG-peptide aggregates had significantly higher interaction energy with the cell membrane compared with the free peptide, which led to a higher nonspecific interaction with the cell membrane and loss of osteoinductive potential. Conjugation of the BMP-2 peptide to PEG increased CMC and osteoinductive potential of the peptide whereas conjugation to lactide-capped PEG reduced CMC and osteoinductive potential of the peptide. Experimental and simulation results revealed that osteoinductive potential of the BMP-2 peptide is correlated with its CMC and the free peptide concentration in aqueous medium and not the

  9. Iron-chelating activity of chickpea protein hydrolysate peptides.

    PubMed

    Torres-Fuentes, Cristina; Alaiz, Manuel; Vioque, Javier

    2012-10-01

    Chickpea-chelating peptides were purified and analysed for their iron-chelating activity. These peptides were purified after affinity and gel filtration chromatography from a chickpea protein hydrolysate produced with pepsin and pancreatin. Iron-chelating activity was higher in purified peptide fractions than in the original hydrolysate. Histidine contents were positively correlated with the iron-chelating activity. Hence fractions with histidine contents above 20% showed the highest chelating activity. These results show that iron-chelating peptides are generated after chickpea protein hydrolysis with pepsin plus pancreatin. These peptides, through metal chelation, may increase iron solubility and bioavailability and improve iron absorption. PMID:25005984

  10. Investigation into the mechanism of action of the antimicrobial peptides Os and Os-C derived from a tick defensin.

    PubMed

    Taute, Helena; Bester, Megan J; Neitz, Albert W H; Gaspar, Anabella R M

    2015-09-01

    Os and Os-C are two novel antimicrobial peptides, derived from a tick defensin, which have been shown to have a larger range of antimicrobial activity than the parent peptide, OsDef2. The aim of this study was to determine whether the peptides Os and Os-C are mainly membrane acting, or if these peptides have possible additional intracellular targets in Escherichia coli and Bacillus subtilis. Transmission electron microscopy revealed that both peptides adversely affected intracellular structure of both bacteria causing different degrees of granulation of the intracellular contents. At the minimum bactericidal concentrations, permeabilization as determined with the SYTOX green assay seemed not to be the principle mode of killing when compared to melittin. However, fluorescent triple staining indicated that the peptides caused permeabilization of stationary phase bacteria and TEM indicated membrane effects. Studies using fluorescently labeled peptides revealed that the membrane penetrating activity of Os and Os-C was similar to buforin II. Os-C was found to associate with the septa of B. subtilis. Plasmid binding studies showed that Os and Os-C binds E. coli plasmid DNA at a similar charge ratio as melittin. These studies suggest membrane activity for Os and Os-C with possible intracellular targets such as DNA. The differences in permeabilization at lower concentrations and binding to DNA between Os and Os-C, suggest that the two peptides have dissimilar modes of action. PMID:26215047

  11. Design of p53-derived peptides with cytotoxicity on breast cancer.

    PubMed

    Fang, Yi; Jin, Rongzhong; Gao, Yinqi; Gao, Jidong; Wang, Jing

    2014-08-01

    The tumor suppressor p53 plays essential role in conserving stability by preventing genome mutation, which is inactivated naturally by its negative regulator MDM2. Thus, targeting p53-MDM2 protein-protein interaction has been raised as a new cancer therapy in the medicinal community. In the current study, we report a successful application of an integrative protocol to design novel p53-derived peptides with cytotoxicity on human breast cancer cells. A quantitative structure-activity relationship-improved statistical potential was used to evaluate the binding potency of totally 24,054 single- and dual-point mutants of p53 peptide to MDM2 in a high-throughput manner, from which 46 peptide mutants with high predicted affinity and typical helical feature were involved in a rigorous modeling procedure that employed molecular dynamics simulations and post-binding energy analysis to systematically investigate the structural, energetic and dynamic aspects of peptide interactions with MDM2. Subsequently, a biological analysis was performed on a number of promising peptide candidates to determine their cytotoxic effects on human breast cancer cell line MDF-7. Six dual-point mutants were found to have moderate or high activities with their IC50 values ranging from 16.3 to 137.0 μM, which are better than that of wild-type p53 peptide (IC50 = 182.6 μM) and close to that of classical anticancer agent cis-platin (IC50 = 4.3 μM). Further, the most active peptide ETFSDWWKLLAE was selected as parent to further derive new mutants on the basis of the structural and energetic profile of its complex with MDM2. Consequently, three triple-point mutants (LTFSDWWKLLAE, ESFSDWWKLLAE and ETFADWWKLLAE) were obtained, and their biological activities (IC50 = 15.1, 27.0 and 8.7 μM, respectively) were determined to be comparable or better than the parent (IC50 = 16.3 μM). PMID:24830845

  12. The TFPI-2 Derived Peptide EDC34 Improves Outcome of Gram-Negative Sepsis

    PubMed Central

    Papareddy, Praveen; Kalle, Martina; Sørensen, Ole E.; Malmsten, Martin; Mörgelin, Matthias; Schmidtchen, Artur

    2013-01-01

    Sepsis is characterized by a dysregulated host-pathogen response, leading to high cytokine levels, excessive coagulation and failure to eradicate invasive bacteria. Novel therapeutic strategies that address crucial pathogenetic steps during infection are urgently needed. Here, we describe novel bioactive roles and therapeutic anti-infective potential of the peptide EDC34, derived from the C-terminus of tissue factor pathway inhibitor-2 (TFPI-2). This peptide exerted direct bactericidal effects and boosted activation of the classical complement pathway including formation of antimicrobial C3a, but inhibited bacteria-induced activation of the contact system. Correspondingly, in mouse models of severe Escherichia coli and Pseudomonas aeruginosa infection, treatment with EDC34 reduced bacterial levels and lung damage. In combination with the antibiotic ceftazidime, the peptide significantly prolonged survival and reduced mortality in mice. The peptide's boosting effect on bacterial clearance paired with its inhibiting effect on excessive coagulation makes it a promising therapeutic candidate for invasive Gram-negative infections. PMID:24339780

  13. Production of angiotensin-I-converting enzyme inhibitory peptides from β-lactoglobulin- and casein-derived peptides: an integrative approach.

    PubMed

    Welderufael, Fisseha T; Gibson, Trevor; Jauregi, Paula

    2012-01-01

    Angiotensin I-converting enzyme (ACE) inhibition is one of the mechanisms by which reduction in blood pressure is exerted. Whey proteins are a rich source of ACE inhibitory peptides and have shown a blood pressure reduction effect i.e. antihypertensive activity. The aim of this work was to develop a simplified process using a combination of adsorption and microfiltration steps for the production of hydrolysates from whey with high ACE inhibitory activity and potency; the latter was measured as the IC50, which is the peptide concentration required to reduce ACE activity by half. This process integrates the selective separation of β-lactoglobulin- and casein-derived peptides (CDP) from rennet whey and their hydrolysis, which results in partially pure, less complex hydrolysates with high bioactive potency. Hydrolysis was carried out with protease N "Amano" in a thermostatically controlled membrane reactor operated in a batch mode. By applying the integrative approach it was possible to produce from the same feedstock two different hydrolysates that exhibited high ACE inhibition. One hydrolysate was mainly composed of casein-derived peptides with IC50=285 μg/mL. In this hydrolysate we identified the well-known potent ACE-inhibitor and antihypertensive tripeptide Ile-Pro-Pro (IPP) and another novel octapeptide Gln-Asp-Lys-Thr-Glu-Ile-Pro-Thr (QDKTEIPT). The second hydrolysate was mainly composed of β-lactoglobulin derived peptides with IC50=28 μg/mL. This hydrolysate contained a tetrapeptide (Ile-Ile-Ala-Glu) IIAE as one of the two major peptides. A further advantage to this process is that enzyme activity was substantially increased as enzyme product inhibition was reduced. PMID:22467199

  14. Histatin 5-Derived Peptide with Improved Fungicidal Properties Enhances Human Immunodeficiency Virus Type 1 Replication by Promoting Viral Entry

    PubMed Central

    Groot, Fedde; Sanders, Rogier W.; ter Brake, Olivier; Nazmi, Kamran; Veerman, Enno C. I.; Bolscher, Jan G. M.; Berkhout, Ben

    2006-01-01

    Antimicrobial peptides are found in a number of body compartments and are secreted at mucosal surfaces, where they form part of the innate immune system. Many of these small peptides have a broad spectrum of inhibitory activity against bacteria, fungi, parasites, and viruses. Generally, the peptide's mode of action is binding and disruption of membranes due to its amphipathic properties. Histatin 5 is a salivary peptide that inhibits Candida albicans, an opportunistic fungus that causes oropharyngeal candidiasis in a majority of human immunodeficiency virus type 1 (HIV-1)-infected patients progressing towards AIDS. Previously, we increased the fungicidal properties of histatin 5 by replacing amino acids in the active domain of histatin 5 (Dh-5) (A. L. Ruissen, J. Groenink, E. J. Helmerhorst, E. Walgreen-Weterings, W. van’t Hof, E. C. Veerman, and A. V. Nieuw Amerongen, Biochem. J. 356:361-368, 2001). In the current study, we tested the anti-HIV-1 activity of Dh-5 and its derivatives. Although Dh-5 inhibited HIV-1 replication, none of the peptide variants were more effective in this respect. In contrast, one of the derivatives, Dhvar2, significantly increased HIV-1 replication by promoting the envelope-mediated cell entry process. Most likely, Dhvar2 affects membranes, thereby facilitating fusion of viral and cellular membranes. This study shows that modification of antimicrobial peptides in order to improve their activity against a pathogen may have unpredictable and unwanted side effects on other pathogens. PMID:16940535

  15. Identification of Equine Lactadherin-derived Peptides That Inhibit Rotavirus Infection via Integrin Receptor Competition*

    PubMed Central

    Civra, Andrea; Giuffrida, Maria Gabriella; Donalisio, Manuela; Napolitano, Lorenzo; Takada, Yoshikazu; Coulson, Barbara S.; Conti, Amedeo; Lembo, David

    2015-01-01

    Human rotavirus is the leading cause of severe gastroenteritis in infants and children under the age of 5 years in both developed and developing countries. Human lactadherin, a milk fat globule membrane glycoprotein, inhibits human rotavirus infection in vitro, whereas bovine lactadherin is not active. Moreover, it protects breastfed infants against symptomatic rotavirus infections. To explore the potential antiviral activity of lactadherin sourced by equines, we undertook a proteomic analysis of milk fat globule membrane proteins from donkey milk and elucidated its amino acid sequence. Alignment of the human, bovine, and donkey lactadherin sequences revealed the presence of an Asp-Gly-Glu (DGE) α2β1 integrin-binding motif in the N-terminal domain of donkey sequence only. Because integrin α2β1 plays a critical role during early steps of rotavirus host cell adhesion, we tested a minilibrary of donkey lactadherin-derived peptides containing DGE sequence for anti-rotavirus activity. A 20-amino acid peptide containing both DGE and RGD motifs (named pDGE-RGD) showed the greatest activity, and its mechanism of antiviral action was characterized; pDGE-RGD binds to integrin α2β1 by means of the DGE motif and inhibits rotavirus attachment to the cell surface. These findings suggest the potential anti-rotavirus activity of equine lactadherin and support the feasibility of developing an anti-rotavirus peptide that acts by hindering virus-receptor binding. PMID:25814665

  16. Multimerized HIV-gp41-derived peptides as fusion inhibitors and vaccines.

    PubMed

    Nomura, Wataru; Mizuguchi, Takaaki; Tamamura, Hirokazu

    2016-11-01

    To date, several antigens based on the amino-terminal leucine/isoleucine heptad repeat (NHR) region of an HIV-1 envelope protein gp41 and fusion inhibitors based on the carboxy-terminal leucine/isoleucine heptad repeat (CHR) region of gp41 have been reported. We have developed a synthetic antigen targeting the membrane-fusion mechanism of HIV-1. This uses a template designed with C3-symmetric linkers and mimics the trimeric form of the NHR-derived peptide N36. The antiserum obtained by immunization of the N36 trimeric antigen binds preferentially to the N36 trimer and blocks HIV-1 infection effectively, compared with the antiserum obtained by immunization of the N36 monomer. Using another template designed with different C3-symmetric linkers, we have also developed a synthetic peptide mimicking the trimeric form of the CHR-derived peptide C34, with ∼100 times the inhibitory activity against the HIV-1 fusion mechanism than that of the monomer C34 peptide. A dimeric derivative of C34 has potent inhibitory activity at almost the same levels as this C34 trimer mimic, suggesting that presence of a dimeric form of C34 is structurally critical for fusion inhibitors. As examples of rising mid-size drugs, this review describes an effective strategy for the design of HIV vaccines and fusion inhibitors based on a relationship with the native structure of proteins involved in HIV fusion mechanisms. © 2015 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 106: 622-628, 2016. PMID:26583370

  17. Studies on Anticancer Activities of Antimicrobial Peptides

    PubMed Central

    Hoskin, David W.; Ramamoorthy, Ayyalusamy

    2008-01-01

    In spite of great advances in cancer therapy, there is considerable current interest in developing anticancer agents with a new mode of action because of the development of resistance by cancer cells towards current anticancer drugs. A growing number of studies have shown that some of the cationic antimicrobial peptides (AMPs), which are toxic to bacteria but not to normal mammalian cells, exhibit a broad spectrum of cytotoxic activity against cancer cells. Such studies have considerably enhanced the significance of AMPs, both synthetic and from natural sources, which have been of importance both for an increased understanding of the immune system and for their potential as clinical antibiotics. The electrostatic attraction between the negatively charged components of bacterial and cancer cells and the positively charged AMPs is believed to play a major role in the strong binding and selective disruption of bacterial and cancer cell membranes, respectively. However, it is unclear why some host defense peptides are able to kill cancer cells when others do not. In addition, it is not clear whether the molecular mechanism(s) underlying the antibacterial and anticancer activities of AMPs are the same or different. In this article, we review various studies on different AMPs that exhibit cytotoxic activity against cancer cells. The suitability of cancer cell-targeting AMPs as cancer therapeutics is also discussed. PMID:18078805

  18. Peptide Array on Cellulose Support—A Screening Tool to Identify Peptides with Dipeptidyl-Peptidase IV Inhibitory Activity within the Sequence of α-Lactalbumin

    PubMed Central

    Lacroix, Isabelle M. E.; Li-Chan, Eunice C. Y.

    2014-01-01

    The inhibition of the enzyme dipeptidyl-peptidase IV (DPP-IV) is an effective pharmacotherapeutic approach for the management of type 2 diabetes. Recent findings have suggested that dietary proteins, including bovine α-lactalbumin, could be precursors of peptides able to inhibit DPP-IV. However, information on the location of active peptide sequences within the proteins is far from being comprehensive. Moreover, the traditional approach to identify bioactive peptides from foods can be tedious and long. Therefore, the objective of this study was to use peptide arrays to screen α-lactalbumin-derived peptides for their interaction with DPP-IV. Deca-peptides spanning the entire α-lactalbumin sequence, with a frame shift of 1 amino acid between successive sequences, were synthesized on cellulose membranes using “SPOT” technology, and their binding to and inhibition of DPP-IV was studied. Among the 114 α-lactalbumin-derived decamers investigated, the peptides 60WCKDDQNPHS69 (αKi = 76 µM), 105LAHKALCSEK114 (Ki = 217 µM) and 110LCSEKLDQWL119 (Ki = 217 µM) were among the strongest DPP-IV inhibitors. While the SPOT- and traditionally-synthesized peptides showed consistent trends in DPP-IV inhibitory activity, the cellulose-bound peptides’ binding behavior was not correlated to their ability to inhibit the enzyme. This research showed, for the first time, that peptide arrays are useful screening tools to identify DPP-IV inhibitory peptides from dietary proteins. PMID:25402645

  19. The Multiplicity of Post-Translational Modifications in Pro-Opiomelanocortin-Derived Peptides

    PubMed Central

    Yasuda, Akikazu; Jones, Leslie Sargent; Shigeri, Yasushi

    2013-01-01

    The precursor protein, pro-opiomelanocortin (POMC) undergoes extensive post-translational processing in a tissue-specific manner to yield various biologically active peptides involved in diverse cellular functions. The recently developed method of matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) for direct tissue analysis has proved to be a powerful tool for investigating the distribution of peptides and proteins. In particular, topological mass spectrometry analysis using MALDI-MS can selectively provide a mass profile of the hormones included in cell secretory granules. An advantage of this technology is that it is possible to analyze a frozen thin slice section, avoiding an extraction procedure. Subsequently, tandem mass spectrometry (MS/MS) has a profound impact on addressing the modified residues in the hormone molecules. Based on these strategies with mass spectrometry, several interesting molecular forms of POMC-derived peptides have been found in the fish pituitary, such as novel sites of acetylation in α-melanocyte-stimulating hormone (MSH), hydroxylation of a proline residue in β-MSH, and the phosphorylated form of corticotropin-like intermediate lobe peptide. PMID:24348461

  20. Protective efficacy of a peptide derived from a potential adhesin of Pseudomonas aeruginosa against corneal infection.

    PubMed

    Yuan, Qing; Wu, Yuting; Wang, Yiqiang; Chen, Lin; Qu, Mingli; Duan, Kangmin; Zhao, Ge

    2016-02-01

    Dissecting the interactions between Pseudomonas aeruginosa and corneal cells is important to identify a novel target for prevention and treatment of Pseudomonas keratitis. The current study began with a peptide identified by phage display, and was to investigate the protective efficacy against P. aeruginosa infection in cornea. The original peptide Pc-E, with high homology to a hypothetical membrane protein (HmpA) in P. aeruginosa, and the derived peptide Pc-EP, with the same sequence as a region in HmpA, were synthesized. Peptide Pc-EP could directly bind to HCEC, stronger than Pc-E, and specifically activate toll-like receptor 5, and thereby significantly induce the production of pro-inflammatory factors, such as IL-1β, IL-6, IFN-γ and IL-17. Moreover, Pc-EP could act as an antagonist to inhibit the adhesion of wild-type P. aeruginosa to HCEC and mouse corneas. No inhibitory effect was observed on the adhesion of the strain loss of HmpA. When compared to the wild-type strain, the adhesion of the hmpA mutant to corneal cells was significantly decreased. Treatment of infected mouse corneas with Pc-EP before infection significantly decreased the bacterial load in the cornea and attenuated the corneal pathology. These results indicate that Pc-EP can be a useful prophylactic agent for P. aeruginosa keratitis. PMID:26500187

  1. Interactions of histatin 5 and histatin 5-derived peptides with liposome membranes: surface effects, translocation and permeabilization.

    PubMed Central

    Den Hertog, Alice L; Wong Fong Sang, Harro W; Kraayenhof, Ruud; Bolscher, Jan G M; Van't Hof, Wim; Veerman, Enno C I; Nieuw Amerongen, Arie V

    2004-01-01

    A number of cationic antimicrobial peptides, among which are histatin 5 and the derived peptides dhvar4 and dhvar5, enter their target cells and interact with internal organelles. There still are questions about the mechanisms by which antimicrobial peptides translocate across the membrane. We used a liposome model to study membrane binding, translocation and membrane-perturbing capacities of histatin 5, dhvar4 and dhvar5. Despite the differences in amphipathic characters of these peptides, they bound equally well to liposomes, whereas their membrane activities differed remarkably: dhvar4 translocated at the fastest rate, followed by dhvar5, whereas the histatin 5 translocation rate was much lower. The same pattern was seen for the extent of calcein release: highest with dhvar4, less with dhvar5 and almost none with histatin 5. The translocation and disruptive actions of dhvar5 did not seem to be coupled, because translocation occurred on a much longer timescale than calcein release, which ended within a few minutes. We conclude that peptide translocation can occur through peptide-phospholipid interactions, and that this is a possible mechanism by which antimicrobial peptides enter cells. However, the translocation rate was much lower in this model membrane system than that seen in yeast cells. Thus it is likely that, at least for some peptides, additional features promoting the translocation across biological membranes are involved as well. PMID:14733612

  2. Non-Peptide Macrocyclic Histone Deacetylase Inhibitors Derived from Tricyclic Ketolide Skeleton

    PubMed Central

    Mwakwari, Sandra C.; Guerrant, William; Patil, Vishal; Khan, Shabana I.; Tekwani, Babu L.; Gurard-Levin, Zachary A.; Mrksich, Milan; Oyelere, Adegboyega K.

    2010-01-01

    Inhibition of histone deacetylase (HDAC) function is a validated therapeutic strategy for cancer treatment. Of the several structurally distinct small molecule histone deacetylase inhibitors (HDACi) reported, macrocyclic depsipeptides possess the most complex cap-groups and have demonstrated excellent HDAC inhibition potency and isoform selectivity. Unfortunately, the development of macrocyclic depsipeptides has been hampered in part due to development problems characteristic of large peptides and the complex reaction schemes required for their synthesis. Herein we report that tricyclic ketolide TE-802 is an excellent mimetic for the peptide backbone of macrocyclic HDACi. Compounds derived from this template are particularly selective against HDAC 1 and 2 with nanomolar inhibitory activity. Interrogation of the association between a subset of these compounds and key HDAC isoforms, using AutoDock, enables a molecular description of the interaction between the HDAC enzyme's outer rim and the inhibitors’ macrocyclic cap group that are responsible for compound affinity and presumably isoform selectivity. PMID:20669972

  3. Peptide mini-scaffold facilitates JNK3 activation in cells

    PubMed Central

    Zhan, Xuanzhi; Stoy, Henriette; Kaoud, Tamer S.; Perry, Nicole A.; Chen, Qiuyan; Perez, Alejandro; Els-Heindl, Sylvia; Slagis, Jack V.; Iverson, Tina M.; Beck-Sickinger, Annette G.; Gurevich, Eugenia V.; Dalby, Kevin N.; Gurevich, Vsevolod V.

    2016-01-01

    Three-kinase mitogen-activated protein kinase (MAPK) signaling cascades are present in virtually all eukaryotic cells. MAPK cascades are organized by scaffold proteins, which assemble cognate kinases into productive signaling complexes. Arrestin-3 facilitates JNK activation in cells, and a short 25-residue arrestin-3 peptide was identified as the critical JNK3-binding element. Here we demonstrate that this peptide also binds MKK4, MKK7, and ASK1, which are upstream JNK3-activating kinases. This peptide is sufficient to enhance JNK3 activity in cells. A homologous arrestin-2 peptide, which differs only in four positions, binds MKK4, but not MKK7 or JNK3, and is ineffective in cells at enhancing activation of JNK3. The arrestin-3 peptide is the smallest MAPK scaffold known. This peptide or its mimics can regulate MAPKs, affecting cellular decisions to live or die. PMID:26868142

  4. Immunological features of T cells induced by human telomerase reverse transcriptase-derived peptides in patients with hepatocellular carcinoma.

    PubMed

    Mizukoshi, Eishiro; Nakagawa, Hidetoshi; Kitahara, Masaaki; Yamashita, Tatsuya; Arai, Kuniaki; Sunagozaka, Hajime; Fushimi, Kazumi; Kobayashi, Eiji; Kishi, Hiroyuki; Muraguchi, Atsushi; Kaneko, Shuichi

    2015-08-10

    Human telomerase reverse transcriptase (hTERT) is a catalytic enzyme required for telomere elongation. In this study, we investigated the safety and immunogenicity of an hTERT-derived peptide (hTERT461) as a vaccine and characterized the hTERT-specific T cell responses induced. Fourteen hepatocellular carcinoma (HCC) patients were enrolled in the study. The hTERT-derived peptide was emulsified in incomplete Freund's adjuvant and administered via subcutaneous immunization three times biweekly. The maximum toxicity observed was grade 2 according to the common terminology criteria and mainly consisted of skin reactions at the site of vaccination. The vaccination induced hTERT-specific immunity in 71.4% of patients and 57.1% of patients administered with hTERT461 peptide-specific T cells could prevent HCC recurrence after vaccination. In phenotypic analysis, the post-vaccinated increase in hTERT-specific T cells was due to an increase in cells with the effector memory phenotype, with the potential to produce multiple cytokines. Seven hTERT-specific T cell receptors were obtained from the vaccinated patients, showing their cytotoxic activities to hTERT-derived peptide-bearing cells. In conclusion, the safety and effects of immune boosting by hTERT461 peptide have shown the potential of the peptide to provide clinical benefits in HCC patients. PMID:25982205

  5. Spectroscopic and structural elucidation of amino acid derivatives and small peptides: experimental and theoretical tools.

    PubMed

    Kolev, Tsonko; Spiteller, Michael; Koleva, Bojidarka

    2010-01-01

    This mini review deals with the modern aspects of the spectroscopy and structural elucidation of amino acid derivatives and small biologically active compounds. Free peptide bond rotation in these systems yields various conformers, which possess differing biological activities. Another phenomenon is the intermolecular or intramolecular stacking observed in aromatic small peptides. Specifically, the main aim is to illustrate the successful application of the "complex tool", consisting of a combination of the theoretical approximation methods with experimental linear polarized infrared (IR-LD) and/or Raman spectroscopy of oriented colloid suspensions in a nematic host. The possibilities and limitations of the approach for detailed vibrational assignment and structural elucidation of small peptides are discussed. Having in mind that physical and chemical properties of these systems can be precisely calculated by means of ab initio and DFT methods at Hartee-Fock, MP2 and B3LYP level of theory, varying basis sets, the results obtained allow a precise assignment of many vibrational bands to the corresponding normal modes, electronic structures and conformational state. The validity of the conclusions about the structure or vibrational properties of these systems have been supported, compared and/or additionally proved by the results from independent physical methods. In this respect (1)H and (13)C-NMR, single crystal X-ray diffraction, HPLC tandem mass spectrometry as well as thermal methods are all employed. A well ordered crystal must first be grown in order to determine the molecular structure by the absolute method of single crystal X-ray diffraction. Although the 3D structures of peptides have been determined over the past decades, peptide crystallization is still a major obstacle to X-ray diffraction work, the presence of chiral centre/s makes for this difficulty. For this reason the "complex tool" presented can be regarded as an alternative method for obtaining of

  6. Enhanced antimicrobial activity of peptide-cocktails against common bacterial contaminants of ex vivo stored platelets.

    PubMed

    Mohan, K V K; Rao, S Sainath; Gao, Y; Atreya, C D

    2014-01-01

    Bacterial contamination of blood components such as ex vivo-stored platelets is a major safety risk in transfusion medicine. We have recently shown that synthetic antimicrobial peptides named PD1-PD4 derived from the thrombin-induced human platelet-derived antimicrobial proteins, and repeats of Arg-Trp (RW1-RW5) demonstrate microbicidal activity against selected bacteria and viruses. In the present study, we selected PD3, PD4, RW2, RW3 and RW4 and evaluated each individual peptide and their various combinations to see whether the cocktail regimen enhances the antimicrobial activity above and over the individual peptides. Stored platelet or plasma samples spiked with known titres of Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae and Bacillus cereus were treated with either individual peptides or with peptides in various combinations. Analyses revealed that individual peptides show moderate microbicidal activity (10- to 100-fold reduction) against the tested bacteria relative to their combined regimen. The peptide combinations (RW2 + RW4, RW2 + RW3 + RW4 and PD4 + RW3 + RW4) on the other hand enhanced the microbicidal activity (c.10 000-fold reduction) and revealed a minimal inhibitory concentration of 5 μM. Time-kill kinetics indicated that these three peptide combinations exhibited enhanced antimicrobial activity bringing about a 100-fold reduction of bacterial titres within 20 min of incubation. The present study therefore demonstrates the synergistic effect of antimicrobial peptides when used in combinations and provides a proof-of-concept of its potential application as a molecular tool towards pathogen reduction and further extends the possibility of using peptide combinatorial therapeutics as broad-spectrum antibiotics or as alternatives to combat drug-resistant bacteria. PMID:23926880

  7. [Prospects for use of peptides and their derivatives, structurally corresponding to the G protein-coupled receptors, in medicine].

    PubMed

    Shpakov, A O; Shpakova, E A

    2015-01-01

    The regulation of signaling pathways involved in the control of many physiological functions is carried out via the heterotrimeric G protein-coupled receptors (GPCR). The search of effective and selective regulators of GPCR and intracellular signaling cascades coupled with them is one of the important problems of modern fundamental and clinical medicine. Recently data suggest that synthetic peptides and their derivatives, structurally corresponding to the intracellular and transmembrane regions of GPCR, can interact with high efficiency and selectivity with homologous receptors and influence, thus, the functional activity of intracellular signaling cascades and fundamental cellular processes controlled by them. GPCR-peptides are active in both in vitro and in vivo. They regulate hematopoiesis, angiogenesis and cell proliferation, inhibit tumor growth and metastasis, and prevent the inflammatory diseases and septic shock. These data show greatest prospects in the development of the new generations of drugs based on GPCR-derived peptides, capable of regulating the important functions of the organism. PMID:25762596

  8. Purification and characterisation of antibacterial peptide-containing compound derived from palm kernel cake.

    PubMed

    Tan, Yen Nee; Ayob, Mohd Khan; Wan Yaacob, Wan Ahmad

    2013-01-01

    Palm kernel cake (PKC), the most useful by-product resulted from palm kernel oil production. In this study, PKC-derived protein product was found suitable for use as an antimicrobial agent with potent antibacterial activity, particularly against Bacillus species, after enzymatic hydrolysis with alcalase. The hydrolysate was further purified by gel filtration chromatography. The purified fraction was found to have 14.63±0.70% (w/w) protein, a molecular mass of 2.4kDa and low hemolytic activity (<50% hemolysis of human erythrocytes at concentration of 1000μg/ml). The presence of lysine and the major component lauric acid derivative, as indicated by electrospray ionisation-mass spectrometry (ESI-MS) direct infusion and nuclear magnetic resonance (NMR) spectroscopy, may have contributed to the antibacterial effect of purified PKC fraction. This study suggests that the antibacterial PKC compound may be not a pure peptide but instead a peptide-containing compound high in lauric acid derivative. PMID:23017424

  9. Chemical activity of simple basic peptides

    NASA Astrophysics Data System (ADS)

    Brack, André; Barbier, Bernard

    1990-03-01

    Alternating all-L poly(leucyl-lysyl) increases markedly the rate of hydrolysis of oligoribonucleotides. Pure D poly (leucyl-lysyl) is as active as the all-L polymer. The homochiral polypeptides adopt aβ-sheet structure when complexed to the oligonucleotides. Alternating poly(D,L-Leu-D,L-Lys) made of racemic amino acids is much less efficient and is unable to adopt aβ-sheet structure. A set of alternating poly (leucyl-lysyl) ranging from the racemic to the homochiral all-L polymer has been checked. Their conformations can be described as a mixture of random coil andβ-sheet conformations, the amount ofβ-sheet increasing with the optical purity of the polymer. The hydrolytic activity follows the proportion ofβ-sheets, suggesting that the chemical activity is related to the geometry of the chain. Short peptides were prepared in order to evaluate the critical chain length required for the hydrolytic activity. A decapeptide is long enough to present 90% of the activity of the corresponding polypeptide.

  10. Constitutive expression of transgenes encoding derivatives of the synthetic antimicrobial peptide BP100: impact on rice host plant fitness

    PubMed Central

    2012-01-01

    Background The Biopeptide BP100 is a synthetic and strongly cationic α-helical undecapeptide with high, specific antibacterial activity against economically important plant-pathogenic bacteria, and very low toxicity. It was selected from a library of synthetic peptides, along with other peptides with activities against relevant bacterial and fungal species. Expression of the BP100 series of peptides in plants is of major interest to establish disease-resistant plants and facilitate molecular farming. Specific challenges were the small length, peptide degradation by plant proteases and toxicity to the host plant. Here we approached the expression of the BP100 peptide series in plants using BP100 as a proof-of-concept. Results Our design considered up to three tandemly arranged BP100 units and peptide accumulation in the endoplasmic reticulum (ER), analyzing five BP100 derivatives. The ER retention sequence did not reduce the antimicrobial activity of chemically synthesized BP100 derivatives, making this strategy possible. Transformation with sequences encoding BP100 derivatives (bp100der) was over ten-fold less efficient than that of the hygromycin phosphotransferase (hptII) transgene. The BP100 direct tandems did not show higher antimicrobial activity than BP100, and genetically modified (GM) plants constitutively expressing them were not viable. In contrast, inverted repeats of BP100, whether or not elongated with a portion of a natural antimicrobial peptide (AMP), had higher antimicrobial activity, and fertile GM rice lines constitutively expressing bp100der were produced. These GM lines had increased resistance to the pathogens Dickeya chrysanthemi and Fusarium verticillioides, and tolerance to oxidative stress, with agronomic performance comparable to untransformed lines. Conclusions Constitutive expression of transgenes encoding short cationic α-helical synthetic peptides can have a strong negative impact on rice fitness. However, GM plants expressing, for

  11. Characterization of the antimicrobial peptide derived from sapecin B, an antibacterial protein of Sarcophaga peregrina (flesh fly).

    PubMed Central

    Yamada, K; Natori, S

    1994-01-01

    Sapecin B, an antibacterial protein of Sarcophaga peregrina, was divided into four peptides. A hendecapeptide derived from its helix region was found to have comparable antibacterial activity with that of the complete protein. This peptide had a much wider spectrum of antimicrobial activity than that of sapecin B, exhibiting activity on not only Staphylococcus aureus (Gram-positive) and Escherichia coli (Gram-negative), but also some yeasts, including Candida albicans. The peptide was shown to bind to liposomes containing acidic phospholipids and cause release of entrapped glucose, suggesting that its primary site of action is the bacterial membrane. Its antimicrobial activity could be increased by substituting various amino acid residues for hydrophobic and/or basic ones. PMID:8141776

  12. Improving short antimicrobial peptides despite elusive rules for activity.

    PubMed

    Mikut, Ralf; Ruden, Serge; Reischl, Markus; Breitling, Frank; Volkmer, Rudolf; Hilpert, Kai

    2016-05-01

    Antimicrobial peptides (AMPs) can effectively kill a broad range of life threatening multidrug-resistant bacteria, a serious threat to public health worldwide. However, despite great hopes novel drugs based on AMPs are still rare. To accelerate drug development we studied different approaches to improve the antibacterial activity of short antimicrobial peptides. Short antimicrobial peptides seem to be ideal drug candidates since they can be synthesized quickly and easily, modified and optimized. In addition, manufacturing a short peptide drug will be more cost efficient than long and structured ones. In contrast to longer and structured peptides short AMPs seem hard to design and predict. Here, we designed, synthesized and screened five different peptide libraries, each consisting of 600 9-mer peptides, against Pseudomonas aeruginosa. Each library is presenting a different approach to investigate effectiveness of an optimization strategy. The data for the 3000 peptides were analyzed using models based on fuzzy logic bioinformatics and plausible descriptors. The rate of active or superior active peptides was improved from 31.0% in a semi-random library from a previous study to 97.8% in the best new designed library. This article is part of a Special Issue entitled: Antimicrobial peptides edited by Karl Lohner and Kai Hilpert. PMID:26687790

  13. A common landscape for membrane-active peptides

    PubMed Central

    Last, Nicholas B; Schlamadinger, Diana E; Miranker, Andrew D

    2013-01-01

    Three families of membrane-active peptides are commonly found in nature and are classified according to their initial apparent activity. Antimicrobial peptides are ancient components of the innate immune system and typically act by disruption of microbial membranes leading to cell death. Amyloid peptides contribute to the pathology of diverse diseases from Alzheimer's to type II diabetes. Preamyloid states of these peptides can act as toxins by binding to and permeabilizing cellular membranes. Cell-penetrating peptides are natural or engineered short sequences that can spontaneously translocate across a membrane. Despite these differences in classification, many similarities in sequence, structure, and activity suggest that peptides from all three classes act through a small, common set of physical principles. Namely, these peptides alter the Brownian properties of phospholipid bilayers, enhancing the sampling of intrinsic fluctuations that include membrane defects. A complete energy landscape for such systems can be described by the innate membrane properties, differential partition, and the associated kinetics of peptides dividing between surface and defect regions of the bilayer. The goal of this review is to argue that the activities of these membrane-active families of peptides simply represent different facets of what is a shared energy landscape. PMID:23649542

  14. Peptide fibrils with altered stability, activity, and cell selectivity

    PubMed Central

    Chen, Long; Liang, Jun F.

    2014-01-01

    Peptides have some unique and superior features compared to proteins. However, the use of peptides as therapeutics is hampered by their low stability and cell selectivity. In this study, a new lytic peptide (CL-1, FLGALFRALSRLL) was constructed. Under the physiological condition, peptide CL-1 self-assembled into dynamically stable aggregates with fibrils-like structures. Aggregated CL-1 demonstrated dramatically altered activity and stability in comparison with single molecule CL-1 and other lytic peptides: when incubated with co-cultured bacteria and tissue cells, CL-1 aggregates killed bacteria selectively but spared co-cultured human cells; CL-1 aggregates kept intact in human serum for more than five hours. Peptide-cell interaction studies performed on lipid monolayers and live human tissue cells revealed that in comparison with monomeric CL-1, aggregated CL-1 had decreased cell affinity and membrane insertion capability on tissue cells. A dynamic process involving aggregate dissociation and rearrangement seemed to be an essential step for membrane bound CL-1 aggregates to realize its cytotoxicity to tissue cells. Our study suggests that peptide aggregation could be as important as the charge and secondary structure of a peptide in affecting peptide-cell interactions. Controlling peptide self-assembly represents a new way to increase the stability and cell selectivity of bioactive peptides for wide biomedical applications. PMID:23713839

  15. A Tetrameric Peptide Derived from Bovine Lactoferricin Exhibits Specific Cytotoxic Effects against Oral Squamous-Cell Carcinoma Cell Lines

    PubMed Central

    Solarte, Víctor A.; Rosas, Jaiver E.; Rivera, Zuly J.; Arango-Rodríguez, Martha L.; García, Javier E.; Vernot, Jean-Paul

    2015-01-01

    Several short linear peptides derived from cyclic bovine lactoferricin were synthesized and tested for their cytotoxic effect against the oral cavity squamous-cell carcinoma (OSCC) cell lines CAL27 and SCC15. As a control, an immortalized and nontumorigenic cell line, Het-1A, was used. Linear peptides based on the RRWQWR core sequence showed a moderate cytotoxic effect and specificity towards tumorigenic cells. A tetrameric peptide, LfcinB(20–25)4, containing the RRWQWR motif, exhibited greater cytotoxic activity (>90%) in both OSCC cell lines compared to the linear lactoferricin peptide or the lactoferrin protein. Additionally, this tetrameric peptide showed the highest specificity towards tumorigenic cells among the tested peptides. Interestingly, this effect was very fast, with cell shrinkage, severe damage to cell membrane permeability, and lysis within one hour of treatment. Our results are consistent with a necrotic effect rather than an apoptotic one and suggest that this tetrameric peptide could be considered as a new candidate for the therapeutic treatment of OSCC. PMID:26609531

  16. Design and Evaluation of Antimalarial Peptides Derived from Prediction of Short Linear Motifs in Proteins Related to Erythrocyte Invasion

    PubMed Central

    Bianchin, Alessandra; Bell, Angus; Chubb, Anthony J.; Doolan, Nathalie; Leneghan, Darren; Stavropoulos, Ilias; Shields, Denis C.; Mooney, Catherine

    2015-01-01

    The purpose of this study was to investigate the blood stage of the malaria causing parasite, Plasmodium falciparum, to predict potential protein interactions between the parasite merozoite and the host erythrocyte and design peptides that could interrupt these predicted interactions. We screened the P. falciparum and human proteomes for computationally predicted short linear motifs (SLiMs) in cytoplasmic portions of transmembrane proteins that could play roles in the invasion of the erythrocyte by the merozoite, an essential step in malarial pathogenesis. We tested thirteen peptides predicted to contain SLiMs, twelve of them palmitoylated to enhance membrane targeting, and found three that blocked parasite growth in culture by inhibiting the initiation of new infections in erythrocytes. Scrambled peptides for two of the most promising peptides suggested that their activity may be reflective of amino acid properties, in particular, positive charge. However, one peptide showed effects which were stronger than those of scrambled peptides. This was derived from human red blood cell glycophorin-B. We concluded that proteome-wide computational screening of the intracellular regions of both host and pathogen adhesion proteins provides potential lead peptides for the development of anti-malarial compounds. PMID:26039561

  17. Improved biological activity of antisense oligonucleotides conjugated to a fusogenic peptide.

    PubMed Central

    Bongartz, J P; Aubertin, A M; Milhaud, P G; Lebleu, B

    1994-01-01

    Recently several groups reported a dramatic improvement of reporter gene transfection efficiency using a fusogenic peptide, derived from the Influenza hemagglutinin envelop protein. This peptide changes conformation at acidic pH and destabilizes the endosomal membranes thus resulting in an increased cytoplasmic gene delivery. We describe the use of a similar fusogenic peptide in order to improve the antiviral potency of antisense oligodeoxynucleotides (anti TAT) and oligophosphorothioates (S-dC28) on de novo HIV infected CEM-SS lymphocytes in serum-free medium. We observed as 5 to 10 fold improvement of the anti HIV activities of the phosphodiester antisense oligonucleotides after chemical coupling to the peptide in a one to one ratio by a disulfide or thioether bond. No toxicities were observed at the effective doses (0.1-1 microM). No sequence specificity was obtained and the fusogenic peptide possessed some antiviral activities on its own (IC50: 6 microM). A S-dC28-peptide disulfide linked conjugate and a streptavidin-peptide-biotinylated S-dC28 adduct showed similar activities as the free S-dC28 oligonucleotide (IC50: 0.1-1 nM). As expected, all the compounds were less potent in the presence of serum but the relative contribution of peptide coupling was maintained. Images PMID:7984418

  18. Some Active Derivatives of Penicillin

    PubMed Central

    Brown, Loman D.; Zygmunt, Walter A.; Stavely, Homer E.

    1969-01-01

    The antibacterial activities of a number of amide derivatives of penicillin against both penicillin-sensitive and penicillin-resistant cultures were determined. Several of them were found to possess significant inhibitory activity against certain gram-positive bacteria. The amides, although resistant to the destructive action of β-lactamase, did not protect G in competitive experiments. One derivative, the O-benzylhydroxamide of penicillin G, was active against six or eight penicillin-resistant strains of Staphylococcus aureus (minimal inhibitory concentration, 0.2 μg/ml or less), but was found to have only a minimal in vivo activity against mouse Streptococcus infections. PMID:5780394

  19. A recombinant slow-release PACAP-derived peptide alleviates diabetes by promoting both insulin secretion and actions.

    PubMed

    Ma, Yi; Fang, Shixiong; Zhao, Shaojun; Wang, Xiaoli; Wang, Dongbo; Ma, Min; Luo, Tianjie; Hong, An

    2015-05-01

    Pituitary adenylate cyclase activating polypeptide (PACAP) is a neuroendocrine factor that activates both the receptor VPAC1 and VPAC2. Although PACAP possesses insulinotropic activity, its therapeutic application is limited by the extremely short acting half-life and the stimulatory effects on glucagon production via a VPAC1-dependent mechanism. Here we have generated a recombinant PACAP-derived peptide (named as MHDBAY) comprising a 7-mer albumin-binding peptide identified by phage display screening (WQRPSSW), a cleavage peptide for Factor Xa (FXa) and dipeptidyl peptidase IV (DPP IV), and a 31-amino acid PACAP-derived peptide (DBAY) that can specifically bind to the VPAC2 receptor. MHDBAY binds to albumin both in vitro and in animals, thereby leading to an orderly slow release of the active peptide DBAY via the protease cleavage. In db/db mice and New Zealand rabbits, the circulating half-life of MHDBAY is approximately 12.2 h, which is 146-fold longer than DBAY (∼5 min). A single injection of MHDBAY into db/db diabetic mice markedly increases insulin secretion, thereby leading to sustained alleviation of hyperglycemia. The potency and duration of MHDBAY in increasing insulin secretion and decreasing blood glucose levels is much greater than Exendin-4, an anti-diabetic drug via its insulinotropic actions. Furthermore, chronic administration of MHDBAY by daily injection for 8 weeks significantly improves both glucose and lipid profiles and also greatly increases insulin sensitivity in db/db mice. These findings suggest that serum albumin may act as a reservoir for slow-release of small bioactive peptides, and MHDBAY may represent a promising therapeutic peptide for diabetes. PMID:25771000

  20. Synthetic peptide derived from alpha-fetoprotein inhibits growth of human breast cancer: investigation of the pharmacophore and synthesis optimization.

    PubMed

    DeFreest, L A; Mesfin, F B; Joseph, L; McLeod, D J; Stallmer, A; Reddy, S; Balulad, S S; Jacobson, H I; Andersen, T T; Bennett, J A

    2004-05-01

    Asynthetic peptide that inhibits the growth of estrogen receptor positive (ER+) human breast cancers, growing as xenografts in mice, has been reported. The cyclic 9-mer peptide, cyclo[EMTOVNOGQ], is derived from alpha-fetoprotein (AFP), a safe, naturally occurring human protein produced during pregnancy, which itself has anti-estrogenic and anti-breast cancer activity. To determine the pharmacophore of the peptide, a series of analogs was prepared using solid-phase peptide synthesis. Analogs were screened in a 1-day bioassay, which assessed their ability to inhibit the estrogen-stimulated growth of uterus in immature mice. Deletion of glutamic acid, Glu1, abolished activity of the peptide, but glutamine (Gln) or asparagine (Asn) could be substituted for Glu1 without loss of activity. Methionine (Met2) was replaced with lysine (Lys) or tyrosine (Tyr) with retention of activity. Substitution of Lys for Met2 in the cyclic molecule resulted in a compound with activity comparable with the Met2-containing cyclic molecule, but with a greater than twofold increase in purity and corresponding increase in yield. This Lys analog demonstrated anti-breast cancer activity equivalent to that of the original Met-containing peptide. Therefore, Met2 is not essential for biologic activity and substitution of Lys is synthetically advantageous. Threonine (Thr3) is a nonessential site, and can be substituted with serine (Ser), valine (Val), or alanine (Ala) without significant loss of activity. Hydroxyproline (Hyp), substituted in place of the naturally occurring prolines (Pro4, Pro7), allowed retention of activity and increased stability of the peptide during storage. Replacement of the first Pro (Pro4) with Ser maintains the activity of the peptide, but substitution of Ser for the second Pro (Pro7) abolishes the activity of the peptide. This suggests that the imino acid at residue 7 is important for conformation of the peptide, and the backbone atoms are part of the pharmacophore, but

  1. Antiproliferative effect and characterization of a novel antifungal peptide derived from human Chromogranin A

    PubMed Central

    LI, RUI-FANG; LU, YA-LI; LU, YAN-BO; ZHANG, HUI-RU; HUANG, LIANG; YIN, YANLI; ZHANG, LIN; LIU, SHUAI; LU, ZHIFANG; SUN, YANAN

    2015-01-01

    CGA-N46 is a novel antifungal peptide derived from the N-terminus of human Chromogranin A, corresponding to the 31st to 76th amino acids. Further research on its activities and characteristics may be helpful for the application of CGA-N46 in medical or other situations. In the present study, the antifungal spectrum and physicochemical characteristics of CGA-N46 were investigated using an antifungal assay, its antiproliferative effects on cancer and normal cells were assessed using MTT assay and its combinatorial effect with other antibiotics was analyzed using checkerboard analysis. The results showed that CGA-N46 exhibited antifungal activity against the tested Candidas (C. glabrata, C. parapsilosis, C. krusei, C. tropicalis and C. albicans) at a concentration of <0.8 mM, but had no effect on the growth of filamentous fungi or other types of fungi (Cryptococcus neoformans, Aspergillus fumigatus, Aspergillus flavus, Aspergillus niger, Fusarium moniliforme, Microsporum canis, Microsporum gypseum, Trichophyton rubrum and Trichophyton mentagrophytes), even at a concentration of 3.2 mM. CGA-N46 had an inhibitory effect on the proliferation of lung cancer A549 cells and a reversible effect on the growth of normal primary chicken embryo fibroblast cells, but no hemolytic activity on human erythrocytes at the minimum inhibitory concentration of CGA-N46 against yeasts. The antifungal activity of CGA-N46 was stable at a temperature <40°C or within a broad pH range (pH 5.0–7.0). Its antifungal activity was enhanced when the peptide was used in combination with fluconazole and terbinafine. The present results indicate that CGA-N46 is a safe, physicochemically stable, antifungal peptide with anticancer cell activity that exhibits an additive effect with conventional antibiotics. PMID:26668630

  2. A novel antimicrobial peptide derived from fish goose type lysozyme disrupts the membrane of Salmonella enterica.

    PubMed

    Kumaresan, Venkatesh; Bhatt, Prasanth; Ganesh, Munuswamy-Ramanujam; Harikrishnan, Ramasamy; Arasu, MariadhasValan; Al-Dhabi, Naif Abdullah; Pasupuleti, Mukesh; Marimuthu, Kasi; Arockiaraj, Jesu

    2015-12-01

    In aquaculture, accumulation of antibiotics resulted in development of resistance among bacterial pathogens. Consequently, it became mandatory to find alternative to synthetic antibiotics. Antimicrobial peptides (AMPs) which are described as evolutionary ancient weapons have been considered as promising alternates in recent years. In this study, a novel antimicrobial peptide had been derived from goose type lysozyme (LyzG) which was identified from the cDNA library of freshwater fish Channa striatus (Cs). The identified lysozyme cDNA contains 585 nucleotides which encodes a protein of 194 amino acids. CsLyzG was closely related to Siniperca chuatsi with 92.8% homology. The depicted protein sequence contained a GEWL domain with conserved GLMQ motif, 7 active residues and 2 catalytic residues. Gene expression analysis revealed that CsLyzG was distributed in major immune organs with highest expression in head kidney. Results of temporal expression analysis after bacterial (Aeromonas hydrophila) and fungal (Aphanomyces invadans) challenges indicated a stimulant-dependent expression pattern of CsLyzG. Two antimicrobial peptides IK12 and TS10 were identified from CsLyzG and synthesized. Antibiogram showed that IK12 was active against Salmonella enterica, a major multi-drug resistant (MDR) bacterial pathogen which produces beta lactamase. The IK12 induced loss of cell viability in the bacterial pathogen. Flow cytometry assay revealed that IK12 disrupt the membrane of S. enterica which is confirmed by scanning electron microscope (SEM) analysis that reveals blebs around the bacterial cell membrane. Conclusively, CsLyzG is a potential innate immune component and the identified antimicrobial peptide has great caliber to be used as an ecofriendly antibacterial substance in aquaculture. PMID:26477736

  3. Anticancer and antioxidant activities of the peptide fraction from algae protein waste.

    PubMed

    Sheih, I-Chuan; Fang, Tony J; Wu, Tung-Kung; Lin, Peng-Hsiang

    2010-01-27

    Algae protein waste is a byproduct during production of algae essence from Chlorella vulgaris. There is no known report on the anticancer peptides derived from the microalgae protein waste. In this paper, the peptide fraction isolated from pepsin hydrolysate of algae protein waste had strong dose-dependent antiproliferation and induced a post-G1 cell cycle arrest in AGS cells; however, no cytotoxicity was observed in WI-38 lung fibroblasts cells in vitro. The peptide fraction also revealed much better antioxidant activity toward peroxyl radicals and LDL than those of Trolox. Among these peptides, a potent antiproliferative, antioxidant, and NO-production-inhibiting hendecapeptide was isolated, and its amino acid sequence was VECYGPNRPQF. These results demonstrate that inexpensive algae protein waste could be a new alternative to produce anticancer peptides. PMID:19916544

  4. Identification of Protease Specificity by Combining Proteome-Derived Peptide Libraries and Quantitative Proteomics.

    PubMed

    Biniossek, Martin L; Niemer, Melanie; Maksimchuk, Ken; Mayer, Bettina; Fuchs, Julian; Huesgen, Pitter F; McCafferty, Dewey G; Turk, Boris; Fritz, Guenther; Mayer, Jens; Haecker, Georg; Mach, Lukas; Schilling, Oliver

    2016-07-01

    We present protease specificity profiling based on quantitative proteomics in combination with proteome-derived peptide libraries. Peptide libraries are generated by endoproteolytic digestion of proteomes without chemical modification of primary amines before exposure to a protease under investigation. After incubation with a test protease, treated and control libraries are differentially isotope-labeled using cost-effective reductive dimethylation. Upon analysis by liquid chromatography-tandem mass spectrometry, cleavage products of the test protease appear as semi-specific peptides that are enriched for the corresponding isotope label. We validate our workflow with two proteases with well-characterized specificity profiles: trypsin and caspase-3. We provide the first specificity profile of a protease encoded by a human endogenous retrovirus and for chlamydial protease-like activity factor (CPAF). For CPAF, we also highlight the structural basis of negative subsite cooperativity between subsites S1 and S2'. For A disintegrin and metalloproteinase with thrombospondin motifs (ADAMTS) -4, -5, and -15, we show a canonical preference profile, including glutamate in P1 and glycine in P3'. In total, we report nearly 4000 cleavage sites for seven proteases. Our protocol is fast, avoids enrichment or synthesis steps, and enables probing for lysine selectivity as well as subsite cooperativity. Due to its simplicity, we anticipate usability by most proteomic laboratories. PMID:27122596

  5. Immunogenicity of HLA Class I and II Double Restricted Influenza A-Derived Peptides

    PubMed Central

    Pedersen, Sara Ram; Christensen, Jan Pravsgaard; Buus, Søren; Rasmussen, Michael; Korsholm, Karen Smith; Nielsen, Morten; Claesson, Mogens Helweg

    2016-01-01

    The aim of the present study was to identify influenza A-derived peptides which bind to both HLA class I and -II molecules and by immunization lead to both HLA class I and class II restricted immune responses. Eight influenza A-derived 9-11mer peptides with simultaneous binding to both HLA-A*02:01 and HLA-DRB1*01:01 molecules were identified by bioinformatics and biochemical technology. Immunization of transgenic HLA-A*02:01/HLA-DRB1*01:01 mice with four of these double binding peptides gave rise to both HLA class I and class II restricted responses by CD8 and CD4 T cells, respectively, whereas four of the double binding peptides did result in HLA-A*02:01 restricted responses only. According to their cytokine profile, the CD4 T cell responses were of the Th2 type. In influenza infected mice, we were unable to detect natural processing in vivo of the double restricted peptides and in line with this, peptide vaccination did not decrease virus titres in the lungs of intranasally influenza challenged mice. Our data show that HLA class I and class II double binding peptides can be identified by bioinformatics and biochemical technology. By immunization, double binding peptides can give rise to both HLA class I and class I restricted responses, a quality which might be of potential interest for peptide-based vaccine development. PMID:26731261

  6. In vitro immunostimulatory properties of Abrus lectins derived peptides in tumor bearing mice.

    PubMed

    Bhutia, Sujit K; Mallick, Sanjaya K; Maiti, Tapas K

    2009-08-01

    In vitro immunostimulatory effect of Abrus lectins derived peptide fractions (AGP and ABP) was investigated in DL bearing mice. Both AGP and ABP were found to activate splenocytes and induced production of cytokines like IL-2, IFN-gamma and TNF-alpha indicating a Th1 type of immune response. Analysis of in vitro treated splenocytes by flow cytometry revealed an increase in percentage of T and B cell with high expression of activation markers (CD25(+) and CD71(+)). At the same time, expression of co-stimulatory markers was significantly high compared to tumor control. The tumor associated macrophages were able to stimulate NO production, IL-1 secretion, increased phagocytosis and decreased expression of mannose receptor. It was also observed that NK cell was activated by AGP and ABP. These results suggest that both AGP and ABP act as immunostimulants in vitro in DL bearing mice. PMID:19303750

  7. Food-derived sensory cues modulate longevity via distinct neuroendocrine insulin-like peptides.

    PubMed

    Artan, Murat; Jeong, Dae-Eun; Lee, Dongyeop; Kim, Young-Il; Son, Heehwa G; Husain, Zahabiya; Kim, Jinmahn; Altintas, Ozlem; Kim, Kyuhyung; Alcedo, Joy; Lee, Seung-Jae V

    2016-05-01

    Environmental fluctuations influence organismal aging by affecting various regulatory systems. One such system involves sensory neurons, which affect life span in many species. However, how sensory neurons coordinate organismal aging in response to changes in environmental signals remains elusive. Here, we found that a subset of sensory neurons shortens Caenorhabditis elegans' life span by differentially regulating the expression of a specific insulin-like peptide (ILP), INS-6. Notably, treatment with food-derived cues or optogenetic activation of sensory neurons significantly increases ins-6 expression and decreases life span. INS-6 in turn relays the longevity signals to nonneuronal tissues by decreasing the activity of the transcription factor DAF-16/FOXO. Together, our study delineates a mechanism through which environmental sensory cues regulate aging rates by modulating the activities of specific sensory neurons and ILPs. PMID:27125673

  8. Antimicrobial activity of mosquito cecropin peptides against Francisella.

    PubMed

    Kaushal, Akanksha; Gupta, Kajal; Shah, Ruhee; van Hoek, Monique L

    2016-10-01

    Francisella tularensis is the cause of the zoonotic disease tularemia. In Sweden and Scandinavia, epidemiological studies have implicated mosquitoes as a vector. Prior research has demonstrated the presence of Francisella DNA in infected mosquitoes but has not shown definitive transmission of tularemia from a mosquito to a mammalian host. We hypothesized that antimicrobial peptides, an important component of the innate immune system of higher organisms, may play a role in mosquito host-defense to Francisella. We established that Francisella sp. are susceptible to two cecropin antimicrobial peptides derived from the mosquito Aedes albopictus as well as Culex pipiens. We also demonstrated induced expression of Aedes albopictus antimicrobial peptide genes by Francisella infection C6/36 mosquito cell line. We demonstrate that mosquito antimicrobial peptides act against Francisella by disrupting the cellular membrane of the bacteria. Thus, it is possible that antimicrobial peptides may play a role in the inability of mosquitoes to establish an effective natural transmission of tularemia. PMID:27235883

  9. Antibody Constant Region Peptides Can Display Immunomodulatory Activity through Activation of the Dectin-1 Signalling Pathway

    PubMed Central

    Cenci, Elio; Monari, Claudia; Magliani, Walter; Ciociola, Tecla; Conti, Stefania; Gatti, Rita; Bistoni, Francesco; Polonelli, Luciano; Vecchiarelli, Anna

    2012-01-01

    We previously reported that a synthetic peptide with sequence identical to a CDR of a mouse monoclonal antibody specific for difucosyl human blood group A exerted an immunomodulatory activity on murine macrophages. It was therapeutic against systemic candidiasis without possessing direct candidacidal properties. Here we demonstrate that a selected peptide, N10K, putatively deriving from the enzymatic cleavage of the constant region (Fc) of human IgG1, is able to induce IL-6 secretion and pIkB-α activation. More importantly, it causes an up-regulation of Dectin-1 expression. This leads to an increased activation of β-glucan-induced pSyk, CARD9 and pIkB-α, and an increase in the production of pro-inflammatory cytokines such as IL-6, IL-12, IL-1β and TNF-α. The increased activation of this pathway coincides with an augmented phagocytosis of non opsonized Candida albicans cells by monocytes. The findings suggest that some Fc-peptides, potentially deriving from the proteolysis of immunoglobulins, may cause an unexpected immunoregulation in a way reminiscent of innate immunity molecules. PMID:22952831

  10. Anti-Legionella activity of staphylococcal hemolytic peptides.

    PubMed

    Marchand, A; Verdon, J; Lacombe, C; Crapart, S; Héchard, Y; Berjeaud, J M

    2011-05-01

    A collection of various Staphylococci was screened for their anti-Legionella activity. Nine of the tested strains were found to secrete anti-Legionella compounds. The culture supernatants of the strains, described in the literature to produce hemolytic peptides, were successfully submitted to a two step purification process. All the purified compounds, except one, corresponded to previously described hemolytic peptides and were not known for their anti-Legionella activity. By comparison of the minimal inhibitory concentrations, minimal permeabilization concentrations, decrease in the number of cultivable bacteria, hemolytic activity and selectivity, the purified peptides could be separated in two groups. First group, with warnericin RK as a leader, corresponds to the more hemolytic and bactericidal peptides. The peptides of the second group, represented by the PSMα from Staphylococcus epidermidis, appeared bacteriostatic and poorly hemolytic. PMID:21291938

  11. Prediction of Antibacterial Activity from Physicochemical Properties of Antimicrobial Peptides

    PubMed Central

    Melo, Manuel N.; Ferre, Rafael; Feliu, Lídia; Bardají, Eduard; Planas, Marta; Castanho, Miguel A. R. B.

    2011-01-01

    Consensus is gathering that antimicrobial peptides that exert their antibacterial action at the membrane level must reach a local concentration threshold to become active. Studies of peptide interaction with model membranes do identify such disruptive thresholds but demonstrations of the possible correlation of these with the in vivo onset of activity have only recently been proposed. In addition, such thresholds observed in model membranes occur at local peptide concentrations close to full membrane coverage. In this work we fully develop an interaction model of antimicrobial peptides with biological membranes; by exploring the consequences of the underlying partition formalism we arrive at a relationship that provides antibacterial activity prediction from two biophysical parameters: the affinity of the peptide to the membrane and the critical bound peptide to lipid ratio. A straightforward and robust method to implement this relationship, with potential application to high-throughput screening approaches, is presented and tested. In addition, disruptive thresholds in model membranes and the onset of antibacterial peptide activity are shown to occur over the same range of locally bound peptide concentrations (10 to 100 mM), which conciliates the two types of observations. PMID:22194847

  12. Oncolytic Activities of Host Defense Peptides

    PubMed Central

    Al-Benna, Sammy; Shai, Yechiel; Jacobsen, Frank; Steinstraesser, Lars

    2011-01-01

    Cancer continues to be a leading source of morbidity and mortality worldwide in spite of progress in oncolytic therapies. In addition, the incidence of cancers affecting the breast, kidney, prostate and skin among others continue to rise. Chemotherapeutic drugs are widely used in cancer treatment but have the serious drawback of nonspecific toxicity because these agents target any rapidly dividing cell without discriminating between healthy and malignant cells. In addition, many neoplasms eventually become resistant to conventional chemotherapy due to selection for multidrug-resistant variants. The limitations associated with existing chemotherapeutic drugs have stimulated the search for new oncolytic therapies. Host defense peptides (HDPs) may represent a novel family of oncolytic agents that can avoid the shortcomings of conventional chemotherapy because they exhibit selective cytotoxicity against a broad spectrum of malignant human cells, including multi-drug-resistant neoplastic cells. Oncolytic activity by HDPs is usually via necrosis due to cell membrane lysis, but some HDPs can trigger apoptosis in cancer cells via mitochondrial membrane disruption. In addition, certain HDPs are anti-angiogenic which may inhibit cancer progression. This paper reviews oncolytic HDP studies in order to address the suitability of selected HDPs as oncolytic therapies. PMID:22174648

  13. Intervention With an Erythropoietin-Derived Peptide Protects Against Neuroglial and Vascular Degeneration During Diabetic Retinopathy

    PubMed Central

    McVicar, Carmel M.; Hamilton, Ross; Colhoun, Liza M.; Gardiner, Tom A.; Brines, Michael; Cerami, Anthony; Stitt, Alan W.

    2011-01-01

    OBJECTIVE Erythropoietin (EPO) may be protective for early stage diabetic retinopathy, although there are concerns that it could exacerbate retinal angiogenesis and thrombosis. A peptide based on the EPO helix-B domain (helix B-surface peptide [pHBSP]) is nonerythrogenic but retains tissue-protective properties, and this study evaluates its therapeutic potential in diabetic retinopathy. RESEARCH DESIGN AND METHODS After 6 months of streptozotocin-induced diabetes, rats (n = 12) and age-matched nondiabetic controls (n = 12) were evenly split into pHBSP and scrambled peptide groups and injected daily (10 μg/kg per day) for 1 month. The retina was investigated for glial dysfunction, microglial activation, and neuronal DNA damage. The vasculature was dual stained with isolectin and collagen IV. Retinal cytokine expression was quantified using real-time RT-PCR. In parallel, oxygen-induced retinopathy (OIR) was used to evaluate the effects of pHBSP on retinal ischemia and neovascularization (1–30 μg/kg pHBSP or control peptide). RESULTS pHBSP or scrambled peptide treatment did not alter hematocrit. In the diabetic retina, Müller glial expression of glial fibrillary acidic protein was increased when compared with nondiabetic controls, but pHBSP significantly reduced this stress-related response (P < 0.001). CD11b+ microglia and proinflammatory cytokines were elevated in diabetic retina responses, and some of these responses were attenuated by pHBSP (P < 0.01–0.001). pHBSP significantly reduced diabetes-linked DNA damage as determined by 8-hydroxydeoxyguanosine and transferase-mediated dUTP nick-end labeling positivity and also prevented acellular capillary formation (P < 0.05). In OIR, pHBSP had no effect on preretinal neovascularization at any dose. CONCLUSIONS Treatment with an EPO-derived peptide after diabetes is fully established can significantly protect against neuroglial and vascular degenerative pathology without altering hematocrit or exacerbating

  14. Fighting microbial infections: A lesson from amphibian skin-derived esculentin-1 peptides.

    PubMed

    Mangoni, Maria Luisa; Luca, Vincenzo; McDermott, Alison M

    2015-09-01

    Due to the growing emergence of resistance to commercially available antibiotics/antimycotics in virtually all clinical microbial pathogens, the discovery of alternative anti-infective agents, is greatly needed. Gene-encoded antimicrobial peptides (AMPs) hold promise as novel therapeutics. In particular, amphibian skin is one of the richest storehouses of AMPs, especially that of the genus Rana, with esculentins-1 being among the longest (46 amino acids) AMPs found in nature to date. Here, we report on the recently discovered in vitro and in vivo activities and mechanism of action of two derivatives of the N-terminal part of esculentin-1a and -1b peptides, primarily against two relevant opportunistic microorganisms causing a large number of life-threatening infections worldwide; i.e. the Gram-negative bacterium Pseudomonas aeruginosa and the yeast Candida albicans. Because of distinct advantages compared to several mammalian AMPs, the two selected frog skin AMP-derivatives represent attractive candidates for the development of new antimicrobial compounds with expanded properties, for both human and veterinary medicine. PMID:25959536

  15. Kinetics of the inhibition of calcium/calmodulin-dependent protein kinase II by pea protein-derived peptides.

    PubMed

    Li, Huan; Aluko, Rotimi E

    2005-11-01

    Calcium/calmodulin-dependent protein kinase II (CaMKII) catalyzes the phosphorylation of various cellular proteins and excessive activities have been implicated in the pathogenesis of various chronic diseases. We hypothesized that positively charged peptides can be produced through enzymatic hydrolysis of pea proteins; such peptides could then bind to negatively charged calmodulin (CaM) at a physiological pH level and inhibit CaMKII activity. Pea protein isolate was hydrolyzed with an alkaline protease (alcalase) and filtered through a 1000-mol wt cutoff membrane. The permeate, which contained low-molecular weight peptides, was used to isolate cationic peptides on an SP-Sepharose column by ion exchange chromatography. Separation of the permeate on the SP-Sepharose column yielded two fractions with net positive charges that were subsequently used for enzyme inhibition studies. Fraction I eluted earlier from the column and contained lower contents of lysine and arginine than Fraction II, which eluted later. Results show that both peptide fractions inhibited CaMKII activity mostly in a competitive manner, although kinetic data suggested that inhibition by Fraction II may be of the mixed type. Kinetic analysis (K(m) and K(i)) showed that affinity of peptides in Fraction II for CaM was more than that in Fraction I, which was directly correlated with the higher inhibitory properties of Fraction II against CaMKII. The results suggest that it may be possible to use pea protein-derived cationic peptides to modulate CaMKII activities. PMID:16111873

  16. Mammalian peptide isomerase: platypus-type activity is present in mouse heart.

    PubMed

    Koh, Jennifer M S; Chow, Stephanie J P; Crossett, Ben; Kuchel, Philip W

    2010-06-01

    Male platypus (Ornithorhynchus anatinus) venom has a peptidyl aminoacyl L/D-isomerase (hereafter called peptide isomerase) that converts the second amino acid residue in from the N-terminus from the L- to the D-form, and vice versa. A reversed-phase high-performance liquid chromatography (RP-HPLC) assay has been developed to monitor the interconversion using synthetic hexapeptides derived from defensin-like peptide-2 (DLP-2) and DLP-4 as substrates. It was hypothesised that animals other than the platypus would have peptide isomerase with the same substrate specificity. Accordingly, eight mouse tissues were tested and heart was shown to have the activity. This is notable for being the first evidence of a peptide isomerase being present in a higher mammal and heralds finding the activity in man. PMID:20564672

  17. Solid-Phase Synthesis, Characterization, and Cellular Activities of Collagen-Model Nanodiamond-Peptide Conjugates

    PubMed Central

    Knapinska, Anna M.; Tokmina-Roszyk, Dorota; Amar, Sabrina; Tokmina-Roszyk, Michal; Mochalin, Vadym N.; Gogotsi, Yury; Cosme, Patrick; Terentis, Andrew C.; Fields, Gregg B.

    2015-01-01

    Nanodiamonds (NDs) have received considerable attention as potential drug delivery vehicles. NDs are small (~5 nm diameter), can be surface modified in a controllable fashion with a variety of functional groups, and have little observed toxicity in vitro and in vivo. However, most biomedical applications of NDs utilize surface adsorption of biomolecules, as opposed to covalent attachment. Covalent modification provides reliable and reproducible ND–biomolecule ratios, and alleviates concerns over biomolecule desorption prior to delivery. The present study has outlined methods for the efficient solid-phase conjugation of ND to peptides and characterization of ND–peptide conjugates. Utilizing collagen-derived peptides, the ND was found to support or even enhance the cell adhesion and viability activities of the conjugated sequence. Thus, NDs can be incorporated into peptides and proteins in a selective manner, where the presence of the ND could potentially enhance the in vivo activities of the biomolecule it is attached to. PMID:25753561

  18. Atrial Natriuretic Peptide Inhibits Spontaneous Contractile Activity of Lymph Nodes.

    PubMed

    Lobov, G I; Pan'kova, M N

    2016-06-01

    Atrial natriuretic peptide dose-dependently inhibited spontaneous phase and tonic activity of smooth muscle strips from the capsule of isolated bovine mesenteric lymph nodes. Pretreatment with L-NAME, diclofenac, and methylene blue had practically no effect on the peptide-induced relaxation responses. In contrast, glibenclamide significantly reduced the inhibitory effect of atrial natriuretic peptide. We suppose that the NO-dependent and cyclooxygenase signaling pathways are not involved in implementation of the inhibitory effects of atrial natriuretic peptide. ATP-sensitive K(+)-channels of the smooth muscle cell membrane are the last component in the signaling pathway leading to relaxation of smooth muscles of the lymph node capsule caused by atrial natriuretic peptide; activation of these channels leads to membrane hyperpolarization and smooth muscle relaxation. PMID:27383173

  19. Phospholipase C gamma mediates endogenous brain-derived neurotrophic factor-regulated calcitonin gene-related peptide expression in colitis-induced visceral pain

    PubMed Central

    Hashmi, Fiza; Liu, Miao; Shen, Shanwei

    2016-01-01

    Background Visceral hypersensitivity is a complex pathophysiological paradigm with unclear mechanisms. Primary afferent neuronal plasticity marked by alterations in neuroactive compounds such as calcitonin gene-related peptide is suggested to underlie the heightened sensory responses. Signal transduction that leads to calcitonin gene-related peptide expression thereby sensory neuroplasticity during colitis remains to be elucidated. Results In a rat model with colitis induced by 2,4,6-trinitrobenzene sulfonic acid, we found that endogenously elevated brain-derived neurotrophic factor elicited an up-regulation of calcitonin gene-related peptide in the lumbar L1 dorsal root ganglia. At seven days of colitis, neutralization of brain-derived neurotrophic factor with a specific brain-derived neurotrophic factor antibody reversed calcitonin gene-related peptide up-regulation in the dorsal root ganglia. Colitis-induced calcitonin gene-related peptide transcription was also inhibited by brain-derived neurotrophic factor antibody treatment. Signal transduction studies with dorsal root ganglia explants showed that brain-derived neurotrophic factor-induced calcitonin gene-related peptide expression was mediated by the phospholipase C gamma, but not the phosphatidylinositol 3-kinase/Akt or the mitogen-activated protein kinase/extracellular signal-regulated protein kinase pathway. Application of PLC inhibitor U73122 in vivo confirmed that colitis-induced and brain-derived neurotrophic factor-mediated calcitonin gene-related peptide up-regulation in the dorsal root ganglia was regulated by the phospholipase C gamma pathway. In contrast, suppression of the phosphatidylinositol 3-kinase activity in vivo had no effect on colitis-induced calcitonin gene-related peptide expression. During colitis, calcitonin gene-related peptide also co-expressed with phospholipase C gamma but not with p-Akt. Calcitonin gene-related peptide up-regulation during colitis correlated to the activation

  20. Antimicrobial peptides: a review of how peptide structure impacts antimicrobial activity

    NASA Astrophysics Data System (ADS)

    Soares, Jason W.; Mello, Charlene M.

    2004-03-01

    Antimicrobial peptides (AMPs) have been discovered in insects, mammals, reptiles, and plants to protect against microbial infection. Many of these peptides have been isolated and studied exhaustively to decipher the molecular mechanisms that impart protection against infectious bacteria, fungi, and viruses. Unfortunately, the molecular mechanisms are still being debated within the scientific community but valuable clues have been obtained through structure/function relationship studies1. Biophysical studies have revealed that cecropins, isolated from insects and pigs, exhibit random structure in solution but undergo a conformational change to an amphipathic α-helix upon interaction with a membrane surface2. The lack of secondary structure in solution results in an extremely durable peptide able to survive exposure to high temperatures, organic solvents and incorporation into fibers and films without compromising antibacterial activity. Studies to better understand the antimicrobial action of cecropins and other AMPs have provided insight into the importance of peptide sequence and structure in antimicrobial activities. Therefore, enhancing our knowledge of how peptide structure imparts function may result in customized peptide sequences tailored for specific applications such as targeted cell delivery systems, novel antibiotics and food preservation additives. This review will summarize the current state of knowledge with respect to cell binding and antimicrobial activity of AMPs focusing primarily upon cecropins.

  1. Prevention of passively transferred experimental autoimmune myasthenia gravis by a phage library-derived cyclic peptide

    PubMed Central

    Venkatesh, Natarajan; Im, Sin-Heyog; Balass, Moshe; Fuchs, Sara; Katchalski-Katzir, Ephraim

    2000-01-01

    Many pathogenic antibodies in myasthenia gravis (MG) and its animal model, experimental autoimmune MG (EAMG), are directed against the main immunogenic region (MIR) of the acetylcholine receptor (AcChoR). These antibodies are highly conformation dependent; hence, linear peptides derived from native receptor sequences are poor candidates for their immunoneutralization. We employed a phage-epitope library to identify peptide-mimotopes capable of preventing the pathogenicity of the anti-MIR mAb 198. We identified a 15-mer peptide (PMTLPENYFSERPYH) that binds specifically to mAb 198 and inhibits its binding to AcChoR. A 10-fold increase in the affinity of this peptide was achieved by incorporating flanking amino acid residues from the coat protein as present in the original phage library. This extended peptide (AEPMTLPENYFSERPYHPPPP) was constrained by the addition of cysteine residues on both ends of the peptide, thus generating a cyclic peptide that inhibited the binding of mAb 198 to AcChoR with a potency that is three orders of magnitude higher when compared with the parent library peptide. This cyclic peptide inhibited the in vitro binding of mAb 198 to AcChoR and prevented the antigenic modulation of AcChoR caused by mAb 198 in human muscle cell cultures. The cyclic peptide also reacted with several other anti-MIR mAbs and the sera of EAMG rats. In addition, this peptide blocked the ability of mAb 198 to passively transfer EAMG in rats. Further derivatization of the cyclic peptide may aid in the design of suitable synthetic mimotopes for modulation of MG. PMID:10639153

  2. Evaluation of tetravalent and conserved synthetic peptides vaccines derived from Dengue virus Envelope domain I and II.

    PubMed

    Rocha, Raissa Prado; Livonesi, Márcia Cristina; Fumagalli, Marcilio Jorge; Rodrigues, Naiara Ferreira; da Costa, Lauro César Felipe; Dos Santos, Michelle Cristina Silva Gomes; de Oliveira Rocha, Eliseu Soares; Kroon, Erna Geessien; Malaquias, Luiz Cosme Cotta; Coelho, Luiz Felipe Leomil

    2014-08-01

    Dengue is a major worldwide public health problem, especially in the tropical and subtropical regions of the world. Primary infection with a single Dengue virus (DENV) serotype causes a mild, self-limiting febrile illness called dengue fever. However, a subset of patients experiencing a secondary infection with a different serotype progress to the severe form of the disease, called dengue hemorrhagic fever. In this study, the vaccine potential of three tetravalent and conserved synthetic peptides derived from DENV envelope domain I (named Pep01) and II (named Pep02 and Pep03) was evaluated. Human dengue IgM/IgG positive serum (n=16) showed reactivity against Pep01, Pep02 and Pep03 in different degrees. Mice immunization experiments showed that these peptides were able to induce a humoral response characterized by antibodies with low neutralizing activity. The spleen cells derived from mice immunized with the peptides showed a significant cytotoxic activity (only for Pep02 and Pep03), a high expression of IL-10 (P<0.01) and a reduced expression of TNF-α and IFN-gamma (P<0.001) compared to DENV-1 infected splenocytes. Thus these peptides, and specially the Pep03, can induce a humoral response characterized by antibodies with low neutralizing activities and probably a T cell response that could be beneficial to induce an effective immune response against all DENV serotypes and do not contributed to the immunopathogenesis. However, further studies in peptide sequence will be required to induce the production of neutralizing antibodies against all four DENV serotypes and also to improve immunogenicity of these peptides. PMID:24768848

  3. Synthetic peptides derived from the prosegments of proprotein convertase 1/3 and furin are potent inhibitors of both enzymes.

    PubMed Central

    Basak, Ajoy; Lazure, Claude

    2003-01-01

    Proprotein convertases (PCs) are Ca(2+)-dependent serine proteases of the subtilisin/kexin family which are known specifically to cleave propeptide and proprotein substrates at the C-terminal of R-X-(K/R)-R/ to generate the relevant biologically active peptides. PCs are initially synthesized as enzymically inactive proenzyme forms where the prosegments play an important inhibitory role to the respective enzymes. Here we investigated whether synthetic peptides derived from the pro-region could also represent specific and potent inhibitors. Based upon sequence alignment, secondary structure analysis and hydrophilicity plot, a number of peptides ranging from 8 to 33 residues were selected. These included segments encompassing residues 55-62, 50-62, 39-62, 50-83, 55-83, 64-83 and 74-83 in the pro-mouse PC1/3 sequence and residues 54-62, 48-62 and 39-62 of the pro-human furin sequence. All peptides were prepared by solid-phase FastMoc chemistry, purified by reversed-phase HPLC and characterized by MS and amino acid analysis. These peptides were tested in vitro for inhibitory activity towards recombinant mouse PC1/3 and human furin. Progress-curve and end-time kinetic analysis demonstrated that a number of these peptides, particularly those containing both the primary and the secondary processing sites, displayed strong inhibition of both enzymes with inhibition constants (K (i)) in the high nanomolar range. Unlike the whole propeptide, these small synthetic peptide inhibitors exhibited either true competitive or mixed competitive inhibition, depending on the sequence. Our data revealed further the critical role of the last two basic amino acid residues (e.g. Lys(82)-Arg(83) for the mouse PC1/3 sequence) of the prodomain in imparting a strong anti-convertase activity. The study also establishes the inhibitory potential of certain regions contained within the prosegment of the two convertases. PMID:12662153

  4. Modulation of CD44 Activity by A6-Peptide

    PubMed Central

    Finlayson, Malcolm

    2015-01-01

    Hyaluronan (HA) is a non-sulfated glycosaminoglycan distributed throughout the extracellular matrix that plays a major role in cell adhesion, migration, and proliferation. CD44, a multifunctional cell surface glycoprotein, is a receptor for HA. In addition, CD44 is known to interact with other receptors and ligands, and to mediate a number of cellular functions as well as disease progression. Studies have shown that binding of HA to CD44 in cancer cells activates survival pathways resulting in cancer cell survival. This effect can be blocked by anti-CD44 monoclonal antibodies. A6 is a capped, eight l-amino acid peptide (Ac-KPSSPPEE-NH2) derived from the biologically active connecting peptide domain of the serine protease, human urokinase plasminogen activator (uPA). A6 neither binds to the uPA receptor (uPAR) nor interferes with uPA/uPAR binding. A6 binds to CD44 resulting in the inhibition of migration, invasion, and metastasis of tumor cells, and the modulation of CD44-mediated cell signaling. A6 has been shown to have no dose-limiting toxicity in animal studies. A6 has demonstrated efficacy and an excellent safety profile in Phase 1a, 1b, and 2 clinical trials. In animal models, A6 has also exhibited promising results for the treatment of diabetic retinopathy and wet age-related macular degeneration through the reduction of retinal vascular permeability and inhibition of choroidal neovascularization, respectively. Recently, A6 has been shown to be directly cytotoxic for B-lymphocytes obtained from patients with chronic lymphocytic leukemia expressing the kinase, ZAP-70. This review will discuss the activity of A6, A6 modulation of HA and CD44, and a novel strategy for therapeutic intervention in disease. PMID:25870596

  5. Signal peptides are allosteric activators of the protein translocase.

    PubMed

    Gouridis, Giorgos; Karamanou, Spyridoula; Gelis, Ioannis; Kalodimos, Charalampos G; Economou, Anastassios

    2009-11-19

    Extra-cytoplasmic polypeptides are usually synthesized as 'preproteins' carrying amino-terminal, cleavable signal peptides and secreted across membranes by translocases. The main bacterial translocase comprises the SecYEG protein-conducting channel and the peripheral ATPase motor SecA. Most proteins destined for the periplasm and beyond are exported post-translationally by SecA. Preprotein targeting to SecA is thought to involve signal peptides and chaperones like SecB. Here we show that signal peptides have a new role beyond targeting: they are essential allosteric activators of the translocase. On docking on their binding groove on SecA, signal peptides act in trans to drive three successive states: first, 'triggering' that drives the translocase to a lower activation energy state; second, 'trapping' that engages non-native preprotein mature domains docked with high affinity on the secretion apparatus; and third, 'secretion' during which trapped mature domains undergo several turnovers of translocation in segments. A significant contribution by mature domains renders signal peptides less critical in bacterial secretory protein targeting than currently assumed. Rather, it is their function as allosteric activators of the translocase that renders signal peptides essential for protein secretion. A role for signal peptides and targeting sequences as allosteric activators may be universal in protein translocases. PMID:19924216

  6. Dual-functioning phage-derived peptides encourage human bone marrow cell-specific attachment to mineralized biomaterials.

    PubMed

    Ramaraju, Harsha; Miller, Sharon J; Kohn, David H

    2014-08-01

    Cell instructive mineralized biomaterials are a promising alternative to conventional auto-, allo-, and xenograft therapies for the reconstruction of critical sized defects. Extracellular matrix proteins, peptide domains, and functional motifs demonstrating cell and mineral binding activity have been used to improve cell attachment. However, these strategies vary in their tissue regeneration outcomes due to lack of specificity to both regenerative cell populations and the material substrates. In order to mediate cell-specific interactions on apatite surfaces, we identified peptide sequences with high affinity towards apatite (VTKHLNQISQSY, VTK) and clonally derived human bone marrow stromal cells (DPIYALSWSGMA, DPI) using phage display. The primary aims of this study were to measure apatite binding affinity, human bone marrow stromal cell (hBMSC) adhesion strength, and peptide specificity to hBMSCs when the apatite and cell-specific peptides are combined into a dual-functioning peptide. To assess binding affinity to hydroxyapatite (HA), binding isotherms were constructed and peptide binding affinity (K1) determined. HBMSC, MC3T3 and mouse dermal fibroblast (MDF) adhesion strength on biomimetic apatite functionalized with single- and dual-functioning peptide sequences were evaluated using a centrifugation assay. DPI-VTK had the highest binding strength towards hBMSCs (p < 0.01). DPI-VTK, while promoting strong initial attachment to hBMSCs, did not encourage strong adhesions to MC3T3s or fibroblasts (p < 0.01). Taken together, phage display is a promising strategy to identify preferential cell and material binding peptide sequences that can tether specific cell populations onto specific biomaterial chemistries. PMID:25158203

  7. Synthesis, characterization and anti-cancer activity of a peptide nucleolipid bioconjugate.

    PubMed

    Rana, Niki; Huang, Suiying; Patel, Pradeepkumar; Samuni, Uri; Sabatino, David

    2016-08-01

    The synthesis, characterization and anti-cancer activity of a novel peptide nucleolipid bioconjugate is reported in this study. The prerequisite 5'-carboxy derived nucleolipid was synthesized following a five-step solution-phase approach and then coupled to the cytotoxic D-(KLAKLAK)2 sequence by solid-phase bioconjugation. The biophysical and structural properties of the peptide-nucleolipid bioconjugate were evaluated and compared to the peptide controls. These characterization studies revealed that the amphiphilic peptides favored helical-type secondary structures and well-defined nanoparticle formulations that were found to be contributive towards their biological activity. The peptide-nucleolipid bioconjugate displayed greater lethality in comparison to the native D-(KLAKLAK)2AK sequence when treated within the human A549 non-small cell lung carcinoma cell line. Thus, the amphiphilic peptide-nucleolipid forms a new class of anti-cancer peptides that may be developed into promising leads in the fight against cancer. PMID:27329798

  8. Functional characterization of a synthetic hydrophilic antifungal peptide derived from the marine snail Cenchritis muricatus.

    PubMed

    López-Abarrategui, Carlos; Alba, Annia; Silva, Osmar N; Reyes-Acosta, Osvaldo; Vasconcelos, Ilka M; Oliveira, Jose T A; Migliolo, Ludovico; Costa, Maysa P; Costa, Carolina R; Silva, Maria R R; Garay, Hilda E; Dias, Simoni C; Franco, Octávio L; Otero-González, Anselmo J

    2012-04-01

    Antimicrobial peptides have been found in mollusks and other sea animals. In this report, a crude extract of the marine snail Cenchritis muricatus was evaluated against human pathogens responsible for multiple deleterious effects and diseases. A peptide of 1485.26 Da was purified by reversed-phase HPLC and functionally characterized. This trypsinized peptide was sequenced by MS/MS technology, and a sequence (SRSELIVHQR), named Cm-p1 was recovered, chemically synthesized and functionally characterized. This peptide demonstrated the capacity to prevent the development of yeasts and filamentous fungi. Otherwise, Cm-p1 displayed no toxic effects against mammalian cells. Molecular modeling analyses showed that this peptide possible forms a single hydrophilic α-helix and the probable cationic residue involved in antifungal activity action is proposed. The data reported here demonstrate the importance of sea animals peptide discovery for biotechnological tools development that could be useful in solving human health and agribusiness problems. PMID:22210491

  9. Immunization of cattle with synthetic peptides derived from the Boophilus microplus gut protein (Bm86).

    PubMed

    Patarroyo, J H; Portela, R W; De Castro, R O; Pimentel, J Couto; Guzman, F; Patarroyo, M E; Vargas, M I; Prates, A A; Mendes, M A Dias

    2002-09-25

    Three synthetic peptides (SBm4912, SBm7462 and SBm19733), derived from the Bm86 glycoprotein from Boophilus microplus gut, were constructed and used to immunize cattle from a tick-free area. The immunized animals received three subcutaneous doses of the peptides, with saponin as adjuvant, at 30-day intervals. The immune response was evaluated by IgG elicited against the peptides by the detection of anti-Bm86 specific antibodies in situ and by Western blotting analysis. After tick challenge, reduction in the number, weight and oviposition capacity of engorged females was observed in the tick population that had fed on immunized animals. The results pointed a high efficacy (81.05%) for the SBm7462 synthetic peptide in relation to the others (p<0.01), demonstrating the efficiency of the immune response elicited by synthetic peptides to control the cattle tick B. microplus. PMID:12127414

  10. Competitive Interactions of Collagen and a Jararhagin-derived Disintegrin Peptide with the Integrin α2-I Domain*

    PubMed Central

    Lambert, Lester J.; Bobkov, Andrey A.; Smith, Jeffrey W.; Marassi, Francesca M.

    2008-01-01

    Integrin α2β1 is a major receptor required for activation and adhesion of platelets, through the specific recognition of collagen by the α2-I domain (α2-I), which binds fibrillar collagen via Mg2+-bridged interactions. The crystal structure of a truncated form of the α2-I domain, bound to a triple helical collagen peptide, revealed conformational changes suggestive of a mechanism where the ligand-bound I domain can initiate and propagate conformational change to the full integrin complex. Collagen binding by α2-I and fibrinogen-dependent platelet activity can be inhibited by snake venom polypeptides. Here we describe the inhibitory effect of a short cyclic peptide derived from the snake toxin metalloprotease jararhagin, with specific amino acid sequence RKKH, on the ability of α2-I to bind triple helical collagen. Isothermal titration calorimetry measurements showed that the interactions of α2-I with collagen or RKKH peptide have similar affinities, and NMR chemical shift mapping experiments with 15N-labeled α2-I, and unlabeled RKKH peptide, indicate that the peptide competes for the collagen-binding site of α2-I but does not induce a large scale conformational rearrangement of the I domain. PMID:18417478

  11. Antimicrobial activities of chicken β-defensin (4 and 10) peptides against pathogenic bacteria and fungi

    PubMed Central

    Yacoub, Haitham A.; Elazzazy, Ahmed M.; Abuzinadah, Osama A. H.; Al-Hejin, Ahmed M.; Mahmoud, Maged M.; Harakeh, Steve M.

    2015-01-01

    Host Defense Peptides (HDPs) are small cationic peptides found in several organisms. They play a vital role in innate immunity response and immunomodulatory stimulation. This investigation was designed to study the antimicrobial activities of β-defensin peptide-4 (sAvBD-4) and 10 (sAvBD-4) derived from chickens against pathogenic organisms including bacteria and fungi. Ten bacterial strains and three fungal species were used in investigation. The results showed that the sAvBD-10 displayed a higher bactericidal potency against all the tested bacterial strains than that of sAvBD-4. The exhibited bactericidal activity was significant against almost the different bacterial strains at different peptide concentrations except for that of Pseudomonas aeruginosa (P. aeruginosa) and Streptococcus bovis (Str. bovis) strains where a moderate effect was noted. Both peptides were effective in the inactivation of fungal species tested yielding a killing rate of up to 95%. The results revealed that the synthetic peptides were resistant to salt at a concentration of 50 mM NaCl. However, they lost antimicrobial potency when applied in the presence of high salt concentrations. Based on blood hemolysis studies, a little hemolytic effect was showed in the case of both peptides even when applied at high concentrations. The data obtained from this study indicated that synthetic avian peptides exhibit strong antibacterial and antifungal activity. In conclusion, future work and research should be tailored to a better understanding of the mechanisms of action of those peptides and their potential use in the pharmaceutical industry to help reduce the incidence and impact of infectious agent and be marketed as a naturally occurring antibiotic. PMID:25941665

  12. Antimicrobial activities of chicken β-defensin (4 and 10) peptides against pathogenic bacteria and fungi.

    PubMed

    Yacoub, Haitham A; Elazzazy, Ahmed M; Abuzinadah, Osama A H; Al-Hejin, Ahmed M; Mahmoud, Maged M; Harakeh, Steve M

    2015-01-01

    Host Defense Peptides (HDPs) are small cationic peptides found in several organisms. They play a vital role in innate immunity response and immunomodulatory stimulation. This investigation was designed to study the antimicrobial activities of β-defensin peptide-4 (sAvBD-4) and 10 (sAvBD-4) derived from chickens against pathogenic organisms including bacteria and fungi. Ten bacterial strains and three fungal species were used in investigation. The results showed that the sAvBD-10 displayed a higher bactericidal potency against all the tested bacterial strains than that of sAvBD-4. The exhibited bactericidal activity was significant against almost the different bacterial strains at different peptide concentrations except for that of Pseudomonas aeruginosa (P. aeruginosa) and Streptococcus bovis (Str. bovis) strains where a moderate effect was noted. Both peptides were effective in the inactivation of fungal species tested yielding a killing rate of up to 95%. The results revealed that the synthetic peptides were resistant to salt at a concentration of 50 mM NaCl. However, they lost antimicrobial potency when applied in the presence of high salt concentrations. Based on blood hemolysis studies, a little hemolytic effect was showed in the case of both peptides even when applied at high concentrations. The data obtained from this study indicated that synthetic avian peptides exhibit strong antibacterial and antifungal activity. In conclusion, future work and research should be tailored to a better understanding of the mechanisms of action of those peptides and their potential use in the pharmaceutical industry to help reduce the incidence and impact of infectious agent and be marketed as a naturally occurring antibiotic. PMID:25941665

  13. Specific interactions between amyloid-β peptide and curcumin derivatives: Ab initio molecular simulations

    NASA Astrophysics Data System (ADS)

    Ishimura, Hiromi; Kadoya, Ryushi; Suzuki, Tomoya; Murakawa, Takeru; Shulga, Sergiy; Kurita, Noriyuki

    2015-07-01

    Alzheimer's disease is caused by accumulation of amyloid-β (Aβ) peptides in a brain. To suppress the production of Aβ peptides, it is effective to inhibit the cleavage of amyloid precursor protein (APP) by secretases. However, because the secretases also play important roles to produce vital proteins for human body, inhibitors for the secretases may have side effects. To propose new agents for protecting the cleavage site of APP from the attacking of the γ-secretase, we have investigated here the specific interactions between a short APP peptide and curcumin derivatives, using protein-ligand docking as well as ab initio molecular simulations.

  14. A Phage Display Screening Derived Peptide with Affinity for the Adeninyl Moiety

    PubMed Central

    Elmlund, Louise; Söderberg, Pernilla; Suriyanarayanan, Subramanian; Nicholls, Ian A.

    2014-01-01

    Phage display screening of a surface-immobilized adenine derivative led to the identification of a heptameric peptide with selectivity for adenine as demonstrated through quartz crystal microbalance (QCM) studies. The peptide demonstrated a concentration dependent affinity for an adeninyl moiety decorated surface (KD of 968 ± 53.3 μM), which highlights the power of piezoelectric sensing in the study of weak interactions. PMID:25587414

  15. Cm-p5: an antifungal hydrophilic peptide derived from the coastal mollusk Cenchritis muricatus (Gastropoda: Littorinidae).

    PubMed

    López-Abarrategui, Carlos; McBeth, Christine; Mandal, Santi M; Sun, Zhenyu J; Heffron, Gregory; Alba-Menéndez, Annia; Migliolo, Ludovico; Reyes-Acosta, Osvaldo; García-Villarino, Mónica; Nolasco, Diego O; Falcão, Rosana; Cherobim, Mariana D; Dias, Simoni C; Brandt, Wolfgang; Wessjohann, Ludger; Starnbach, Michael; Franco, Octavio L; Otero-González, Anselmo J

    2015-08-01

    Antimicrobial peptides form part of the first line of defense against pathogens for many organisms. Current treatments for fungal infections are limited by drug toxicity and pathogen resistance. Cm-p5 (SRSELIVHQRLF), a peptide derived from the marine mollusk Cenchritis muricatus peptide Cm-p1, has a significantly increased fungistatic activity against pathogenic Candida albicans (minimal inhibitory concentration, 10 µg/ml; EC50, 1.146 µg/ml) while exhibiting low toxic effects against a cultured mammalian cell line. Cm-p5 as characterized by circular dichroism and nuclear magnetic resonance revealed an α-helical structure in membrane-mimetic conditions and a tendency to random coil folding in aqueous solutions. Additional studies modeling Cm-p5 binding to a phosphatidylserine bilayer in silico and isothermal titration calorimetry using lipid monophases demonstrated that Cm-p5 has a high affinity for the phospholipids of fungal membranes (phosphatidylserine and phosphatidylethanolamine), only moderate interactions with a mammalian membrane phospholipid, low interaction with ergosterol, and no interaction with chitin. Adhesion of Cm-p5 to living C. albicans cells was confirmed by fluorescence microscopy with FITC-labeled peptide. In a systemic candidiasis model in mice, intraperitoneal administration of Cm-p5 was unable to control the fungal kidney burden, although its low amphiphaticity could be modified to generate new derivatives with improved fungicidal activity and stability. PMID:25921828

  16. Protection against the Metabolic Syndrome by Guar Gum-Derived Short-Chain Fatty Acids Depends on Peroxisome Proliferator-Activated Receptor γ and Glucagon-Like Peptide-1.

    PubMed

    den Besten, Gijs; Gerding, Albert; van Dijk, Theo H; Ciapaite, Jolita; Bleeker, Aycha; van Eunen, Karen; Havinga, Rick; Groen, Albert K; Reijngoud, Dirk-Jan; Bakker, Barbara M

    2015-01-01

    The dietary fiber guar gum has beneficial effects on obesity, hyperglycemia and hypercholesterolemia in both humans and rodents. The major products of colonic fermentation of dietary fiber, the short-chain fatty acids (SCFAs), have been suggested to play an important role. Recently, we showed that SCFAs protect against the metabolic syndrome via a signaling cascade that involves peroxisome proliferator-activated receptor (PPAR) γ repression and AMP-activated protein kinase (AMPK) activation. In this study we investigated the molecular mechanism via which the dietary fiber guar gum protects against the metabolic syndrome. C57Bl/6J mice were fed a high-fat diet supplemented with 0% or 10% of the fiber guar gum for 12 weeks and effects on lipid and glucose metabolism were studied. We demonstrate that, like SCFAs, also guar gum protects against high-fat diet-induced metabolic abnormalities by PPARγ repression, subsequently increasing mitochondrial uncoupling protein 2 expression and AMP/ATP ratio, leading to the activation of AMPK and culminating in enhanced oxidative metabolism in both liver and adipose tissue. Moreover, guar gum markedly increased peripheral glucose clearance, possibly mediated by the SCFA-induced colonic hormone glucagon-like peptide-1. Overall, this study provides novel molecular insights into the beneficial effects of guar gum on the metabolic syndrome and strengthens the potential role of guar gum as a dietary-fiber intervention. PMID:26292284

  17. [Derivatives of N-amidinoproline and their use in conventional and solid phase peptide synthesis].

    PubMed

    Burov, S V; Moskalenko, Iu E; Leko, M V; Dorosh, M Iu; Panarin, E F

    2006-01-01

    N-Amidinoproline, a hybrid structure modeling key features of the Arg-Pro sequence, was synthesized. The activation of carboxyl group of free N-amidinoproline was found to result in the formation of a cyclic side product, whose structure was confirmed by ESI MS, 1H NMR, and 13C NMR spectra. The preparation of N-(mesitylenesulfonylamidino)-L-proline using the mesitylenesulfonyl derivative of 2-methylisourea was demonstrated to be accompanied by partial racemization. The target product was synthesized by modification of N-amidinoproline by mesitylenesulfonyl chloride. The possibility of using N-amidinoproline in the N-terminal modification of a peptide chain was shown by the example of synthesis of an analogue of the 95-98 fragment of fibrinogen alpha chain. PMID:17180906

  18. A Nonribosomal Peptide Synthetase-derived Iron(III) Complex from the Pathogenic Fungus Aspergillus fumigatus

    PubMed Central

    Yin, Wen-Bing; Baccile, Joshua A.; Bok, Jin Woo; Chen, Yiming; Keller, Nancy P.; Schroeder, Frank C.

    2013-01-01

    Small molecules (SMs) play central roles as virulence factors of pathogenic fungi and bacteria; however, genomic analyses suggest that the majority of microbial SMs have remained uncharacterized. Based on microarray analysis followed by comparative metabolomics of overexpression/knockout mutants we identified a tryptophan-derived iron(III)-complex, hexadehydroastechrome (HAS), as the major product of the cryptic has non-ribosomal peptide synthetase (NRPS) gene cluster in the human pathogen Aspergillus fumigatus. Activation of the has cluster created a highly virulent A. fumigatus strain that increased mortality of infected mice. Comparative metabolomics of different mutant strains allowed to propose a pathway for HAS biosynthesis and further revealed cross-talk with another NRPS pathway producing the anti-cancer fumitremorgins. PMID:23360537

  19. Thrombin-receptor agonist peptides, in contrast to thrombin itself, are not full agonists for activation and signal transduction in human platelets in the absence of platelet-derived secondary mediators.

    PubMed Central

    Lau, L F; Pumiglia, K; Côté, Y P; Feinstein, M B

    1994-01-01

    Synthetic thrombin receptor peptides (TRPs), comprising the first 6-14 amino acids of the new N-terminus tethered ligand of the thrombin receptor that is generated by thrombin's proteolytic activity, were reported to activate platelets equally with thrombin itself and are considered to be full agonists [Vu et al. (1991) Cell 64, 1057-1068]. Using aspirin plus ADP-scavengers or the ADP-receptor antagonist adenosine 5'-[alpha-thio]triphosphate to prevent the secondary effects of the potent agonists that are normally released from stimulated platelets (i.e. ADP and thromboxane A2), we assessed the direct actions of thrombin and TRPs (i.e. TRP42-47 and TRP42-55). Compared with thrombin, under these conditions, TRPs: (1) failed to aggregate platelets completely; (2) produced less activation of glycoprotein (GP)IIb-IIIa; (3) did not cause association of GPIIb and pp60c-src with the cytoskeleton; and (4) caused less alpha-granule secretion, phosphorylation of cytoplasmic phospholipase A2, arachidonic acid release and phosphatidyl inositol (PtdOH) production. Furthermore, TRPs induced transient increases in protein phosphorylation mediated by protein kinase C and protein tyrosine phosphorylation, whereas these same responses to thrombin were greater and more sustained. Hirudin added after thrombin accelerated protein dephosphorylation, thereby mimicking the rate of spontaneous dephosphorylation seen after stimulation by TRPs. Platelets totally desensitized to very high concentrations of TRPs, by prior exposure to maximally effective concentrations of the peptides, remained responsive to alpha- and gamma-thrombins. Thrombin-stimulated PtdOH production in permeabilized platelets desensitized to TRPs was abolished by guanosine 5'-[beta-thio]diphosphate (GDP[beta S]), as in normal platelets. These results are discussed in terms of the allosteric Ternary Complex Model for G-protein linked receptors [Samama et al. (1993) J. Biol. Chem. 268, 4625-4636]. We conclude that: (1) TRPs

  20. Development of a lytic peptide derived from BH3-only proteins.

    PubMed

    Liu, Q; Zhao, H; Jiang, Y; Wu, M; Tian, Y; Wang, D; Lao, Y; Xu, N; Li, Z

    2016-01-01

    Despite great advances in cancer therapy, drug resistance is a difficult hurdle to overcome that requires development of anticancer agents with novel and effective modes of action. In a number of studies, lytic peptides have shown remarkable ability to eliminate cancer cells through a different way from traditional treatments. Lytic peptides are positively charged, amphiphilic, and are efficient at binding and disrupting the negatively charged cell membrane of cancer cells. In this study, we described the anticancer properties of a lytic peptide that was developed on the basis of the alignment of amphiphilic BH3 peptides. Our results demonstrated that the positive charge and conformation constraint were favourable for efficient cancer cell elimination. Artificial BCL-2 homology 3 peptides (ABH3) exhibited effective anticancer effects against a series of cancer cell lines in vitro and in HeLa human cervical tumour xenografts in vivo. ABH3 induced cell death in an apoptosis-independent manner through the lytic properties of the peptide that caused disruption of cell membrane. Our results showed that charge tuning and conformation constraining in a lytic peptide could be applied to optimise the anticancer activity of lytic peptides. These results also suggest that ABH3 may be a promising beginning for the development of additional lytic peptides as anticancer reagents. PMID:27551502

  1. Development of a lytic peptide derived from BH3-only proteins

    PubMed Central

    Liu, Q; Zhao, H; Jiang, Y; Wu, M; Tian, Y; Wang, D; Lao, Y; Xu, N; Li, Z

    2016-01-01

    Despite great advances in cancer therapy, drug resistance is a difficult hurdle to overcome that requires development of anticancer agents with novel and effective modes of action. In a number of studies, lytic peptides have shown remarkable ability to eliminate cancer cells through a different way from traditional treatments. Lytic peptides are positively charged, amphiphilic, and are efficient at binding and disrupting the negatively charged cell membrane of cancer cells. In this study, we described the anticancer properties of a lytic peptide that was developed on the basis of the alignment of amphiphilic BH3 peptides. Our results demonstrated that the positive charge and conformation constraint were favourable for efficient cancer cell elimination. Artificial BCL-2 homology 3 peptides (ABH3) exhibited effective anticancer effects against a series of cancer cell lines in vitro and in HeLa human cervical tumour xenografts in vivo. ABH3 induced cell death in an apoptosis-independent manner through the lytic properties of the peptide that caused disruption of cell membrane. Our results showed that charge tuning and conformation constraining in a lytic peptide could be applied to optimise the anticancer activity of lytic peptides. These results also suggest that ABH3 may be a promising beginning for the development of additional lytic peptides as anticancer reagents. PMID:27551502

  2. Novel angiotensin I-converting enzyme inhibitory peptides derived from edible mushroom Agaricus bisporus (J.E. Lange) Imbach identified by LC-MS/MS.

    PubMed

    Lau, Ching Ching; Abdullah, Noorlidah; Shuib, Adawiyah Suriza; Aminudin, Norhaniza

    2014-04-01

    Angiotensin I-converting enzyme (ACE) inhibitors derived from foods are valuable auxiliaries to agents such as captopril. Eight highly functional ACE inhibitory peptides from the mushroom, Agaricus bisporus, were identified by LC-MS/MS. Among these peptides, the most potent ACE inhibitory activity was exhibited by AHEPVK, RIGLF and PSSNK with IC₅₀ values of 63, 116 and 129 μM, respectively. These peptides exhibited high ACE inhibitory activity after gastrointestinal digestion. Lineweaver-Burk plots suggested that AHEPVK and RIGLF act as competitive inhibitors against ACE, whereas PSSNK acts as a non-competitive inhibitor. Mushrooms can be a good component of dietary supplement due to their readily available source and, in addition, they rarely cause food allergy. Compared to ACE inhibitory peptides isolated from other edible mushrooms, AHEPVK, RIGLF and PSSNK have lower IC₅₀ values. Therefore, these peptides may serve as an ideal ingredient in the production of antihypertensive supplements. PMID:24262574

  3. Cm-p5: an antifungal hydrophilic peptide derived from the coastal mollusk Cenchritis muricatus (Gastropoda: Littorinidae)

    PubMed Central

    López-Abarrategui, Carlos; McBeth, Christine; Mandal, Santi M.; Sun, Zhenyu J.; Heffron, Gregory; Alba-Menéndez, Annia; Migliolo, Ludovico; Reyes-Acosta, Osvaldo; García-Villarino, Mónica; Nolasco, Diego O.; Falcão, Rosana; Cherobim, Mariana D.; Dias, Simoni C.; Brandt, Wolfgang; Wessjohann, Ludger; Starnbach, Michael; Franco, Octavio L.; Otero-González, Anselmo J.

    2015-01-01

    Antimicrobial peptides form part of the first line of defense against pathogens for many organisms. Current treatments for fungal infections are limited by drug toxicity and pathogen resistance. Cm-p5 (SRSELIVHQRLF), a peptide derived from the marine mollusk Cenchritis muricatus peptide Cm-p1, has a significantly increased fungistatic activity against pathogenic Candida albicans (minimal inhibitory concentration, 10 µg/ml; EC50, 1.146 µg/ml) while exhibiting low toxic effects against a cultured mammalian cell line. Cm-p5 as characterized by circular dichroism and nuclear magnetic resonance revealed an α-helical structure in membrane-mimetic conditions and a tendency to random coil folding in aqueous solutions. Additional studies modeling Cm-p5 binding to a phosphatidylserine bilayer in silico and isothermal titration calorimetry using lipid monophases demonstrated that Cm-p5 has a high affinity for the phospholipids of fungal membranes (phosphatidylserine and phosphatidylethanolamine), only moderate interactions with a mammalian membrane phospholipid, low interaction with ergosterol, and no interaction with chitin. Adhesion of Cm-p5 to living C. albicans cells was confirmed by fluorescence microscopy with FITC-labeled peptide. In a systemic candidiasis model in mice, intraperitoneal administration of Cm-p5 was unable to control the fungal kidney burden, although its low amphiphaticity could be modified to generate new derivatives with improved fungicidal activity and stability.—López-Abarrategui, C., McBeth, C., Mandal, S. M., Sun, Z. J., Heffron, G., Alba-Menéndez, A., Migliolo, L., Reyes-Acosta, O., García-Villarino, M., Nolasco, D. O., Falcão, R., Cherobim, M. D., Dias, S. C., Brandt, W., Wessjohann, L., Starnbach, M., Franco, O. L., Otero-González, A. J. Cm-p5: an antifungal hydrophilic peptide derived from the coastal mollusk Cenchritis muricatus (Gastropoda: Littorinidae). PMID:25921828

  4. The influence of isoleucine and arginine on biological activity and peptide-membrane interactions of antimicrobial peptides from the bactericidal domain of AvBD4.

    PubMed

    Hu, Wan-Ning; Jiao, Wen-Jing; Ma, Zhi; Dong, Na; Ma, Qing-Quan; Shao, Chang-Xuan; Shan, An-Shan

    2013-11-01

    In this study, the influence of isoleucine and arginine on the biological activity and peptide-membrane interactions of linear avian β-defensin-4 (RL38) analogs was investigated. Results of biological activities showed that the antimicrobial activities of AvBD-4 analogs were closely related to hydrophobicity and amphipathicity. The peptide GLI19 with high hydrophobicity value and amphipathicity displayed broad spectrum antimicrobial activity against both gram-negative and gram-positive, whereas GLR19 with increasing multiple charges only exhibited activity against gram-negative. The interaction between peptides and the liposome membrane demonstrated that the peptides preferentially bound to negatively charged phospholipids over zwitterionic phospholipids, which supported the antimicrobial activity data. The outer membranes assay further demonstrated that GLI19 had a greater capacity than the other tested peptides to penetrate the cell membrane at a low concentration. Collectively, the peptides derived from the bactericidal domain of linear β- defensins by truncation and hydrophobic amino acid substitution may be effective high-potential antibacterial agents. PMID:23746111

  5. [Biologically Active Peptides Isolated from Dill Anethum graveolens L].

    PubMed

    Kulikova, O G; Maltsev, D I; Ilyina, A P; Burdina, A V; Yamskova, V P; Yamskov, I A

    2015-01-01

    Peptide mixtures with molecular weights of 1000-2000 Da and in vivo membrano-trophic activity against mouse hepatocyte culture at very low concentrations were isolated from dill Anethum graveolens L. leaves. It has been found that plant peptides in aqueous solution formed larger nanosized particles of approximately 90 nm with a secondary structure mainly composed of β-structures and random coil structures. We demonstrated that peptides isolated from A. graveolens in vitro at an ultra-low dosage affected the size of the area of pigmented cells of amphibian liver, which are analogous to Kupffer cells of the mammalian liver, using roller organotypic newt liver culture models. PMID:26204780

  6. Salivary gland derived peptides as a new class of anti-inflammatory agents: review of preclinical pharmacology of C-terminal peptides of SMR1 protein

    PubMed Central

    2010-01-01

    The limitations of steroidal and non steroidal anti-inflammatory drugs have prompted investigation into other biologically based therapeutics, and identification of immune selective anti-inflammatory agents of salivary origin. The traditional view of salivary glands as accessory digestive structures is changing as their importance as sources of systemically active immunoregulatory and anti-inflammatory factors is recognized. Salivary gland involvement in maintenance of whole body homeostasis is regulated by the nervous system and thus constitutes a "neuroendocrine axis". The potent anti-inflammatory activities, both in vivo and in vitro, of the tripeptide Phe-Glu-Gly (FEG) are reviewed. FEG is a carboxyl terminal peptide of the prohormone SMR1 identified in the rat submandibular salivary gland, The D-isomeric form (feG) mimics the activity of its L-isomer FEG. Macropharmacologically, feG attenuates the cardiovascular and inflammatory effects of endotoxemia and anaphylaxis, by inhibition of hypotension, leukocyte migration, vascular leak, and disruption of pulmonary function and intestinal motility. Mechanistically, feG affects activated inflammatory cells, especially neutrophils, by regulating integrins and inhibiting intracellular production of reactive oxygen species. Pharmacodynamically, feG is active at low doses (100 μg/kg) and has a long (9-12 hour) biological half life. As a therapeutic agent, feG shows promise in diseases characterized by over exuberant inflammatory responses such as systemic inflammatory response syndrome and other acute inflammatory diseases. Arthritis, sepsis, acute pancreatitis, asthma, acute respiratory inflammation, inflammatory bowel disease, and equine laminitis are potential targets for this promising therapeutic peptide. The term "Immune Selective Anti-Inflammatory Derivatives" (ImSAIDs) is proposed for salivary-derived peptides to distinguish this class of agents from corticosteroids and nonsteroidal anti-inflammatory drugs

  7. Isolation, Purification and Molecular Mechanism of a Peanut Protein-Derived ACE-Inhibitory Peptide

    PubMed Central

    Shi, Aimin; Liu, Hongzhi; Liu, Li; Hu, Hui; Wang, Qiang; Adhikari, Benu

    2014-01-01

    Although a number of bioactive peptides are capable of angiotensin I-converting enzyme (ACE) inhibitory effects, little is known regarding the mechanism of peanut peptides using molecular simulation. The aim of this study was to obtain ACE inhibiting peptide from peanut protein and provide insight on the molecular mechanism of its ACE inhibiting action. Peanut peptides having ACE inhibitory activity were isolated through enzymatic hydrolysis and ultrafiltration. Further chromatographic fractionation was conducted to isolate a more potent peanut peptide and its antihypertensive activity was analyzed through in vitro ACE inhibitory tests and in vivo animal experiments. MALDI-TOF/TOF-MS was used to identify its amino acid sequence. Mechanism of ACE inhibition of P8 was analyzed using molecular docking and molecular dynamics simulation. A peanut peptide (P8) having Lys-Leu-Tyr-Met-Arg-Pro amino acid sequence was obtained which had the highest ACE inhibiting activity of 85.77% (half maximal inhibitory concentration (IC50): 0.0052 mg/ml). This peanut peptide is a competitive inhibitor and show significant short term (12 h) and long term (28 days) antihypertensive activity. Dynamic tests illustrated that P8 can be successfully docked into the active pocket of ACE and can be combined with several amino acid residues. Hydrogen bond, electrostatic bond and Pi-bond were found to be the three main interaction contributing to the structural stability of ACE-peptide complex. In addition, zinc atom could form metal-carboxylic coordination bond with Tyr, Met residues of P8, resulting into its high ACE inhibiting activity. Our finding indicated that the peanut peptide (P8) having a Lys-Leu-Tyr-Met-Arg-Pro amino acid sequence can be a promising candidate for functional foods and prescription drug aimed at control of hypertension. PMID:25347076

  8. Inhibiting bladder tumor growth with a cell penetrating R11 peptide derived from the p53 C-terminus.

    PubMed

    Zhang, Tingting; Wu, Kaijie; Ding, Chen; Sun, Kangwei; Guan, Zhenfeng; Wang, Xinyang; Hsieh, Jer-Tsong; He, Dalin; Fan, Jinhai

    2015-11-10

    Urothelial carcinoma of the bladder (UCB) is the most common malignancy of the urinary tract, nearly half of which contains a mutation in TP53 gene. Hence, therapeutic approach by restoring functional p53 protein in cancer cells will be beneficial. Recent studies have demonstrated the inhibition of cancer cell growth by p53 reactivation using a peptide derived from the p53 C-terminus (p53C). However, the outcome of reactivating p53 in controlling bladder cancer development is limited by its efficiency and specificity of peptide delivery, especially in metastatic animal models. Herein, we report that the cell penetrating peptide (polyarginine, R11)-conjugated p53C can exhibit a preferential uptake and growth inhibit of UCB cells expressing either mutant or wild-type TP53 by the activation of p53-dependent pathway. R11-p53C peptide treatment of preclinical orthotopic and metastatic bladder cancer models significantly decreased the tumor burden and increased the lifespan without a significant cytotoxicity. Based on these results, we believe that R11-p53C peptide has therapeutic potential for primary and metastatic bladder cancer, and R11-mediated transduction may be a useful strategy for the therapeutic delivery of large tumor suppressor molecules to tumor cells in vitro and in vivo. PMID:26462022

  9. Structure-activity relationship of crustacean peptide hormones.

    PubMed

    Katayama, Hidekazu

    2016-04-01

    In crustaceans, various physiological events, such as molting, vitellogenesis, and sex differentiation, are regulated by peptide hormones. To understanding the functional sites of these hormones, many structure-activity relationship (SAR) studies have been published. In this review, the author focuses the SAR of crustacean hyperglycemic hormone-family peptides and androgenic gland hormone and describes the detailed results of our and other research groups. The future perspectives will be also discussed. PMID:26624010

  10. How Membrane-Active Peptides Get into Lipid Membranes.

    PubMed

    Sani, Marc-Antoine; Separovic, Frances

    2016-06-21

    The structure-function relationship for a family of antimicrobial peptides (AMPs) from the skin of Australian tree frogs is discussed and compared with that of peptide toxins from bee and Australian scorpion venoms. Although these membrane-active peptides induce a similar cellular fate by disrupting the lipid bilayer integrity, their lytic activity is achieved via different modes of action, which are investigated in relation to amino acid sequence, secondary structure, and membrane lipid composition. In order to better understand what structural features govern the interaction between peptides and lipid membranes, cell-penetrating peptides (CPPs), which translocate through the membrane without compromising its integrity, are also discussed. AMPs possess membrane lytic activities that are naturally designed to target the cellular membrane of pathogens or competitors. They are extremely diverse in amino acid composition and often show specificity against a particular strain of microbe. Since our antibiotic arsenal is declining precariously in the face of the rise in multiantibiotic resistance, AMPs increasingly are seen as a promising alternative. In an effort to understand their molecular mechanism, biophysical studies of a myriad of AMPs have been reported, yet no unifying mechanism has emerged, rendering difficult the rational design of drug leads. Similarly, a wide variety of cytotoxic peptides are found in venoms, the best known being melittin, yet again, predicting their activity based on a particular amino acid composition or secondary structure remains elusive. A common feature of these membrane-active peptides is their preference for the lipid environment. Indeed, they are mainly unstructured in solution and, in the presence of lipid membranes, quickly adsorb onto the surface, change their secondary structure, eventually insert into the hydrophobic core of the membrane bilayer, and finally disrupt the bilayer integrity. These steps define the molecular

  11. A cyclic peptide derived from alpha-fetoprotein inhibits the proliferative effects of the epidermal growth factor and estradiol in MCF7 cells.

    PubMed

    Torres, Cristian; Antileo, Elmer; Epuñán, Maráa José; Pino, Ana María; Valladares, Luis Emilio; Sierralta, Walter Daniel

    2008-06-01

    A cyclic peptide derived from the active domain of alpha-fetoprotein (AFP) significantly inhibited the proliferation of MCF7 cells stimulated with the epidermal growth factor (EGF) or estradiol (E2). The action of these three agents on cell growth was independent of the presence of calf serum in the culture medium. Our results demonstrated that the cyclic peptide interfered markedly with the regulation of MAPK by activated c-erbB2. The cyclic peptide showed no effect on the E2-stimulated release of matrix metalloproteinases 2 and 9 nor on the shedding of heparin-binding EGF into the culture medium. We propose that the AFP-derived cyclic peptide represents a valuable novel antiproliferative agent for treating breast cancer. PMID:18497971

  12. Membrane-Active Peptides and the Clustering of Anionic Lipids

    PubMed Central

    Wadhwani, P.; Epand, R.F.; Heidenreich, N.; Bürck, J.; Ulrich, A.S.; Epand, R.M.

    2012-01-01

    There is some overlap in the biological activities of cell-penetrating peptides (CPPs) and antimicrobial peptides (AMPs). We compared nine AMPs, seven CPPs, and a fusion peptide with regard to their ability to cluster anionic lipids in a mixture mimicking the cytoplasmic membrane of Gram-negative bacteria, as measured by differential scanning calorimetry. We also studied their bacteriostatic effect on several bacterial strains, and examined their conformational changes upon membrane binding using circular dichroism. A remarkable correlation was found between the net positive charge of the peptides and their capacity to induce anionic lipid clustering, which was independent of their secondary structure. Among the peptides studied, six AMPs and four CPPs were found to have strong anionic lipid clustering activity. These peptides also had bacteriostatic activity against several strains (particularly Gram-negative Escherichia coli) that are sensitive to lipid clustering agents. AMPs and CPPs that did not cluster anionic lipids were not toxic to E. coli. As shown previously for several types of AMPs, anionic lipid clustering likely contributes to the mechanism of antibacterial action of highly cationic CPPs. The same mechanism could explain the escape of CPPs from intracellular endosomes that are enriched with anionic lipids. PMID:22853904

  13. Aliphatic acid-conjugated antimicrobial peptides--potential agents with anti-tumor, multidrug resistance-reversing activity and enhanced stability.

    PubMed

    Deng, Xin; Qiu, Qianqian; Ma, Ke; Wang, Xuekun; Huang, Wenlong; Qian, Hai

    2015-07-28

    Compared with traditional therapeutics, antimicrobial peptides as novel anti-tumor agents have prominent advantages of higher specificity and circumvention of multi-drug resistance. In a previous study, we found that B1, an antimicrobial peptide derived from Cathelicidin-BF15, presented specific anti-tumor activity against several tumor cells. Since aliphatic chain-conjugated peptides have shown ameliorative activity and stability, we conjugated aliphatic acids with different lengths to the amino terminal of B1. All the conjugated peptides exhibited improved anti-tumor activity over B1. Further investigations revealed that the peptides were capable of disrupting the cell membrane, stimulating cytochrome c release into the cytosol, which results in apoptosis. The peptides also acted against multidrug resistant cells and had multidrug resistance-reversing effects. Additionally, conjugation of aliphatic acid enhanced the peptide stability in plasma. In summary, aliphatic acid-modified peptides might be promising anti-tumor agents in the future. PMID:26083110

  14. Interaction study between wheat-derived peptides and procyanidin B3 by mass spectrometry.

    PubMed

    Dias, Ricardo; Perez-Gregorio, Maria Rosa; Mateus, Nuno; De Freitas, Victor

    2016-03-01

    Tannins have the ability to complex and precipitate proteins, being particularly reactive towards the proline-rich ones. The main structural feature of the wheat peptides responsible for the onset of Celiac Disease (CD) is their high content in proline residues. The aim of this work was to characterize the binding between a common food tannin (procyanidin B3) and different wheat-derived peptidic fractions. For this, seven peptide mixtures were obtained after in vitro digestion of a wheat gliadins crude extract and further characterized by LC-ESI-MS/MS. Several soluble B3-peptide complexes were identified by ESI-MS. The peptides involved in complex formation varied in terms of their size and diversity in CD epitopes. Although binding selectivity of procyanidin B3 towards peptides containing CD epitopes was not found, the major complexes contained or could contain immunoreactive peptides. This study highlights the potential beneficial effects of food polyphenols as a nutritional approach in the modulation of CD. PMID:26471686

  15. Peptide derived from Pvfp-1 as bioadhesive on bio-inert surface.

    PubMed

    Jiang, Zhen; Yu, Yabiao; Du, Lina; Ding, Xiyu; Xu, Hui; Sun, Yanan; Zhang, Qiqing

    2012-02-01

    Surface property is one important characteristic of materials, especially for ones that are bio-inert but designed for bio-medical application. In this study, we designed a series of peptides and compared their capacities as bioadhesive to improve the surface bioactivity of bio-inert material. The peptides were designed according to the sequence of Perna viridis foot protein 1 (Pvfp-1), one of the Mfp-1s (mussel foot protein 1) which play key roles in wet adhesion of mussel byssus. And the Teflon (PTFE) was chosen as a model of bio-inert material. With adsorption, adhesion and coating analysis, it was found that peptide C2 (M) (derived from the non-repeating region of Pvfp-1, contains modified DOPA) has superior coating and adhesion abilities especially on the bio-inert surface of PTFE. After coating with peptide C2 (M), the cell adhesion and spreading of osteoblast MC3T3-E1 cells on PTFE were significantly improved compared with those on non-coated surface, and the peptide-coating did not show any cell toxicity. Therefore, peptide C2 (M) is effective for improving the bioactivity of bio-inert PTFE, and could be potentially used as a bioadhesive on other bio-inert materials for biomedical application. Moreover, this study also provided new insights in designing other peptide-based bioadhesive materials. PMID:22079698

  16. Characterization and Biological Activities of Ocellatin Peptides from the Skin Secretion of the Frog Leptodactylus pustulatus.

    PubMed

    Marani, Mariela Mirta; Dourado, Flávio Santos; Quelemes, Patrick Veras; de Araujo, Alyne Rodrigues; Perfeito, Márcia Luana Gomes; Barbosa, Eder Alves; Véras, Leiz Maria Costa; Coelho, Andreia Luísa Rodrigues; Andrade, Etielle Barroso; Eaton, Peter; Longo, João Paulo Figueiró; Azevedo, Ricardo Bentes; Delerue-Matos, Cristina; Leite, José Roberto S A

    2015-07-24

    Eight new peptides were isolated from the skin secretion of the frog Leptodactylus pustulatus and their amino acid sequences determined by de novo sequencing and by cDNA cloning. Structural similarities between them and other antimicrobial peptides from the skin secretion of Leptodactylus genus frogs were found. Ocellatins-PT1 to -PT5 (25 amino acid residues) are amidated at the C-terminus, while ocellatins-PT6 to -PT8 (32 amino acid residues) have free carboxylates. Antimicrobial activity, hemolytic tests, and cytotoxicity against a murine fibroblast cell line were investigated. All peptides, except for ocellatin-PT2, have antimicrobial activity against at least one Gram-negative strain. Ocellatin-PT8 inhibited the growth of Escherichia coli, Staphylococcus aureus, Klebsiella pneumoniae, and Salmonella choleraesuis strains with MICs in the 60-240 μM range. No significant effect was observed in human erythrocytes and in a murine fibroblast cell line after exposure to the peptides at MICs. A comparison between sequences obtained by both direct HPLC-MS de novo sequencing and cDNA cloning demonstrates the secretion of mature peptides derived from a pre-pro-peptide structure. PMID:26107622

  17. A peptide derived from alpha-fetoprotein prevents the growth of estrogen-dependent human breast cancers sensitive and resistant to tamoxifen.

    PubMed

    Bennett, James A; Mesfin, Fassil B; Andersen, Thomas T; Gierthy, John F; Jacobson, Herbert I

    2002-02-19

    An 8-mer peptide (EMTOVNOG) derived from alpha-fetoprotein was compared with tamoxifen for activity against growth of human breast cancer xenografts implanted in immune-deficient mice. Both peptide and tamoxifen prevented growth of estrogen-receptor-positive MCF-7 and T47D human breast cancer xenografts. A subline of MCF-7, made resistant to tamoxifen by a 6-month exposure to this drug in culture, was found to be resistant to tamoxifen in vivo. Peptide completely prevented the xenograft growth of this tamoxifen-resistant subline of MCF-7. Neither peptide nor tamoxifen was effective in slowing the xenograft growth of the estrogen-receptor-negative MDA-MB-231 human breast cancer. A worrisome side effect of tamoxifen is its hypertrophic effect on the uterus. In this study, tamoxifen was shown to stimulate the growth of the immature mouse uterus in vivo, and the peptide significantly inhibited tamoxifen's uterotrophic effect. The mechanism of action of peptide is different from that of tamoxifen in that the peptide does not interfere with the binding of [(3)H]estradiol to the estrogen receptor. In conclusion, alpha-fetoprotein-derived peptide appears to be a novel agent that interferes with the growth of tamoxifen-sensitive as well as tamoxifen-resistant estrogen-receptor-positive human breast cancers; it inhibits the uterotrophic side effect of tamoxifen and, thus, it may be useful in combination with or in place of tamoxifen for treatment of estrogen-receptor-positive human breast cancers. PMID:11830647

  18. Myostatin inhibition by a follistatin-derived peptide ameliorates the pathophysiology of muscular dystrophy model mice

    PubMed Central

    Tsuchida, K

    2008-01-01

    Summary Gene-targeted therapies, such as adeno-associated viral vector (AAV)-mediated gene therapy and cell-mediated therapy using myogenic stem cells, are hopeful molecular strategies for muscular dystrophy. In addition, drug therapies based on the pathophysiology of muscular dystrophy patients are desirable. Multidisciplinary approaches to drug design would offer promising therapeutic strategies. Myostatin, a member of the transforming growth factor-β superfamily, is predominantly produced by skeletal muscle and negatively regulates the growth and differentiation of cells of the skeletal muscle lineage. Myostatin inhibition would increase the skeletal muscle mass and prevent muscle degeneration, regardless of the type of muscular dystrophy. Myostatin inhibitors include myostatin antibodies, myostatin propeptide, follistatin and follistatin-related protein. Although follistatin possesses potent myostatin-inhibiting activity, it works as an efficient inhibitor of activins. Unlike myostatin, activins regulate the growth and differentiation of nearly all cell types, including cells of the gonads, pituitary gland and skeletal muscle. We have developed a myostatin-specific inhibitor derived from follistatin, designated FS I-I. Transgenic mice expressing this myostatin-inhibiting peptide under the control of a skeletal muscle-specific promoter showed increased skeletal muscle mass and strength. mdx mice were crossed with FS I-I transgenic mice and any improvement of the pathological signs was investigated. The resulting mdx/FS I-I mice exhibited increased skeletal muscle mass and reduced cell infiltration in muscles. Muscle strength was also recovered in mdx/FS I-I mice. Our data indicate that myostatin inhibition by this follistatin-derived peptide has therapeutic potential for muscular dystrophy. PMID:19108572

  19. Solid-State NMR Characterization of Autofluorescent Fibrils Formed by the Elastin-Derived Peptide GVGVAGVG

    PubMed Central

    2011-01-01

    The characterization of the molecular structure and physical properties of self-assembling peptides is an important aspect of optimizing their utility as scaffolds for biomaterials and other applications. Here we report the formation of autofluorescent fibrils by an octapeptide (GVGVAGVG) derived via a single amino acid substitution in one of the hydrophobic repeat elements of human elastin. This is the shortest and most well-defined peptide so far reported to exhibit intrinsic fluorescence in the absence of a discrete fluorophore. Structural characterization by FTIR and solid-state NMR reveals a predominantly β-sheet conformation for the peptide in the fibrils, which are likely assembled in an amyloid-like cross-β structure. Investigation of dynamics and the effects of hydration on the peptide are consistent with a rigid, water excluded structure, which has implications for the likely mechanism of intrinsic fibril fluorescence. PMID:21456595

  20. A biologically active peptide mimetic of N-acetylgalactosamine/galactose

    PubMed Central

    Eggink, Laura L; Hoober, J Kenneth

    2009-01-01

    Background Glycosylated proteins and lipids are important regulatory factors whose functions can be altered by addition or removal of sugars to the glycan structure. The glycans are recognized by sugar-binding lectins that serve as receptors on the surface of many cells and facilitate initiation of an intracellular signal that changes the properties of the cells. We identified a peptide that mimics the ligand of an N-acetylgalactosamine (GalNAc)-specific lectin and asked whether the peptide would express specific biological activity. Findings A 12-mer phage display library was screened with a GalNAc-specific lectin to identify an amino acid sequence that binds to the lectin. Phage particles that were eluted from the lectin with free GalNAc were considered to have been bound to a GalNAc-binding site. Peptides were synthesized with the selected sequence as a quadravalent structure to facilitate receptor crosslinking. Treatment of human peripheral blood mononuclear cells for 24 h with the peptide stimulated secretion of interleukin-8 (IL-8) but not of IL-1β, IL-6, IL-10, or tumor necrosis factor-α (TNF-α). The secretion of IL-21 was stimulated as strongly with the peptide as with interferon-γ. Conclusion The data indicate that the quadravalent peptide has biological activity with a degree of specificity. These effects occurred at concentrations in the nanomolar range, in contrast to free sugars that generally bind to proteins in the micro- to millimolar range. PMID:19284521

  1. Efficient one-pot synthesis of CXCL14 and its derivative using an N-sulfanylethylanilide peptide as a peptide thioester equivalent and their biological evaluation.

    PubMed

    Tsuji, Kohei; Tanegashima, Kosuke; Sato, Kohei; Sakamoto, Ken; Shigenaga, Akira; Inokuma, Tsubasa; Hara, Takahiko; Otaka, Akira

    2015-09-01

    CXCL14 is a CXC-type chemokine that exhibits chemotactic activity for immature dendritic cells, activated macrophages, and activated natural killer cells. However, its specific receptor and signaling pathway remain obscure. Recently, it was reported that CXCL14 binds to CXCR4 with high affinity and inhibits CXCL12-mediated chemotaxis. Furthermore, the CXCL14 C-terminal α-helical region is important for binding to its receptor. In this context, we chemically synthesized CXCL14 and its derivative with a one-pot method using N-sulfanylethylanilide peptide as a thioester equivalent. The synthetic CXCL14 proteins possessed inhibitory activities to CXCL12-mediated chemotaxis comparable with that of recombinant CXCL14. Moreover, we proved that chemically biotinylated CXCL14 binds to CXCR4 on cells by flow cytometry analysis. PMID:26187016

  2. Nonerythropoietic Erythropoietin-Derived Peptide Suppresses Adipogenesis, Inflammation, Obesity and Insulin Resistance

    PubMed Central

    Liu, Yuqi; Luo, Bangwei; Shi, Rongchen; Wang, Jinsong; Liu, Zongwei; Liu, Wei; Wang, Shufeng; Zhang, Zhiren

    2015-01-01

    Erythropoietin (EPO) has been identified as being crucial for obesity modulation; however, its erythropoietic activity may limit its clinical application. EPO-derived Helix B-surface peptide (pHBSP) is nonerythrogenic but has been reported to retain other functions of EPO. The current study aimed to evaluate the effects and potential mechanisms of pHBSP in obesity modulation. We found that pHBSP suppressed adipogenesis, adipokine expression and peroxisome proliferator-activated receptor γ (PPARγ) levels during 3T3-L1 preadipocyte maturation through the EPO receptor (EPOR). In addition, also through EPOR, pHBSP attenuated macrophage inflammatory activation and promoted PPARγ expression. Furthermore, PPARγ deficiency partly ablated the anti-inflammatory activity of pHBSP in macrophages. Correspondingly, pHBSP administration to high-fat diet (HFD)-fed mice significantly improved obesity, insulin resistance (IR) and adipose tissue inflammation without stimulating hematopoiesis. Therefore, pHBSP can significantly protect against obesity and IR partly by inhibiting adipogenesis and inflammation. These findings have therapeutic implications for metabolic disorders, such as obesity and diabetes. PMID:26459940

  3. Potent inhibition of the classical pathway of complement by a novel C1q-binding peptide derived from the human astrovirus coat protein.

    PubMed

    Gronemus, Jenny Q; Hair, Pamela S; Crawford, Katrina B; Nyalwidhe, Julius O; Cunnion, Kenji M; Krishna, Neel K

    2010-01-01

    Previous work from our laboratories has demonstrated that purified, recombinant human astrovirus coat protein (HAstV CP) binds C1q and mannose-binding lectin (MBL) inhibiting activation of the classical and lectin pathways of complement, respectively. Analysis of the 787 amino acid CP molecule revealed that residues 79-139 share limited sequence homology with human neutrophil defensin-1 (HNP-1), a molecule previously demonstrated to bind C1q and MBL, inhibiting activation of the classical and lectin pathways of complement, respectively. A 30 amino acid peptide derived from this region of the CP molecule competitively inhibited the binding of wild-type CP to C1q. The parent peptide and various derivatives were subsequently assayed for C1q binding, inhibition of C1 and C4 activation as well as suppression of complement activation in hemolytic assays. The parent peptide and several derivatives inhibited complement activation in these functional assays to varying degrees. One peptide derivative in particular (E23A) displayed superior inhibition of complement activation in multiple assays of classical complement pathway activation. Further analysis revealed homology to a plant defensin allowing development of a proposed structural model for E23A. Based upon these findings, we hypothesize that further rationale optimization of E23A may result in a promising therapeutic inhibitor for the treatment of inflammatory and autoimmune diseases in which dysregulated activation of the classical and lectin pathways of complement contribute to pathogenesis. PMID:20728940

  4. Antimicrobial peptides with potential for biofilm eradication: synthesis and structure activity relationship studies of battacin peptides.

    PubMed

    De Zoysa, Gayan Heruka; Cameron, Alan James; Hegde, Veena V; Raghothama, Srinivasarao; Sarojini, Vijayalekshmi

    2015-01-22

    We report on the first chemical syntheses and structure-activity analyses of the cyclic lipopeptide battacin which revealed that conjugation of a shorter fatty acid, 4-methyl-hexanoic acid, and linearization of the peptide sequence improves antibacterial activity and reduces hemolysis of mouse blood cells. This surprising finding of higher potency in linear lipopeptides than their cyclic counterparts is economically beneficial. This novel lipopeptide was membrane lytic and exhibited antibiofilm activity against Pseudomonas aeruginosa, Staphylococcus aureus, and, for the first time, Pseudomonas syringe pv. actinidiae. The peptide was unstructured in aqueous buffer and dimyristoylphosphatidylcholine-polymerized diacetylene vesicles, with 12% helicity induced in 50% v/v of trifluoroethanol. Our results indicate that a well-defined secondary structure is not essential for the observed antibacterial activity of this novel lipopeptide. A truncated pentapeptide conjugated to 4-methyl hexanoic acid, having similar potency against Gram negative and Gram positive pathogens was identified through alanine scanning. PMID:25495219

  5. Pharmacological characteristics of endokinin C/D-derived peptides in nociceptive and inflammatory processing in rats.

    PubMed

    Naono-Nakayama, Rumi; Sunakawa, Natsuki; Ikeda, Tetsuya; Matsushima, Osamu; Nishimori, Toshikazu

    2011-12-01

    Endokinins designated from the human TAC4 gene consist of endokinin A, endokinin B, endokinin C (EKC) and endokinin D (EKD). EKC/D is a peptide using the common carboxyl-terminal in EKC and EKD and consists of 12 amino acids, and exerts antagonistic effects on the induction of scratching behavior by substance P (SP). Some of SP-preferring receptor antagonists have several d-tryptophan (d-Trp); however, the pharmacological effect of EKC/D-derived peptides with d-Trp remains to be solved. Therefore, to clarify the pharmacological characteristics of EKC/D-derived peptides, effects of pretreatment with these peptides on SP-induced scratching and thermal hyperalgesia, formalin-induced flinching and carrageenan-induced inflammation were evaluated. Intrathecal administration of [d-Trp(8)]-EKC/D and [d-Trp(10)]-EKC/D showed a markedly long inhibitory effect, at least 14 h, whereas the antagonistic effects of [d-Trp(8,10)]-EKC/D and EKC/D without d-Trp disappeared after 1h. Furthermore, the inhibitory effect of [d-Trp(10)]-EKC/D-derived peptides was dependent on the number of amino acids from the amino-terminus, and the more numerous the amino acids, the more marked the antagonistic effect. Thus, these results indicate that the effective duration of EKC/D-derived peptides is dependent on the number of d-Trp in the carboxyl-terminal region and the amino-terminal region regulates the antagonistic effect of EKC/D. PMID:22074956

  6. Nutritional value of D-amino acids, D-peptides, and amino acid derivatives in mice

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This paper describes a method for determining the nutritional value of D-amino acids, D-peptides, and amino acid derivatives using a growth assay in mice fed a synthetic all-amino acid diet. A large number of experiments were carried out in which a molar equivalent of the test compound replaced a n...

  7. A proline-derived transannular N-cap for nucleation of short α-helical peptides.

    PubMed

    Tian, Yuan; Wang, Dongyuan; Li, Jingxu; Shi, Chuan; Zhao, Hui; Niu, Xiaogang; Li, Zigang

    2016-07-28

    We report herein a proline-derived transannular N-cap as a helix nucleating template in diverse bio-related peptide sequences via macrolactamization on resin. This approach takes advantage of synergistic stabilization effects of both N-capping properties of proline and substitution of a main chain hydrogen bond with a covalent bond. PMID:27357119

  8. Scolopendin 2, a cationic antimicrobial peptide from centipede, and its membrane-active mechanism.

    PubMed

    Lee, Heejeong; Hwang, Jae-Sam; Lee, Jaeho; Kim, Jae Il; Lee, Dong Gun

    2015-02-01

    Scolopendin 2 is a 16-mer peptide (AGLQFPVGRIGRLLRK) derived from the centipede Scolopendra subspinipes mutilans. We observed that this peptide exhibited antimicrobial activity in a salt-dependent manner against various fungal and bacterial pathogens and showed no hemolytic effect in the range of 1.6 μM to 100 μM. Circular dichroism analysis showed that the peptide has an α-helical properties. Furthermore, we determined the mechanism(s) of action using flow cytometry and by investigating the release of intracellular potassium. The results showed that the peptide permeabilized the membranes of Escherichia coli O157 and Candida albicans, resulting in loss of intracellular potassium ions. Additionally, bis-(1,3-dibutylbarbituric acid) trimethine oxonol and 3,3'-dipropylthiacarbocyanine iodide assays showed that the peptide caused membrane depolarization. Using giant unilamellar vesicles encapsulating calcein and large unilamellar vesicles containing fluorescein isothiocyanate-dextran, which were similar in composition to typical E. coli O157 and C. albicans membranes, we demonstrated that scolopendin 2 disrupts membranes, resulting in a pore size between 4.8 nm and 5.0 nm. Thus, we have demonstrated that a cationic antimicrobial peptide, scolopendin 2, exerts its broad-spectrum antimicrobial effects by forming pores in the cell membrane. PMID:25462167

  9. A peptide antigen derived from EGFR T790M is immunogenic in non-small cell lung cancer

    PubMed Central

    OFUJI, KAZUYA; TADA, YOSHITAKA; YOSHIKAWA, TOSHIAKI; SHIMOMURA, MANAMI; YOSHIMURA, MAYUKO; SAITO, KEIGO; NAKAMOTO, YASUNARI; NAKATSURA, TETSUYA

    2015-01-01

    Lung cancer is the leading cause of cancer-related deaths worldwide. Epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs), such as gefitinib and erlotinib, have demonstrated marked clinical activity against non-small cell lung cancer (NSCLC) harboring activating epidermal growth factor receptor (EGFR) mutations. However, in most cases, patients develop acquired resistance to EGFR-TKI therapy. The threonine to methionine change at codon 790 of EGFR (EGFR T790M) mutation is the most common acquired resistance mutation, and is present in ~50% cases of TKI resistance. New treatment strategies for NSCLC patients harboring the EGFR T790M mutation are required. We evaluated the immunogenicity of an antigen derived from EGFR with the T790M mutation. Using BIMAS we selected several EGFR T790M-derived peptides bound to human leukocyte antigen (HLA)-A*02:01. T790M-A peptide (789–797) (IMQLMPFGC)-specific cytotoxic T lymphocytes (CTLs) were induced from peripheral blood mononuclear cells (PBMCs) of HLA-A2+ healthy donors. An established T790M-A-specific CTL line showed reactivity against the NCSLC cell line, H1975-A2 (HLA-A2+, T790M+), but not H1975 (HLA-A2−, T790M+), and the corresponding wild-type peptide (ITQLMPFGC)-pulsed T2 cells using an interferon-γ (IFN-γ) enzyme-linked immuno spot (ELISPOT) assay. This CTL line also demonstrated peptide-specific cytotoxicity against H1975-A2 cells. This finding suggests that the EGFR T790M mutation-derived antigen could be a new target for cancer immunotherapy. PMID:25532027

  10. Inhibition of HIV-1 infection by synthetic peptides derived CCR5 fragments

    SciTech Connect

    Imai, Masaki; Baranyi, Lajos; Okada, Noriko; Okada, Hidechika; E-mail: hiokada@med.nagoya-cu.ac.jp

    2007-02-23

    HIV-1 infection requires interaction of viral envelope protein gp160 with CD4 and a chemokine receptor, CCR5 or CXCR4 as entry coreceptor. We designed HIV-inhibitory peptides targeted to CCR5 using a novel computer program (ANTIS), which searched all possible sense-antisense amino acid pairs between proteins. Seven AHBs were found in CCR5 receptor. All AHB peptides were synthesized and tested for their ability to prevent HIV-1 infection to human T cells. A peptide fragment (LC5) which is a part of the CCR5 receptor corresponding to the loop between the fifth and sixth transmembrane regions (amino acids 222-240) proved to inhibit HIV-1{sub IIIB} infection of MT-4 cells. Interaction of these antisense peptides could be involved in sustaining HIV-1 infectivity. LC5 effectively indicated dose-dependent manner, and the suppression was enhanced additively by T20 peptide, which inhibits infection in vitro by disrupting the gp41 conformational changes necessary for membrane fusion. Thus, these results indicate that CCR5-derived AHB peptides could provide a useful tool to define the mechanism(s) of HIV infection, and may provide insight which will contribute to the development of an anti-HIV-1 reagent.

  11. Anti-infective efficacy of the lactoferrin-derived antimicrobial peptide HLR1r.

    PubMed

    Björn, Camilla; Mahlapuu, Margit; Mattsby-Baltzer, Inger; Håkansson, Joakim

    2016-07-01

    Antimicrobial peptides (AMPs) have emerged as a new class of drug candidates for the treatment of infectious diseases. Here we describe a novel AMP, HLR1r, which is structurally derived from the human milk protein lactoferrin and demonstrates a broad spectrum microbicidal action in vitro. The minimum concentration of HLR1r needed for killing ≥99% of microorganisms in vitro, was in the range of 3-50μg/ml for common Gram-negative and Gram-positive bacteria, including methicillin-resistant Staphylococcus aureus (MRSA), and for the yeast Candida albicans, when assessed in diluted brain-heart infusion medium. We found that HLR1r also possesses anti-inflammatory properties as evidenced by inhibition of tumor necrosis factor alpha (TNF-α) secretion from human monocyte-derived macrophages and by repression of interleukin-6 (IL-6) and plasminogen activator inhibitor-1 (PAI-1) secretion from human mesothelial cells, without any cytotoxic effect observed at the concentration range tested (up to 400μg/ml). HLR1r demonstrated pronounced anti-infectious effect in in vivo experimental models of cutaneous candidiasis in mice and of excision wounds infected with MRSA in rats as well as in an ex vivo model of pig skin infected with S. aureus. In conclusion, HLR1r may constitute a new therapeutic alternative for local treatment of skin infections. PMID:27155369

  12. Comparative surface antimicrobial properties of synthetic biocides and novel human apolipoprotein E derived antimicrobial peptides.

    PubMed

    Forbes, Sarah; McBain, Andrew J; Felton-Smith, Susan; Jowitt, Thomas A; Birchenough, Holly L; Dobson, Curtis B

    2013-07-01

    Medical device infection remains a major clinical concern. Biocidal compounds have been incorporated into medical device materials ideally to inhibit bacterial colonisation whilst exhibiting relatively low cytotoxicity. We compared the antibacterial activity, anti-biofilm efficacy and cytotoxicity of a novel peptide derivative of human apolipoprotein E (apoEdpL-W) to that of commonly used biocides, before and after coating onto a range of standard polymers. Since the antimicrobial function of most biocides frequently involves associations with cellular membranes, we have also studied the detailed interactions of the test antimicrobials with phospholipid bilayers, using the quartz crystal microbalance device combined with dual-polarisation interferometry. ApoEdpL-W displayed broad-spectrum antibacterial activity and marked efficacy against nascent Staphylococcus aureus biofilms. Compounds showed better antimicrobial activity when combined with hydrogel materials than with non-porous materials. The membrane interactions of apoEdpL-W were most similar to that of PHMB, with both agents appearing to readily bind and insert into lipid bilayers, possibly forming pores. However apoEdpL-W showed lower cytotoxicity than PHMB, its efficacy was less affected by the presence of serum, and it demonstrated the highest level of biocompatibility of all the biocides, as indicated by our measurement of its antimicrobial biocompatibility index. This work shows the potential of apoEdpL-W as an effective antiseptic coating agent. PMID:23623325

  13. Tuftsin-derived T-peptide prevents cellular immunosuppression and improves survival rate in septic mice

    PubMed Central

    Gao, Yu-Lei; Chai, Yan-Fen; Dong, Ning; Han, Su; Zhu, Xiao-Mei; Zhang, Qing-Hong; Yao, Yong-Ming

    2015-01-01

    The primary mechanisms of sepsis induced cellular immunesuppression involve immune dysfunction of T lymphocytes and negative immunoregulation of regulatory T cells (Tregs). It has been found that tuftsin is an immune modulating peptide derived from IgG in spleen. T-peptide is one of tuftsin analogs. Herein, we examined the effect of T-peptide on cell-mediated immunity in the presence of lipopolysaccharide (LPS) and the survival rate in septic mice. T-peptide regulated the proliferative ability of CD4+CD25− T cells in dual responses. Meanwhile, 10 and 100 μg/ml T-peptides were able to enhance the apoptotic rate of CD4+CD25− T cells compared with 1 μg/ml T-peptide, but markedly lowered interleukin (IL)-2 levels. When CD4+CD25+ Tregs were treated with T-peptide for 24 hours, and co-cultured with normal CD4+CD25− T cells, the suppressive ability of CD4+CD25+ Tregs on CD4+CD25− T cells was significantly lowered, along with decreased expression in forkhead/winged helix transcription factor p-3 (Foxp-3) as well as cytotoxic T lymphocyte-associated antigen (CTLA)-4, and secretion of transforming growth factor (TGF)-β. Moreover, T-peptide has the ability to improve outcome of septic mice in a dose- and time- dependent manner, and associated with improvement in the microenvironment of cellular immunosuppression in septic mice. PMID:26577833

  14. Short, Synthetic Cationic Peptides Have Antibacterial Activity against Mycobacterium smegmatis by Forming Pores in Membrane and Synergizing with Antibiotics

    PubMed Central

    Gupta, Kajal; Singh, Sameer; van Hoek, Monique L.

    2015-01-01

    Multicellular organisms are constantly exposed to a multitude of pathogenic microbes. Infection is inhibited in vivo by the innate and adaptive immune system. Mycobacterium species have emerged that are resistant to most antibiotics. We identified several naturally occurring cationic antimicrobial peptides that were active at low micromolar concentrations against Mycobacterium smegmatis. Human-derived cathelicidin LL-37 is well characterized and studied against M. smegmatis; we compared LL-37 with Chinese cobra-derived cathelicidin NA-CATH and mouse cathelicidin (mCRAMP). Two synthetic 11-residue peptides (ATRA-1A and ATRA-2) containing variations of a repeated motif within NA-CATH were tested for their activity against M. smegmatis along with a short synthetic peptide derivative from the human beta-defensin hBD3 (hBD3-Pep4). We hypothesized that these smaller synthetic peptides may demonstrate antimicrobial effectiveness with shorter length (and at less cost), making them strong potential candidates for development into broad-spectrum antimicrobial compounds or use in combination with antibiotics. These peptides have antimicrobial activity with EC50 ranging from 0.05 to 1.88 μg/mL against Mycobacterium smegmatis. The ATRA-1A short peptide was found to be the most effective antimicrobial peptide (AMP) (EC50 = 0.05 μg/mL). High bactericidal activity correlated with bacterial membrane depolarization and permeabilization activities. The efficacy of the peptides was further analyzed through Minimal Inhibitory Concentration (MIC) assays. The MICs were determined by the microdilution method. The peptide mCRAMP showed the best MIC activity at 15.6 μg/mL. Neither of the effective short synthetic peptides demonstrated synergy with the antibiotic rifampicin, although both demonstrated synergy with the cyclic peptide antibiotic polymyxin B. The peptides LL-37 and mCRAMP displayed synergism with rifampicin in MIC assays, whereas antibiotic polymyxin B displayed synergism

  15. Evaluation of the effect of Sm28GST-derived peptides in murine hepatosplenic schistosomiasis: interest of the lipopeptidic form of the C-terminal peptide.

    PubMed

    Pancré, V; Wolowczuk, I; Bossus, M; Gras-Masse, H; Guerret, S; Delanoye, A; Capron, A; Auriault, C

    1994-11-01

    Among the synthetic peptides derived from the 28-kDa Schistosoma mansoni glutathione S-transferase (Sm28GST), immunization with the C-terminal peptide comprising amino acid residues 190-211 induced a reduction in splenomegaly, in the number of hepatic eggs and in hepatic fibrosis in mice infected by Schistosoma mansoni. The absence of antibodies specific for the Sm28GST or for the 190-211 peptide observed in our conditions of immunization with this peptide argued in favour of the involvement of cellular-dependent mechanisms in the reduction in hepatic pathology. This was confirmed by the passive transfer of 190-211 peptide-specific T-cell enriched spleen cells which reproduced the protective effect conferred by immunization with the 190-211 peptide. These 190-211 peptide-specific cells produced little IL4 and high levels of IFN-gamma, a potent inhibitor of collagen synthesis. Furthermore, the use of a lipopeptidic form of the 190-211 peptide significantly improved the reduction in hepatic pathology obtained with the uncoupled peptide and induced a durable protective response. These results provide encouraging information for the possible use of synthetic peptides in the immunoprophylaxis of Schistosomiasis. PMID:7969186

  16. Tumor-Specific Peptide, Selected from a Phage Peptide Library, Enhances Antitumor Activity of Lactaptin

    PubMed Central

    Makartsova, Anna A.; Fomin, Alexandr S.; Nushtaeva, Anna A.; Koval, Olga A.

    2016-01-01

    A recombinant analogue of lactaptin (RL2), a new potential anticancer molecule, induces apoptosis in cultured tumor cells. The tumor suppression efficacy of RL2 was shown against mouse hepatoma-1 cells and MDA-MB-231 human breast adenocarcinoma cells. The RL2-based therapeutic drug lactaptin is distributed evenly throughout the organism, which reduces its antitumor efficacy. In the current study, we obtained a genetic construct that allows production of the recombinant fusion protein T3-RL2, consisting of RL2 and T3 peptide (YTYDPWLIFPAN), in E. coli cells. T3 peptide was selected from a phage peptide library as a result of two screenings: in vitro using MDA-MB-231 cell culture and in vivo using a mouse xenograft model of breast cancer MDA-MB-231. It was shown that the displayed peptide T3 provides binding and internalization of phage particles by MDA-MB-231 cells and their specific accumulation in MDA-MB-231 tumor tissue. In addition, based on the nucleotide sequences coding RL2 and the known tumor-targeting peptide iRGD, we obtained genetic constructs that provide synthesis of fusion proteins RL2-iRGD and RL-iRGD-His. We studied the cytotoxic activity of fusion proteins T3-RL2, RL2-iRGD and RL-iRGD-His in vitro using MDA-MB-231 and MCF-7 human adenocarcinoma cells. The in vitro results showed that the fusion proteins inhibit proliferation of both cell cultures, and their cytotoxic activity is higher than that of RL2. In vivo experiments on the study of the antitumor efficacy of the obtained fusion proteins demonstrated that T3-RL2 protein significantly inhibits MDA-MB-231 tumor growth in a xenograft model compared with RL2, while the antitumor effect of RL2-iRGD and RL-iRGD-His proteins is comparable to the effect of RL2. PMID:27513518

  17. Interactions between the plasma membrane and the antimicrobial peptide HP (2-20) and its analogues derived from Helicobacter pylori

    PubMed Central

    Lee, Kwang H.; Lee, Dong G.; Park, Yoonkyung; Kang, Dong-Il; Shin, Song Y.; Hahm, Kyung-Soo; Kim, Yangmee

    2005-01-01

    HP (2-20), a 19-residue peptide derived from the N-terminus of Helicobacter pylori ribosomal protein L1, has antimicrobial activity but is not cytotoxic to human erythrocytes. We synthesized several peptide analogues to investigate the effects of substitutions on structure and antimicrobial activity. Replacement of Gln16 and Asp18 with tryptophan [anal-3 (analogue-3)] caused a dramatic increase in lytic activities against bacteria and fungi. By contrast, a decrease in amphiphilicity caused by replacement of Phe5 or Leu11 with serine was accompanied by a reduction in antimicrobial activity. Analysis of the tertiary structures of the peptides in SDS micelles by NMR spectroscopy revealed that they have a well-defined α-helical structure. Among the analogues, anal-3 has the longest α-helix, from Val4 to Trp18. The enhanced hydrophobicity and increased α-helicity results in enhanced antimicrobial activity in anal-3 without an increase in haemolytic activity. Fluorescence experiments proved that the bacterial-cell selectivity of the anal-3 peptide is due to its high binding affinity for negatively charged phospholipids in bacterial cells. Results showing the effect of spin-labels on the NMR spectra indicated that the side chains in the hydrophobic phase of the amphiphilic α-helix are buried on the surface of the micelle and the tryptophan indole ring is anchored in the membrane surface. Because anal-3 shows high selectivity towards bacterial and fungal cells, it may provide an avenue for the development of new antibiotics. PMID:16255716

  18. Design and characterization of an acid-activated antimicrobial peptide.

    PubMed

    Li, Lina; He, Jian; Eckert, Randal; Yarbrough, Daniel; Lux, Renate; Anderson, Maxwell; Shi, Wenyuan

    2010-01-01

    Dental caries is a microbial biofilm infection in which the metabolic activities of plaque bacteria result in a dramatic pH decrease and shift the demineralization/remineralization equilibrium on the tooth surface towards demineralization. In addition to causing a net loss in tooth minerals, creation of an acidic environment favors growth of acid-enduring and acid-generating species, which causes further reduction in the plaque pH. In this study, we developed a prototype antimicrobial peptide capable of achieving high activity exclusively at low environmental pH to target bacterial species like Streptococcus mutans that produce acid and thrive under the low pH conditions detrimental for tooth integrity. The features of clavanin A, a naturally occurring peptide rich in histidine and phenylalanine residues with pH-dependent antimicrobial activity, served as a design basis for these prototype 'acid-activated peptides' (AAPs). Employing the major cariogenic species S. mutans as a model system, the two AAPs characterized in this study exhibited a striking pH-dependent antimicrobial activity, which correlated well with the calculated charge distribution. This type of peptide represents a potential new way to combat dental caries. PMID:19878192

  19. Ion/ion reactions of MALDI-derived peptide ions: increased sequence coverage via covalent and electrostatic modification upon charge inversion.

    PubMed

    Stutzman, John R; McLuckey, Scott A

    2012-12-18

    Atmospheric pressure matrix-assisted laser desorption/ionization (AP-MALDI)-derived tryptic peptide ions have been subjected to ion/ion reactions with doubly deprotonated 4-formyl-1,3-benzenedisulfonic acid (FBDSA) in the gas-phase. The ion/ion reaction produces a negatively charged electrostatic complex composed of the peptide cation and reagent dianion, whereupon dehydration of the complex via collision-induced dissociation (CID) produces a Schiff base product anion. Collisional activation of modified lysine-terminated tryptic peptide anions is consistent with a covalent modification of unprotonated primary amines (i.e., N-terminus and ε-NH(2) of lysine). Modified arginine-terminated tryptic peptides have shown evidence of a covalent modification at the N-terminus and a noncovalent interaction with the arginine residue. The modified anions yield at least as much sequence information upon CID as the unmodified cations for the small tryptic peptides examined here and more sequence information for the large tryptic peptides. This study represents the first demonstration of gas-phase ion/ion reactions involving MALDI-derived ions. In this case, covalent and electrostatic modification charge inversion is shown to enhance MALDI tandem mass spectrometry of tryptic peptides. PMID:23078018

  20. Repetitive Gly-Leu-Lys-Gly-Glu-Asn-Arg-Gly-Asp peptide derived from collagen and fibronectin for improving cell-scaffold interaction.

    PubMed

    Chaisri, Patcharaporn; Chingsungnoen, Artit; Siri, Sineenat

    2015-03-01

    Suitable scaffolds for tissue engineering should provide a microenvironment for cell dwelling and directing cell behavior that resemble the native environment. Three-dimensional geometry of electrospun scaffolds well supports cell deposition, but they often lack biomacromolecules to induce cell responses. In this work, the repetitive collagen and fibronectin motif (rCF) peptide containing multiple repeats of Gly-Leu-Lys-Gly-Glu-Asn-Arg-Gly-Asp sequence derived from the cell adhesion motifs of collagen and fibronectin was produced as the alternative agent to induce cell-scaffold interaction. The DNA fragment encoding rCF peptide was amplified by a polymerase chain reaction using overlap primers without a DNA template, cloned into a protein expression vector, and expressed as a His-tag fusion peptide in Escherichia coli. The purified rCF peptide possessed cell adhesion activity about 1.5-fold of the commercial RGD peptide. The rCF peptide was grafted onto the electrospun PCL scaffold via RF plasma of Ar/O2 discharge and acrylic acid treatment. The immobilized rCF peptide significantly increased surface hydrophilicity and enhanced cell proliferation of the electrospun PCL scaffold. These findings suggest the potential application of rCF peptide for improving the biomimetic functions of polymeric scaffolds for tissue engineering. PMID:25503361

  1. Immunization with a Neural-Derived Peptide Protects the Spinal Cord from Apoptosis after Traumatic Injury

    PubMed Central

    Rodríguez-Barrera, Roxana; Fernández-Presas, Ana M.; García, Elisa; Flores-Romero, Adrian; Martiñón, Susana; González-Puertos, Viridiana Yazmín; Mestre, Humberto; Flores-Dominguez, Carmina; Rodriguez-Mata, Verónica; Königsberg, Mina; Solano, Sandra; Ibarra, Antonio

    2013-01-01

    Apoptosis is one of the most destructive mechanisms that develop after spinal cord (SC) injury. Immunization with neural-derived peptides (INDPs) such as A91 has shown to reduce the deleterious proinflammatory response and the amount of harmful compounds produced after SC injury. With the notion that the aforementioned elements are apoptotic inducers, we hypothesized that INDPs would reduce apoptosis after SC injury. In order to test this assumption, adult rats were subjected to SC contusion and immunized either with A91 or phosphate buffered saline (PBS; control group). Seven days after injury, animals were euthanized to evaluate the number of apoptotic cells at the injury site. Apoptosis was evaluated using DAPI and TUNEL techniques; caspase-3 activity was also evaluated. To further elucidate the mechanisms through which A91 exerts this antiapoptotic effects we quantified tumor necrosis factor-alpha (TNF-α). To also demonstrate that the decrease in apoptotic cells correlated with a functional improvement, locomotor recovery was evaluated. Immunization with A91 significantly reduced the number of apoptotic cells and decreased caspase-3 activity and TNF-α concentration. Immunization with A91 also improved the functional recovery of injured rats. The present study shows the beneficial effect of INDPs on preventing apoptosis and provides more evidence on the neuroprotective mechanisms exerted by this strategy. PMID:24236295

  2. Cleavage Specificity Analysis of Six Type II Transmembrane Serine Proteases (TTSPs) Using PICS with Proteome-Derived Peptide Libraries

    PubMed Central

    Béliveau, François; Leduc, Richard; Overall, Christopher M.

    2014-01-01

    Background Type II transmembrane serine proteases (TTSPs) are a family of cell membrane tethered serine proteases with unclear roles as their cleavage site specificities and substrate degradomes have not been fully elucidated. Indeed just 52 cleavage sites are annotated in MEROPS, the database of proteases, their substrates and inhibitors. Methodology/Principal Finding To profile the active site specificities of the TTSPs, we applied Proteomic Identification of protease Cleavage Sites (PICS). Human proteome-derived database searchable peptide libraries were assayed with six human TTSPs (matriptase, matriptase-2, matriptase-3, HAT, DESC and hepsin) to simultaneously determine sequence preferences on the N-terminal non-prime (P) and C-terminal prime (P’) sides of the scissile bond. Prime-side cleavage products were isolated following biotinylation and identified by tandem mass spectrometry. The corresponding non-prime side sequences were derived from human proteome databases using bioinformatics. Sequencing of 2,405 individual cleaved peptides allowed for the development of the family consensus protease cleavage site specificity revealing a strong specificity for arginine in the P1 position and surprisingly a lysine in P1′ position. TTSP cleavage between R↓K was confirmed using synthetic peptides. By parsing through known substrates and known structures of TTSP catalytic domains, and by modeling the remainder, structural explanations for this strong specificity were derived. Conclusions Degradomics analysis of 2,405 cleavage sites revealed a similar and characteristic TTSP family specificity at the P1 and P1′ positions for arginine and lysine in unfolded peptides. The prime side is important for cleavage specificity, thus making these proteases unusual within the tryptic-enzyme class that generally has overriding non-prime side specificity. PMID:25211023

  3. Nerve-derived Transmitters Including Peptides Influence Cutaneous Immunology

    PubMed Central

    Madva, Elizabeth N.; Granstein, Richard D.

    2013-01-01

    Clinical observations suggest that the nervous and immune systems are closely related. For example, inflammatory skin disorders; such as psoriasis, atopic dermatitis, rosacea and acne; are widely believed to be exacerbated by stress. A growing body of research now suggests that neuropeptides and neurotransmitters serve as a link between these two systems. Neuropeptides and neurotransmitters are released by nerves innervating the skin to influence important actors of the immune system, such as Langerhans cells and mast cells, which are located within close anatomic proximity. Catecholamines and other sympathetic transmitters that are released in response to activation of the sympathetic nervous system are also able to reach the skin and affect immune cells. Neuropeptides appear to direct the outcome of Langerhans cell antigen presentation with regard to the subtypes of Th cells generated and neuropeptides induce the degranulation of mast cells, among other effects. Additionally, endothelial cells, which release many inflammatory mediators and express cell surface molecules that allow leukocytes to exit the bloodstream, appear to be regulated by certain neuropeptides and transmitters. This review focuses on the evidence that products of nerves have important regulatory activities on antigen presentation, mast cell function and endothelial cell biology. These activities are highly likely to have clinical and therapeutic relevance. PMID:23517710

  4. Isolation and characterization of anti-inflammatory peptides derived from whey protein.

    PubMed

    Ma, Ye; Liu, Jie; Shi, Haiming; Yu, Liangli Lucy

    2016-09-01

    The present study was conducted to isolate and characterize anti-inflammatory peptides from whey protein hydrolysates using alcalase. Nine subfractions were obtained after sequential purification by ultrafiltration, Sephadex G-25 gel (GE Healthcare, Uppsala, Sweden) filtration chromatography, and preparative HPLC. Among them, subfraction F4e showed the strongest inhibitory activity on interleukin-1β (IL-1β), cyclooxygenase-2, and tumor necrosis factor-α (TNF-α) mRNA expression in lipopolysaccharide-induced RAW 264.7 mouse macrophages. Eight peptides, including 2 new peptides-Asp-Tyr-Lys-Lys-Tyr (DYKKY) and Asp-Gln-Trp-Leu (DQWL)-were identified from subfractions F4c and F4e, respectively, using ultra-high performance liquid chromatography-quadrupole-time-of-flight mass spectrometry. Peptide DQWL showed the strongest inhibitory ability on IL-1β, cyclooxygenase-2, and TNF-α mRNA expression and production of IL-1β and TNF-α proteins at concentrations of 10 and 100μg/mL, respectively. Additionally, DQWL treatment significantly inhibited nuclear factor-κB activation by suppressing nuclear translocation of nuclear factor-κB p65 and blocking inhibitor κB kinase phosphorylation and inhibitor κB degradation together with p38 mitogen-activated protein kinase activation. Our study suggests that peptide DQWL has anti-inflammatory potential; further confirmation using an in vivo model is needed. PMID:27394940

  5. Rational design of tryptophan-rich antimicrobial peptides with enhanced antimicrobial activities and specificities.

    PubMed

    Yu, Hui-Yuan; Huang, Kuo-Chun; Yip, Bak-Sau; Tu, Chih-Hsiang; Chen, Heng-Li; Cheng, Hsi-Tsung; Cheng, Jya-Wei

    2010-11-01

    Trp-rich antimicrobial peptides play important roles in the host innate defense mechanism of many plants and animals. A series of short Trp-rich peptides derived from the C-terminal region of Bothrops asper myothoxin II, a Lys49 phospholipase A(2) (PLA(2)), were found to reproduce the antimicrobial activities of their parent molecule. Of these peptides, KKWRWWLKALAKK-designated PEM-2-was found to display improved activity against both Gram-positive and Gram-negative bacteria. To improve the antimicrobial activity of PEM-2 for potential clinical applications further, we determined the solution structure of PEM-2 bound to membrane-mimetic dodecylphosphocholine (DPC) micelles by two-dimensional NMR methods. The DPC micelle-bound structure of PEM-2 adopts an α-helical conformation and the positively charged residues are clustered together to form a hydrophilic patch. The surface electrostatic potential map indicates that two of the three tryptophan residues are packed against the peptide backbone and form a hydrophobic face with Leu7, Ala9, and Leu10. A variety of biophysical and biochemical experiments, including circular dichroism, fluorescence spectroscopy, and microcalorimetry, were used to show that PEM-2 interacted with negatively charged phospholipid vesicles and efficiently induced dye release from these vesicles, suggesting that the antimicrobial activity of PEM-2 could be due to interactions with bacterial membranes. Potent analogues of PEM-2 with enhanced antimicrobial and less pronounced hemolytic activities were designed with the aid of these structural studies. PMID:20865718

  6. Presence of chromogranin-derived antimicrobial peptides in plasma during coronary artery bypass surgery and evidence of an immune origin of these peptides.

    PubMed

    Tasiemski, Aurélie; Hammad, Hamida; Vandenbulcke, Franck; Breton, Christophe; Bilfinger, Thomas J; Pestel, Joel; Salzet, Michel

    2002-07-15

    Chromogranin A (CGA) and chromogranin B (CGB) are acidic proteins stored in secretory organelles of endocrine cells and neurons. In addition to their roles as helper proteins in the packaging of peptides, they may serve as prohormones to generate biologically active peptides such as vasostatin-1 and secretolytin. These molecules derived from CGA and CGB, respectively, possess antimicrobial properties. The present study demonstrates that plasmatic levels of both vasostatin-1 and secretolytin increase during surgery in patients undergoing cardiopulmonary bypass (CPB). Vasostatin-1 and secretolytin, initially present in plasma at low levels, are released just after skin incision. Consequently, they can be added to enkelytin, an antibacterial peptide derived from proenkephalin A, for the panoply of components acting as a first protective barrier against hypothetical invasion of pathogens, which may occur during surgery. CGA and CGB, more commonly viewed as markers for endocrine and neuronal cells, were also found to have an immune origin. RNA messengers coding for CGB were amplified by reverse transcription-polymerase chain reaction in human monocytes, and immunocytochemical analysis by confocal microscopy revealed the presence of CGA or CGB or both in monocytes and neutrophils. A combination of techniques including confocal microscopic analysis, mass spectrometry measurement, and antibacterial tests allowed for the identification of the positive role of interleukin 6 (IL-6) in the secretolytin release from monocytes in vitro. Because IL-6 release is known to be strongly enhanced during CPB, we suggest a possible relationship between IL-6 and the increased level of secretolytin in patients undergoing CPB. PMID:12091348

  7. Amyloid beta peptides do not form peptide-derived free radicals spontaneously, but can enhance metal-catalyzed oxidation of hydroxylamines to nitroxides.

    PubMed

    Dikalov, S I; Vitek, M P; Maples, K R; Mason, R P

    1999-04-01

    Amyloid beta (Abeta) peptides play an important role in the pathogenesis of Alzheimer's disease. Free radical generation by Abeta peptides was suggested to be a key mechanism of their neurotoxicity. Reports that neurotoxic free radicals derived from Abeta-(1-40) and Abeta-(25-35) peptides react with the spin trap N-tert-butyl-alpha-phenylnitrone (PBN) to form a PBN/.Abeta peptide radical adduct with a specific triplet ESR signal assert that the peptide itself was the source of free radicals. We now report that three Abeta peptides, Abeta-(1-40), Abeta-(25-35), and Abeta-(40-1), do not yield radical adducts with PBN from the Oklahoma Medical Research Foundation (OMRF). In contrast to OMRF PBN, incubation of Sigma PBN in phosphate buffer without Abeta peptides produced a three-line ESR spectrum. It was shown that this nitroxide is di-tert-butylnitroxide and is formed in the Sigma PBN solution as a result of transition metal-catalyzed auto-oxidation of the respective hydroxylamine present as an impurity in the Sigma PBN. Under some conditions, incubation of PBN from Sigma with Abeta-(1-40) or Abeta-(25-35) can stimulate the formation of di-tert-butylnitroxide. It was shown that Abeta peptides enhanced oxidation of cyclic hydroxylamine 1-hydroxy-4-oxo-2,2,6, 6-tetramethylpiperidine (TEMPONE-H), which was strongly inhibited by the treatment of phosphate buffer with Chelex-100. It was shown that ferric and cupric ions are effective oxidants of TEMPONE-H. The data obtained allow us to conclude that under some conditions toxic Abeta peptides Abeta-(1-40) and Abeta-(25-35) enhance metal-catalyzed oxidation of hydroxylamine derivatives, but do not spontaneously form peptide-derived free radicals. PMID:10092619

  8. Calpastatin exon 1B-derived peptide, a selective inhibitor of calpain: enhancing cell permeability by conjugation with penetratin.

    PubMed

    Gil-Parrado, Shirley; Assfalg-Machleidt, Irmgard; Fiorino, Ferdinando; Deluca, Dominga; Pfeiler, Dietmar; Schaschke, Norbert; Moroder, Luis; Machleidt, Werner

    2003-03-01

    The ubiquitous calpains, mu- and m-calpain, have been implicated in essential physiological processes and various pathologies. Cell-permeable specific inhibitors are important tools to elucidate the roles of calpains in cultivated cells and animal models. The synthetic N-acetylated 27-mer peptide derived from exon B of the inhibitory domain 1 of human calpastatin (CP1B) is unique as a potent and highly selective reversible calpain inhibitor, but is poorly cell-permeant. By addition of N-terminal cysteine residues we have generated a disulfide-conjugated CP1B with the cell-penetrating 16-mer peptide penetratin derived from the third helix of the Antennapedia homeodomain protein. The inhibitory potency and selectivity of CP1B for calpain versus cathepsin B and L, caspase 3 and the proteasome was not affected by the conjugation with penetratin. The conjugate was shown to efficiently penetrate into living LCLC 103H cells, since it prevents ionomycin-induced calpain activation at 200-fold lower concentration than the non-conjugated inhibitor and is able to reduce calpain-triggered apoptosis of these cells. Penetratin-conjugated CP1B seems to be a promising alternative to the widely used cell-permeable peptide aldehydes (e.g. calpain inhibitor 1) which inhibit the lysosomal cathepsins and partially the proteasome as well or even better than the calpains. PMID:12715890

  9. Novel Antimicrobial Peptides with High Anticancer Activity and Selectivity

    PubMed Central

    Chen, Kuan-Hao; Yu, Hui-Yuan; Chih, Ya-Han; Cheng, Hsi-Tsung; Chou, Yu-Ting; Cheng, Jya-Wei

    2015-01-01

    We describe a strategy to boost anticancer activity and reduce normal cell toxicity of short antimicrobial peptides by adding positive charge amino acids and non-nature bulky amino acid β-naphthylalanine residues to their termini. Among the designed peptides, K4R2-Nal2-S1 displayed better salt resistance and less toxicity to hRBCs and human fibroblast than Nal2-S1 and K6-Nal2-S1. Fluorescence microscopic studies indicated that the FITC-labeled K4R2-Nal2-S1 preferentially binds cancer cells and causes apoptotic cell death. Moreover, a significant inhibition in human lung tumor growth was observed in the xenograft mice treated with K4R2-Nal2-S1. Our strategy provides new opportunities in the development of highly effective and selective antimicrobial and anticancer peptide-based therapeutics. PMID:25970292

  10. Monitoring Criminal Activity through Invisible Fluorescent "Peptide Coding" Taggants.

    PubMed

    Gooch, James; Goh, Hilary; Daniel, Barbara; Abbate, Vincenzo; Frascione, Nunzianda

    2016-04-19

    Complementing the demand for effective crime reduction measures are the increasing availability of commercial forensic "taggants", which may be used to physically mark an object in order to make it uniquely identifiable. This study explores the use of a novel "peptide coding" reagents to establish evidence of contact transfer during criminal activity. The reagent, containing a fluorophore dispersed within an oil-based medium, also includes a unique synthetic peptide sequence that acts as a traceable "code" to identify the origin of the taggant. The reagent is detectable through its fluorescent properties, which then allows the peptide to be recovered by swabbing and extracted for electrospray ionization-mass spectrometry (ESI-MS) analysis via a simple liquid-liquid extraction procedure. The performance of the reagent in variable conditions that mimic the limits of a real world use are investigated. PMID:27010696

  11. Osteoinductive Effects of Free and Immobilized Bone Forming Peptide-1 on Human Adipose-Derived Stem Cells.

    PubMed

    Li, Wenyue; Zheng, Yunfei; Zhao, Xianghui; Ge, Yanjun; Chen, Tong; Liu, Yunsong; Zhou, Yongsheng

    2016-01-01

    Most synthetic polymeric materials currently used for bone tissue engineering lack specific signals through which cells can identify and interact with the surface, resulting in incompatibility and compromised osteogenic activity. Soluble inductive factors also have issues including a short half-live in vivo. Bone forming peptide-1 is a truncated peptide from the immature form of bone morphogenetic protein-7 (BMP-7) that displays higher osteogenic activity than full-length, mature BMP-7. In this study, we used a mussel-inspired immobilization strategy mediated by polymerization of dopamine to introduce recently discovered stimulators of bone forming peptide-1 (BFP-1) onto the surface of poly-lactic-co-glycolic acid (PLGA) substrate to form a biomaterial that overcomes these challenges. Human adipose-derived stem cells (hASCs), being abundant and easy accessible, were used to test the osteogenic activity of BFP-1 and the novel biomaterial. Under osteoinductive conditions, cells treated with both BFP-1 alone and BFP-1-coated biomaterials displayed elevated expression of the osteogenic markers alkaline phosphatase (ALP), osteocalcin (OC), and RUNX2. Furthermore, hASCs associated with poly-dopamine-assisted BFP-1-immobilized PLGA (pDA-BFP-1-PLGA) scaffolds promoted in vivo bone formation in nude mice. Our novel materials may hold great promise for future bone tissue engineering applications. PMID:26930062

  12. Osteoinductive Effects of Free and Immobilized Bone Forming Peptide-1 on Human Adipose-Derived Stem Cells

    PubMed Central

    Zhao, Xianghui; Ge, Yanjun; Chen, Tong; Liu, Yunsong; Zhou, Yongsheng

    2016-01-01

    Most synthetic polymeric materials currently used for bone tissue engineering lack specific signals through which cells can identify and interact with the surface, resulting in incompatibility and compromised osteogenic activity. Soluble inductive factors also have issues including a short half-live in vivo. Bone forming peptide-1 is a truncated peptide from the immature form of bone morphogenetic protein-7 (BMP-7) that displays higher osteogenic activity than full-length, mature BMP-7. In this study, we used a mussel-inspired immobilization strategy mediated by polymerization of dopamine to introduce recently discovered stimulators of bone forming peptide-1 (BFP-1) onto the surface of poly-lactic-co-glycolic acid (PLGA) substrate to form a biomaterial that overcomes these challenges. Human adipose-derived stem cells (hASCs), being abundant and easy accessible, were used to test the osteogenic activity of BFP-1 and the novel biomaterial. Under osteoinductive conditions, cells treated with both BFP-1 alone and BFP-1-coated biomaterials displayed elevated expression of the osteogenic markers alkaline phosphatase (ALP), osteocalcin (OC), and RUNX2. Furthermore, hASCs associated with poly-dopamine-assisted BFP-1-immobilized PLGA (pDA-BFP-1-PLGA) scaffolds promoted in vivo bone formation in nude mice. Our novel materials may hold great promise for future bone tissue engineering applications. PMID:26930062

  13. A chirality change in XPC- and Sfi1-derived peptides affects their affinity for centrin.

    PubMed

    Grecu, Dora; Irudayaraj, Victor Paul Raj; Martinez-Sanz, Juan; Mallet, Jean-Maurice; Assairi, Liliane

    2016-04-01

    The Ca(2+)-binding protein centrin binds to a hydrophobic motif (W(1)xxL(4)xxxL(8)) included in the sequence of several cellular targets: XPC (xeroderma pigmentosum group C protein), Sfi1 (suppressor of fermentation-induced loss of stress resistance protein1), and Sac3 [the central component of the transcription and mRNA export (TREX-2) complex]. However, centrin binding occurs in a reversed orientation (L(8)xxxL(4)xxW(1)) for Sfi1 and Sac3 compared with XPC. Because D-peptides have been investigated for future therapeutic use, we analyzed their centrin-binding properties. Their affinity for centrin was measured using isothermal titration calorimetry. The chirality change in the target-derived peptides affected their ability to bind centrin in a specific manner depending on the sequence orientation of the centrin-binding motif. In contrast to L-XPC-P10, D-XPC-P10 bound C-HsCen1 in a Ca(2+)-dependent manner and to a lesser extent. D-XPC-P10 exhibited a reduced affinity for C-HsCen1 (Ka=0.064 × 10(6) M(-1)) by a factor of 2000 compared with L-XPC-P10 (Ka=132 × 10(6) M(-1)). D-peptides have a lower affinity than L-peptides for centrin, and the strength of this affinity depends on the sequence orientation of the target-derived peptides. The residual affinity observed for D-XPC suggests that the use of d-peptides represents a promising strategy for inhibiting centrin binding to its targets. PMID:26923803

  14. Cementomimetics—constructing a cementum-like biomineralized microlayer via amelogenin-derived peptides

    PubMed Central

    Gungormus, Mustafa; Oren, Ersin E; Horst, Jeremy A; Fong, Hanson; Hnilova, Marketa; Somerman, Martha J; Snead, Malcolm L; Samudrala, Ram; Tamerler, Candan; Sarikaya, Mehmet

    2012-01-01

    Cementum is the outer-, mineralized-tissue covering the tooth root and an essential part of the system of periodontal tissue that anchors the tooth to the bone. Periodontal disease results from the destructive behavior of the host elicited by an infectious biofilm adhering to the tooth root and left untreated, may lead to tooth loss. We describe a novel protocol for identifying peptide sequences from native proteins with the potential to repair damaged dental tissues by controlling hydroxyapatite biomineralization. Using amelogenin as a case study and a bioinformatics scoring matrix, we identified regions within amelogenin that are shared with a set of hydroxyapatite-binding peptides (HABPs) previously selected by phage display. One 22-amino acid long peptide regions referred to as amelogenin-derived peptide 5 (ADP5) was shown to facilitate cell-free formation of a cementum-like hydroxyapatite mineral layer on demineralized human root dentin that, in turn, supported attachment of periodontal ligament cells in vitro. Our findings have several implications in peptide-assisted mineral formation that mimic biomineralization. By further elaborating the mechanism for protein control over the biomineral formed, we afford new insights into the evolution of protein–mineral interactions. By exploiting small peptide domains of native proteins, our understanding of structure–function relationships of biomineralizing proteins can be extended and these peptides can be utilized to engineer mineral formation. Finally, the cementomimetic layer formed by ADP5 has the potential clinical application to repair diseased root surfaces so as to promote the regeneration of periodontal tissues and thereby reduce the morbidity associated with tooth loss. PMID:22743342

  15. Thiol-disulfide exchange in peptides derived from human growth hormone.

    PubMed

    Chandrasekhar, Saradha; Epling, Daniel E; Sophocleous, Andreas M; Topp, Elizabeth M

    2014-04-01

    Disulfide bonds stabilize proteins by cross-linking distant regions into a compact three-dimensional structure. They can also participate in hydrolytic and oxidative pathways to form nonnative disulfide bonds and other reactive species. Such covalent modifications can contribute to protein aggregation. Here, we present experimental data for the mechanism of thiol-disulfide exchange in tryptic peptides derived from human growth hormone in aqueous solution. Reaction kinetics was monitored to investigate the effect of pH (6.0-10.0), temperature (4-50°C), oxidation suppressants [ethylenediaminetetraacetic acid (EDTA) and N2 sparging], and peptide secondary structure (amide cyclized vs. open form). The concentrations of free thiol containing peptides, scrambled disulfides, and native disulfide-linked peptides generated via thiol-disulfide exchange and oxidation reactions were determined using reverse-phase HPLC and liquid chromatography-mass spectrometry. Concentration versus time data were fitted to a mathematical model using nonlinear least squares regression analysis. At all pH values, the model was able to fit the data with R(2) ≥ 0.95. Excluding oxidation suppressants (EDTA and N2 sparging) resulted in an increase in the formation of scrambled disulfides via oxidative pathways but did not influence the intrinsic rate of thiol-disulfide exchange. In addition, peptide secondary structure was found to influence the rate of thiol-disulfide exchange. PMID:24549831

  16. Characterization of Spontaneous Immune Responses against Long Peptides Derived from Bcl-X(L) in Cancer Patients Using Elispot

    PubMed Central

    Larsen, Stine Kiaer; Hansen, Morten; Svane, Inge Marie; Straten, Per Thor; Andersen, Mads Hald

    2012-01-01

    In recent years we and others have used the ELISPOT assay successfully to identify novel tumor antigens by the characterization of spontaneous HLA class I restricted immune responses against a number of minimal 9–10 amino acid long peptide epitopes. In the present study, we examined the capability of using longer peptides when scrutinizing Peripheral Blood Mononuclear Cells (PMBC) from melanoma patients for spontaneous immunity by means of ELISPOT IFN-γ secretion assay. To this end, we examined PBMC for the presence of specific T-cell responses against long peptides derived from the tumor associated antigen BCL-X(L). The protein product of the larger BCL-X(L) differs from Bcl-X(S) protein by an inserted region (amino acids 126–188). Thus, we scrutinized eight long peptides covering this inserted region for spontaneous immunity. The peptides were overlapping and consisted of 20–23 amino acids. PBMC were pre-stimulated with peptide-pulsed autologous dendritic cells (DC) and subjected to the IFN-γ ELISPOT assay. Four of the BCL-X(L) derived peptides elicited very frequent responses in several patients. Additionally, in all patients responses against more than one of the peptides could be detected. In conclusion several long BCL-X(L) derived peptide epitopes exist, which may be used in anti-cancer immunity. Furthermore, the ELISPOT assay offers an attractive and sensitive method for the characterization of spontaneous immune reactivity against long peptides. PMID:24710413

  17. Anti-HIV screening for cell-penetrating peptides using chloroquine and identification of anti-HIV peptides derived from matrix proteins.

    PubMed

    Mizuguchi, Takaaki; Ohashi, Nami; Nomura, Wataru; Komoriya, Mao; Hashimoto, Chie; Yamamoto, Naoki; Murakami, Tsutomu; Tamamura, Hirokazu

    2015-08-01

    Previously, compounds which inhibit the HIV-1 replication cycle were found in overlapping peptide libraries covering the whole sequence of an HIV-1 matrix (MA) protein constructed with the addition of an octa-arginyl group. The two top lead compounds are sequential fragments MA-8L and MA-9L. In the present study, the addition of chloroquine in cell-based anti-HIV assays was proven to be an efficient method with which to find anti-HIV compounds among several peptides conjugated by cell-penetrating signals such as an octa-arginyl group: the conjugation of an octa-arginyl group to individual peptides contained in whole proteins in combination with the addition of chloroquine in cells is a useful assay method to search active peptides. To find more potent fragment peptides, individual peptides between MA-8L and MA-9L, having the same peptide chain length but with sequences shifted by one amino acid residue, were synthesized in this paper and their anti-HIV activity was evaluated with an anti-HIV assay using chloroquine. As a result, the peptides in the C-terminal side of the series, which are relatively close to MA-9L, showed more potent inhibitory activity against both X4-HIV-1 and R5-HIV-1 than the peptides in the N-terminal side. PMID:26094944

  18. Antibody Derived Peptides for Detection of Ebola Virus Glycoprotein

    PubMed Central

    López-Pacheco, Felipe; Pérez-Chavarría, Roberto; González-Vázquez, Juan Carlos; González-González, Everardo; Trujillo-de Santiago, Grissel; Ponce-Ponce de León, César Alejandro; Zhang, Yu Shrike; Dokmeci, Mehmet Remzi; Khademhosseini, Ali; Alvarez, Mario Moisés

    2015-01-01

    Background Current Ebola virus (EBOV) detection methods are costly and impractical for epidemic scenarios. Different immune-based assays have been reported for the detection and quantification of Ebola virus (EBOV) proteins. In particular, several monoclonal antibodies (mAbs) have been described that bind the capsid glycoprotein (GP) of EBOV GP. However, the currently available platforms for the design and production of full-length mAbs are cumbersome and costly. The use of antibody fragments, rather than full-length antibodies, might represent a cost-effective alternative for the development of diagnostic and possibly even therapeutic alternatives for EBOV. Methods/Principal Findings We report the design and expression of three recombinant anti-GP mAb fragments in Escherichia coli cultures. These fragments contained the heavy and light variable portions of the three well-studied anti-GP full-length mAbs 13C6, 13F6, and KZ52, and are consequently named scFv-13C6, scFv-13F6, and Fab-KZ52, respectively. All three fragments exhibited specific anti-GP binding activity in ELISA experiments comparable to that of full-length anti-GP antibodies (i.e., the same order of magnitude) and they are easily and economically produced in bacterial cultures. Conclusion/Significance Antibody fragments might represent a useful, effective, and low cost alternative to full-length antibodies in Ebola related capture and diagnostics applications. PMID:26489048

  19. Increase of anti-HIV activity of C-peptide fusion inhibitors using a bivalent drug design approach.

    PubMed

    Ling, Yanbo; Xue, Huifang; Jiang, Xifeng; Cai, Lifeng; Liu, Keliang

    2013-09-01

    We reported the design of fusion inhibitors with improved activity using a multivalent inhibitor design strategy. First, we chose C29 as the template sequence, which is a 29-mer peptide derived from HIV-1 gp41 CHR domain and has anti-HIV activity of IC50 118 nM in a cell-cell fusion assay. We optimized the crosslink sites and linkers of the template peptide. We found that N-terminal crosslink caused activity improvement based on the multivalent co-operative effect. Especially, the IC50 of peptide (CAcaC29)2 was improved from 49.02 (monomeric form) to 5.71 nM. Compared with long peptides, short peptides may be more suitable to analyze the co-operative effect. So we selected a shorter peptide C22 to synthesize the bivalent inhibitors. Due its weak helicity, no co-operative effect appeared. Therefore, we chose SC22EK, which were introduced salt bridges to consolidate the helicity based on the natural sequence C22. The cross-linked (CAcaSC22EK)2 was four times more potent than the monomer SC22EK in anti-HIV activity, with an IC50 value of 4.92 nM close to the high active peptide fusion inhibitor C34. The strategy used in this study may be used to design new fusion inhibitors to interfere similar processes. PMID:23906421

  20. Targeting Leishmania major parasite with peptides derived from a combinatorial phage display library.

    PubMed

    Rhaiem, Rafik Ben; Houimel, Mehdi

    2016-07-01

    Cutaneous leishmaniasis (CL) is a global problem caused by intracellular protozoan pathogens of the genus Leishmania for which there are no suitable vaccine or chemotherapy options. Thus, de novo identification of small molecules binding to the Leishmania parasites by direct screening is a promising and appropriate alternative strategy for the development of new drugs. In this study, we used a random linear hexapeptide library fused to the gene III protein of M13 filamentous bacteriophage to select binding peptides to metacyclic promastigotes from a highly virulent strain of Leishmania major (Zymodeme MON-25; MHOM/TN/94/GLC94). After four rounds of stringent selection and amplification, polyclonal and monoclonal phage-peptides directed against L. major metacyclic promastigotes were assessed by ELISA, and the optimal phage-peptides were grown individually and characterized for binding to L. major by monoclonal phage ELISA. The DNA of 42 phage-peptides clones was amplified by PCR, sequenced, and their amino acid sequences deduced. Six different peptide sequences were obtained with frequencies of occurrence ranging from 2.3% to 85.7%. The biological effect of the peptides was assessed in vitro on human monocytes infected with L. major metacyclic promastigotes, and in vivo on susceptible parasite-infected BALB/c mice. The development of cutaneous lesions in the right hind footpads of infected mice after 13 weeks post-infection showed a protection rate of 81.94% with the injected peptide P2. Moreover, Western blots revealed that the P2 peptide interacted with the major surface protease gp63, a protein of 63kDa molecular weight. Moreover, bioinformatics were used to predict the interaction between peptides and the major surface molecule of the L. major. The molecular docking showed that the P2 peptide has the minimum interaction energy and maximum shape complimentarity with the L. major gp63 active site. Our study demonstrated that the P2 peptide occurs at high frequency

  1. Targeting diverse protein–protein interaction interfaces with α/β-peptides derived from the Z-domain scaffold

    SciTech Connect

    Checco, James W.; Kreitler, Dale F.; Thomas, Nicole C.; Belair, David G.; Rettko, Nicholas J.; Murphy, William L.; Forest, Katrina T.; Gellman, Samuel H.

    2015-04-14

    Peptide-based agents derived from well-defined scaffolds offer an alternative to antibodies for selective and high-affinity recognition of large and topologically complex protein surfaces. Here, we describe a strategy for designing oligomers containing both α- and β-amino acid residues ("α/β-peptides") that mimic several peptides derived from the three-helix bundle "Z-domain" scaffold. We show that α/β-peptides derived from a Z-domain peptide targeting vascular endothelial growth factor (VEGF) can structurally and functionally mimic the binding surface of the parent peptide while exhibiting significantly decreased susceptibility to proteolysis. The tightest VEGF-binding α/β-peptide inhibits the VEGF₁₆₅-induced proliferation of human umbilical vein endothelial cells. We demonstrate the versatility of this strategy by showing how principles underlying VEGF signaling inhibitors can be rapidly extended to produce Z-domain–mimetic α/β-peptides that bind to two other protein partners, IgG and tumor necrosis factor-α. Because well-established selection techniques can identify high-affinity Z-domain derivatives from large DNA-encoded libraries, our findings should enable the design of biostable α/β-peptides that bind tightly and specifically to diverse targets of biomedical interest. Such reagents would be useful for diagnostic and therapeutic applications.

  2. Anti-Hemagglutinin Antibody Derived Lead Peptides for Inhibitors of Influenza Virus Binding.

    PubMed

    Memczak, Henry; Lauster, Daniel; Kar, Parimal; Di Lella, Santiago; Volkmer, Rudolf; Knecht, Volker; Herrmann, Andreas; Ehrentreich-Förster, Eva; Bier, Frank F; Stöcklein, Walter F M

    2016-01-01

    Antibodies against spike proteins of influenza are used as a tool for characterization of viruses and therapeutic approaches. However, development, production and quality control of antibodies is expensive and time consuming. To circumvent these difficulties, three peptides were derived from complementarity determining regions of an antibody heavy chain against influenza A spike glycoprotein. Their binding properties were studied experimentally, and by molecular dynamics simulations. Two peptide candidates showed binding to influenza A/Aichi/2/68 H3N2. One of them, termed PeB, with the highest affinity prevented binding to and infection of target cells in the micromolar region without any cytotoxic effect. PeB matches best the conserved receptor binding site of hemagglutinin. PeB bound also to other medical relevant influenza strains, such as human-pathogenic A/California/7/2009 H1N1, and avian-pathogenic A/Mute Swan/Rostock/R901/2006 H7N1. Strategies to improve the affinity and to adapt specificity are discussed and exemplified by a double amino acid substituted peptide, obtained by substitutional analysis. The peptides and their derivatives are of great potential for drug development as well as biosensing. PMID:27415624

  3. Anti-Hemagglutinin Antibody Derived Lead Peptides for Inhibitors of Influenza Virus Binding

    PubMed Central

    Kar, Parimal; Di Lella, Santiago; Volkmer, Rudolf; Knecht, Volker; Herrmann, Andreas; Ehrentreich-Förster, Eva; Bier, Frank F.; Stöcklein, Walter F. M.

    2016-01-01

    Antibodies against spike proteins of influenza are used as a tool for characterization of viruses and therapeutic approaches. However, development, production and quality control of antibodies is expensive and time consuming. To circumvent these difficulties, three peptides were derived from complementarity determining regions of an antibody heavy chain against influenza A spike glycoprotein. Their binding properties were studied experimentally, and by molecular dynamics simulations. Two peptide candidates showed binding to influenza A/Aichi/2/68 H3N2. One of them, termed PeB, with the highest affinity prevented binding to and infection of target cells in the micromolar region without any cytotoxic effect. PeB matches best the conserved receptor binding site of hemagglutinin. PeB bound also to other medical relevant influenza strains, such as human-pathogenic A/California/7/2009 H1N1, and avian-pathogenic A/Mute Swan/Rostock/R901/2006 H7N1. Strategies to improve the affinity and to adapt specificity are discussed and exemplified by a double amino acid substituted peptide, obtained by substitutional analysis. The peptides and their derivatives are of great potential for drug development as well as biosensing. PMID:27415624

  4. Modulating the activity of short arginine-tryptophan containing antibacterial peptides with N-terminal metallocenoyl groups

    PubMed Central

    Albada, H Bauke; Chiriac, Alina-Iulia; Wenzel, Michaela; Penkova, Maya; Bandow, Julia E; Sahl, Hans-Georg

    2012-01-01

    Summary A series of small synthetic arginine and tryptophan containing peptides was prepared and analyzed for their antibacterial activity. The effect of N-terminal substitution with metallocenoyl groups such as ferrocene (FcCO) and ruthenocene (RcCO) was investigated. Antibacterial activity in different media, growth inhibition, and killing kinetics of the most active peptides were determined. The toxicity of selected derivatives was determined against erythrocytes and three human cancer cell lines. It was shown that the replacement of an N-terminal arginine residue with a metallocenoyl moiety modulates the activity of WRWRW-peptides against Gram-positive and Gram-negative bacteria. MIC values of 2–6 µM for RcCO-W(RW)2 and 1–11 µM for (RW)3 were determined. Interestingly, W(RW)2-peptides derivatized with ferrocene were significantly less active than those derivatized with ruthenocene which have similar structural but different electronic properties, suggesting a major influence of the latter. The high activities observed for the RcCO-W(RW)2- and (RW)3-peptides led to an investigation of the origin of activity of these peptides using several important activity-related parameters. Firstly, killing kinetics of the RcCO-W(RW)2-peptide versus killing kinetics of the (RW)3 derivative showed faster reduction of the colony forming units for the RcCO-W(RW)2-peptide, although MIC values indicated higher activity for the (RW)3-peptide. This was confirmed by growth inhibition studies. Secondly, hemolysis studies revealed that both peptides did not lead to significant destruction of erythrocytes, even up to 500 µg/mL for (RW)3 and 250 µg/mL for RcCO-W(RW)2. In addition, toxicity against three human cancer cell lines (HepG2, HT29, MCF7) showed that the (RW)3-peptide had an IC50 value of ~140 µM and the RcW(RW)2 one of ~90 µM, indicating a potentially interesting therapeutic window. Both the killing kinetics and growth inhibition studies presented in this work point to

  5. [Regulation of peptide hydrolase activity in psoriasis].

    PubMed

    Suworow, A P

    1990-01-01

    Clinico-biological examination of 154 patients with psoriasis resulted in data showing high activity of endo- and exopeptidases in efflorescences of that dermatosis. This was accompanied by depressed activity of trypsin inhibitor. At the same time magnesium deficiency, polysaccharide decrease and leucocyte increase were stated to be in the focus of skin damage. That character of interrelation, which play an important role in the pathogenesis of this widespread skin disease, is demonstrated. PMID:2257941

  6. Structure-Activity Relationship of Chlorotoxin-Like Peptides

    PubMed Central

    Ali, Syed Abid; Alam, Mehtab; Abbasi, Atiya; Undheim, Eivind A. B.; Fry, Bryan Grieg; Kalbacher, Hubert; Voelter, Wolfgang

    2016-01-01

    Animal venom (e.g., scorpion) is a rich source of various protein and peptide toxins with diverse physio-/pharmaco-logical activities, which generally exert their action via target-specific modulation of different ion channel functions. Scorpion venoms are among the most widely-known source of peptidyl neurotoxins used for callipering different ion channels, such as; Na+, K+, Ca+, Cl−, etc. A new peptide of the chlorotoxin family (i.e., Bs-Tx7) has been isolated, sequenced and synthesized from scorpion Buthus sindicus (family Buthidae) venom. This peptide demonstrates 66% with chlorotoxin (ClTx) and 82% with CFTR channel inhibitor (GaTx1) sequence identities reported from Leiurus quinquestriatus hebraeus venom. The toxin has a molecular mass of 3821 Da and possesses four intra-chain disulphide bonds. Amino acid sequence analysis of Bs-Tx7 revealed the presence of a scissile peptide bond (i.e., Gly-Ile) for human MMP2, whose activity is increased in the case of tumour malignancy. The effect of hMMP2 on Bs-Tx7, or vice versa, observed using the FRET peptide substrate with methoxycoumarin (Mca)/dinitrophenyl (Dnp) as fluorophore/quencher, designed and synthesized to obtain the lowest Km value for this substrate, showed approximately a 60% increase in the activity of hMMP2 upon incubation of Bs-Tx7 with the enzyme at a micromolar concentration (4 µM), indicating the importance of this toxin in diseases associated with decreased MMP2 activity. PMID:26848686

  7. Structure-Activity Relationship of Chlorotoxin-Like Peptides.

    PubMed

    Ali, Syed Abid; Alam, Mehtab; Abbasi, Atiya; Undheim, Eivind A B; Fry, Bryan Grieg; Kalbacher, Hubert; Voelter, Wolfgang

    2016-02-01

    Animal venom (e.g., scorpion) is a rich source of various protein and peptide toxins with diverse physio-/pharmaco-logical activities, which generally exert their action via target-specific modulation of different ion channel functions. Scorpion venoms are among the most widely-known source of peptidyl neurotoxins used for callipering different ion channels, such as; Na⁺, K⁺, Ca⁺, Cl(-), etc. A new peptide of the chlorotoxin family (i.e., Bs-Tx7) has been isolated, sequenced and synthesized from scorpion Buthus sindicus (family Buthidae) venom. This peptide demonstrates 66% with chlorotoxin (ClTx) and 82% with CFTR channel inhibitor (GaTx1) sequence identities reported from Leiurus quinquestriatus hebraeus venom. The toxin has a molecular mass of 3821 Da and possesses four intra-chain disulphide bonds. Amino acid sequence analysis of Bs-Tx7 revealed the presence of a scissile peptide bond (i.e., Gly-Ile) for human MMP2, whose activity is increased in the case of tumour malignancy. The effect of hMMP2 on Bs-Tx7, or vice versa, observed using the FRET peptide substrate with methoxycoumarin (Mca)/dinitrophenyl (Dnp) as fluorophore/quencher, designed and synthesized to obtain the lowest Km value for this substrate, showed approximately a 60% increase in the activity of hMMP2 upon incubation of Bs-Tx7 with the enzyme at a micromolar concentration (4 µM), indicating the importance of this toxin in diseases associated with decreased MMP2 activity. PMID:26848686

  8. Muraymycin nucleoside-peptide antibiotics: uridine-derived natural products as lead structures for the development of novel antibacterial agents

    PubMed Central

    Wirth, Marius; Niro, Giuliana; Leyerer, Kristin

    2016-01-01

    Summary Muraymycins are a promising class of antimicrobial natural products. These uridine-derived nucleoside-peptide antibiotics inhibit the bacterial membrane protein translocase I (MraY), a key enzyme in the intracellular part of peptidoglycan biosynthesis. This review describes the structures of naturally occurring muraymycins, their mode of action, synthetic access to muraymycins and their analogues, some structure–activity relationship (SAR) studies and first insights into muraymycin biosynthesis. It therefore provides an overview on the current state of research, as well as an outlook on possible future developments in this field. PMID:27340469

  9. A Novel Intracellular Peptide Derived from G1/S Cyclin D2 Induces Cell Death*

    PubMed Central

    de Araujo, Christiane B.; Russo, Lilian C.; Castro, Leandro M.; Forti, Fábio L.; do Monte, Elisabete R.; Rioli, Vanessa; Gozzo, Fabio C.; Colquhoun, Alison; Ferro, Emer S.

    2014-01-01

    Intracellular peptides are constantly produced by the ubiquitin-proteasome system, and many are probably functional. Here, the peptide WELVVLGKL (pep5) from G1/S-specific cyclin D2 showed a 2-fold increase during the S phase of HeLa cell cycle. pep5 (25–100 μm) induced cell death in several tumor cells only when it was fused to a cell-penetrating peptide (pep5-cpp), suggesting its intracellular function. In vivo, pep5-cpp reduced the volume of the rat C6 glioblastoma by almost 50%. The tryptophan at the N terminus of pep5 is essential for its cell death activity, and N terminus acetylation reduced the potency of pep5-cpp. WELVVL is the minimal active sequence of pep5, whereas Leu-Ala substitutions totally abolished pep5 cell death activity. Findings from the initial characterization of the cell death/signaling mechanism of pep5 include caspase 3/7 and 9 activation, inhibition of Akt2 phosphorylation, activation of p38α and -γ, and inhibition of proteasome activity. Further pharmacological analyses suggest that pep5 can trigger cell death by distinctive pathways, which can be blocked by IM-54 or a combination of necrostatin-1 and q-VD-OPh. These data further support the biological and pharmacological potential of intracellular peptides. PMID:24764300

  10. Mitochondrial protein-derived cryptides: Are endogenous N-formylated peptides including mitocryptide-2 components of mitochondrial damage-associated molecular patterns?

    PubMed

    Marutani, Takayuki; Hattori, Tatsuya; Tsutsumi, Koki; Koike, Yusuke; Harada, Akihiko; Noguchi, Kosuke; Kiso, Yoshiaki; Mukai, Hidehito

    2016-11-01

    Recently, much attention has been paid to "nonclassical" bioactive peptides, which are fragmented peptides simultaneously produced during maturation and degradation of various functional proteins. We identified many fragmented peptides derived from various mitochondrial proteins including mitocryptide-1 and mitocryptide-2 that efficiently activate neutrophils. These endogenous, functionally active, fragmented peptides are referred to as "cryptides." Among them, mitocryptide-2 is an N-formylated cryptide cleaved from mitochondrial cytochrome b that is encoded in mitochondrial DNA (mtDNA). It is known that 13 proteins encoded in mtDNA are translated in mitochondria as N-formylated forms, suggesting the existence of endogenous N-formylated peptides other than mitocryptide-2. Here, we investigated the effects of N-formylated peptides presumably cleaved from mtDNA-encoded proteins other than cytochrome b on the functions of neutrophilic cells to elucidate possible regulation by endogenous N-formylated cryptides. Four N-formylated cryptides derived from cytochrome c oxidase subunit I and NADH dehydrogenase subunits 4, 5, and 6 among 12 peptides from mtDNA-encoded proteins efficiently induced not only migration but also β-hexosaminidase release, which is an indicator of neutrophilic phagocytosis, in HL-60 cells differentiated into neutrophilic cells. These activities were comparable to or higher than those induced by mitocryptide-2. Although endogenous N-formylated peptides that are contained in mitochondrial damage-associated molecular patterns (DAMPs) have yet to be molecularly identified, they have been implicated in innate immunity. Thus, N-formylated cryptides including mitocryptide-2 are first-line candidates for the contents of mitochondrial DAMPs to promote innate immune responses. © 2015 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 106: 580-587, 2016. PMID:26600263

  11. A novel peptide inhibitor of classical and lectin complement activation including ABO incompatibility

    PubMed Central

    Mauriello, Clifford T.; Pallera, Haree K.; Sharp, Julia A.; Woltmann, Jon L.; Qian, Shizhi; Hair, Pamela S.; van der Pol, Pieter; van Kooten, Cees; Thielens, Nicole M.; Lattanzio, Frank A.; Cunnion, Kenji M.; Krishna, Neel K.

    2012-01-01

    Previous experiments from our laboratories have identified peptides derived from the human astrovirus coat protein (CP) that bind C1q and mannose binding lectin (MBL) inhibiting activation of the classical and lectin pathways of complement, respectively. The purpose of this study was to evaluate the function of these coat protein peptides (CPPs) in an in vitro model of complement-mediated disease (ABO incompatibility), preliminarily assess their in vivo complement suppression profile and develop more highly potent derivatives of these molecules. E23A, a 30 amino acid CPP derivative previously demonstrated to inhibit classical pathway activation was able to dose-dependently inhibit lysis of AB erythrocytes treated with mismatched human O serum. Additionally, when injected into rats, E23A inhibited the animals’ serum from lysing antibody-sensitized erythrocytes, providing preliminary in vivo functional evidence that this CPP can cross the species barrier to inhibit serum complement activity in rodents. A rational drug design approach was implemented to identify more potent CPP derivatives, resulting in the identification and characterization of a 15 residue peptide (Polar Assortant (PA)), which demonstrated both superior inhibition of classical complement pathway activation and robust binding to C1q collagen-like tails. PA also inhibited ABO incompatibility in vitro and demonstrated in vivo complement suppression up to 24 hours post-injection. CPP’s ability to inhibit ABO incompatibility in vitro, proof of concept in vivo inhibitory activity in rats and the development of the highly potent PA derivative set the stage for preclinical testing of this molecule in small animal models of complement-mediated disease. PMID:22906481

  12. VY6, a β-lactoglobulin-derived peptide, altered metabolic lipid pathways in the zebra fish liver.

    PubMed

    Mohammed-Geba, K; Arrutia, F; Do-Huu, H; Borrell, Y J; Galal-Khallaf, A; Ardura, A; Riera, Francisco A; Garcia-Vazquez, Eva

    2016-04-20

    Today enormous research efforts are being focused on alleviating the massive, adverse effects of obesity. Short peptides are key targets for research as they can be generated from natural proteins, like milk. Here we conducted trypsinogen digestion of beta-lactoglobulin (β-lg), the major mammalian milk protein, to release the hexamer VY6. It was assayed in vivo for its activities on lipid metabolism using zebra fish as a vertebrate model. Zebra fish juveniles were injected with two different doses of the peptide: 100 and 800 μg per g fish and left for 5 days before sacrificing. Lipid measurements showed significant reduction in liver triglycerides and free cholesterol, as well as increased liver HDL cholesterol. Dose-dependent increases of the mRNA levels of the genes coding for the enzymes acyl coenzyme A oxidase 1 (acox1) and lipoprotein lipase (lpl) were also found. The complete results suggest significant anti-obesity activity of the β-lg-derived VY6 peptide. Its use as a nutraceutical has been discussed. PMID:26983953

  13. Enhancement of complement-mediated lysis by a peptide derived from SCR 13 of complement factor H.

    PubMed

    Stoiber, H; Ammann, C; Spruth, M; Müllauer, B; Eberhart, A; Harris, C L; Huber, C G; Longhi, R; Falkensammer, B; Würzner, R; Dierich, M P

    2001-05-01

    Complement factor H (fH) is an important regulator of complement activation. It contributes to protection of cells against homologous complement attack. In this study we tested the effect of fH-depletion of normal human serum (NHS) on lysis of antibody-coated sheep and human erythrocytes (EshA and EhuA). In the absence of fH, lysis of sensitised Esh and Ehu was clearly increased. Addition of fH to fH-depleted serum re-established protection of cells against complement similar to that seen with NHS. A fH-derived peptide (pepAred), covering the N-terminal half of SCR 13 in fH, was able to enhance complement-mediated lysis of EhuA significantly. However, the oxidised form of this peptide (pepAox) had no effect. Biotinylated pepAred, but not pepAox, was able to directly bind to cells. Additionally, pepAred competed with direct fH-cell interaction which was observable only after treatment of purified fH with mercaptoethanol. Only pepAred increased the amount of C3 fragments and reduced levels of fH detectable on cells as shown by FACS analysis and radio-immuno assay. Furthermore, fH and factor I (fI)-mediated cleavage of agarose bound C3b into iC3b was decreased in the presence of pepAred. These data indicate that a fH-derived peptide can enhance complement-mediated lysis. We will continue to investigate whether the use of a fH peptide can be exploited for therapeutical purposes. PMID:11402501

  14. Antimicrobial Activity of Lactoferrin-Related Peptides and Applications in Human and Veterinary Medicine.

    PubMed

    Bruni, Natascia; Capucchio, Maria Teresa; Biasibetti, Elena; Pessione, Enrica; Cirrincione, Simona; Giraudo, Leonardo; Corona, Antonio; Dosio, Franco

    2016-01-01

    Antimicrobial peptides (AMPs) represent a vast array of molecules produced by virtually all living organisms as natural barriers against infection. Among AMP sources, an interesting class regards the food-derived bioactive agents. The whey protein lactoferrin (Lf) is an iron-binding glycoprotein that plays a significant role in the innate immune system, and is considered as an important host defense molecule. In search for novel antimicrobial agents, Lf offers a new source with potential pharmaceutical applications. The Lf-derived peptides Lf(1-11), lactoferricin (Lfcin) and lactoferrampin exhibit interesting and more potent antimicrobial actions than intact protein. Particularly, Lfcin has demonstrated strong antibacterial, anti-fungal and antiparasitic activity with promising applications both in human and veterinary diseases (from ocular infections to osteo-articular, gastrointestinal and dermatological diseases). PMID:27294909

  15. Synthetic Long Peptide Derived from Mycobacterium tuberculosis Latency Antigen Rv1733c Protects against Tuberculosis

    PubMed Central

    Coppola, Mariateresa; van den Eeden, Susan J. F.; Wilson, Louis; Franken, Kees L. M. C.; Ottenhoff, Tom H. M.

    2015-01-01

    Responsible for 9 million new cases of active disease and nearly 2 million deaths each year, tuberculosis (TB) remains a global health threat of overwhelming dimensions. Mycobacterium bovis BCG, the only licensed vaccine available, fails to confer lifelong protection and to prevent reactivation of latent infection. Although 15 new vaccine candidates are now in clinical trials, an effective vaccine against TB remains elusive, and new strategies for vaccination are vital. BCG vaccination fails to induce immunity against Mycobacterium tuberculosis latency antigens. Synthetic long peptides (SLPs) combined with adjuvants have been studied mostly for therapeutic cancer vaccines, yet not for TB, and proved to induce efficient antitumor immunity. This study investigated an SLP derived from Rv1733c, a major M. tuberculosis latency antigen which is highly expressed by “dormant” M. tuberculosis and well recognized by T cells from latently M. tuberculosis-infected individuals. In order to assess its in vivo immunogenicity and protective capacity, Rv1733c SLP in CpG was administered to HLA-DR3 transgenic mice. Immunization with Rv1733c SLP elicited gamma interferon-positive/tumor necrosis factor-positive (IFN-γ+/TNF+) and IFN-γ+ CD4+ T cells and Rv1733c-specific antibodies and led to a significant reduction in the bacterial load in the lungs of M. tuberculosis-challenged mice. This was observed both in a pre- and in a post-M. tuberculosis challenge setting. Moreover, Rv1733c SLP immunization significantly boosted the protective efficacy of BCG, demonstrating the potential of M. tuberculosis latency antigens to improve BCG efficacy. These data suggest a promising role for M. tuberculosis latency antigen Rv1733c-derived SLPs as a novel TB vaccine approach, both in a prophylactic and in a postinfection setting. PMID:26202436

  16. ZOT-derived peptide and chitosan functionalized nanocarrier for oral delivery of protein drug.

    PubMed

    Lee, Jong Hyun; Sahu, Abhishek; Choi, Won Il; Lee, Jae Young; Tae, Giyoong

    2016-10-01

    In this study, we developed a dual ligand functionalized pluronic-based nanocarrier (NC) for oral delivery of insulin. Chitosan and zonula occludins toxin (ZOT)-derived, tight junction opening peptide were conjugated to NC to increase the permeability of loaded insulin across the small intestine through the paracellular pathway. Surface functionalized NC, either by chitosan or peptide, could modulate the tight junction (TJ) integrity in contrast to no effect of unmodified NC, as evidenced by the change in transepithelial electrical resistance (TEER) and immunostaining of Claudin-4, a tight junction marker, in Caco-2 cell monolayer. On the other hand, dual ligand (chitosan and peptide) functionalized NC significantly further increased the permeation of insulin across Caco-2 cell monolayer. More importantly, insulin loaded, dual ligand functionalized NC could increase the plasma insulin level and efficiently regulate the glycemic response for a prolonged period of time (∼1 day) upon oral administration to diabetic rats, whereas delivery of insulin by single ligand functionalized NCs, either by chitosan or peptide, as well as by unmodified NC and free insulin, could not induce the effective regulation of the blood glucose level. The use of fluorescence dye labeled insulin (FITC-insulin) and Cy5.5 labeled NC revealed that both insulin and dual ligand functionalized NC were adequately penetrated across the whole intestine villi in contrast to limited adsorption of insulin and NC mainly onto the epithelial surface of the intestine for single ligand functionalized NCs. These results suggest that dual conjugation of ZOT-derived peptide and chitosan is a promising approach to functionalize the surface of nanocarrier for oral delivery of protein drugs. PMID:27380442

  17. Mitochondrial-derived N-formyl peptides: novel links between trauma, vascular collapse and sepsis.

    PubMed

    Wenceslau, C F; McCarthy, C G; Goulopoulou, S; Szasz, T; NeSmith, E G; Webb, R C

    2013-10-01

    Sepsis is a major cause of mortality and morbidity in trauma patients despite aggressive treatment. Traumatic injury may trigger infective or non-infective systemic inflammatory response syndrome (SIRS) and sepsis. Sepsis and SIRS are accompanied by an inability to regulate the inflammatory response but the cause of this perturbation is still unknown. The major pathophysiological characteristic of sepsis is the vascular collapse (i.e., loss of control of vascular tone); however, at the cellular level the final mediator of extreme vasodilatation has yet to be identified. After trauma, cellular injury releases endogenous damage-associated molecular patterns (DAMPs) that activate the innate immune system. Mitochondrial DAMPs express at least two molecular signatures, N-formyl peptides and mitochondrial DNA that act on formyl peptide receptors (FPRs) and Toll-like receptor 9, respectively. N-Formyl peptides are potent immunocyte activators and, once released in the circulation, they induce modulation of vascular tone by cellular mechanisms that are not completely understood. We have observed that N-formyl peptides from bacterial (FMLP) and mitochondrial (FMIT) sources induce FPR-mediated vasodilatation in resistance arteries. Accordingly, we propose that tissue and cellular trauma induces the release of N-formyl peptides from mitochondria triggering inflammation and vascular collapse via activation of FPR and contributing to the development of sepsis. The proposed hypothesis provides clinically significant information linking trauma, mitochondrial N-formyl peptides and inflammation to vascular collapse and sepsis. If our hypothesis is true, it may lead to new strategies in the management of sepsis that can help clinicians effectively manage non-infectious and infectious inflammatory responses. PMID:23890799

  18. Novel angiotensin I-converting enzyme inhibitory peptides derived from an edible mushroom, Pleurotus cystidiosus O.K. Miller identified by LC-MS/MS

    PubMed Central

    2013-01-01

    Background Angiotensin I-converting enzyme (ACE) inhibitors have been reported to reduce mortality in patients with hypertension. Compared to chemosynthetic drugs, ACE inhibitors derived from natural sources such as food proteins are believed to be safer for consumption and to have fewer adverse effects. Some edible mushrooms have been reported to significantly reduce blood pressure after oral administration. In addition, mushrooms are known to be rich in protein content. This makes them a potential source of ACE inhibitory peptides. Hence, the objective of the current study was to isolate and characterise ACE inhibitory peptides from an edible mushroom, Pleurotus cystidiosus. Methods ACE inhibitory proteins were isolated from P. cystidiosus based on the bioassay guided purification steps, i.e. ammonium sulphate precipitation, reverse phase high performance liquid chromatography and size exclusion chromatography. Active fraction was then analysed by LC-MS/MS and potential ACE inhibitory peptides identified were chemically synthesized. Effect of in vitro gastrointestinal digestions on the ACE inhibitory activity of the peptides and their inhibition patterns were evaluated. Results Two potential ACE inhibitory peptides, AHEPVK and GPSMR were identified from P. cystidiosus with molecular masses of 679.53 and 546.36 Da, respectively. Both peptides exhibited potentially high ACE inhibitory activity with IC50 values of 62.8 and 277.5 μM, respectively. SEC chromatograms and BIOPEP analysis of these peptides revealed that the peptide sequence of the hexapeptide, AHEPVK, was stable throughout gastrointestinal digestion. The pentapeptide, GPSMR, was hydrolysed after digestion and it was predicted to release a dipeptide ACE inhibitor, GP, from its precursor. The Lineweaver-Burk plot of AHEPVK showed that this potent and stable ACE inhibitor has a competitive inhibitory effect against ACE. Conclusion The present study indicated that the peptides from P. cystidiosus could be

  19. Delivery of a Protease-Activated Cytolytic Peptide Prodrug by Perfluorocarbon Nanoparticles.

    PubMed

    Jallouk, Andrew P; Palekar, Rohun U; Marsh, Jon N; Pan, Hua; Pham, Christine T N; Schlesinger, Paul H; Wickline, Samuel A

    2015-08-19

    Melittin is a cytolytic peptide derived from bee venom that inserts into lipid membranes and oligomerizes to form membrane pores. Although this peptide is an attractive candidate for treatment of cancers and infectious processes, its nonspecific cytotoxicity and hemolytic activity have limited its therapeutic applications. Several groups have reported the development of cytolytic peptide prodrugs that only exhibit cytotoxicity following activation by site-specific proteases. However, systemic administration of these constructs has proven difficult because of their poor pharmacokinetic properties. Here, we present a platform for the design of protease-activated melittin derivatives that may be used in conjunction with a perfluorocarbon nanoparticle delivery system. Although native melittin was substantially hemolytic (HD50: 1.9 μM) and cytotoxic (IC50: 2.4 μM), the prodrug exhibited 2 orders of magnitude less hemolytic activity (HD50: > 100 μM) and cytotoxicity (IC50: > 100 μM). Incubation with matrix metalloproteinase-9 (MMP-9) led to cleavage of the prodrug at the expected site and restoration of hemolytic activity (HD50: 3.4 μM) and cytotoxicity (IC50: 8.1 μM). Incubation of the prodrug with perfluorocarbon nanoparticles led to stable loading of 10,250 peptides per nanoparticle. Nanoparticle-bound prodrug was also cleaved and activated by MMP-9, albeit at a fourfold slower rate. Intravenous administration of prodrug-loaded nanoparticles in a mouse model of melanoma significantly decreased tumor growth rate (p = 0.01). Because MMPs and other proteases play a key role in cancer invasion and metastasis, this platform holds promise for the development of personalized cancer therapies directed toward a patient's individual protease expression profile. PMID:26083278

  20. The chain length of biologically produced (R)-3-hydroxyalkanoic acid affects biological activity and structure of anti-cancer peptides.

    PubMed

    Szwej, Emilia; Devocelle, Marc; Kenny, Shane; Guzik, Maciej; O'Connor, Stephen; Nikodinovic-Runic, Jasmina; Radivojevic, Jelena; Maslak, Veselin; Byrne, Annete T; Gallagher, William M; Zulian, Qun Ren; Zinn, Manfred; O'Connor, Kevin E

    2015-06-20

    Conjugation of DP18L peptide with (R)-3-hydroxydecanoic acid, derived from the biopolymer polyhydroxyalkanoate, enhances its anti-cancer activity (O'Connor et al., 2013. Biomaterials 34, 2710-2718). However, it is unknown if other (R)-3-hydroxyalkanoic acids (R3HAs) can enhance peptide activity, if chain length affects enhancement, and what effect R3HAs have on peptide structure. Here we show that the degree of enhancement of peptide (DP18L) anti-cancer activity by R3HAs is carbon chain length dependent. In all but one example the R3HA conjugated peptides were more active against cancer cells than the unconjugated peptides. However, R3HAs with 9 and 10 carbons were most effective at improving DP18L activity. DP18L peptide variant DP17L, missing a hydrophobic amino acid (leucine residue 4) exhibited lower efficacy against MiaPaCa cells. Circular dichroism analysis showed DP17L had a lower alpha helix content and the conjugation of any R3HA ((R)-3-hydroxyhexanoic acid to (R)-3-hydroxydodecanoic acid) to DP17L returned the helix content back to levels of DP18L. However (R)-3-hydroxyhexanoic did not enhance the anti-cancer activity of DP17L and at least 7 carbons were needed in the R3HA to enhance activity of D17L. DP17L needs a longer chain R3HA to achieve the same activity as DP18L conjugated to an R3HA. As a first step to assess the synthetic potential of polyhydroxyalkanoate derived R3HAs, (R)-3-hydroxydecanoic acid was synthetically converted to (±)3-chlorodecanoic acid, which when conjugated to DP18L improved its antiproliferative activity against MiaPaCa cells. PMID:25820126

  1. [Peptide 612-627 of thyrotropin receptor and its modified derivatives as the regulators of adenylyl cyclase in the rat thyroid gland].

    PubMed

    Shpakov, A O; Shpakova, E A; Tarasenko, I I; Derkach, K V

    2014-01-01

    The regulation of the specific activity of the thyroid gland is carried by thyroid-stimulating hormone (TSH) through TSH receptor (TSHR). This receptor is coupled to different types of G-proteins, including the G(s)-proteins, through which TSH stimulates the enzyme adenylyl cyclase (AC). As the application of TSH in medicine is limited, the development of selective regulators of TSHR with agonistic and antagonistic activity is carried out. One of the approaches to their creation is to develop the peptides corresponding to functionally important regions of TSHR which are located in its intracellular loops (ICL) and are involved in the binding and activation of G-proteins. We have synthesized peptide corresponding to the C-terminal region 612-627 of the third ICL of TSHR and its derivatives modified by palmitic acid residue (at the N- or the C-terminus) or by polylysine dendrimer (at the N-terminus), and studied their effect on the basal and TSH-stimulated AC activity in the membrane fraction isolated from the rat thyroid. The most active was peptide 612-627-K(Pal)A modified by palmitate at the C-terminus, where in TSHR the hydrophobic transmembrane region is located. At the micromolar concentrations the peptide increased AC activity and reduced the AC stimulating effect of TSH. The action of the 612-627-K(Pal)A has been directed onto TSHR homologous to it, as indicated by the following facts: 1) the inhibition of G(s)-protein, the downstream component of AC system, by treating the membranes with cholera toxin led to the blocking of peptide AC effect, 2) this effect was not detected in the tissues where no TSHR, 3) the peptide did not significantly affect the AC stimulating effects of hormones acting via other receptors. The unmodified peptide and the peptide with N-terminal dendrimer are far behind the 612-627-K(Pal)A in their ability to activate AC in the thyroid, while the peptide modified by palmitate at the N-terminus was inactive. At the same time, the peptide

  2. Potent and Broad Anti-HIV-1 Activity Exhibited by a Glycosyl-Phosphatidylinositol-Anchored Peptide Derived from the CDR H3 of Broadly Neutralizing Antibody PG16▿†‡

    PubMed Central

    Liu, Lihong; Wen, Michael; Wang, Weiming; Wang, Shumei; Yang, Lifei; Liu, Yong; Qian, Mengran; Zhang, Linqi; Shao, Yiming; Kimata, Jason T.; Zhou, Paul

    2011-01-01

    PG9 and PG16 are two recently isolated quaternary-specific human monoclonal antibodies that neutralize 70 to 80% of circulating HIV-1 isolates. The crystal structure of PG16 shows that it contains an exceptionally long CDR H3 that forms a unique stable subdomain that towers above the antibody surface to confer fine specificity. To determine whether this unique architecture of CDR H3 itself is sufficient for epitope recognition and neutralization, we cloned CDR H3 subdomains derived from human monoclonal antibodies PG16, PG9, b12, E51, and AVF and genetically linked them to a glycosyl-phosphatidylinositol (GPI) attachment signal. Each fusion gene construct is expressed and targeted to lipid rafts of plasma membranes through a GPI anchor. Moreover, GPI-CDR H3(PG16, PG9, and E51), but not GPI-CDR H3(b12 and AVF), specifically neutralized multiple clades of HIV-1 isolates with a great degree of potency when expressed on the surface of transduced TZM-bl cells. Furthermore, GPI-anchored CDR H3(PG16), but not GPI-anchored CDR H3(AVF), specifically confers resistance to HIV-1 infection when expressed on the surface of transduced human CD4+ T cells. Finally, the CDR H3 mutations (Y100HF, D100IA, and G7) that were previously shown to compromise the neutralization activity of antibody PG16 also abolished the neutralization activity of GPI-CDR H3(PG16). Thus, we conclude that the CDR H3 subdomain of PG16 neutralizes HIV-1 when targeted to the lipid raft of the plasma membrane of HIV-1-susceptible cells and that GPI-CDR H3 can be an alternative approach for determining whether the CDR H3 of certain antibodies alone can exert epitope recognition and neutralization. PMID:21715497

  3. Prokaryotic expression and antimicrobial mechanism of XPF-St7-derived α-helical peptides.

    PubMed

    Yi, Tonghui; Huang, Yibing; Chen, Yuxin

    2015-01-01

    XPF-St7 (GLLSNVAGLLKQFAKGGVNAVLNPK) is an antimicrobial peptide isolated from Silurana tropicalis. We developed an α-helical segment of XPF-St7 termed as XPF2. Using the XPF2 as a framework, we increased the positive net charge of XPF2 by amino acid substitutions, and thus obtained two novel antimicrobial peptides XPF4 and XPF6. These were each fused with an ubiquitin tag and successfully expressed in Escherichia coli. This ubiquitin fusion system may present a viable alternative for industrial production of antimicrobial peptides. XPF4 and XPF6 showed much better overall antimicrobial activity against both Gram-negative and Gram-positive bacteria than XPF2. The therapeutic index of XPF4 and XPF6 was 5.6-fold and 6.7-fold of XPF2, respectively. Bacterial cell membrane permeabilization and genomic DNA interaction assays were utilized to explore the mechanism of action of XPF serial peptides. The results revealed that the target of these antimicrobial peptides was the bacterial cytoplasmic membrane. PMID:25421112

  4. The production of recombinant cationic α-helical antimicrobial peptides in plant cells induces the formation of protein bodies derived from the endoplasmic reticulum.

    PubMed

    Company, Nuri; Nadal, Anna; La Paz, José-Luis; Martínez, Sílvia; Rasche, Stefan; Schillberg, Stefan; Montesinos, Emilio; Pla, Maria

    2014-01-01

    Synthetic linear antimicrobial peptides with cationic α-helical structures, such as BP100, are valuable as novel therapeutics and preservatives. However, they tend to be toxic when expressed at high levels as recombinant peptides in plants, and they can be difficult to detect and isolate from complex plant tissues because they are strongly cationic and display low extinction coefficient and extremely limited immunogenicity. We therefore expressed BP100 with a C-terminal tag which preserved its antimicrobial activity and demonstrated significant accumulation in plant cells. We used a fluorescent tag to trace BP100 following transiently expression in Nicotiana benthamiana leaves and showed that it accumulated in large vesicles derived from the endoplasmic reticulum (ER) along with typical ER luminal proteins. Interestingly, the formation of these vesicles was induced by BP100. Similar vesicles formed in stably transformed Arabidopsis thaliana seedlings, but the recombinant peptide was toxic to the host during latter developmental stages. This was avoided by selecting active BP100 derivatives based on their low haemolytic activity even though the selected peptides remained toxic to plant cells when applied exogenously at high doses. Using this strategy, we generated transgenic rice lines producing active BP100 derivatives with a yield of up to 0.5% total soluble protein. PMID:24102775

  5. Immunoregulatory activity of peptides related to platelet factor 4.

    PubMed Central

    Zucker, M B; Katz, I R; Thorbecke, G J; Milot, D C; Holt, J

    1989-01-01

    Platelet factor 4 (PF4), a secreted platelet protein, alleviates concanavalin A-induced immunosuppression in mice. We now find that activity also resides in (i) the C-terminal tridecapeptide of PF4 (P13S), (ii) an analog of this in which arginine replaces the lysine residues and in which the last two amino acids are absent, (iii) the C-terminal 18 amino acids of low-affinity platelet factor 4, which is very similar to P13S, and (iv) peptide fragments of P13S that contain only 5-9 amino acids. P13S treated with fluorescamine to derivatize the free amino groups retained immunoregulatory activity but did not bind to heparin-agarose. The N-terminal and middle portions of PF4, polylysine, protamine, and three unrelated peptides were inactive in this assay. PMID:2678107

  6. Determinants of Human Immunodeficiency Virus Type 1 Resistance to gp41-Derived Inhibitory Peptides

    PubMed Central

    Rimsky, Laurence T.; Shugars, Diane C.; Matthews, Thomas J.

    1998-01-01

    A synthetic peptide, DP178, containing amino acids 127 to 162 of the human immunodeficiency virus type 1 (HIV-1) gp41 Env glycoprotein, is a potent inhibitor of virus infection and virus mediated cell-to-cell fusion (C. Wild, T. Greenwell, and T. Matthews, AIDS Res. Hum. Retroviruses 9:1051–1053, 1993). In an effort to understand the mechanism of action of this peptide, we derived resistant variants of HIV-1IIIB and NL4-3 by serial virus passage in the presence of increasing doses of the peptide. Sequence analysis of the resistant isolates suggested that a contiguous 3-amino-acid sequence within the amino-terminal heptad repeat motif of gp41 was associated with resistance. Site-directed mutagenesis studies confirmed this observation and indicated that changes in two of these three residues were necessary for development of the resistant phenotype. Direct binding of DP178 to recombinant protein and synthetic peptide analogs containing the wild-type and mutant heptad repeat sequences revealed a strong correlation between DP178 binding and the biological sensitivity of the corresponding virus isolates to DP178. The results are discussed from the standpoints of the mechanism of action of DP178 and recent crystallographic information for a core structure of the gp41 ectodomain. PMID:9444991

  7. Penetration of Milk-Derived Antimicrobial Peptides into Phospholipid Monolayers as Model Biomembranes

    PubMed Central

    Rogalska, Ewa; Więcław-Czapla, Katarzyna

    2013-01-01

    Three antimicrobial peptides derived from bovine milk proteins were examined with regard to penetration into insoluble monolayers formed with 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) or 1,2-dipalmitoyl-sn-glycero-3-phospho-rac-(1-glycerol) sodium salt (DPPG). Effects on surface pressure (Π) and electric surface potential (ΔV) were measured, Π with a platinum Wilhelmy plate and ΔV with a vibrating plate. The penetration measurements were performed under stationary diffusion conditions and upon the compression of the monolayers. The two type measurements showed greatly different effects of the peptide-lipid interactions. Results of the stationary penetration show that the peptide interactions with DPPC monolayer are weak, repulsive, and nonspecific while the interactions with DPPG monolayer are significant, attractive, and specific. These results are in accord with the fact that antimicrobial peptides disrupt bacteria membranes (negative) while no significant effect on the host membranes (neutral) is observed. No such discrimination was revealed from the compression isotherms. The latter indicate that squeezing the penetrant out of the monolayer upon compression does not allow for establishing the penetration equilibrium, so the monolayer remains supersaturated with the penetrant and shows an under-equilibrium orientation within the entire compression range, practically. PMID:24455264

  8. Penetration of milk-derived antimicrobial peptides into phospholipid monolayers as model biomembranes.

    PubMed

    Barzyk, Wanda; Rogalska, Ewa; Więcław-Czapla, Katarzyna

    2013-01-01

    Three antimicrobial peptides derived from bovine milk proteins were examined with regard to penetration into insoluble monolayers formed with 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) or 1,2-dipalmitoyl-sn-glycero-3-phospho-rac-(1-glycerol) sodium salt (DPPG). Effects on surface pressure (Π) and electric surface potential (ΔV) were measured, Π with a platinum Wilhelmy plate and ΔV with a vibrating plate. The penetration measurements were performed under stationary diffusion conditions and upon the compression of the monolayers. The two type measurements showed greatly different effects of the peptide-lipid interactions. Results of the stationary penetration show that the peptide interactions with DPPC monolayer are weak, repulsive, and nonspecific while the interactions with DPPG monolayer are significant, attractive, and specific. These results are in accord with the fact that antimicrobial peptides disrupt bacteria membranes (negative) while no significant effect on the host membranes (neutral) is observed. No such discrimination was revealed from the compression isotherms. The latter indicate that squeezing the penetrant out of the monolayer upon compression does not allow for establishing the penetration equilibrium, so the monolayer remains supersaturated with the penetrant and shows an under-equilibrium orientation within the entire compression range, practically. PMID:24455264

  9. Heat shock protein-mediated cell penetration and cytosolic delivery of macromolecules by a telomerase-derived peptide vaccine.

    PubMed

    Lee, Seoung-Ae; Kim, Bo-Ram; Kim, Bu-Kyung; Kim, Dong-Won; Shon, Won-Jun; Lee, Na-Rae; Inn, Kyung-Soo; Kim, Bum-Joon

    2013-10-01

    A reverse-transcriptase-subunit of telomerase (hTERT) derived peptide, GV1001, has been developed as a vaccine against various cancers. Here, we report an unexpected function of GV1001 as a cell-penetrating peptide (CPP). GV1001 was delivered into a variety of cells including various cancer cell lines and primary blood cells. Moreover, the delivered GV1001 was predominantly located in the cytoplasm of the cells, while a significantly higher proportion of TAT peptide was localized in the nucleus. Macromolecules such as proteins, DNA and siRNA, which were linked to GV1001 by direct covalent conjugation or non-covalent complexation through poly-lysine, were successfully delivered into cells, indicating that GV1001 can be used as a carrier for macromolecules. Expression of the delivered DNA, and lowered expression of the target gene by the delivered siRNA, suggest the potential therapeutic use of GV1001. Pull-down analysis identified Heat Shock Protein 90 (HSP90) and 70 (HSP70) as GV1001 interacting proteins. Treatment of Anti-HSP90 and HSP70 antibodies lowered the internalization of GV1001, indicating that the interaction is critical for the efficient internalization of GV1001. Collectively, the results of this study suggest the pharmaceutical potential of GV1001, already proven safe in clinical trials, as a carrier for the delivery of macromolecular therapeutics into cells, in addition to its own anti-cancer activity. PMID:23827187

  10. Biological activities of selected peptides: skin penetration ability of copper complexes with peptides.

    PubMed

    Mazurowska, Lena; Mojski, Miroslaw

    2008-01-01

    This study concerning the permeability through skin barriers of copper complexes with peptides is an important part of the research on their biological activity. The transport of copper complexes through the skin is essential in treatment of dermatological dysfunctions connected to the deficiency of these elements in the skin. During the last several years, a special interest in transepidermal copper delivery has been observed. This is the reason why copper compounds have been used as active compounds in care cosmetics. Yet, the transport process of copper complexes with tripeptides, glycyl-histidyl-lysine GHK, or gamma-glutamyl-cysteinyl-glycine GSH through the stratum corneum has received very little attention in the literature so far. The penetration ability of GHK-Cu and GSH-Cu through the stratum corneum and the influence of the complexes with tripeptide on the copper ion transport process is the key factor in their cosmetic and pharmaceutical activity. The in vitro penetration process was studied in the model system, a Franz diffusion cell with a liposome membrane, where liquid crystalline systems of physicochemical properties similar to the ones of the intercellular cement of stratum corneum were used as a standard model of a skin barrier. The results obtained demonstrated that copper complexes permeate through the membranes modeling the horny lipid layer and showed the influence of peptides on the dynamics of copper ion diffusion. PMID:18350235

  11. Splicing of distant peptide fragments occurs in the proteasome by transpeptidation and produces the spliced antigenic peptide derived from fibroblast growth factor-5.

    PubMed

    Dalet, Alexandre; Vigneron, Nathalie; Stroobant, Vincent; Hanada, Ken-Ichi; Van den Eynde, Benoît J

    2010-03-15

    Peptide splicing is a newly described mode of production of antigenic peptides presented by MHC class I molecules, whereby two noncontiguous fragments of the parental protein are joined together after excision of the intervening segment. Three spliced peptides have been described. In two cases, splicing involved the excision of a short intervening segment of 4 or 6 aa and was shown to occur in the proteasome by transpeptidation resulting from the nucleophilic attack of an acyl-enzyme intermediate by the N terminus of the other peptide fragment. For the third peptide, which is derived from fibroblast growth factor-5 (FGF-5), the splicing mechanism remains unknown. In this case, the intervening segment is 40 aa long. This much greater length made the transpeptidation model more difficult to envision. Therefore, we evaluated the role of the proteasome in the splicing of this peptide. We observed that the spliced FGF-5 peptide was produced in vitro after incubation of proteasomes with a 49-aa-long precursor peptide. We evaluated the catalytic mechanism by incubating proteasomes with various precursor peptides. The results confirmed the transpeptidation model of splicing. By transfecting a series of mutant FGF-5 constructs, we observed that reducing the length of the intervening segment increased the production of the spliced peptide, as predicted by the transpeptidation model. Finally, we observed that trans-splicing (i.e., splicing of fragments from two distinct proteins) can occur in the cell, but with a much lower efficacy than splicing of fragments from the same protein. PMID:20154207

  12. Biologically active peptides obtained by enzymatic hydrolysis of Adzuki bean seeds.

    PubMed

    Durak, Agata; Baraniak, Barbara; Jakubczyk, Anna; Świeca, Michał

    2013-12-01

    This study investigated the antioxidant and antihypertensive activities of peptides obtained from protein fractions of Adzuki bean seeds. Peptides were obtained by the use of hydrolytic enzymes in vitro under gastrointestinal conditions. A determination was made of the activity of the peptide inhibitors of the angiotensin I converting enzyme (ACE), and the antiradical and ion chelating activity of peptides from different protein fractions. The highest peptide levels after the absorption process (<7 kDa) were noted in the albumin fraction (50.69 μg/ml). Furthermore, it was found that peptides from the prolamin fraction were characterised by the highest antiradical activity and ACE inhibitory activity (IC50=0.17 mg/ml). Peptides obtained from the globulin fraction showed the highest ability to chelate iron ions, and peptides from the glutelin fraction were characterised as being the most effective in the chelation of copper ions. PMID:23870945

  13. Thermoase-Derived Flaxseed Protein Hydrolysates and Membrane Ultrafiltration Peptide Fractions Have Systolic Blood Pressure-Lowering Effects in Spontaneously Hypertensive Rats

    PubMed Central

    Nwachukwu, Ifeanyi D.; Girgih, Abraham T.; Malomo, Sunday A.; Onuh, John O.; Aluko, Rotimi E.

    2014-01-01

    Thermoase-digested flaxseed protein hydrolysate (FPH) samples and ultrafiltration membrane-separated peptide fractions were initially evaluated for in vitro inhibition of angiotensin I-converting enzyme (ACE) and renin activities. The two most active FPH samples and their corresponding peptide fractions were subsequently tested for in vivo antihypertensive activity in spontaneously hypertensive rats (SHR). The FPH produced with 3% thermoase digestion showed the highest ACE- and renin-inhibitory activities. Whereas membrane ultrafiltration resulted in significant (p < 0.05) increases in ACE inhibition by the <1 and 1–3 kDa peptides, only a marginal improvement in renin-inhibitory activity was observed for virtually all the samples after membrane ultrafiltration. The FPH samples and membrane fractions were also effective in lowering systolic blood pressure (SBP) in SHR with the largest effect occurring after oral administration (200 mg/kg body weight) of the 1–3 kDa peptide fraction of the 2.5% FPH and the 3–5 kDa fraction of the 3% FPH. Such potent SBP-lowering capacity indicates the potential of flaxseed protein-derived bioactive peptides as ingredients for the formulation of antihypertensive functional foods and nutraceuticals. PMID:25302619

  14. Thermoase-derived flaxseed protein hydrolysates and membrane ultrafiltration peptide fractions have systolic blood pressure-lowering effects in spontaneously hypertensive rats.

    PubMed

    Nwachukwu, Ifeanyi D; Girgih, Abraham T; Malomo, Sunday A; Onuh, John O; Aluko, Rotimi E

    2014-01-01

    Thermoase-digested flaxseed protein hydrolysate (FPH) samples and ultrafiltration membrane-separated peptide fractions were initially evaluated for in vitro inhibition of angiotensin I-converting enzyme (ACE) and renin activities. The two most active FPH samples and their corresponding peptide fractions were subsequently tested for in vivo antihypertensive activity in spontaneously hypertensive rats (SHR). The FPH produced with 3% thermoase digestion showed the highest ACE- and renin-inhibitory activities. Whereas membrane ultrafiltration resulted in significant (p < 0.05) increases in ACE inhibition by the <1 and 1-3 kDa peptides, only a marginal improvement in renin-inhibitory activity was observed for virtually all the samples after membrane ultrafiltration. The FPH samples and membrane fractions were also effective in lowering systolic blood pressure (SBP) in SHR with the largest effect occurring after oral administration (200 mg/kg body weight) of the 1-3 kDa peptide fraction of the 2.5% FPH and the 3-5 kDa fraction of the 3% FPH. Such potent SBP-lowering capacity indicates the potential of flaxseed protein-derived bioactive peptides as ingredients for the formulation of antihypertensive functional foods and nutraceuticals. PMID:25302619

  15. Differential distribution of VGF-derived peptides in the adrenal medulla and evidence for their selective modulation.

    PubMed

    D'Amato, Filomena; Noli, Barbara; Brancia, Carla; Cocco, Cristina; Flore, Giovanna; Collu, Maria; Nicolussi, Paola; Ferri, Gian-Luca

    2008-05-01

    While vg f gene knockout mice are hyperactive and hypermetabolic, surprisingly the TLQP-21 brain VGF peptide increased energy consumption, suggesting that opposing regulatory effects could be exerted by peptides alternatively cleaved from the VGF precursor. Using antisera to the VGF precursor C-terminus and three cleavage products, we revealed a distinct differential distribution in adrenal, certain peptides (VGF(422-430): PGH peptides) being found throughout bovine and swine medulla, while C-terminus and TLQP peptides were confined to adrenaline cells in the above species and in rat and C-terminally shortened forms (VGF(604-612): HVLL peptides) to nor-adrenaline cells. Random abattoir samples of bovine and swine adrenal contained 520+/-40 and 450+/-60 pmol/g (mean+/-s.e.m. respectively) of C-terminus peptides and similar or lower amounts of others. Upon gel chromatography, bona fide VGF precursor, approximately 7.5 and approximately 3.5 kDa forms were revealed by C-terminus assays, HVLL peptides being limited to small fragments. TLQP peptides included ~7.5 kDa form and peaks accounting for TLQP-21 and predicted TLQP-30 and TLQP-42. Low molecular weight (MW) PGH peptides were revealed, together with a high MW form possibly encompassing the VGF precursor N-terminus. In acutely stressed swine, a striking increase was seen for C-terminus and TLQP peptides, with no significant differences for PGH peptides. A similar response was found in rat TLQP peptides showing a major increase upon an acute swimming stress and 30 min thereafter. A differential processing of the VGF precursor encompassing many areas of its primary sequence and selective modulations of its derived peptides occur in adrenal medullary cells, possibly relevant to adaptive homeostatic responses. PMID:18434366

  16. [Ectopic osteogenesis in vivo using bone morphogenetic protein-2 derived peptide loaded biodegradable hydrogel].

    PubMed

    Zhao, Jingjing; Fang, Zhenhua; Huang, Ruokun; Xiao, Kai; Li, Jing; Xie, Ming; Kan, Wusheng

    2014-08-01

    We investigated the development of an injectable, biodegradable hydrogel composite of poly(trimethylene carbonate)-F127-poly(trimethylene carbonate)(PTMC11-F127-PTMC11 )loaded with bone morphogenetic protein-2 (BMP-2) derived peptide P24 for ectopic bone formation in vivo and evaluated its release kinetics in vitro. Then we evaluated P24 peptide release kinetics from different concentration of PTMC11-F127-PTMC11 hydrogel in vitro using bicinchoninic acid (BCA)assay. P24/ PTMC11-F127-PTMC11 hydrogel was implanted into each rat's erector muscle of spine and ectopic bone formation of the implanted gel in vivo was detected by hematoxylin and eosin stain (HE). PTMC11-F127-PTMC11 hydrogel with concentration more than 20 percent showed sustained slow release for one month after the initial burst release. Bone trabeculae surround the P24/ PTMC11-F127-PTMC11 hydrogel was shown at the end of six weeks by hematoxylin and eosin stain. These results indicated that encapsulated bone morphogenetic protein (BMP-2) derived peptide P24 remained viable in vivo, thus suggesting the potential of PTMC11-F127-PT- MC11 composite hydrogels as part of a novel strategy for localized delivery of bioactive molecules. PMID:25508424

  17. [Ectopic osteogenesis in vivo using bone morphogenetic protein-2 derived peptide loaded biodegradable hydrogel].

    PubMed

    Zhao, Jingjing; Fang, Zhenhua; Huang, Ruokun; Xiao, Kai; Li, Jing; Xie, Ming; Kan, Wusheng

    2014-08-01

    We investigated the development of an injectable, biodegradable hydrogel composite of poly(trimethylene carbonate)-F127-poly(trimethylene carbonate)(PTMC11-F127-PTMC11 )loaded with bone morphogenetic protein-2 (BMP-2) derived peptide P24 for ectopic bone formation in vivo and evaluated its release kinetics in vitro. Then we evaluated P24 peptide release kinetics from different concentration of PTMC11-F127-PTMC11 hydrogel in vitro using bicinchoninic acid (BCA)assay. P24/ PTMC11-F127-PTMC11 hydrogel was implanted into each rat's erector muscle of spine and ectopic bone formation of the implanted gel in vivo was detected by hematoxylin and eosin stain (HE). PTMC11-F127-PTMC11 hydrogel with concentration more than 20 percent showed sustained slow release for one month after the initial burst release. Bone trabeculae surround the P24/ PTMC11-F127-PTMC11 hydrogel was shown at the end of six weeks by hematoxylin and eosin stain. These results indicated that encapsulated bone morphogenetic protein (BMP-2) derived peptide P24 remained viable in vivo, thus suggesting the potential of PTMC11-F127-PT- MC11 composite hydrogels as part of a novel strategy for localized delivery of bioactive molecules. PMID:25464793

  18. Anti-inflammatory and anti-endotoxin properties of peptides derived from the carboxy-terminal region of a defensin from the tick Ornithodoros savignyi.

    PubMed

    Malan, Melissa; Serem, June C; Bester, Megan J; Neitz, Albert W H; Gaspar, Anabella R M

    2016-01-01

    Antimicrobial peptides are small cationic peptides that possess a large spectrum of bioactivities, including antimicrobial, anti-inflammatory and antioxidant activities. Several antimicrobial peptides are known to inhibit lipopolysaccharide (LPS)-induced inflammation in vitro and to protect animals from sepsis. In this study, the cellular anti-inflammatory and anti-endotoxin activities of Os and Os-C, peptides derived from the carboxy-terminal of a tick defensin, were investigated. Both Os and Os-C were found to bind LPS in vitro, albeit to a lesser extent than polymyxin B and melittin, known endotoxin-binding peptides. Binding to LPS was found to reduce the bactericidal activity of Os and Os-C against Escherichia coli confirming the affinity of both peptides for LPS. At a concentration of 25 µM, the nitric oxide (NO) scavenging activity of Os was higher than glutathione, a known NO scavenger. In contrast, Os-C showed no scavenging activity. Os and Os-C inhibited LPS/IFN-γ induced NO and TNF-α production in RAW 264.7 cells in a concentration-dependent manner, with no cellular toxicity even at a concentration of 100 µM. Although inhibition of NO and TNF-α secretion was more pronounced for melittin and polymyxin B, significant cytotoxicity was observed at concentrations of 1.56 µM and 25 µM for melittin and polymyxin B, respectively. In addition, Os, Os-C and glutathione protected RAW 264.7 cells from oxidative damage at concentrations as low as 25 µM. This study identified that besides previously reported antibacterial activity of Os and Os-C, both peptides have in addition anti-inflammatory and anti-endotoxin properties. PMID:26662999

  19. Anti-Biofilm and Immunomodulatory Activities of Peptides That Inhibit Biofilms Formed by Pathogens Isolated from Cystic Fibrosis Patients

    PubMed Central

    de la Fuente-Núñez, César; Mansour, Sarah C.; Wang, Zhejun; Jiang, Lucy; Breidenstein, Elena B.M.; Elliott, Melissa; Reffuveille, Fany; Speert, David P.; Reckseidler-Zenteno, Shauna L.; Shen, Ya; Haapasalo, Markus; Hancock, Robert E.W.

    2014-01-01

    Cystic fibrosis (CF) patients often acquire chronic respiratory tract infections due to Pseudomonas aeruginosa and Burkholderia cepacia complex (Bcc) species. In the CF lung, these bacteria grow as multicellular aggregates termed biofilms. Biofilms demonstrate increased (adaptive) resistance to conventional antibiotics, and there are currently no available biofilm-specific therapies. Using plastic adherent, hydroxyapatite and flow cell biofilm models coupled with confocal and scanning electron microscopy, it was demonstrated that an anti-biofilm peptide 1018 prevented biofilm formation, eradicated mature biofilms and killed biofilms formed by a wide range of P. aeruginosa and B. cenocepacia clinical isolates. New peptide derivatives were designed that, compared to their parent peptide 1018, showed similar or decreased anti-biofilm activity against P. aeruginosa biofilms, but increased activity against biofilms formed by the Gram-positive bacterium methicillin resistant Staphylococcus aureus. In addition, some of these new peptide derivatives retained the immunomodulatory activity of 1018 since they induced the production of the chemokine monocyte chemotactic protein-1 (MCP-1) and suppressed lipopolysaccharide-mediated tumor necrosis factor-α (TNF-α) production by human peripheral blood mononuclear cells (PBMC) and were non-toxic towards these cells. Peptide 1018 and its derivatives provide promising leads for the treatment of chronic biofilm infections and hyperinflammatory lung disease in CF patients. PMID:26221537

  20. The Polyomavirus BK Large T-Antigen-Derived Peptide Elicits an HLA-DR Promiscuous and Polyfunctional CD4+ T-Cell Response▿

    PubMed Central

    Ramaswami, Bala; Popescu, Iulia; Macedo, Camila; Luo, Chunqing; Shapiro, Ron; Metes, Diana; Chalasani, Geetha; Randhawa, Parmjeet S.

    2011-01-01

    BK virus (BKV) nephropathy and hemorrhagic cystitis are increasingly recognized causes of disease in renal and hematopoietic stem cell transplant recipients, respectively. Functional characterization of the immune response to BKV is important for clinical diagnosis, prognosis, and vaccine design. A peptide mix (PepMix) and overlapping (OPP) or random (RPP) peptide pools derived from BKV large T antigen (LTA) were used to restimulate 14-day-expanded peripheral blood mononuclear cells (PBMC) from 27 healthy control subjects in gamma interferon (IFN-γ)-specific enzyme-linked immunospot (ELISPOT) assays. A T-cell response to LTA PepMix was detected in 15/27 subjects. A response was frequently observed with peptides derived from the helicase domain (9/15 subjects), while the DNA binding and host range domains were immunologically inert (0/15 subjects). For all nine subjects who responded to LTA peptide pools, the immune response could be explained largely by a 15-mer peptide designated P313. P313-specific CD4+ T-cell clones demonstrated (i) stringent LTA peptide specificity; (ii) promiscuous recognition in the context of HLA-DR alleles; (iii) cross recognition of homologous peptides from the polyomavirus simian virus 40 (SV40); (iv) an effector memory phenotype, CD107a expression, and intracellular production of IFN-γ and tumor necrosis factor alpha (TNF-α); (v) cytotoxic activity in a chromium release assay; and (vi) the ability to directly present cognate antigen to autologous T cells. In conclusion, T-cell-mediated immunity to BKV in healthy subjects is associated with a polyfunctional population of CD4+ T cells with dual T-helper and T-cytotoxic properties. HLA class II promiscuity in antigen presentation makes the targeted LTA peptide sequence a suitable candidate for inclusion in immunotherapy protocols. PMID:21367979

  1. NMR structures of anti-HIV D-peptides derived from the N-terminus of viral chemokine vMIP-II

    SciTech Connect

    Mori, Mayuko; Liu Dongxiang; Kumar, Santosh; Huang Ziwei; E-mail: ziweihuang@burnham.org

    2005-09-30

    The viral macrophage inflammatory protein-II (vMIP-II) encoded by Kaposi's sarcoma-associated herpesvirus has unique biological activities in that it blocks the cell entry by several different human immunodeficiency virus type 1 (HIV-1) strains via chemokine receptors including CXCR4 and CCR5. In this paper, we report the solution structure of all-D-amino acid peptides derived from the N-terminus of vMIP-II, which have been shown to have strong CXCR4 binding activity and potently inhibit HIV-1 entry via CXCR4, by using long mixing time two-dimensional nuclear Overhauser enhancement spectroscopy experiments. Both of all-D-peptides vMIP-II (1-10) and vMIP-II (1-21), which are designated as DV3 and DV1, respectively, have higher CXCR4 binding ability than their L-peptide counterparts. They are partially structured in aqueous solution, displaying a turn-like structure over residues 5-8. The small temperature coefficients of His-6 amide proton for both peptides also suggest the formation of a small hydrophobic pocket centered on His-6. The structural features of DV3 are very similar to the reported solution structure of all-L-peptide vMIP-II (1-10) [M.P. Crump, E. Elisseeva, J. Gong, I. Clark-Lewis, B.D. Sykes, Structure/function of human herpesvirus-8 MIP-II (1-71) and the antagonist N-terminal segment (1-10), FEBS Lett. 489 (2001) 171], which is consistent with the notion that D- and L-enantiomeric peptides can adopt mirror image conformations. The NMR structures of the D-peptides provide a structural basis to understand their mechanism of action and design new peptidomimetic analogs to further explore the structure-activity relationship of D-peptide ligand binding to CXCR4.

  2. Allosterically Regulated Phosphatase Activity from Peptide-PNA Conjugates Folded Through Hybridization.

    PubMed

    Machida, Takuya; Dutt, Som; Winssinger, Nicolas

    2016-07-18

    The importance of spatial organization in short peptide catalysts is well recognized. We synthesized and screened a library of peptides flanked by peptide nucleic acids (PNAs) such that the peptide would be constrained in a hairpin loop upon hybridization. A screen for phosphatase activity led to the discovery of a catalyst with >25-fold rate acceleration over the linear peptide. We demonstrated that the hybridization-enforced folding of the peptide is necessary for activity, and designed a catalyst that is allosterically controlled using a complementary PNA sequence. PMID:27320214

  3. Amyloid fibril formation of peptides derived from the C-terminus of CETP modulated by lipids

    SciTech Connect

    García-González, Victor; Mas-Oliva, Jaime

    2013-04-26

    Highlights: •The secondary structure of a C-terminal peptide derived from CETP was studied. •Lipids modulate secondary structure changes of a C-terminal peptide derived from CETP. •Lysophosphatidic acid maintains a functional α-helix and prevents fibril formation. •Transfer of lipids by CETP is related to the presence of an α-helix at its C-end. -- Abstract: Cholesteryl-ester transfer protein (CETP) is a plasmatic protein involved in neutral lipid transfer between lipoproteins. Focusing on the last 12 C-terminus residues we have previously shown that mutation D{sub 470}N promotes a conformational change towards a β-secondary structure. In turn, this modification leads to the formation of oligomers and fibrillar structures, which cause cytotoxic effects similar to the ones provoked by amyloid peptides. In this study, we evaluated the role of specific lipid arrangements on the structure of peptide helix-Z (D{sub 470}N) through the use of thioflavin T fluorescence, peptide bond absorbance, circular dichroism and electron microscopy. The results indicate that the use of micelles formed with lysophosphatidylcholine and lysophosphatidic acid (LPA) under neutral pH induce a conformational transition of peptide helix-Z containing a β-sheet conformation to a native α-helix structure, therefore avoiding the formation of amyloid fibrils. In contrast, incubation with phosphatidic acid does not change the profile for the β-sheet conformation. When the electrostatic charge at the surface of micelles or vesicles is regulated through the use of lipids such as phospholipid and LPA, minimal changes and the presence of β-structures were recorded. Mixtures with a positive net charge diminished the percentage of β-structure and the amount of amyloid fibrils. Our results suggest that the degree of solvation determined by the presence of a free hydroxyl group on lipids such as LPA is a key condition that can modulate the secondary structure and the consequent formation of

  4. The immunology of host defence peptides: beyond antimicrobial activity.

    PubMed

    Hancock, Robert E W; Haney, Evan F; Gill, Erin E

    2016-05-01

    Host defence peptides (HDPs) are short, cationic amphipathic peptides with diverse sequences that are produced by various cells and tissues in all complex life forms. HDPs have important roles in the body's response to infection and inflammation. This Review focuses on human HDPs and explores the diverse immunomodulatory effects of HDPs from a systems biology perspective, which highlights the interconnected nature of the effect (or effects) of HDPs on the host. Studies have demonstrated that HDPs are expressed throughout the body and mediate a broad range of activities, which explains their association with various inflammatory diseases and autoimmune disorders. The diverse actions of HDPs, such as their roles in wound healing and in the maintenance of the microbiota, are also explored, in addition to potential therapeutic applications. PMID:27087664

  5. Short communication: Measuring the angiotensin-converting enzyme inhibitory activity of an 8-amino acid (8mer) fragment of the C12 antihypertensive peptide.

    PubMed

    Paul, Moushumi; Phillips, John G; Renye, John A

    2016-05-01

    An 8-AA (8mer) fragment (PFPEVFGK) of a known antihypertensive peptide derived from bovine αS1-casein (C12 antihypertensive peptide) was synthesized by microwave-assisted solid-phase peptide synthesis and purified by reverse phase HPLC. Its ability to inhibit angiotensin-converting enzyme (ACE) was assessed and compared with that of the parent 12mer peptide (FFVAPFPEVFGK) to determine the effect of truncating the sequence on overall hypotensive activity. The activity of the truncated 8mer peptide was found to be almost 1.5 times less active than that of the 12mer, with ACE-inhibiting IC50 (half-maximal inhibitory concentration) values of 108 and 69μM, for the 8mer and 12mer, respectively. Although the 8mer peptide is less active than the original 12mer peptide, its overall activity is comparable to activities reported for other small proteins that elicit physiological responses within humans. These results suggest that microbial degradation of the 12mer peptide would not result in a complete loss of antihypertensive activity if used to supplement fermented foods and that the stable 8mer peptide could have potential as a blood pressure-lowering agent for use in functional foods. PMID:26971162

  6. Peptide array-based screening of human mesenchymal stem cell-adhesive peptides derived from fibronectin type III domain

    SciTech Connect

    Okochi, Mina; Nomura, Shigeyuki; Kaga, Chiaki; Honda, Hiroyuki

    2008-06-20

    Human mesenchymal stem cell-adhesive peptides were screened based on the amino acid sequence of fibronectin type III domain 8-11 (FN-III{sub 8-11}) using a peptide array synthesized by the Fmoc-chemistry. Using hexameric peptide library of FN-III{sub 8-11} scan, we identified the ALNGR (Ala-Leu-Asn-Gly-Arg) peptide that induced cell adhesion as well as RGDS (Arg-Gly-Asp-Ser) peptide. After incubation for 2 h, approximately 68% of inoculated cells adhere to the ALNGR peptide disk. Adhesion inhibition assay with integrin antibodies showed that the ALNGR peptide interacts with integrin {beta}1 but not with {alpha}v{beta}3, indicating that the receptors for ALNGR are different from RGDS. Additionally, the ALNGR peptide expressed cell specificities for adhesion: cell adhesion was promoted for fibroblasts but not for keratinocytes or endotherial cells. The ALNGR peptide induced cell adhesion and promoted cell proliferation without changing its property. It is therefore useful for the construction of functional biomaterials.

  7. Lysine-tagged peptide coupling onto polylactide nanoparticles coated with activated ester-based amphiphilic copolymer: a route to highly peptide-functionalized biodegradable carriers.

    PubMed

    Handké, Nadège; Ficheux, Damien; Rollet, Marion; Delair, Thierry; Mabrouk, Kamel; Bertin, Denis; Gigmes, Didier; Verrier, Bernard; Trimaille, Thomas

    2013-03-01

    Efficient biomolecule conjugation to the surface of biodegradable colloidal carriers is crucial for their targeting efficiency in drug/vaccine delivery applications. We here propose a potent strategy to drastically improve peptide immobilization on biodegradable polylactide (PLA) nanoparticles (NPs). Our approach particularly relies on the use of an amphiphilic block copolymer PLA-b-poly(N-acryloxysuccinimide-co-N-vinylpyrrolidone) (PLA-b-P(NAS-co-NVP)) as NP surface modifier, whose the N-succinimidyl (NS) ester functions of the NAS units along the polymer chain ensure N-terminal amine peptide coupling. The well-known immunostimulatory peptide sequence derived from the human interleukin 1β (IL-1β), VQGEESNDK, was coupled on the NPs of 169 nm mean diameter in phosphate buffer (pH 8, 10 mM). A maximum amount of 2 mg immobilized per gram of NPs (i.e. 0.042 peptidenm(-2)) was obtained. Introduction of a three lysine tag at the peptide N-terminus (KKKVQGEESNDK) resulted in a dramatic improvement of the immobilized peptide amounts (27.5 mg/g NP, i.e. 0.417 peptidenm(-2)). As a comparison, the density of tagged peptide achievable on surfactant free PLA NPs of similar size (140 nm), through classical EDC or EDC/NHS activation of the surface PLA carboxylic end-groups, was found to be 6 mg/g NP (i.e. 0.075 peptidenm(-2)), showing the decisive impact of the P(NAS-co-NVP)-based hairy corona for high peptide coupling. These results demonstrate that combined use of lysine tag and PLA-b-P(NAS-co-NVP) surfactant represents a valuable platform to tune and optimize surface bio-functionalization of PLA-based biodegradable carriers. PMID:23277324

  8. In vivo activities of peptide and pseudo-peptide analogs of the C-terminal octapeptide of cholecystokinin on pancreatic secretion in the rat.

    PubMed

    Nagain, C; Rodriguez, M; Martinez, J; Rozé, C

    1987-01-01

    Most studies measuring the agonist and antagonist activities of CCK analogs and derivatives on the exocrine pancreas have been done with in vitro models. However, extrapolation to the in vivo situation may be sometimes hazardous, due to the catabolism of the peptides by circulating and tissue peptidases, and to their eventual interaction with various endogenous factors. The present experiments were organized to measure the efficacy and potency on pancreatic secretion of the rat in vivo of a series of CCK 8 analogs whose binding and activity had been previously measured on guinea-pig and rat isolated acini. The molecules tested were derivatives of Boc-(Nle 28-Nle 31)-CCK 26-33 (1), and comprised 2-phenylethylester derivatives, des-Phe derivatives, and a series of pseudo-peptides with a "reduced" bond CH2-NH replacing the peptide bond in position 28-29 to 32-33. They were perfused in anaesthetized rats, and the outputs of sodium, bicarbonate and total protein were measured. All of the derivatives studied had in vivo the same efficacy as (1) on the output of protein, and were 10 to 500 times less potent. For most compounds, the relative order of potencies measured in vivo was similar to that measured in vitro on amylase secretion by rat acini. However, the derivatives with reduced bonds in positions 28-29 and 29-30 were respectively 3 and 2 times less potent in vivo, relative to (1), while derivatives with reduced bonds in positions 30-31, 31-32 and 32-33 were 1.5 to 2.5 times more potent in vivo.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:3441441

  9. A Prosaposin-Derived Peptide Alleviates Kainic Acid-Induced Brain Injury

    PubMed Central

    Nabeka, Hiroaki; Shimokawa, Tetsuya; Doihara, Takuya; Saito, Shouichiro; Wakisaka, Hiroyuki; Hamada, Fumihiko; Kobayashi, Naoto; Matsuda, Seiji

    2015-01-01

    Four sphingolipid activator proteins (i.e., saposins A–D) are synthesized from a single precursor protein, prosaposin (PS), which exerts exogenous neurotrophic effects in vivo and in vitro. Kainic acid (KA) injection in rodents is a good model in which to study neurotrophic factor elevation; PS and its mRNA are increased in neurons and the choroid plexus in this animal model. An 18-mer peptide (LSELIINNATEELLIKGL; PS18) derived from the PS neurotrophic region prevents neuronal damage after ischemia, and PS18 is a potent candidate molecule for use in alleviating ischemia-induced learning disabilities and neuronal loss. KA is a glutamate analog that stimulates excitatory neurotransmitter release and induces ischemia-like neuronal degeneration; it has been used to define mechanisms involved in neurodegeneration and neuroprotection. In the present study, we demonstrate that a subcutaneous injection of 0.2 and 2.0 mg/kg PS18 significantly improved behavioral deficits of Wistar rats (n = 6 per group), and enhanced the survival of hippocampal and cortical neurons against neurotoxicity induced by 12 mg/kg KA compared with control animals. PS18 significantly protected hippocampal synapses against KA-induced destruction. To evaluate the extent of PS18- and KA-induced effects in these hippocampal regions, we performed histological evaluations using semithin sections stained with toluidine blue, as well as ordinal sections stained with hematoxylin and eosin. We revealed a distinctive feature of KA-induced brain injury, which reportedly mimics ischemia, but affects a much wider area than ischemia-induced injury: KA induced neuronal degeneration not only in the CA1 region, where neurons degenerate following ischemia, but also in the CA2, CA3, and CA4 hippocampal regions. PMID:25993033

  10. Modulation of host defense peptide-mediated human mast cell activation by LPS

    PubMed Central

    Gupta, Kshitij; Subramanian, Hariharan; Ali, Hydar

    2016-01-01

    Human β-defensin3 (hBD3) and the cathelicidin LL-37 are host defense peptides (HDPs) that directly kill microbes and display immunomodulatory/wound healing properties via the activation of chemokine, formylpeptide and epidermal growth factor receptors on monocytes and epithelial cells. A C-terminal 14 amino acid hBD3 peptide with all Cys residues replaced with Ser (CHRG01) and an LL-37 peptide consisting of residues 17-29 (FK-13) display antimicrobial activity but lack immunomodulatory property. Surprisingly, we found that CHRG01 and FK-13 caused Ca2+ mobilization and degranulation in human mast cells via a novel G protein coupled receptor (GPCR) known as Mas-related gene-X2 (MrgX2). At local sites of bacterial infection, the negatively charged LPS likely interacts with cationic HDPs to inhibit their activity and thus providing a mechanism for pathogens to escape the host defense mechanisms. We found that LPS caused almost complete inhibition of hBD3 and LL-37-induced Ca2+ mobilization and mast cell degranulation. In contrast, it had no effect on CHRG01 and FK-13-induced mast cell responses. These findings suggest that HDP derivatives that kill microbes, harness mast cell’s host defense and wound healing properties via the activation of MrgX2 but are resistant to inhibition by LPS could be utilized for the treatment of antibiotic-resistant microbial infections. PMID:26511058

  11. Structure and Activity of Human Mitochondrial Peptide Deformylase, a Novel Cancer Target

    SciTech Connect

    Escobar-Alvarez, Sindy; Goldgur, Yehuda; Yang, Guangli; Ouerfelli, Ouathek; Li, Yueming; Scheinberg, David A.

    2009-07-21

    Peptide deformylase proteins (PDFs) participate in the N-terminal methionine excision pathway of newly synthesized peptides. We show that the human PDF (HsPDF) can deformylate its putative substrates derived from mitochondrial DNA-encoded proteins. The first structural model of a mammalian PDF (1.7 A), HsPDF, shows a dimer with conserved topology of the catalytic residues and fold as non-mammalian PDFs. The HsPDF C-terminus topology and the presence of a helical loop (H2 and H3), however, shape a characteristic active site entrance. The structure of HsPDF bound to the peptidomimetic inhibitor actinonin (1.7 A) identified the substrate-binding site. A defined S1' pocket, but no S2' or S3' substrate-binding pockets, exists. A conservation of PDF-actinonin interaction across PDFs was observed. Despite the lack of true S2' and S3' binding pockets, confirmed through peptide binding modeling, enzyme kinetics suggest a combined contribution from P2'and P3' positions of a formylated peptide substrate to turnover.

  12. Structure and activity of human mitochondrial peptide deformylase, a novel cancer target.

    PubMed

    Escobar-Alvarez, Sindy; Goldgur, Yehuda; Yang, Guangli; Ouerfelli, Ouathek; Li, Yueming; Scheinberg, David A

    2009-04-17

    Peptide deformylase proteins (PDFs) participate in the N-terminal methionine excision pathway of newly synthesized peptides. We show that the human PDF (HsPDF) can deformylate its putative substrates derived from mitochondrial DNA-encoded proteins. The first structural model of a mammalian PDF (1.7 A), HsPDF, shows a dimer with conserved topology of the catalytic residues and fold as non-mammalian PDFs. The HsPDF C-terminus topology and the presence of a helical loop (H2 and H3), however, shape a characteristic active site entrance. The structure of HsPDF bound to the peptidomimetic inhibitor actinonin (1.7 A) identified the substrate-binding site. A defined S1' pocket, but no S2' or S3' substrate-binding pockets, exists. A conservation of PDF-actinonin interaction across PDFs was observed. Despite the lack of true S2' and S3' binding pockets, confirmed through peptide binding modeling, enzyme kinetics suggest a combined contribution from P2'and P3' positions of a formylated peptide substrate to turnover. PMID:19236878

  13. Enhanced Amphiphilic Profile of a Short β-Stranded Peptide Improves Its Antimicrobial Activity

    PubMed Central

    Manzo, Giorgia; Scorciapino, Mariano A.; Wadhwani, Parvesh; Bürck, Jochen; Montaldo, Nicola Pietro; Pintus, Manuela; Sanna, Roberta; Casu, Mariano; Giuliani, Andrea; Pirri, Giovanna; Luca, Vincenzo; Ulrich, Anne S.; Rinaldi, Andrea C.

    2015-01-01

    SB056 is a novel semi-synthetic antimicrobial peptide with a dimeric dendrimer scaffold. Active against both Gram-negative and -positive bacteria, its mechanism has been attributed to a disruption of bacterial membranes. The branched peptide was shown to assume a β-stranded conformation in a lipidic environment. Here, we report on a rational modification of the original, empirically derived linear peptide sequence [WKKIRVRLSA-NH2, SB056-lin]. We interchanged the first two residues [KWKIRVRLSA-NH2, β-SB056-lin] to enhance the amphipathic profile, in the hope that a more regular β-strand would lead to a better antimicrobial performance. MIC values confirmed that an enhanced amphiphilic profile indeed significantly increases activity against both Gram-positive and -negative strains. The membrane binding affinity of both peptides, measured by tryptophan fluorescence, increased with an increasing ratio of negatively charged/zwitterionic lipids. Remarkably, β-SB056-lin showed considerable binding even to purely zwitterionic membranes, unlike the original sequence, indicating that besides electrostatic attraction also the amphipathicity of the peptide structure plays a fundamental role in binding, by stabilizing the bound state. Synchrotron radiation circular dichroism and solid-state 19F-NMR were used to characterize and compare the conformation and mobility of the membrane bound peptides. Both SB056-lin and β-SB056-lin adopt a β-stranded conformation upon binding POPC vesicles, but the former maintains an intrinsic structural disorder that also affects its aggregation tendency. Upon introducing some anionic POPG into the POPC matrix, the sequence-optimized β-SB056-lin forms well-ordered β-strands once electro-neutrality is approached, and it aggregates into more extended β-sheets as the concentration of anionic lipids in the bilayer is raised. The enhanced antimicrobial activity of the analogue correlates with the formation of these extended β-sheets, which

  14. Specific interaction between Mycobacterium tuberculosis lipoprotein-derived peptides and target cells inhibits mycobacterial entry in vitro

    PubMed Central

    Ocampo, Marisol; Curtidor, Hernando; Vanegas, Magnolia; Patarroyo, Manuel Alfonso; Patarroyo, Manuel Elkin

    2014-01-01

    Summary Tuberculosis (TB) continues being one of the diseases having the greatest mortality rates around the world, 8.7 million cases having been reported in 2011. An efficient vaccine against TB having a great impact on public health is an urgent need. Usually, selecting antigens for vaccines has been based on proteins having immunogenic properties for patients suffering TB and having had promising results in mice and non-human primates. Our approach has been based on a functional approach involving the pathogen–host interaction in the search for antigens to be included in designing an efficient, minimal, subunit-based anti-tuberculosis vaccine. This means that Mycobacterium tuberculosis has mainly been involved in studies and that lipoproteins represent an important kind of protein on the cell envelope which can also contribute towards this pathogen's virulence. This study has assessed the expression of four lipoproteins from M. tuberculosis H37Rv, i.e. Rv1411c (LprG), Rv1911c (LppC), Rv2270 (LppN) and Rv3763 (LpqH), and the possible biological activity of peptides derived from these. Five peptides were found for these proteins which had high specific binding to both alveolar A549 epithelial cells and U937 monocyte-derived macrophages which were able to significantly inhibit mycobacterial entry to these cells in vitro. PMID:25041568

  15. Study on glyco-modification of endostatin-derived synthetic peptide endostatin2 (ES2) by soluble chitooligosaccharide.

    PubMed

    Yu, Yang; Sun, Feng; Zhang, Congcong; Wang, Zhendong; Liu, Jinfeng; Tan, Haining

    2016-12-10

    Soluble O-(2-hydroxyl)propyl-3-trimethyl ammonium chitooligosaccharide chloride (HTCOSC) was covalently conjugated to the 11-amino-acid peptide derived from amino terminus of endostatin (endostatin2, ES2, IVRRADRAAVP) to overcome its poor stability, low cell affinity and instable activity. Nuclear magnetic resonance spectroscopy and mass spectrometry was used to study the structure and molecular weight information. The anti-angiogenic activities were evaluated using cell counting Kit-8 assay, flow cytometry assay, wounding migration assay, transwell migration assay, chicken chorioallantoic membrane (CAM) assay and zebra fish angiogenesis assay. In contrast with ES2, the novel carbohydrate-polymer HTCOSC-ES2 displayed improved heat stability, higher cell affinity, better inhibition on endothelial cell proliferation, tube formation, 2-dimensional and 3-dimensional migration in vitro. According to the evaluation in CAM and zebra fish, HTCOSC-ES2 also displayed better anti-angiogenic activity than ES2 in vivo. These results indicate that HTCOSC has good properties as potential candidate for protein/peptide modifier and HTCOSC-ES2 has good potential in angiogenesis related diseases treatment. PMID:27577911

  16. Ghrelin-Derived Peptides: A Link between Appetite/Reward, GH Axis, and Psychiatric Disorders?

    PubMed Central

    Labarthe, Alexandra; Fiquet, Oriane; Hassouna, Rim; Zizzari, Philippe; Lanfumey, Laurence; Ramoz, Nicolas; Grouselle, Dominique; Epelbaum, Jacques; Tolle, Virginie

    2014-01-01

    Psychiatric disorders are often associated with metabolic and hormonal alterations, including obesity, diabetes, metabolic syndrome as well as modifications in several biological rhythms including appetite, stress, sleep–wake cycles, and secretion of their corresponding endocrine regulators. Among the gastrointestinal hormones that regulate appetite and adapt the metabolism in response to nutritional, hedonic, and emotional dysfunctions, at the interface between endocrine, metabolic, and psychiatric disorders, ghrelin plays a unique role as the only one increasing appetite. The secretion of ghrelin is altered in several psychiatric disorders (anorexia, schizophrenia) as well as in metabolic disorders (obesity) and in animal models in response to emotional triggers (psychological stress …) but the relationship between these modifications and the physiopathology of psychiatric disorders remains unclear. Recently, a large literature showed that this key metabolic/endocrine regulator is involved in stress and reward-oriented behaviors and regulates anxiety and mood. In addition, preproghrelin is a complex prohormone but the roles of the other ghrelin-derived peptides, thought to act as functional ghrelin antagonists, are largely unknown. Altered ghrelin secretion and/or signaling in psychiatric diseases are thought to participate in altered appetite, hedonic response and reward. Whether this can contribute to the mechanism responsible for the development of the disease or can help to minimize some symptoms associated with these psychiatric disorders is discussed in the present review. We will thus describe (1) the biological actions of ghrelin and ghrelin-derived peptides on food and drugs reward, anxiety and depression, and the physiological consequences of ghrelin invalidation on these parameters, (2) how ghrelin and ghrelin-derived peptides are regulated in animal models of psychiatric diseases and in human psychiatric disorders in relation with the GH axis

  17. Ghrelin-Derived Peptides: A Link between Appetite/Reward, GH Axis, and Psychiatric Disorders?

    PubMed

    Labarthe, Alexandra; Fiquet, Oriane; Hassouna, Rim; Zizzari, Philippe; Lanfumey, Laurence; Ramoz, Nicolas; Grouselle, Dominique; Epelbaum, Jacques; Tolle, Virginie

    2014-01-01

    Psychiatric disorders are often associated with metabolic and hormonal alterations, including obesity, diabetes, metabolic syndrome as well as modifications in several biological rhythms including appetite, stress, sleep-wake cycles, and secretion of their corresponding endocrine regulators. Among the gastrointestinal hormones that regulate appetite and adapt the metabolism in response to nutritional, hedonic, and emotional dysfunctions, at the interface between endocrine, metabolic, and psychiatric disorders, ghrelin plays a unique role as the only one increasing appetite. The secretion of ghrelin is altered in several psychiatric disorders (anorexia, schizophrenia) as well as in metabolic disorders (obesity) and in animal models in response to emotional triggers (psychological stress …) but the relationship between these modifications and the physiopathology of psychiatric disorders remains unclear. Recently, a large literature showed that this key metabolic/endocrine regulator is involved in stress and reward-oriented behaviors and regulates anxiety and mood. In addition, preproghrelin is a complex prohormone but the roles of the other ghrelin-derived peptides, thought to act as functional ghrelin antagonists, are largely unknown. Altered ghrelin secretion and/or signaling in psychiatric diseases are thought to participate in altered appetite, hedonic response and reward. Whether this can contribute to the mechanism responsible for the development of the disease or can help to minimize some symptoms associated with these psychiatric disorders is discussed in the present review. We will thus describe (1) the biological actions of ghrelin and ghrelin-derived peptides on food and drugs reward, anxiety and depression, and the physiological consequences of ghrelin invalidation on these parameters, (2) how ghrelin and ghrelin-derived peptides are regulated in animal models of psychiatric diseases and in human psychiatric disorders in relation with the GH axis

  18. Successful immunotherapy with matrix metalloproteinase-derived peptides in adjuvant arthritis depends on the timing of peptide administration

    PubMed Central

    van Bilsen, Jolanda HM; Wagenaar-Hilbers, Josée PA; van der Cammen, Maarten JF; van Dijk, Mariska EA; van Eden, Willem; Wauben, Marca HM

    2002-01-01

    We have recently found that matrix metalloproteinases (MMPs) are targets for T-cell and B-cell reactivity in experimental arthritis. In the present article, we investigate whether modulation of MMP-specific T-cell responses could influence the course of adjuvant arthritis (AA). Lewis rats were treated nasally with MMP peptides prior to or after AA induction. Administration of the MMP-10 or the MMP-16 peptide prior to AA induction reduced the arthritic symptoms. In contrast, administration of the MMP-10 peptide after AA induction aggravated the arthritic symptoms. The present study shows the possible usefulness of MMP peptides for immunotherapy. However, a clear understanding of proper timing of peptide administration is crucial for the development of such therapies. PMID:12106501

  19. Tetramer-organizing polyproline-rich peptides differ in CHO cell-expressed and plasma-derived human butyrylcholinesterase tetramers.

    PubMed

    Schopfer, Lawrence M; Lockridge, Oksana

    2016-06-01

    Tetrameric butyrylcholinesterase (BChE) in human plasma is the product of multiple genes, namely one BCHE gene on chromosome 3q26.1 and multiple genes that encode polyproline-rich peptides. The function of the polyproline-rich peptides is to assemble BChE into tetramers. CHO cells transfected with human BChE cDNA express BChE monomers and dimers, but only low quantities of tetramers. Our goal was to identify the polyproline-rich peptides in CHO-cell derived human BChE tetramers. CHO cell-produced human BChE tetramers were purified from serum-free culture medium. Peptides embedded in the tetramerization domain were released from BChE tetramers by boiling and identified by liquid chromatography-tandem mass spectrometry. A total of 270 proline-rich peptides were sequenced, ranging in size from 6-41 residues. The peptides originated from 60 different proteins that reside in multiple cell compartments including the nucleus, cytoplasm, and endoplasmic reticulum. No single protein was the source of the polyproline-rich peptides in CHO cell-expressed human BChE tetramers. In contrast, 70% of the tetramer-organizing peptides in plasma-derived BChE tetramers originate from lamellipodin. No protein source was identified for polyproline peptides containing up to 41 consecutive proline residues. In conclusion, the use of polyproline-rich peptides as a tetramerization motif is documented only for the cholinesterases, but is expected to serve other tetrameric proteins as well. The CHO cell data suggest that the BChE tetramer-organizing peptide can arise from a variety of proteins. PMID:26947244

  20. Proteome-derived Peptide Libraries to Study the Substrate Specificity Profiles of Carboxypeptidases*

    PubMed Central

    Tanco, Sebastian; Lorenzo, Julia; Garcia-Pardo, Javier; Degroeve, Sven; Martens, Lennart; Aviles, Francesc Xavier; Gevaert, Kris; Van Damme, Petra

    2013-01-01

    Through processing peptide and protein C termini, carboxypeptidases participate in the regulation of various biological processes. Few tools are however available to study the substrate specificity profiles of these enzymes. We developed a proteome-derived peptide library approach to study the substrate preferences of carboxypeptidases. Our COFRADIC-based approach takes advantage of the distinct chromatographic behavior of intact peptides and the proteolytic products generated by the action of carboxypeptidases, to enrich the latter and facilitate its MS-based identification. Two different peptide libraries, generated either by chymotrypsin or by metalloendopeptidase Lys-N, were used to determine the substrate preferences of human metallocarboxypeptidases A1 (hCPA1), A2 (hCPA2), and A4 (hCPA4). In addition, our approach allowed us to delineate the substrate specificity profile of mouse mast cell carboxypeptidase (MC-CPA or mCPA3), a carboxypeptidase suggested to function in innate immune responses regulation and mast cell granule homeostasis, but which thus far lacked a detailed analysis of its substrate preferences. mCPA3 was here shown to preferentially remove bulky aromatic amino acids, similar to hCPA2. This was also shown by a hierarchical cluster analysis, grouping hCPA1 close to hCPA4 in terms of its P1 primed substrate specificity, whereas hCPA2 and mCPA3 cluster separately. The specificity profile of mCPA3 may further aid to elucidate the function of this mast cell carboxypeptidase and its biological substrate repertoire. Finally, we used this approach to evaluate the substrate preferences of prolylcarboxypeptidase, a serine carboxypeptidase shown to cleave C-terminal amino acids linked to proline and alanine. PMID:23620545

  1. Anthranilate-Activating Modules from Fungal Nonribosomal Peptide Assembly Lines†

    PubMed Central

    Ames, Brian D.; Walsh, Christopher T.

    2010-01-01

    Fungal natural products containing benzodiazepinone- and quinazolinone-fused ring systems can be assembled by nonribosomal peptide synthetases (NRPS) using the conformationally restricted β-amino acid anthranilate as one of the key building blocks. We validated that the first module of the acetylaszonalenin synthetase of Neosartorya fischeri NRRL 181 activates anthranilate to anthranilyl-AMP. With this as starting point, we then used bioinformatic predictions about fungal adenylation domain selectivities to identify and confirm an anthranilate-activating module in the fumiquinazoline A producer Aspergillus fumigatus Af293 as well as a second anthranilate-activating NRPS in N. fischeri. This establishes an anthranilate adenylation domain code for fungal NRPS and should facilitate detection and cloning of gene clusters for benzodiazepine- and quinazoline-containing polycyclic alkaloids with a wide range of biological activities. PMID:20225828

  2. Novel antimicrobial peptide specifically active against Porphyromonas gingivalis.

    PubMed

    Suwandecha, T; Srichana, T; Balekar, N; Nakpheng, T; Pangsomboon, K

    2015-09-01

    Porphyromonas gingivalis, the major etiologic agent of chronic periodontitis, produces a broad spectrum of virulence factors, including outer membrane vesicles, lipopolysaccharides, hemolysins and proteinases. Antimicrobial peptides (AMPs) including bacteriocins have been found to inhibit the growth of P. gingivalis; however, these peptides are relatively large molecules. Hence, it is difficult to synthesize them by a scale-up production. Therefore, this study aimed to synthesize a shorter AMP that was still active against P. gingivalis. A peptide that contained three cationic amino acids (Arg, His and Lys), two anionic amino acids (Glu and Asp), hydrophobic amino acids residues (Leu, Ile, Val, Ala and Pro) and hydrophilic residues (Ser and Gly) was obtained and named Pep-7. Its bioactivity and stability were tested after various treatments. The mechanism of action of Pep-7 and its toxicity to human red blood cells were investigated. The Pep-7 inhibited two pathogenic P. gingivalis ATCC 33277 and P. gingivalis ATCC 53978 (wp50) strains at a minimum bactericidal concentration (MBC) of 1.7 µM, but was ineffective against other oral microorganisms (P. intermedia, Tannerella forsythensis, Streptococcus salivarius and Streptococcus sanguinis). From transmission electron microscopy studies, Pep-7 caused pore formation at the poles of the cytoplasmic membranes of P. gingivalis. A concentration of Pep-7 at four times that of its MBC induced some hemolysis but only at 0.3%. The Pep-7 was heat stable under pressure (autoclave at 110 and 121 °C) and possessed activity over a pH range of 6.8-8.5. It was not toxic to periodontal cells over a range of 70.8-4.4 μM and did not induce toxic pro-inflammatory cytokines. The Pep-7 showed selective activity against Porphyromonas sp. by altering the permeability barriers of P. gingivalis. The Pep-7 was not mutagenic in vitro. This work highlighted the potential for the use of this synthetic Pep-7 against P. gingivalis. PMID:26041027

  3. Diverse HLA-I Peptide Repertoires of the APC Lines MUTZ3-Derived Immature and Mature Dendritic Cells and THP1-Derived Macrophages.

    PubMed

    Nyambura, Lydon Wainaina; Jarmalavicius, Saulius; Baleeiro, Renato Brito; Walden, Peter

    2016-09-15

    Dendritic cells (DCs) and macrophages are specialized APCs that process and present self-Ags for induction of tolerance and foreign Ags to initiate T cell-mediated immunity. Related to differentiation states they have specific phenotypes and functions. However, the impact of these differentiations on Ag processing and presentation remains poorly defined. To gain insight into this, we analyzed and compared the HLA-I peptidomes of MUTZ3-derived human immature and mature DC lines and THP1-derived macrophages by liquid chromatography tandem mass spectrometry. We found that the HLA-I peptidomes were heterogeneous and individualized and were dominated by nonapeptides with similar HLA-I binding affinities and anchor residues. MUTZ3-derived DCs and THP1-derived macrophages were able to sample peptides from source proteins of almost all subcellular locations and were involved in various cellular functions in similar proportion, with preference to proteins involved in cell communication, signal transduction, protein metabolism, and transcription factor/regulator activity. PMID:27543614

  4. Charge properties of peptides derived from casein affect their bioavailability and cytoprotection against H2O2-induced oxidative stress.

    PubMed

    Wang, Bo; Xie, Ningning; Li, Bo

    2016-04-01

    The effects of charge properties of casein peptides on absorption stability, antioxidant activity, and cytoprotection were evaluated. Alcalase hydrolysates of casein were separated into 4 fractions by cation-exchange chromatography according to charge properties. After simulated digestion and Caco-2 cell transmembrane transport, we determined the total antioxidant capacity (Trolox equivalent antioxidative capacity and oxygen radical antioxidant activity) and nitrogen content of peptide fractions to estimate available antioxidant efficacy and bioavailability (BA) of peptides. Results showed that negatively charged peptide fractions had greater BA and antioxidant activities after digestion and absorption. The peptide permeates were used to test the cytoprotective effect against H2O2-induced oxidative damage in HepG-2 cells. All peptide permeates increased cell viability, elevated catalase activity, and decreased superoxide dismutase activity. However, negatively charged peptide fractions preserved cell viability to a greater degree. Therefore, the negatively charged peptides from casein may be potential antioxidants and could be used as ingredients in functional foods and dietary supplements. PMID:26851854

  5. DBAASP v.2: an enhanced database of structure and antimicrobial/cytotoxic activity of natural and synthetic peptides

    PubMed Central

    Pirtskhalava, Malak; Gabrielian, Andrei; Cruz, Phillip; Griggs, Hannah L.; Squires, R. Burke; Hurt, Darrell E.; Grigolava, Maia; Chubinidze, Mindia; Gogoladze, George; Vishnepolsky, Boris; Alekseev, Vsevolod; Rosenthal, Alex; Tartakovsky, Michael

    2016-01-01

    Antimicrobial peptides (AMPs) are anti-infectives that may represent a novel and untapped class of biotherapeutics. Increasing interest in AMPs means that new peptides (natural and synthetic) are discovered faster than ever before. We describe herein a new version of the Database of Antimicrobial Activity and Structure of Peptides (DBAASPv.2, which is freely accessible at http://dbaasp.org). This iteration of the database reports chemical structures and empirically-determined activities (MICs, IC50, etc.) against more than 4200 specific target microbes for more than 2000 ribosomal, 80 non-ribosomal and 5700 synthetic peptides. Of these, the vast majority are monomeric, but nearly 200 of these peptides are found as homo- or heterodimers. More than 6100 of the peptides are linear, but about 515 are cyclic and more than 1300 have other intra-chain covalent bonds. More than half of the entries in the database were added after the resource was initially described, which reflects the recent sharp uptick of interest in AMPs. New features of DBAASPv.2 include: (i) user-friendly utilities and reporting functions, (ii) a ‘Ranking Search’ function to query the database by target species and return a ranked list of peptides with activity against that target and (iii) structural descriptions of the peptides derived from empirical data or calculated by molecular dynamics (MD) simulations. The three-dimensional structural data are critical components for understanding structure–activity relationships and for design of new antimicrobial drugs. We created more than 300 high-throughput MD simulations specifically for inclusion in DBAASP. The resulting structures are described in the database by novel trajectory analysis plots and movies. Another 200+ DBAASP entries have links to the Protein DataBank. All of the structures are easily visualized directly in the web browser. PMID:26578581

  6. DBAASP v.2: an enhanced database of structure and antimicrobial/cytotoxic activity of natural and synthetic peptides.

    PubMed

    Pirtskhalava, Malak; Gabrielian, Andrei; Cruz, Phillip; Griggs, Hannah L; Squires, R Burke; Hurt, Darrell E; Grigolava, Maia; Chubinidze, Mindia; Gogoladze, George; Vishnepolsky, Boris; Alekseev, Vsevolod; Rosenthal, Alex; Tartakovsky, Michael

    2016-01-01

    Antimicrobial peptides (AMPs) are anti-infectives that may represent a novel and untapped class of biotherapeutics. Increasing interest in AMPs means that new peptides (natural and synthetic) are discovered faster than ever before. We describe herein a new version of the Database of Antimicrobial Activity and Structure of Peptides (DBAASPv.2, which is freely accessible at http://dbaasp.org). This iteration of the database reports chemical structures and empirically-determined activities (MICs, IC50, etc.) against more than 4200 specific target microbes for more than 2000 ribosomal, 80 non-ribosomal and 5700 synthetic peptides. Of these, the vast majority are monomeric, but nearly 200 of these peptides are found as homo- or heterodimers. More than 6100 of the peptides are linear, but about 515 are cyclic and more than 1300 have other intra-chain covalent bonds. More than half of the entries in the database were added after the resource was initially described, which reflects the recent sharp uptick of interest in AMPs. New features of DBAASPv.2 include: (i) user-friendly utilities and reporting functions, (ii) a 'Ranking Search' function to query the database by target species and return a ranked list of peptides with activity against that target and (iii) structural descriptions of the peptides derived from empirical data or calculated by molecular dynamics (MD) simulations. The three-dimensional structural data are critical components for understanding structure-activity relationships and for design of new antimicrobial drugs. We created more than 300 high-throughput MD simulations specifically for inclusion in DBAASP. The resulting structures are described in the database by novel trajectory analysis plots and movies. Another 200+ DBAASP entries have links to the Protein DataBank. All of the structures are easily visualized directly in the web browser. PMID:26578581

  7. Peptide-induced membrane leakage by lysine derivatives of gramicidin A in liposomes, planar bilayers, and erythrocytes.

    PubMed

    Sorochkina, Alexandra I; Kovalchuk, Sergei I; Omarova, Elena O; Sobko, Alexander A; Kotova, Elena A; Antonenko, Yuri N

    2013-11-01

    Introducing a charged group near the N-terminus of gramicidin A (gA) is supposed to suppress its ability to form ion channels by restricting its head-to-head dimerization. The present study dealt with the activity of [Lys1]gA, [Lys3]gA, [Glu1]gA, [Glu3]gA, [Lys2]gA, and [Lys5]gA in model membrane systems (planar lipid bilayers and liposomes) and erythrocytes. In contrast to the Glu-substituted peptides, the lysine derivatives of gA caused non-specific liposomal leakage monitored by fluorescence dequenching of lipid vesicles loaded with carboxyfluorescein or other fluorescent dyes. Measurements of electrical current through a planar lipid membrane revealed formation of giant pores by Lys-substituted analogs, which depended on the presence of solvent in the bilayer lipid membrane. The efficacy of unselective pore formation in liposomes depended on the position of the lysine residue in the amino acid sequence, increasing in the row: [Lys2]gA<[Lys5]gA<[Lys1]gA<[Lys3]gA. The similar series of potency was exhibited by the Lys-substituted gA analogs in facilitating erythrocyte hemolysis, whereas the Glu-substituted analogs showed negligible hemolytic activity. Oligomerization of the Lys-substituted peptides is suggested to be involved in the process of nonselective pore formation. PMID:23806648

  8. Esculentin-1a(1-21)NH2: a frog skin-derived peptide for microbial keratitis

    PubMed Central

    Kolar, Satya Sree N.; Luca, Vincenzo; Baidouri, Hasna; Mannino, Giuseppe; McDermott, Alison M.; Mangoni, Maria Luisa

    2015-01-01

    Pseudomonas aeruginosa is the primary bacterial pathogen causing contact lens related keratitis. Available ophthalmic agents have reduced efficacy and antimicrobial peptides (AMPs) hold promise as future antibiotics. Here we investigated the in vitro and in vivo anti-Pseudomonal activity of esculentin-1a(1-21)-NH2, derived from a frog skin AMP. The data revealed a minimum inhibitory concentration between 2 and 16 μM against reference strains or drug-resistant clinical isolates of P. aeruginosa without showing toxicity to human corneal epithelial cells up to 50 μM. At 1 μM the peptide rapidly killed bacterial cells and this activity was fully retained in 150 mM sodium chloride and 70% (v/v) human basal tears, particularly against the virulent ATCC 19660 strain. Furthermore, its dropwise administration at 40 μM to the ocular surface in a murine model of P. aeruginosa keratitis (three times daily, for 5 days post-infection) resulted in a significant reduction of infection. The mean clinical score was 2.89 ± 0.26 compared to 3.92 ± 0.08 for the vehicle control. In addition, the corneal level of viable bacteria in the peptide treated animals was significantly lower with a difference of 4 log10 colony counts, compared to 7.7 log10 cells recovered in the control. In parallel, recruitment of inflammatory cells was reduced by half compared to that found in the untreated eyes. Similar results were obtained when esculentin-1a(1-21)NH2 was applied prior to induction of keratitis. Overall, our findings highlight esculentin-1a(1-21)NH2 as an attractive candidate for the development of novel topical pharmaceuticals against Pseudomonas keratitis. PMID:25086859

  9. Interactions between chensinin-1, a natural antimicrobial peptide derived from Rana chensinensis, and lipopolysaccharide.

    PubMed

    Dong, Weibing; Sun, Yue; Shang, Dejing

    2015-12-01

    Lipopolysaccharide (LPS) plays a critical role in the pathogenesis of sepsis caused by gram-negative bacterial infections. Therefore, LPS-neutralizing molecules would have important clinical applications. Chensinin-1, a novel antimicrobial peptide with atypical structural features, was found in the skin secretions of the Chinese brown frog Rana chensinensis. To understand the role of LPS in the bacterial susceptibility to chensinin-1 and to investigate its anti-endotoxin effects, the interactions of chensinin-1 with LPS were investigated in this study using circular dichroism, in situ IR, isothermal titration calorimetry, and zeta potential. This study is the first to use in situ IR spectroscopy to evaluate the secondary structural changes of this peptide. The capacity of chensinin-1 to block the LPS-dependent cytokine secretion of macrophages was also investigated. Our results show that chensinin-1 can form α-helical structures in LPS suspensions. LPS can affect the antimicrobial activity of chensinin-1, and chensinin-1 was able to mitigate the effects of LPS. These data may facilitate the development of antimicrobial peptides with potent antimicrobial and anti-endotoxin activities. PMID:26340228

  10. Candidacidal mechanism of the arenicin-3-derived peptide NZ17074 from Arenicola marina.

    PubMed

    Wang, Xiaojie; Wang, Xiumin; Teng, Da; Zhang, Yong; Mao, Ruoyu; Xi, Di; Wang, Jianhua

    2014-09-01

    The candidacidal mechanisms of NZ17074, which is a variant of arenicin-3 from Arenicola marina, against human pathogenic fungus Candida albicans are reported in this work. The minimum inhibitory concentration (MIC) of NZ17074 toward C. albicans was 4 μg/ml, and this peptide exerted marked candidacidal activity in an energy-dependent and salt-sensitive manner. The flow cytometric analysis using propidium iodide (PI) showed that the plasma membrane of cells treated with NZ17074 was perturbed and that the cells were arrested in the G2/M phase. The dihydrorhodamine-123 (DHR-123) staining showed that the reactive oxygen species (ROS) production of C. albicans increased after exposure to NZ17074. Typical cellular disruption events, such as mitochondrial degradation, nuclear fragmentation, nuclear membrane disruption, and chromatin condensation, were further revealed through rhodamine 123 (RH123) staining, 4',6-diamidino-2-phenylindole (DAPI) staining, and transmission electron microscopy. In addition, the intracellular localization of this peptide was concentration dependent: it was located in the membrane at low concentrations (4 to 8 μg/ml) and penetrated into the cytoplasm at high concentrations (16 to 32 μg/ml). Our results suggested that NZ17074 exerts its candidacidal effects by disrupting the cell membrane, inducing apoptosis, and interrupting the cell cycle. These findings showed the potential of NZ17074 as a new candidacidal peptide, in addition to its antibacterial activities. PMID:24816779

  11. Deficiency of dermcidin-derived antimicrobial peptides in sweat of patients with atopic dermatitis correlates with an impaired innate defense of human skin in vivo.

    PubMed

    Rieg, Siegbert; Steffen, Heiko; Seeber, Silke; Humeny, Andreas; Kalbacher, Hubert; Dietz, Klaus; Garbe, Claus; Schittek, Birgit

    2005-06-15

    Antimicrobial peptides are an integral part of the epithelial innate defense system. Dermcidin (DCD) is a recently discovered antimicrobial peptide with a broad spectrum of activity. It is constitutively expressed in human eccrine sweat glands and secreted into sweat. Patients with atopic dermatitis (AD) have recurrent bacterial or viral skin infections and pronounced colonization with Staphylococcus aureus. We hypothesized that patients with AD have a reduced amount of DCD peptides in sweat contributing to the compromised constitutive innate skin defense. Therefore, we performed semiquantitative and quantitative analyses of DCD peptides in sweat of AD patients and healthy subjects using surface-enhanced laser desorption ionization time-of-flight mass spectrometry and ELISA. The data indicate that the amount of several DCD-derived peptides in sweat of patients with AD is significantly reduced. Furthermore, compared with atopic patients without previous infectious complications, AD patients with a history of bacterial and viral skin infections were found to have significantly less DCD-1 and DCD-1L in their sweat. To analyze whether the reduced amount of DCD in sweat of AD patients correlates with a decreased innate defense, we determined the antimicrobial activity of sweat in vivo. We showed that in healthy subjects, sweating leads to a reduction of viable bacteria on the skin surface, but this does not occur in patients with AD. These data indicate that reduced expression of DCD in sweat of patients with AD may contribute to the high susceptibility of these patients to skin infections and altered skin colonization. PMID:15944307

  12. Identification and Characterization of Novel Matrix-Derived Bioactive Peptides: A Role for Collagenase from Santyl® Ointment in Post-Debridement Wound Healing?

    PubMed Central

    Shi, Lei; Ronfard, Vincent; Grover, Komel V.; Herman, Ira M.

    2016-01-01

    Debridement, the removal of diseased, nonviable tissue, is critical for clinicians to readily assess wound status and prepare the wound bed for advanced therapeutics or downstream active healing. Removing necrotic slough and eschar through surgical or mechanical methods is less specific and may be painful for patients. Enzymatic debridement agents, such as Clostridial collagenase, selectively and painlessly degrade devitalized tissue. In addition to its debriding activities, highly-purified Clostridial collagenase actively promotes healing, and our past studies reveal that extracellular matrices digested with this enzyme yield peptides that activate cellular migratory, proliferative and angiogenic responses to injury in vitro, and promote wound closure in vivo. Intriguingly, while collagenase Santyl® ointment, a sterile preparation containing Clostridial collagenases and other non-specific proteases, is a well-accepted enzymatic debridement agent, its role as an active healing entity has never been established. Based on our previous studies of pure Clostridial collagenase, we now ask whether the mixture of enzymes contained within Santyl® produces matrix-derived peptides that promote cellular injury responses in vitro and stimulate wound closure in vivo. Here, we identify novel collagen fragments, along with collagen-associated peptides derived from thrombospondin-1, multimerin-1, fibronectin, TGFβ-induced protein ig-h3 and tenascin-C, generated from Santyl® collagenase-digested human dermal capillary endothelial and fibroblastic matrices, which increase cell proliferation and angiogenic remodeling in vitro by 50–100% over controls. Using an established model of impaired healing, we further demonstrate a specific dose of collagenase from Santyl® ointment, as well as the newly-identified and chemically-synthesized ECM-derived peptides significantly increase wound re-epithelialization by 60–100% over saline-treated controls. These results not only confirm

  13. Identification and Characterization of Novel Matrix-Derived Bioactive Peptides: A Role for Collagenase from Santyl® Ointment in Post-Debridement Wound Healing?

    PubMed

    Sheets, Anthony R; Demidova-Rice, Tatiana N; Shi, Lei; Ronfard, Vincent; Grover, Komel V; Herman, Ira M

    2016-01-01

    Debridement, the removal of diseased, nonviable tissue, is critical for clinicians to readily assess wound status and prepare the wound bed for advanced therapeutics or downstream active healing. Removing necrotic slough and eschar through surgical or mechanical methods is less specific and may be painful for patients. Enzymatic debridement agents, such as Clostridial collagenase, selectively and painlessly degrade devitalized tissue. In addition to its debriding activities, highly-purified Clostridial collagenase actively promotes healing, and our past studies reveal that extracellular matrices digested with this enzyme yield peptides that activate cellular migratory, proliferative and angiogenic responses to injury in vitro, and promote wound closure in vivo. Intriguingly, while collagenase Santyl® ointment, a sterile preparation containing Clostridial collagenases and other non-specific proteases, is a well-accepted enzymatic debridement agent, its role as an active healing entity has never been established. Based on our previous studies of pure Clostridial collagenase, we now ask whether the mixture of enzymes contained within Santyl® produces matrix-derived peptides that promote cellular injury responses in vitro and stimulate wound closure in vivo. Here, we identify novel collagen fragments, along with collagen-associated peptides derived from thrombospondin-1, multimerin-1, fibronectin, TGFβ-induced protein ig-h3 and tenascin-C, generated from Santyl® collagenase-digested human dermal capillary endothelial and fibroblastic matrices, which increase cell proliferation and angiogenic remodeling in vitro by 50-100% over controls. Using an established model of impaired healing, we further demonstrate a specific dose of collagenase from Santyl® ointment, as well as the newly-identified and chemically-synthesized ECM-derived peptides significantly increase wound re-epithelialization by 60-100% over saline-treated controls. These results not only confirm and

  14. Gastrointestinal Endogenous Protein-Derived Bioactive Peptides: An in Vitro Study of Their Gut Modulatory Potential

    PubMed Central

    Dave, Lakshmi A.; Hayes, Maria; Mora, Leticia; Montoya, Carlos A.; Moughan, Paul J.; Rutherfurd, Shane M.

    2016-01-01

    A recently proposed paradigm suggests that, like their dietary counterparts, digestion of gastrointestinal endogenous proteins (GEP) may also produce bioactive peptides. With an aim to test this hypothesis, in vitro digests of four GEP namely; trypsin (TRYP), lysozyme (LYS), mucin (MUC), serum albumin (SA) and a dietary protein chicken albumin (CA) were screened for their angiotensin-I converting (ACE-I), renin, platelet-activating factor-acetylhydrolase (PAF-AH) and dipeptidyl peptidase-IV inhibitory (DPP-IV) and antioxidant potential following simulated in vitro gastrointestinal digestion. Further, the resultant small intestinal digests were enriched to obtain peptides between 3–10 kDa in size. All in vitro digests of the four GEP were found to inhibit ACE-I compared to the positive control captopril when assayed at a concentration of 1 mg/mL, while the LYS < 3-kDa permeate fraction inhibited renin by 40% (±1.79%). The LYS < 10-kDa fraction inhibited PAF-AH by 39% (±4.34%), and the SA < 3-kDa fraction inhibited DPP-IV by 45% (±1.24%). The MUC < 3-kDa fraction had an ABTS-inhibition antioxidant activity of 150 (±24.79) µM trolox equivalent and the LYS < 10-kDa fraction inhibited 2,2-Diphenyl-1-picrylhydrazyl (DPPH) by 54% (±1.62%). Moreover, over 190 peptide-sequences were identified from the bioactive GEP fractions. The findings of the present study indicate that GEP are a significant source of bioactive peptides which may influence gut function. PMID:27043546

  15. Gastrointestinal Endogenous Protein-Derived Bioactive Peptides: An in Vitro Study of Their Gut Modulatory Potential.

    PubMed

    Dave, Lakshmi A; Hayes, Maria; Mora, Leticia; Montoya, Carlos A; Moughan, Paul J; Rutherfurd, Shane M

    2016-01-01

    A recently proposed paradigm suggests that, like their dietary counterparts, digestion of gastrointestinal endogenous proteins (GEP) may also produce bioactive peptides. With an aim to test this hypothesis, in vitro digests of four GEP namely; trypsin (TRYP), lysozyme (LYS), mucin (MUC), serum albumin (SA) and a dietary protein chicken albumin (CA) were screened for their angiotensin-I converting (ACE-I), renin, platelet-activating factor-acetylhydrolase (PAF-AH) and dipeptidyl peptidase-IV inhibitory (DPP-IV) and antioxidant potential following simulated in vitro gastrointestinal digestion. Further, the resultant small intestinal digests were enriched to obtain peptides between 3-10 kDa in size. All in vitro digests of the four GEP were found to inhibit ACE-I compared to the positive control captopril when assayed at a concentration of 1 mg/mL, while the LYS < 3-kDa permeate fraction inhibited renin by 40% (±1.79%). The LYS < 10-kDa fraction inhibited PAF-AH by 39% (±4.34%), and the SA < 3-kDa fraction inhibited DPP-IV by 45% (±1.24%). The MUC < 3-kDa fraction had an ABTS-inhibition antioxidant activity of 150 (±24.79) µM trolox equivalent and the LYS < 10-kDa fraction inhibited 2,2-Diphenyl-1-picrylhydrazyl (DPPH) by 54% (±1.62%). Moreover, over 190 peptide-sequences were identified from the bioactive GEP fractions. The findings of the present study indicate that GEP are a significant source of bioactive peptides which may influence gut function. PMID:27043546

  16. Antimicrobial activities of amphiphilic peptides covalently bonded to a water-insoluble resin.

    PubMed Central

    Haynie, S L; Crum, G A; Doele, B A

    1995-01-01

    A series of polymer-bound antimicrobial peptides was prepared, and the peptides were tested for their antimicrobial activities. The immobilized peptides were prepared by a strategy that used solid-phase peptide synthesis that linked the carboxy-terminal amino acid with an ethylenediamine-modified polyamide resin (PepsynK). The acid-stable, permanent amide bond between the support and the nascent peptide renders the peptide resistant to cleavage from the support during the final acid-catalyzed deprotection step in the synthesis. Select immobilized peptides containing amino acid sequences that ranged from the naturally occurring magainin to simpler synthetic sequences with idealized secondary structures were excellent antimicrobial agents against several organisms. The immobilized peptides typically reduced the number of viable cells by > or = 5 log units. We show that the reduction in cell numbers cannot be explained by the action of a soluble component. We observed no leached or hydrolyzed peptide from the resin, nor did we observe any antimicrobial activity in soluble extracts from the immobilized peptide. The immobilized peptides were washed and reused for repeated microbial contact and killing. These results suggest that the surface actions by magainins and structurally related antimicrobial peptides are sufficient for their lethal activities. PMID:7726486

  17. Peptide-based, irreversible inhibitors of gamma-secretase activity.

    PubMed

    Piper, Siân C; Amtul, Zareen; Galiñanes-Garcia, Laura; Howard, Victor G; Ziani-Cherif, Chewki; McLendon, Chris; Rochette, Marjorie J; Fauq, Abdul; Golde, Todd E; Murphy, M Paul

    2003-06-01

    The characterization of the enzymes responsible for amyloid beta-peptide (Abeta) production is considered to be a primary goal towards the development of future therapeutics for the treatment of Alzheimer's disease. Inhibitors of gamma-secretase activity were critical in demonstrating that the presenilins (PSs) likely comprised at least part of the active site of the gamma-secretase enzyme complex, with two highly conserved membrane aspartates presumably acting as catalytic residues. However, whether or not these aspartates are actually the catalytic residues of the enzyme complex or are merely essential for normal PS function and/or maturation is still unknown. In this paper, we report the development of reactive inhibitors of gamma-secretase activity that are functionally irreversible. Since such inhibitors have been shown to bind catalytic residues in other aspartyl proteases (e.g., HIV protease), they might be used to determine if the transmembrane aspartates of PSs are involved directly in substrate cleavage. PMID:12763025

  18. Dissociation Behavior of a TEMPO-Active Ester Cross-Linker for Peptide Structure Analysis by Free Radical Initiated Peptide Sequencing (FRIPS) in Negative ESI-MS

    NASA Astrophysics Data System (ADS)

    Hage, Christoph; Ihling, Christian H.; Götze, Michael; Schäfer, Mathias; Sinz, Andrea

    2016-07-01

    We have synthesized a homobifunctional amine-reactive cross-linking reagent, containing a TEMPO (2,2,6,6-tetramethylpiperidine-1-oxy) and a benzyl group (Bz), termed TEMPO-Bz-linker, to derive three-dimensional structural information of proteins. The aim for designing this novel cross-linker was to facilitate the mass spectrometric analysis of cross-linked products by free radical initiated peptide sequencing (FRIPS). In an initial study, we had investigated the fragmentation behavior of TEMPO-Bz-derivatized peptides upon collision activation in (+)-electrospray ionization collision-induced dissociation tandem mass spectrometry (ESI-CID-MS/MS) experiments. In addition to the homolytic NO-C bond cleavage FRIPS pathway delivering the desired odd-electron product ions, an alternative heterolytic NO-C bond cleavage, resulting in even-electron product ions mechanism was found to be relevant. The latter fragmentation route clearly depends on the protonation of the TEMPO-Bz-moiety itself, which motivated us to conduct (-)-ESI-MS, CID-MS/MS, and MS3 experiments of TEMPO-Bz-cross-linked peptides to further clarify the fragmentation behavior of TEMPO-Bz-peptide molecular ions. We show that the TEMPO-Bz-linker is highly beneficial for conducting FRIPS in negative ionization mode as the desired homolytic cleavage of the NO-C bond is the major fragmentation pathway. Based on characteristic fragments, the isomeric amino acids leucine and isoleucine could be discriminated. Interestingly, we observed pronounced amino acid side chain losses in cross-linked peptides if the cross-linked peptides contain a high number of acidic amino acids.

  19. Peptide biosensors for the electrochemical measurement of protein kinase activity.

    PubMed

    Kerman, Kagan; Song, Haifeng; Duncan, James S; Litchfield, David W; Kraatz, Heinz-Bernhard

    2008-12-15

    The kinase activities are elucidated using the novel redox-active cosubstrate adenosine 5'-[gamma-ferrocene] triphosphate (Fc-ATP), which enables the kinase-catalyzed transfer of a redox active gamma-phosphate-Fc to a hydroxyamino acid. In this report, a versatile electrochemical biosensor is developed for monitoring the activity and inhibition of a serine/threonine kinase, casein kinase 2 (CK2), and protein tyrosine kinases, Abl1-T315I and HER2, in buffered solutions and in cell lysates. The method is based on the labeling of a specific phosphorylation event with Fc, followed by electrochemical detection. The electrochemical response obtained from the "ferrocenylated" peptides enables monitoring the activity of the kinase and its substrate, as well as the inhibition of small molecule inhibitors on protein phosphorylation. Kinetic information was extracted from the electrochemical measurements for the determination of K(m) and V(m) values, which were in agreement with those previously reported. Kinase reactions were also performed in the presence of well-defined inhibitors of CK2, 4,5,6,7-tetrabromo-2-azabenzimidazole, 2-dimethylamino-4,5,6,7-tetrabromo-1H-benzimidazole, and E-3-(2,3,4,5-tetrabromophenyl)acrylic acid as well as the nonspecific kinase inhibitors, staurosporine and N-benzoylstaurosporine. On the basis of the dependency of the Fc signal on inhibitor concentration, K(i) of the inhibitors was estimated, which were also in agreement with the literature values. The performance of the biosensor was optimized including the kinase reaction, incubation with Fc-ATP, and the small molecule inhibitors. Peptide modified electrochemical biosensors are promising candidates for cost-effective in vitro kinase activity and inhibitor screening assays. PMID:18989981

  20. Biological activities of a synthetic peptide composed of two unlinked domains from a retroviral transmembrane protein sequence.

    PubMed Central

    Wegemer, D E; Kabat, K G; Kloetzer, W S

    1990-01-01

    We report several biological activities of a synthetic peptide whose sequence contains the highly conserved region of feline leukemia virus transmembrane protein (TM) synthetically linked to another short TM-derived sequence particularly rich in polar positive residues. This 29-amino-acid peptide blocked [3H]thymidine uptake 30 to 50% by concanavalin A-stimulated CD4(+)--but not CD8(+)-enriched murine splenocytes. Maximal suppression was detected at 12.5 micrograms (3 microM) to 75 micrograms (19 microM) per ml of growth medium; stimulation of [3H]thymidine uptake was observed at higher peptide concentrations. The synthetic peptide inhibited but did not stimulate [3H]thymidine uptake by mitogen-activated thymocytes and antibody production by splenocytes as determined in a liquid hemolytic plaque assay. Similarities are reported between a consensus sequence of diverse retroviral TMs and a region of alpha interferons shown by others to be important for antiviral and cytostatic properties. The TM sequence-derived synthetic peptide blocked in a nontoxic and sequence-specific manner the release of murine leukemia virus from two chronically infected cell lines. We suggest that some of the biological effects of retroviral TM are mediated through a common pathway shared with alpha interferons. Images PMID:1969500

  1. Immunologically active peptides that accompany hen egg yolk immunoglobulin Y: separation and identification.

    PubMed

    Polanowski, Antoni; Sosnowska, Agnieszka; Zabłocka, Agnieszka; Janusz, Maria; Trziszka, Tadeusz

    2013-07-01

    The protein mixture of cytokine-inducing activity accompanying chicken immunoglobulin Y, named yolkin, consists of several peptides of molecular weight (MW) ranging from over 1 to 35 kDa. Yolkin and its constituent peptides were found to be efficient inducers of interleukin (IL)-1β, IL-6 and IL-10 secretion. N-terminal amino acid sequences of eight of the electrophoretically purified yolkin constituents revealed that all of them are homological to some fragments of the C-terminal domain of vitellogenin II. The fractions of MW about 4 and 12 kDa are free of carbohydrates and start at position 1732 in the vitellogenin amino acid sequence; whereas the other fractions (MW about 16, 19, 23, 29, 32 and 35 kDa) appeared to be glycoproteins corresponding to the amino acid sequence of vitellogenin starting at position 1572. From these data, it is concluded that yolkin most likely represents vitellogenin-derived peptides that possess cytokine-inducing activity and are, at least partially, responsible for such properties of separated immunoglobulin Y preparation. This finding reveals a new role for vitellogenin as a reservoir of polypeptides that may play an important role in the innate immune system of the developing embryo. PMID:23492558

  2. Tuning the anticancer activity of a novel pro-apoptotic peptide using gold nanoparticle platforms

    PubMed Central

    Akrami, Mohammad; Balalaie, Saeed; Hosseinkhani, Saman; Alipour, Mohsen; Salehi, Fahimeh; Bahador, Abbas; Haririan, Ismaeil

    2016-01-01

    Pro-apoptotic peptides induce intrinsic apoptosis pathway in cancer cells. However, poor cellular penetration of the peptides is often associated with limited therapeutic efficacy. In this report, a series of peptide-gold nanoparticle platforms were developed to evaluate the anticancer activity of a novel alpha-lipoic acid-peptide conjugate, LA-WKRAKLAK, with respect to size and shape of nanoparticles. Gold nanoparticles (AuNPs) were found to enhance cell internalization as well as anticancer activity of the peptide conjugates. The smaller nanospheres showed a higher cytotoxicity, morphological change and cellular uptake compared to larger nanospheres and nanorods, whereas nanorods showed more hemolytic activity compared to nanospheres. The findings suggested that the anticancer and biological effects of the peptides induced by intrinsic apoptotic pathway were tuned by peptide-functionalized gold nanoparticles (P-AuNPs) as a function of their size and shape. PMID:27491007

  3. Synergistic enhancement of human bone marrow stromal cell proliferation and osteogenic differentiation on BMP-2-derived and RGD peptide concentration gradients.

    PubMed

    Moore, Nicole M; Lin, Nancy J; Gallant, Nathan D; Becker, Matthew L

    2011-05-01

    Rational design of bioactive tissue engineered scaffolds for directing bone regeneration in vivo requires a comprehensive understanding of cell interactions with the immobilized bioactive molecules. In the current study, substrates possessing gradient concentrations of immobilized peptides were used to measure the concentration-dependent proliferation and osteogenic differentiation of human bone marrow stromal cells. Two bioactive peptides, one derived from extracellular matrix protein (ECM), GRGDS, and one from bone morphogenic protein-2 (BMP-2), KIPKASSVPTELSAISTLYL, were found to synergistically enhance cell proliferation, up-regulate osteogenic mRNA markers bone sialoprotein (BSP) and Runt-related transcription factor 2, and produce mineralization at densities greater than 130 pmol cm(-2) (65 pmol cm(-2) for each peptide). In addition, COOH-terminated self-assembled monolayers alone led to up-regulated BSP mRNA levels at densities above 200 pmol cm(-2) and increased cell proliferation from day 3 to day 14. Taking further advantage of both the synergistic potentials and the concentration-dependent activities of ECM and growth-factor-derived peptides on proliferative activity and osteogenic differentiation, without the need for additional osteogenic supplements, will enable the successful incorporation of the bioactive species into biorelevant tissue engineering scaffolds. PMID:21272672

  4. Antifungal Activity and Action Mechanism of Histatin 5-Halocidin Hybrid Peptides against Candida ssp.

    PubMed

    Han, Juhye; Jyoti, Md Anirban; Song, Ho-Yeon; Jang, Woong Sik

    2016-01-01

    The candidacidal activity of histatin 5 is initiated through cell wall binding, followed by translocation and intracellular targeting, while the halocidin peptide exerts its activity by attacking the Candida cell membrane. To improve antimicrobial activities and to understand the killing mechanism of two peptides, six hybrid peptides were designed by conjugating histatin 5 and halocidin. A comparative approach was established to study the activity, salt tolerance, cell wall glucan binding assay, cytotoxicity, generation of ROS and killing kinetics. CD spectrometry was conducted to evaluate secondary structures of these hybrid peptides. Furthermore the cellular localization of hybrid peptides was investigated by confocal fluorescence microscopy. Of the six hybrid congeners, di-PH2, di-WP2 and HHP1 had stronger activities than other hybrid peptides against all tested Candida strains. The MIC values of these peptides were 1-2, 2-4 and 2-4 μg/ml, respectively. Moreover, none of the hybrid peptides was cytotoxic in the hemolytic assay and cell-based cytotoxicity assay. Confocal laser microscopy showed that di-PH2 and HHP1 were translocated into cytoplasm whereas di-WP2 was accumulated on surface of C. albicans to exert their candidacidal activity. All translocated peptides (Hst 5, P113, di-PH2) were capable of generating intracellular ROS except HHP1. Additionally, the KFH residues at C-terminal end of these peptides were assumed for core sequence for active translocation. PMID:26918792

  5. Antifungal Activity and Action Mechanism of Histatin 5-Halocidin Hybrid Peptides against Candida ssp

    PubMed Central

    Han, Juhye; Jyoti, Md. Anirban; Song, Ho-Yeon; Jang, Woong Sik

    2016-01-01

    The candidacidal activity of histatin 5 is initiated through cell wall binding, followed by translocation and intracellular targeting, while the halocidin peptide exerts its activity by attacking the Candida cell membrane. To improve antimicrobial activities and to understand the killing mechanism of two peptides, six hybrid peptides were designed by conjugating histatin 5 and halocidin. A comparative approach was established to study the activity, salt tolerance, cell wall glucan binding assay, cytotoxicity, generation of ROS and killing kinetics. CD spectrometry was conducted to evaluate secondary structures of these hybrid peptides. Furthermore the cellular localization of hybrid peptides was investigated by confocal fluorescence microscopy. Of the six hybrid congeners, di-PH2, di-WP2 and HHP1 had stronger activities than other hybrid peptides against all tested Candida strains. The MIC values of these peptides were 1–2, 2–4 and 2–4 μg/ml, respectively. Moreover, none of the hybrid peptides was cytotoxic in the hemolytic assay and cell-based cytotoxicity assay. Confocal laser microscopy showed that di-PH2 and HHP1 were translocated into cytoplasm whereas di-WP2 was accumulated on surface of C. albicans to exert their candidacidal activity. All translocated peptides (Hst 5, P113, di-PH2) were capable of generating intracellular ROS except HHP1. Additionally, the KFH residues at C-terminal end of these peptides were assumed for core sequence for active translocation. PMID:26918792

  6. Functional Analysis of Environmental DNA-Derived Microviridins Provides New Insights into the Diversity of the Tricyclic Peptide Family

    PubMed Central

    Gatte-Picchi, Douglas; Weiz, Annika; Ishida, Keishi; Hertweck, Christian

    2014-01-01

    Microviridins represent a unique family of ribosomally synthesized cage-like depsipeptides from cyanobacteria with potent protease-inhibitory activities. The natural diversity of these peptides is largely unexplored. Here, we describe two methodologies that were developed to functionally characterize cryptic microviridin gene clusters from metagenomic DNA. Environmental samples were collected and enriched from cyanobacterial freshwater blooms of different geographical origins containing predominantly Microcystis sp. Microviridins were produced either directly from fosmid clones or after insertion of environmental DNA-derived gene cassettes into a minimal expression platform in Escherichia coli. Three novel microviridin variants were isolated and tested against different serine-type proteases. The comparison of the bioactivity profiles of the new congeners allows deduction of further structure-function relationships for microviridins. Moreover, this study provides new insights into microviridin processing and gene cluster organization. PMID:24334668

  7. Effect of a standardized liver and spleen fraction of peptides on the differentiation of human monocyte-derived macrophages.

    PubMed

    Spessotto, P; Bulla, R; Mittenzwei, H; Dri, P

    1994-06-01

    The effect of Factor AF2 (AF2), a standardized fraction of peptides with a molecular weight of < 10,000 Dalton obtained from livers and spleens of newborn lambs, on the differentiation of human monocyte-derived macrophages was studied, in view of the central role played by these cells in inflammation and tumor cytotoxicity. The results show that the drug 1. increases the cell density of cultures, 2. favours the morphologic differentiation of monocytes into macrophages, and 3. increases the macrophages phagocytic capacity. The first two effects are observed when monocytes are cultured in 1% serum but not in 10% serum while the enhancement of phagocytic activity is detected at both serum concentrations. PMID:8053979

  8. Caffeic acid phenethyl ester (CAPE), an active component of propolis, inhibits Helicobacter pylori peptide deformylase activity.

    PubMed

    Cui, Kunqiang; Lu, Weiqiang; Zhu, Lili; Shen, Xu; Huang, Jin

    2013-05-31

    Helicobacter pylori (H. pylori) is a major causative factor for gastrointestinal illnesses, H. pylori peptide deformylase (HpPDF) catalyzes the removal of formyl group from the N-terminus of nascent polypeptide chains, which is essential for H. pylori survival and is considered as a promising drug target for anti-H. pylori therapy. Propolis, a natural antibiotic from honeybees, is reported to have an inhibitory effect on the growth of H. pylori in vitro. In addition, previous studies suggest that the main active constituents in the propolis are phenolic compounds. Therefore, we evaluated a collection of phenolic compounds derived from propolis for enzyme inhibition against HpPDF. Our study results show that Caffeic acid phenethyl ester (CAPE), one of the main medicinal components of propolis, is a competitive inhibitor against HpPDF, with an IC50 value of 4.02 μM. Furthermore, absorption spectra and crystal structural characterization revealed that different from most well known PDF inhibitors, CAPE block the substrate entrance, preventing substrate from approaching the active site, but CAPE does not have chelate interaction with HpPDF and does not disrupt the metal-dependent catalysis. Our study provides valuable information for understanding the potential anti-H. pylori mechanism of propolis, and CAPE could be served as a lead compound for further anti-H. pylori drug discovery. PMID:23611786

  9. Anti-infectious and anti-inflammatory effects of peptide fragments sequentially derived from the antimicrobial peptide centrocin 1 isolated from the green sea urchin, Strongylocentrotus droebachiensis

    PubMed Central

    2012-01-01

    Bacterial resistance against antibiotic treatment has become a major threat to public health. Antimicrobial peptides (AMPs) have emerged as promising alternative agents for treatment of infectious diseases. This study characterizes novel synthetic peptides sequentially derived from the AMP centrocin 1, isolated from the green sea urchin, for their applicability as anti-infective agents. The microbicidal effect of centrocin 1 heavy chain (CEN1 HC-Br), its debrominated analogue (CEN1 HC), the C-terminal truncated variants of both peptides, i.e. CEN1 HC-Br (1–20) and CEN1 HC (1–20), as well as the cysteine to serine substituted equivalent CEN1 HC (Ser) was evaluated using minimal microbicidal concentration assay. The anti-inflammatory properties were assessed by measuring the inhibition of secretion of pro-inflammatory cytokines. All the peptides tested exhibited marked microbicidal and anti-inflammatory properties. No difference in efficacy was seen comparing CEN1 HC-Br and CEN1 HC, while the brominated variant had higher cytotoxicity. C-terminal truncation of both peptides reduced salt-tolerability of the microbicidal effect as well as anti-inflammatory actions. Also, serine substitution of cysteine residue decreased the microbicidal effect. Thus, from the peptide variants tested, CEN1 HC showed the best efficacy and safety profile. Further, CEN1 HC significantly reduced bacterial counts in two different animal models of infected wounds, while Staphylococcus aureus and methicillin-resistant S. aureus (MRSA) failed to develop resistance against this peptide under continued selection pressure. In summary, CEN1 HC appears a promising new antimicrobial agent, and clinical studies are warranted to evaluate the applicability of this AMP for local treatment of infections in man. PMID:23237525

  10. Rationally Designed Interfacial Peptides Are Efficient In Vitro Inhibitors of HIV-1 Capsid Assembly with Antiviral Activity

    PubMed Central

    Bocanegra, Rebeca; Nevot, María; Doménech, Rosa; López, Inmaculada; Abián, Olga; Rodríguez-Huete, Alicia; Cavasotto, Claudio N.; Velázquez-Campoy, Adrián; Gómez, Javier; Martínez, Miguel Ángel; Neira, José Luis; Mateu, Mauricio G.

    2011-01-01

    Virus capsid assembly constitutes an attractive target for the development of antiviral therapies; a few experimental inhibitors of this process for HIV-1 and other viruses have been identified by screening compounds or by selection from chemical libraries. As a different, novel approach we have undertaken the rational design of peptides that could act as competitive assembly inhibitors by mimicking capsid structural elements involved in intersubunit interfaces. Several discrete interfaces involved in formation of the mature HIV-1 capsid through polymerization of the capsid protein CA were targeted. We had previously designed a peptide, CAC1, that represents CA helix 9 (a major part of the dimerization interface) and binds the CA C-terminal domain in solution. Here we have mapped the binding site of CAC1, and shown that it substantially overlaps with the CA dimerization interface. We have also rationally modified CAC1 to increase its solubility and CA-binding affinity, and designed four additional peptides that represent CA helical segments involved in other CA interfaces. We found that peptides CAC1, its derivative CAC1M, and H8 (representing CA helix 8) were able to efficiently inhibit the in vitro assembly of the mature HIV-1 capsid. Cocktails of several peptides, including CAC1 or CAC1M plus H8 or CAI (a previously discovered inhibitor of CA polymerization), or CAC1M+H8+CAI, also abolished capsid assembly, even when every peptide was used at lower, sub-inhibitory doses. To provide a preliminary proof that these designed capsid assembly inhibitors could eventually serve as lead compounds for development of anti-HIV-1 agents, they were transported into cultured cells using a cell-penetrating peptide, and tested for antiviral activity. Peptide cocktails that drastically inhibited capsid assembly in vitro were also able to efficiently inhibit HIV-1 infection ex vivo. This study validates a novel, entirely rational approach for the design of capsid assembly

  11. Rational modification of a dendrimeric peptide with antimicrobial activity: consequences on membrane-binding and biological properties.

    PubMed

    Batoni, Giovanna; Casu, Mariano; Giuliani, Andrea; Luca, Vincenzo; Maisetta, Giuseppantonio; Mangoni, Maria Luisa; Manzo, Giorgia; Pintus, Manuela; Pirri, Giovanna; Rinaldi, Andrea C; Scorciapino, Mariano A; Serra, Ilaria; Ulrich, Anne S; Wadhwani, Parvesh

    2016-03-01

    Peptide-based antibiotics might help containing the rising tide of antimicrobial resistance. We developed SB056, a semi-synthetic peptide with a dimeric dendrimer scaffold, active against both Gram-negative and Gram-positive bacteria. Being the mechanism of SB056 attributed to disruption of bacterial membranes, we enhanced the amphiphilic profile of the original, empirically derived sequence [WKKIRVRLSA-NH2] by interchanging the first two residues [KWKIRVRLSA-NH2], and explored the effects of this modification on the interaction of peptide, both in linear and dimeric forms, with model membranes and on antimicrobial activity. Results obtained against Escherichia coli and Staphylococcus aureus planktonic strains, with or without salts at physiological concentrations, confirmed the added value of dendrimeric structure over the linear one, especially at physiological ionic strength, and the impact of the higher amphipathicity obtained through sequence modification on enhancing peptide performances. SB056 peptides also displayed intriguing antibiofilm properties. Staphylococcus epidermidis was the most susceptible strain in sessile form, notably to optimized linear analog lin-SB056-1 and the wild-type dendrimer den-SB056. Membrane affinity of all peptides increased with the percentage of negatively charged lipids and was less influenced by the presence of salt in the case of dendrimeric peptides. The analog lin-SB056-1 displayed the highest overall affinity, even for zwitterionic PC bilayers. Thus, in addition to electrostatics, distribution of charged/polar and hydrophobic residues along the sequence might have a significant role in driving peptide-lipid interaction. Supporting this view, dendrimeric analog den-SB056-1 retained greater membrane affinity in the presence of salt than den-SB056, despite the fact that they bear exactly the same net positive charge. PMID:26614437

  12. Coupling to the surface of liposomes alters the immunogenicity of hepatitis C virus-derived peptides and confers sterile immunity.

    PubMed

    Takagi, Akira; Kobayashi, Nobuharu; Taneichi, Maiko; Uchida, Tetsuya; Akatsuka, Toshitaka

    2013-01-01

    We have previously demonstrated that antigens chemically coupled to the surface of liposomes consisting of unsaturated fatty acids were cross-presented by antigen presenting cells to cytotoxic T lymphocytes (CTLs). Liposomal form of immunodominant CTL epitope peptides derived from lymphocytic choriomeningitis virus exhibited highly efficient antiviral CTL responses in immunized mice. In this study, we coupled 15 highly conserved immunodominant CTL epitope peptides derived from hepatitis C virus (HCV) to the surface of liposomes. We also emulsified the peptides in incomplete Freund's adjuvant, and compared the immune responses of the two methods of presenting the peptides by cytotoxicity induction and interferon-gamma (IFN-γ) production by CD8(+) T cells of the immunized mice. We noticed significant variations of the immunogenicity of each peptide between the two antigen delivery systems. In addition, the immunogenicity profiles of the peptides were also different from those observed in the mice infected with recombinant adenoviruses expressing HCV proteins as previously reported. Induction of anti-viral immunity by liposomal peptides was tested by the challenge experiments using recombinant vaccinia viruses expressing corresponding HCV epitopes. One D(b)-restricted and three HLA-A(*)0201-restricted HCV CTL epitope peptides on the surface of liposomes were found to confer complete protection to immunized mice with establishment of long-term memory. Interestingly, their protective efficacy seemed to correlate with the induction of IFN-γ producing cells rather than the cytotoxicity induction suggesting that the immunized mice were protected through non-cytolytic mechanisms. Thus, these liposomal peptides might be useful as HCV vaccines not only for prevention but also for therapeutic use. PMID:23159619

  13. Inhibition of the myostatin/Smad signaling pathway by short decorin-derived peptides.

    PubMed

    El Shafey, Nelly; Guesnon, Mickaël; Simon, Françoise; Deprez, Eric; Cosette, Jérémie; Stockholm, Daniel; Scherman, Daniel; Bigey, Pascal; Kichler, Antoine

    2016-02-15

    Myostatin, also known as growth differentiation factor 8, is a member of the transforming growth factor-beta superfamily that has been shown to play a key role in the regulation of the skeletal muscle mass. Indeed, while myostatin deletion or loss of function induces muscle hypertrophy, its overexpression or systemic administration causes muscle atrophy. Since myostatin blockade is effective in increasing skeletal muscle mass, myostatin inhibitors have been actively sought after. Decorin, a member of the small leucine-rich proteoglycan family is a metalloprotein that was previously shown to bind and inactivate myostatin in a zinc-dependent manner. Furthermore, the myostatin-binding site has been shown to be located in the decorin N-terminal domain. In the present study, we investigated the anti-myostatin activity of short and soluble fragments of decorin. Our results indicate that the murine decorin peptides DCN48-71 and 42-65 are sufficient for inactivating myostatin in vitro. Moreover, we show that the interaction of mDCN48-71 to myostatin is strictly zinc-dependent. Binding of myostatin to activin type II receptor results in the phosphorylation of Smad2/3. Addition of the decorin peptide 48-71 decreased in a dose-dependent manner the myostatin-induced phosphorylation of Smad2 demonstrating thereby that the peptide inhibits the activation of the Smad signaling pathway. Finally, we found that mDCN48-71 displays a specificity towards myostatin, since it does not inhibit other members of the transforming growth factor-beta family. PMID:26844629

  14. A novel role for an RCAN3-derived peptide as a tumor suppressor in breast cancer.

    PubMed

    Martínez-Høyer, Sergio; Solé-Sánchez, Sònia; Aguado, Fernando; Martínez-Martínez, Sara; Serrano-Candelas, Eva; Hernández, José Luis; Iglesias, Mar; Redondo, Juan Miguel; Casanovas, Oriol; Messeguer, Ramon; Pérez-Riba, Mercè

    2015-07-01

    The members of the human regulators of calcineurin (RCAN) protein family are endogenous regulators of the calcineurin (CN)-cytosolic nuclear factor of activated T-cells (NFATc) pathway activation. This function is explained by the presence of a highly conserved calcipressin inhibitor of calcineurin (CIC) motif in RCAN proteins, which has been shown to compete with NFATc for the binding to CN and therefore are able to inhibit NFATc dephosphorylation and activation by CN. Very recently, emerging roles for NFATc proteins in transformation, tumor angiogenesis and metastasis have been described in different cancer cell types. In this work, we report that the overexpression of RCAN3 dramatically inhibits tumor growth and tumor angiogenesis in an orthotopic human breast cancer model. We suggest that RCAN3 exerts these effects in a CN-dependent manner, as mutation of the CIC motif in RCAN3 abolishes the tumor suppressor effect. Moreover, the expression of the EGFP-R3(178-210) peptide, spanning the CIC motif of RCAN3, is able to reproduce all the antitumor effects of RCAN3 full-length protein. Finally, we show that RCAN3 and the EGFP-R3(178-210) peptide inhibit the CN-NFATc signaling pathway and the induction of the NFATc-dependent gene cyclooxygenase-2. Our work suggests that the EGFP-R3(178-210) peptide possess potent tumor suppressor properties and therefore constitutes a novel lead for the development of potent and specific antitumoral agents. Moreover, we propose the targeting of the CN-NFATc pathway in the tumor cells constitutes an effective way to hamper tumor progression by impairing the paracrine network among tumor, endothelial and polymorphonucleated cells. PMID:25916653

  15. Molecular cloning and characterization of novel cathelicidin-derived myeloid antimicrobial peptide from Phasianus colchicus.

    PubMed

    Wang, Yipeng; Lu, Zekuan; Feng, Feifei; Zhu, Wei; Guang, Huijuan; Liu, Jingze; He, Weiyu; Chi, Lianli; Li, Zheng; Yu, Haining

    2011-03-01

    Cathelicidins were initially characterized as a family of antimicrobial peptides. Now it is clear that they fulfill several immune functions in addition to their antimicrobial activity. In the current work, three cDNA sequences encoding pheasant cathelicidins were cloned from a constructed bone marrow cDNA library of Phasianus colchicus, using a nested-PCR-based cloning strategy. The three deduced mature antimicrobial peptides, Pc-CATH1, 2 and 3 are composed of 26, 32, and 29 amino acid residues, respectively. Unlike the mammalian cathelicidins that are highly divergent even within the same genus, Pc-CATHs are remarkably conserved with chicken fowlicidins with only a few of residues mutated according to the phylogenetic analysis result. Synthetic Pc-CATH1 exerted strong antimicrobial activity against most of bacteria and fungi tested, including the clinically isolated (IS) drug-resistant strains. Most MIC values against Gram-positive bacteria were in the range of 0.09-2.95 μM in the presence of 100mM NaCl. Pc-CATH1 displayed a negligible hemolytic activity against human erythrocytes, lysing 3.6% of erythrocytes at 3.15 μM (10 μg/ml), significantly higher than the corresponding MIC. Pc-CATH1 was stable in the human serum for up to 72 h, revealing its extraordinary serum stability. These specific features of Pc-CATH1 may make its applications much wider given the potency and breadth of the peptide's bacteriocidal capacity and its resistance towards serum and high-salt environments. PMID:20955730

  16. Role of Proopiomelanocortin-Derived Peptides and Their Receptors in the Osteoarticular System: From Basic to Translational Research

    PubMed Central

    Grässel, Susanne

    2012-01-01

    Proopiomelanocortin (POMC)-derived peptides such as melanocortins and β-endorphin (β-ED) exert their pleiotropic effects via binding to melanocortin receptors (MCR) and opioid receptors (OR). There is now compelling evidence for the existence of a functional POMC system within the osteoarticular system. Accordingly, distinct cell types of the synovial tissue and bone have been identified to generate POMC-derived peptides like β-ED, ACTH, or α-MSH. MCR subtypes, especially MC1R, MC2R (the ACTH receptor), MC3R, and MC4R, but also the μ-OR and δ-OR, have been detected in various cells of the synovium, cartilage, and bone. The respective ligands of these POMC-derived peptide receptors mediate an increasing number of newly recognized biological effects in the osteoarticular system. These include bone mineralization and longitudinal growth, cell proliferation and differentiation, extracellular matrix synthesis, osteoprotection, and immunomodulation. Importantly, bone formation is also regulated by the central melanocortin system via a complex hormonal interplay with other organs and tissues involved in energy metabolism. Among the POMC-derived peptides examined in cell culture systems from osteoarticular tissue and in animal models of experimentally induced arthritis, α-MSH, ACTH, and MC3R-specific agonists appear to have the most promising antiinflammatory actions. The effects of these melanocortin peptides may be exploited in future for the treatment of patients with inflammatory and degenerative joint diseases. PMID:22736674

  17. Perspectives on Biologically Active Camptothecin Derivatives

    PubMed Central

    Liu, Ying-Qian; Li, Wen-Qun; Morris-Natschke, Susan L.; Qian, Keduo; Yang, Liu; Zhu, Gao-Xiang; Wu, Xiao-Bing; Chen, An-Liang; Zhang, Shao-Yong; Song, Zi-Long; Lee, Kuo-Hsiung

    2015-01-01

    Camptothecins (CPTs) are cytotoxic natural alkaloids that specifically target DNA topoisomerase I. Research on CPTs has undergone a significant evolution from the initial discovery of CPT in the late 1960s through the study of synthetic small molecule derivatives to investigation of macromolecular constructs and formulations. Over the past years, intensive medicinal chemistry efforts have generated numerous CPT derivatives. Three derivatives, topotecan, irinotecan, and belotecan, are currently prescribed as anticancer drugs, and several related compounds are now in clinical trials. Interest in other biological effects, besides anticancer activity, of CPTs is also growing exponentially, as indicated by the large number of publications on the subject during the last decades. Therefore, the main focus of the present review is to provide an ample but condensed overview on various biological activities of CPT derivatives, in addition to continued up-to-date coverage of anticancer effects. PMID:25808858

  18. Interaction between tachyplesin I, an antimicrobial peptide derived from horseshoe crab, and lipopolysaccharide.

    PubMed

    Kushibiki, Takahiro; Kamiya, Masakatsu; Aizawa, Tomoyasu; Kumaki, Yasuhiro; Kikukawa, Takashi; Mizuguchi, Mineyuki; Demura, Makoto; Kawabata, Shun-ichiro; Kawano, Keiichi

    2014-03-01

    Lipopolysaccharide (LPS) is a major constituent of the outer membrane of Gram-negative bacteria and is the very first site of interactions with antimicrobial peptides (AMPs). In order to gain better insight into the interaction between LPS and AMPs, we determined the structure of tachyplesin I (TP I), an antimicrobial peptide derived from horseshoe crab, in its bound state with LPS and proposed the complex structure of TP I and LPS using a docking program. CD and NMR measurements revealed that binding to LPS slightly extends the two β-strands of TP I and stabilizes the whole structure of TP I. The fluorescence wavelength of an intrinsic tryptophan of TP I and fluorescence quenching in the presence or absence of LPS indicated that a tryptophan residue is incorporated into the hydrophobic environment of LPS. Finally, we succeeded in proposing a structural model for the complex of TP I and LPS by using a docking program. The calculated model structure suggested that the cationic residues of TP I interact with phosphate groups and saccharides of LPS, whereas hydrophobic residues interact with the acyl chains of LPS. PMID:24389234

  19. Biophysical analysis of the interaction of granulysin-derived peptides with enterobacterial endotoxins

    PubMed Central

    Chen, Xi; Howe, Jörg; Andrä, Jörg; Rössle, Manfred; Richter, Walter; Silva, Ana Paula Galvão da; Krensky, Alan M.; Clayberger, Carol; Brandenburg, Klaus

    2009-01-01

    To combat infections by Gram-negative bacteria, it is not only necessary to kill the bacteria but also to neutralize pathogenicity factors such as endotoxin (lipopolysaccharide, LPS). The development of antimicrobial peptides based on mammalian endotoxin-binding proteins is a promising tool in the fight against bacterial infections, and septic shock syndrome. Here, synthetic peptides derived from granulysin (Gra-pep) were investigated in microbiological and biophysical assays to understand their interaction with LPS. We analyzed the influence of the binding of Gra-pep on (1) the acyl chain melting of the hydrophobic moiety of LPS, lipid A, by Fourier-transform spectroscopy, (2) the aggregate structure of LPS by small-angle X-ray scattering and cryo-transmission electron microscopy, and 3) the enthalpy change by isothermal titration calorimetry. In addition, the influence of Gra-pep on the incorporation of LPS and LPS-LBP (lipopolysaccharide-binding protein) complexes into negatively charged liposomes was monitored. Our findings demonstrate a characteristic change in the aggregate structure of LPS into multilamellar stacks in the presence of Gra-pep, but little or no change of acyl chain fluidity. Neutralization of LPS by Gra-pep is not due to a scavenging effect in solution, but rather proceeds after incorporation into target membranes, suggesting a requisite membrane-bound step. PMID:17555705

  20. A prawn core histone 4: derivation of N- and C-terminal peptides and their antimicrobial properties, molecular characterization and mRNA transcription.

    PubMed

    Chaurasia, Mukesh Kumar; Palanisamy, Rajesh; Bhatt, Prasanth; Kumaresan, Venkatesh; Gnanam, Annie J; Pasupuleti, Mukesh; Kasi, Marimuthu; Harikrishnan, Ramaswamy; Arockiaraj, Jesu

    2015-01-01

    This study investigates the complete molecular characterization including bioinformatics characterization, gene expression, synthesis of N and C terminal peptides and their antimicrobial activity of the core histone 4 (H4) from freshwater giant prawn Macrobrachium rosenbergii (Mr). A cDNA encoding MrH4 was identified from the constructed cDNA library of M. rosenbergii during screening and the sequence was obtained using internal sequencing primers. The MrH4 coding region possesses a polypeptide of 103 amino acids with a calculated molecular weight of 11kDa and an isoelectric point of 11.5. The bioinformatics analysis showed that the MrH4 polypeptide contains a H4 signature at (15)GAKRH(19). Multiple sequence alignment of MrH4 showed that the N-terminal (21-42) and C-terminal (87-101) antimicrobial peptide regions and the pentapeptide or H4 signature (15-19) are highly conserved including in humans. The phylogenetic tree formed two separate clades of vertebrate and invertebrate H4, wherein MrH4 was located within the arthropod monophyletic clade of invertebrate H4 groups. Three-dimensional model of MrH4 was established using I-TASSER program and the model was validated using Ramachandran plot analysis. Schiffer-Edmundson helical wheel modeling was used to predict the helix propensity of N (21-42) and C (87-101) terminal derived Mr peptides. The highest gene expression was observed in gills and is induced by viral [white spot syndrome baculovirus (WSBV) and M. rosenbergii nodovirus (MrNV)] and bacterial (Aeromonas hydrophila and Vibrio harveyi) infections. The N and C terminal peptides were synthesized and their antimicrobial and hemolytic properties were examined. Both peptides showed activity against the tested Gram negative and Gram positive bacteria; however, the highest activity was noticed against Gram negative bacteria. Among the two peptides used in this study, C-terminal peptide yielded better results than the N-terminal peptide. Therefore, C terminal

  1. HomoSAR: bridging comparative protein modeling with quantitative structural activity relationship to design new peptides.

    PubMed

    Borkar, Mahesh R; Pissurlenkar, Raghuvir R S; Coutinho, Evans C

    2013-11-15

    Peptides play significant roles in the biological world. To optimize activity for a specific therapeutic target, peptide library synthesis is inevitable; which is a time consuming and expensive. Computational approaches provide a promising way to simply elucidate the structural basis in the design of new peptides. Earlier, we proposed a novel methodology termed HomoSAR to gain insight into the structure activity relationships underlying peptides. Based on an integrated approach, HomoSAR uses the principles of homology modeling in conjunction with the quantitative structural activity relationship formalism to predict and design new peptide sequences with the optimum activity. In the present study, we establish that the HomoSAR methodology can be universally applied to all classes of peptides irrespective of sequence length by studying HomoSAR on three peptide datasets viz., angiotensin-converting enzyme inhibitory peptides, CAMEL-s antibiotic peptides, and hAmphiphysin-1 SH3 domain binding peptides, using a set of descriptors related to the hydrophobic, steric, and electronic properties of the 20 natural amino acids. Models generated for all three datasets have statistically significant correlation coefficients (r(2)) and predictive r2 (r(pred)2) and cross validated coefficient ( q(LOO)2). The daintiness of this technique lies in its simplicity and ability to extract all the information contained in the peptides to elucidate the underlying structure activity relationships. The difficulties of correlating both sequence diversity and variation in length of the peptides with their biological activity can be addressed. The study has been able to identify the preferred or detrimental nature of amino acids at specific positions in the peptide sequences. PMID:24105965

  2. Antimicrobial properties of membrane-active dodecapeptides derived from MSI-78.

    PubMed

    Monteiro, Claudia; Fernandes, Mariana; Pinheiro, Marina; Maia, Sílvia; Seabra, Catarina L; Ferreira-da-Silva, Frederico; Costa, Fabíola; Reis, Salette; Gomes, Paula; Martins, M Cristina L

    2015-05-01

    Antimicrobial peptides (AMPs) are a class of broad-spectrum antibiotics known by their ability to disrupt bacterial membranes and their low tendency to induce bacterial resistance, arising as excellent candidates to fight bacterial infections. In this study we aimed at designing short 12-mer AMPs, derived from a highly effective and broad spectrum synthetic AMP, MSI-78 (22 residues), by truncating this peptide at the N- and/or C-termini while spanning its entire sequence with 1 amino acid (aa) shifts. These designed peptides were evaluated regarding antimicrobial activity against selected gram-positive Staphylococcus strains and the gram-negative Pseudomonas aeruginosa (P. aeruginosa). The short 12-mer peptide CEM1 (GIGKFLKKAKKF) was identified as an excellent candidate to fight P. aeruginosa infections as it displays antimicrobial activity against this strain and selectivity, with negligible toxicity to mammalian cells even at high concentrations. However, in general most of the short 12-mer peptides tested showed a reduction in antimicrobial activity, an effect that was more pronounced for gram-positive Staphylococcus strains. Interestingly, CEM1 and a highly similar peptide differing by only one aa-shift (CEM2: IGKFLKKAKKFG), showed a remarkably contrasting AMP activity. These two peptides were chosen for a more detailed study regarding their mechanism of action, using several biophysical assays and simple membrane models that mimic the mammalian and bacterial lipid composition. We confirmed the correlation between peptide helicity and antimicrobial activity and propose a mechanism of action based on the disruption of the bacterial membrane permeability barrier. PMID:25680229

  3. Probing the structure-activity relationship of endogenous histone deacetylase complexes with immobilized peptide-inhibitors.

    PubMed

    Sindlinger, Julia; Bierlmeier, Jan; Geiger, Lydia-Christina; Kramer, Katharina; Finkemeier, Iris; Schwarzer, Dirk

    2016-05-01

    Histone deacetylases (HDACs) are key regulators of numerous cellular proteins by removing acetylation marks from modified lysine residues. Peptide-based HDAC probes containing α-aminosuberic acid ω-hydroxamate have been established as useful tools for investigating substrate selectivity and composition of endogenous HDAC complexes in cellular lysates. Here we report a structure-activity study of potential HDAC-probes containing derivatives of the hydroxamate moieties. While most of these probes did not recruit significant amounts of endogenous HDACs from cellular lysates, peptides containing Nε-acetyl-Nε-hydroxy-L-lysine served as HDAC probe. The recruitment efficiency varied between HDACs and was generally lower than that of α-aminosuberic acid ω-hydroxamate probes, but showed a similar global interaction profile. These findings indicate that Nε-acetyl-Nε-hydroxy-L-lysine might be a useful tool for investigations on HDAC complexes and the development of HDAC inhibitors. Copyright © 2016 European Peptide Society and John Wiley & Sons, Ltd. PMID:27071932

  4. Antimycobacterial Activity of a New Peptide Polydim-I Isolated from Neotropical Social Wasp Polybia dimorpha

    PubMed Central

    das Neves, Rogerio Coutinho; Trentini, Monalisa Martins; de Castro e Silva, Juliana; Simon, Karina Smidt; Bocca, Anamelia Lorenzetti; Silva, Luciano Paulino; Mortari, Marcia Renata; Kipnis, Andre; Junqueira-Kipnis, Ana Paula

    2016-01-01

    Mycobacterium abscessus subsp. massiliense, a rapidly growing mycobacteria (RGM) that is becoming increasingly important among human infectious diseases, is virulent and pathogenic and presents intrinsic resistance to several antimicrobial drugs that might hamper their elimination. Therefore, the identification of new drugs to improve the current treatment or lower the risk of inducing resistance is urgently needed. Wasp venom primarily comprises peptides that are responsible for most of the biological activities in this poison. Here, a novel peptide Polydim-I, from Polybia dimorpha Neotropical wasp, was explored as an antimycobacterial agent. Polydim-I provoked cell wall disruption and exhibited non-cytotoxicity towards mammalian cells. Polydim-I treatment of macrophages infected with different M. abscessus subsp. massiliense strains reduced 40 to 50% of the bacterial load. Additionally, the Polydim-I treatment of highly susceptible mice intravenously infected with M. abscessus subsp. massiliense induced 0.8 to 1 log reduction of the bacterial load in the lungs, spleen, and liver. In conclusion, this is the first study to show the therapeutic potential of a peptide derived from wasp venom in treating mycobacteria infections. Polydim-I acts on the M. abscessus subsp. massiliense cell wall and reduce 40–90% of the bacterial load both in vitro and in vivo. The presented results encourage further studies on the use of Polydim-I as one of the components for M. abscessus subsp. massiliense treatment. PMID:26930596

  5. Urotensin II((4-11)) Azasulfuryl Peptides: Synthesis and Biological Activity.

    PubMed

    Merlino, Francesco; Yousif, Ali M; Billard, Étienne; Dufour-Gallant, Julien; Turcotte, Stéphane; Grieco, Paolo; Chatenet, David; Lubell, William D

    2016-05-26

    Cyclic azasulfuryl (As) peptide analogs of the urotensin II (UII, 1, H-Glu-Thr-Pro-Asp-c[Cys-Phe-Trp-Lys-Tyr-Cys]-Val-OH) fragment 4-11 were synthesized to explore the influences of backbone structure on biological activity. N-Aminosulfamides were inserted as surrogates of the Trp(7) and Lys(8) residues in the biologically relevant Trp-Lys-Tyr triad. A combination of solution- and solid-phase methods were used to prepare novel UII((4-11)) analogs 6-11 by routes featuring alkylation of azasulfuryl-glycine tripeptide precursors to install various side chains. The pharmacological profiles of derivatives 6-11 were tested in vitro using a competitive binding assay and ex vivo using a rat aortic ring bioassay. Although the analogs exhibited weak affinity for the urotensin II receptor (UT) without agonistic activity, azasulfuryl-UII((4-11)) derivatives 7-9 reduced up to 50% of the effects of UII and urotensin II-related peptide (URP) without affecting their potency. PMID:27140209

  6. Identification of novel aminopiperidine derivatives for antibacterial activity against Gram-positive bacteria.

    PubMed

    Lee, Hee-Yeol; An, Kyung-Mi; Jung, Juyoung; Koo, Je-Min; Kim, Jeong-Geun; Yoon, Jong-Min; Lee, Myong-Jae; Jang, HyeonSoo; Lee, Hong-Sub; Park, Soobong; Kang, Jae-Hoon

    2016-07-01

    We have previously reported amidopiperidine derivatives as a novel peptide deformylase (PDF) inhibitor and evaluated its antibacterial activity against Gram-positive bacteria, but poor pharmacokinetic profiles have resulted in low efficacy in in vivo mouse models. In order to overcome these weaknesses, we newly synthesized aminopiperidine derivatives with remarkable antimicrobial properties and oral bioavailability, and also identified their in vivo efficacy against methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant Enterococcus (VRE) and penicillin-resistant Streptococcus pneumoniae (PRSP). PMID:27173797

  7. Metallamacrocycle formation through dimerization of metal bioconjugates derived from amino acids and peptides.

    PubMed

    Álvarez, Celedonio M; García-Rodríguez, Raúl; Miguel, Daniel

    2016-01-21

    Metallamacrocycles of 12, 16, and 22 members are obtained by deprotonation of the carboxylic group of the side chain of iminopyridine complexes derived from the amino acid β-alanine, and the peptides Gly-Gly and Gly-Gly-Gly. Instead of the expected intramolecular attack to give tridentate (N,N,O) ligands, the deprotonated carboxylate attacks in an inter-molecular manner to give dimers in which the ligand acts as a bridge bonded in a κ(2)(N,N') chelating fashion to one metal and as κ(O) to the other metal. The formation of the dimers is supported by NMR spectroscopy, mass spectrometry and X-ray crystallography. PMID:26645303

  8. Polyreactive anti-DNA monoclonal antibodies and a derived peptide as vectors for the intracytoplasmic and intranuclear translocation of macromolecules.

    PubMed

    Avrameas, A; Ternynck, T; Nato, F; Buttin, G; Avrameas, S

    1998-05-12

    Naturally occurring polyreactive anti-DNA mAbs derived from a nonimmunized (NZB x NZW)F1 mouse with spontaneous lupus erythematosus penetrated and accumulated in the nuclei of a variety of cultured cells. These mAbs and their F(ab')2 and Fab' fragments, covalently coupled to fluorescein, peroxidase, or a 15-mer polynucleotide, also translocated to the cell nuclei. A 30-amino acid peptide corresponding to the combined sequences of the complementary-determining regions 2 and 3 of the heavy chain variable region of one mAb was able to penetrate into the cytoplasm and nucleus of cells of several lines. This peptide recognized DNA and was strongly polyreactive. Streptavidin-peroxidase conjugates complexed with the N-biotinylated peptide were rapidly translocated into cells. Similarly, peroxidase or anti-peroxidase polyclonal antibodies covalently coupled to the N-cysteinylated peptide through an heterobifunctional maleimide cross-linker were also rapidly internalized and frequently accumulated in nuclei. The peptide carrying 19 lysine residues at its N-terminal was highly effective in transfecting 3T3 cells with a plasmid containing the luciferase gene. Thus, penetrating mAbs and derived peptides are versatile vectors for the intracellular delivery of proteins and genes. PMID:9576929

  9. Prediction of Antimicrobial Activity of Synthetic Peptides by a Decision Tree Model

    PubMed Central

    Lira, Felipe; Perez, Pedro S.; Baranauskas, José A.

    2013-01-01

    Antimicrobial resistance is a persistent problem in the public health sphere. However, recent attempts to find effective substitutes to combat infections have been directed at identifying natural antimicrobial peptides in order to circumvent resistance to commercial antibiotics. This study describes the development of synthetic peptides with antimicrobial activity, created in silico by site-directed mutation modeling using wild-type peptides as scaffolds for these mutations. Fragments of antimicrobial peptides were used for modeling with molecular modeling computational tools. To analyze these peptides, a decision tree model, which indicated the action range of peptides on the types of microorganisms on which they can exercise biological activity, was created. The decision tree model was processed using physicochemistry properties from known antimicrobial peptides available at the Antimicrobial Peptide Database (APD). The two most promising peptides were synthesized, and antimicrobial assays showed inhibitory activity against Gram-positive and Gram-negative bacteria. Colossomin C and colossomin D were the most inhibitory peptides at 5 μg/ml against Staphylococcus aureus and Escherichia coli. The methods described in this work and the results obtained are useful for the identification and development of new compounds with antimicrobial activity through the use of computational tools. PMID:23455341

  10. Human 20S proteasome activity towards fluorogenic peptides of various chain lengths.

    PubMed

    Rut, Wioletta; Drag, Marcin

    2016-09-01

    The proteasome is a multicatalytic protease responsible for the degradation of misfolded proteins. We have synthesized fluorogenic substrates in which the peptide chain was systematically elongated from two to six amino acids and evaluated the effect of peptide length on all three catalytic activities of human 20S proteasome. In the cases of five- and six-membered peptides, we have also synthesized libraries of fluorogenic substrates. Kinetic analysis revealed that six-amino-acid substrates are significantly better for chymotrypsin-like and caspase-like activity than shorter peptidic substrates. In the case of trypsin-like activity, a five-amino-acid substrate was optimal. PMID:27176742

  11. Antitumor Activity of Peptide Amphiphile Nanofiber-Encapsulated Camptothecin

    SciTech Connect

    Soukasene, Stephen; Toft, Daniel J.; Moyer, Tyson J.; Lu, Hsuming; Lee, Hyung-Kun; Standley, Stephany M.; Cryns, Vincent L.; Stupp, Samuel I.

    2012-04-02

    Self-assembling peptide amphiphile (PA) nanofibers were used to encapsulate camptothecin (CPT), a naturally occurring hydrophobic chemotherapy agent, using a solvent evaporation technique. Encapsulation by PA nanofibers was found to improve the aqueous solubility of the CPT molecule by more than 50-fold. PAs self-assembled into nanofibers in the presence of CPT as demonstrated by transmission electron microscopy. Small-angle X-ray scattering results suggest a slight increase in diameter of the nanofiber to accommodate the hydrophobic cargo. In vitro studies using human breast cancer cells show an enhancement in antitumor activity of the CPT when encapsulated by the PA nanofibers. In addition, using a mouse orthotopic model of human breast cancer, treatment with PA nanofiber-encapsulated CPT inhibited tumor growth. These results highlight the potential of this model PA system to be adapted for delivery of hydrophobic therapies to treat a variety of diseases including cancer.

  12. Single amino acid variation underlies species-specific sensitivity to amphibian skin-derived opioid-like peptides

    PubMed Central

    Vardy, Eyal; Sassano, Maria F.; Rennekamp, Andrew J.; Kroeze, Wesley K.; Mosier, Philip D.; Westkaemper, Richard B.; Stevens, Craig W.; Katritch, Vsevolod; Stevens, Raymond C.; Peterson, Randel T.; Roth, Bryan L.

    2015-01-01

    It has been suggested that the evolution of vertebrate opioid receptors (ORs) follow a vector of increased functionality. Here we test this idea comparing human and frog ORs. Interestingly, some of the most potent opioid peptides known have been isolated from amphibian skin secretions. Here we show that such peptides (dermorphin and deltorphin) are highly potent in the human receptors and inactive in frog ORs. The molecular basis for the insensitivity of the frog ORs to these peptides was studied using chimeras and molecular modeling. Interestingly, the insensitivity of the delta opioid receptor (DOR) to deltorphin was due to variation of a single amino acid– Trp7.35—which is a leucine in mammalian DORs. Notably, Trp7.35 is completely conserved in all known DOR sequences from lamprey, fish and amphibians. The deltorphin-insensitive phenotype was verified in fish. Our results provide a molecular explanation for the species selectivity of skin-derived opioid peptides. PMID:26091169

  13. Identification of Antihypertensive Peptides Derived from Low Molecular Weight Casein Hydrolysates Generated during Fermentation by Bifidobacterium longum KACC 91563.

    PubMed

    Ha, Go Eun; Chang, Oun Ki; Jo, Su-Mi; Han, Gi-Sung; Park, Beom-Young; Ham, Jun-Sang; Jeong, Seok-Geun

    2015-01-01

    Angiotensin-converting enzyme (ACE) inhibitory activity was evaluated for the low-molecular-weight fraction (<3 kDa) obtained from milk fermentation by Bifidobacterium longum KACC91563. The ACE inhibitory activity in this fraction was 62.3%. The peptides generated from the <3 kDa fraction were identified by liquid chromatography-electrospray ionization quantitative time-of-flight mass spectrometry analysis. Of the 28 peptides identified, 11 and 16 were identified as β-casein (CN) and αs1-CN, respectively. One peptide was identified as κ-CN. Three peptides, YQEPVLGPVRGPFPIIV, QEPVLGPVRGPFPIIV, and GPVRGPFPIIV, from β-CN corresponded to known antihypertensive peptides. We also found 15 peptides that were identified as potential antihypertensive peptides because they included a known antihypertensive peptide fragment. These peptides were as follows: RELEELNVPGEIVE (f1-14), YQEPVLGPVRGPFP (f193-206), EPVLGPVRGPFPIIV (f195-206), PVLGPVRGPFPIIV (f196-206), VLGPVRGPFPIIV (f197-206), and LGPVRGPFPIIV (f198-206) for β-CN; and APSFSDIPNPIGSENSEKTTMPLW (f176-199), SFSDIPNPIGSENSEKT- TMPLW (f178-199), FSDIPNPIGSENSEKTTMPLW (f179-199), SDIPNPIGSENSEKTTMPLW (f180-199), DIPNPIGSENSEKTTMPLW (f181-199), IPNPIGSENSEKTTMPLW (f182-199), PIGSENSEKTTMPLW (f185-199), IGSENSEKTTMPLW (f186-199), and SENSEKTTMPLW (f188-199) for αs1-CN. From these results, B. longum could be used as a starter culture in combination with other lactic acid bacteria in the dairy industry, and/or these peptides could be used in functional food manufacturing as additives for the development of a product with beneficial effects for human health. PMID:26877633

  14. Identification of Antihypertensive Peptides Derived from Low Molecular Weight Casein Hydrolysates Generated during Fermentation by Bifidobacterium longum KACC 91563

    PubMed Central

    Ha, Go Eun; Chang, Oun Ki; Jo, Su-Mi; Han, Gi-Sung; Park, Beom-Young; Ham, Jun-Sang; Jeong, Seok-Geun

    2015-01-01

    Angiotensin-converting enzyme (ACE) inhibitory activity was evaluated for the low-molecular-weight fraction (<3 kDa) obtained from milk fermentation by Bifidobacterium longum KACC91563. The ACE inhibitory activity in this fraction was 62.3%. The peptides generated from the <3 kDa fraction were identified by liquid chromatography-electrospray ionization quantitative time-of-flight mass spectrometry analysis. Of the 28 peptides identified, 11 and 16 were identified as β-casein (CN) and αs1-CN, respectively. One peptide was identified as κ-CN. Three peptides, YQEPVLGPVRGPFPIIV, QEPVLGPVRGPFPIIV, and GPVRGPFPIIV, from β-CN corresponded to known antihypertensive peptides. We also found 15 peptides that were identified as potential antihypertensive peptides because they included a known antihypertensive peptide fragment. These peptides were as follows: RELEELNVPGEIVE (f1-14), YQEPVLGPVRGPFP (f193-206), EPVLGPVRGPFPIIV (f195-206), PVLGPVRGPFPIIV (f196-206), VLGPVRGPFPIIV (f197-206), and LGPVRGPFPIIV (f198-206) for β-CN; and APSFSDIPNPIGSENSEKTTMPLW (f176-199), SFSDIPNPIGSENSEKT- TMPLW (f178-199), FSDIPNPIGSENSEKTTMPLW (f179-199), SDIPNPIGSENSEKTTMPLW (f180-199), DIPNPIGSENSEKTTMPLW (f181-199), IPNPIGSENSEKTTMPLW (f182-199), PIGSENSEKTTMPLW (f185-199), IGSENSEKTTMPLW (f186-199), and SENSEKTTMPLW (f188-199) for αs1-CN. From these results, B. longum could be used as a starter culture in combination with other lactic acid bacteria in the dairy industry, and/or these peptides could be used in functional food manufacturing as additives for the development of a product with beneficial effects for human health. PMID:26877633

  15. A novel peptide with potent and broad-spectrum antiviral activities against multiple respiratory viruses

    PubMed Central

    Zhao, Hanjun; Zhou, Jie; Zhang, Ke; Chu, Hin; Liu, Dabin; Poon, Vincent Kwok-Man; Chan, Chris Chung-Sing; Leung, Ho-Chuen; Fai, Ng; Lin, Yong-Ping; Zhang, Anna Jin-Xia; Jin, Dong-Yan; Yuen, Kwok-Yung; Zheng, Bo-Jian

    2016-01-01

    A safe, potent and broad-spectrum antiviral is urgently needed to combat emerging respiratory viruses. In light of the broad antiviral activity of β-defensins, we tested the antiviral activity of 11 peptides derived from mouse β-defensin-4 and found that a short peptide, P9, exhibited potent and broad-spectrum antiviral effects against multiple respiratory viruses in vitro and in vivo, including influenza A virus H1N1, H3N2, H5N1, H7N7, H7N9, SARS-CoV and MERS-CoV. The antiviral activity of P9 was attributed to its high-affinity binding to viral glycoproteins, as well as the abundance of basic amino acids in its composition. After binding viral particles through viral surface glycoproteins, P9 entered into cells together with the viruses via endocytosis and prevented endosomal acidification, which blocked membrane fusion and subsequent viral RNA release. This study has paved the avenue for developing new prophylactic and therapeutic agents with broad-spectrum antiviral activities. PMID:26911565

  16. Proenkephalin system in human polymorphonuclear cells. Production and release of a novel 1.0-kD peptide derived from synenkephalin.

    PubMed Central

    Vindrola, O; Padrós, M R; Sterin-Prync, A; Ase, A; Finkielman, S; Nahmod, V

    1990-01-01

    In the hematopoietic system a pluripotent stem cell generates precursors for lymphoid and myeloid lineages. Proenkephalin-derived peptides were previously detected in differentiated lymphoid cells. We have studied whether the proenkephalin system is expressed in a typical differentiated cell of the myeloid lineage, the neutrophil. Human peripheral polymorphonuclear cells contain and release proenkephalin-derived peptides. The opioid portion of proenkephalin (met-enkephalin-containing peptides) was incompletely processed, resulting in the absence of low molecular weight products. The nonopioid synenkephalin (proenkephalin 1-70) molecule was completely processed to a 1.0-kD peptide derived from the COOH-terminal. This molecule was characterized in neutrophils by biochemical and immunocytochemical methods. The chemotactic peptide FMLP and the calcium ionophore A23187 induced the release of the proenkephalin-derived peptides, and this effect was potentiated by cytochalasin B. The materials secreted were similar to those present in the cell, although in the supernatant a higher proportion corresponded to more processed products. The 1.0-kD peptide was detected in human, bovine, and rat neutrophils, but the chromatographic pattern of synenkephalin-derived peptides suggests a differential posttranslational processing among species. These findings demonstrate the existence of the proenkephalin system in human neutrophils and the production and release of a novel 1.0-kD peptide derived from the synenkephalin molecule. The presence of opioid peptides in neutrophils suggests their participation in the inflammatory process, including a local analgesic effect. Images PMID:2117023

  17. New steroid derivative with hypoglycemic activity

    PubMed Central

    Lauro, Figueroa-Valverde; Francisco, Díaz-Cedillo; Lenin, Hau-Heredia; Elodia, García-Cervera; Eduardo, Pool-Gómez; Marcela, Rosas-Nexticapa; Bety, Sarabia-Alcocer

    2014-01-01

    Data indicates that some steroid derivatives may induce changes on glucose levels; nevertheless, data are very confusing. Therefore, more pharmacological data are needed to characterize the activity induced by the steroid derivatives on glucose levels. The aim of this study was to synthesize a new steroid derivative for evaluate its hypoglycemic activity. The effects of steroid derivative on glucose concentration were evaluated in a diabetic animal model using glibenclamide and metformin as controls. In addition, the pregnenolone-dihydrotestosterone conjugate was bound to Tc-99m using radioimmunoassay methods, to evaluate the pharmacokinetics of the steroid derivative over time. The results showed that the pregnenolone-dihydrotestosterone conjugate induces changes on the glucose levels in similar form than glibenclamide. Other data showed that the biodistribution of Tc-99m-steroid derivativein brain was higher in comparison with spleen, stomach, intestine liver and kidney. In conclusion, the pregnenolone-dihydrotestosterone conjugate exerts hypoglycemic activity and this phenomenon could depend of its physicochemical properties which could be related to the degree of lipophilicity of the steroidderivative. PMID:25550906

  18. A salt-regulated peptide derived from the CAP superfamily protein negatively regulates salt-stress tolerance in Arabidopsis

    PubMed Central

    Chien, Pei-Shan; Nam, Hong Gil; Chen, Yet-Ran

    2015-01-01

    High salinity has negative impacts on plant growth through altered water uptake and ion-specific toxicities. Plants have therefore evolved an intricate regulatory network in which plant hormones play significant roles in modulating physiological responses to salinity. However, current understanding of the plant peptides involved in this regulatory network remains limited. Here, we identified a salt-regulated peptide in Arabidopsis. The peptide was 11 aa and was derived from the C terminus of a cysteine-rich secretory proteins, antigen 5, and pathogenesis-related 1 proteins (CAP) superfamily. This peptide was found by searching homologues in Arabidopsis using the precursor of a tomato CAP-derived peptide (CAPE) that was initially identified as an immune signal. In searching for a CAPE involved in salt responses, we screened CAPE precursor genes that showed salt-responsive expression and found that the PROAtCAPE1 (AT4G33730) gene was regulated by salinity. We confirmed the endogenous Arabidopsis CAP-derived peptide 1 (AtCAPE1) by mass spectrometry and found that a key amino acid residue in PROAtCAPE1 is critical for AtCAPE1 production. Moreover, although PROAtCAPE1 was expressed mainly in the roots, AtCAPE1 was discovered to be upregulated systemically upon salt treatment. The salt-induced AtCAPE1 negatively regulated salt tolerance by suppressing several salt-tolerance genes functioning in the production of osmolytes, detoxification, stomatal closure control, and cell membrane protection. This discovery demonstrates that AtCAPE1, a homologue of tomato immune regulator CAPE1, plays an important role in the regulation of salt stress responses. Our discovery thus suggests that the peptide may function in a trade-off between pathogen defence and salt tolerance. PMID:26093145

  19. Effects of biomineralization peptide topology on the structure and catalytic activity of Pd nanomaterials.

    PubMed

    Janairo, Jose Isagani B; Sakaguchi, Tatsuya; Hara, Kenji; Fukuoka, Atsushi; Sakaguchi, Kazuyasu

    2014-08-25

    Highly branched, coral-like Pd nanostructures were formed using a biomineralization peptide conjugated to an oligomeric peptide that simultaneously controls the spatial orientation, arrangement and valency. The Pd nanocoral showed very high catalytic activity in the reduction of nitrophenol. The results highlight the importance of topological arrangement in nanostructure formation and catalytic activity. PMID:24963622

  20. Protocols to test the activity of antimicrobial peptides against the honey bee pathogen Paenibacillus larvae.

    PubMed

    Khilnani, Jasmin C; Wing, Helen J

    2015-10-01

    Paenibacillus larvae is the causal agent of the honey bee disease American Foulbrood. Two enhanced protocols that allow the activity of antimicrobial peptides to be tested against P. larvae are presented. Proof of principle experiments demonstrate that the honey bee antimicrobial peptide defensin 1 is active in both assays. PMID:26210039

  1. Antidepressant activity of aspartic acid derivatives.

    PubMed

    Petrov, V I; Sergeev, V S; Onishchenko, N V; Piotrovskii, L B

    2001-04-01

    Antidepressant activity of N-phenyl(benzyl)amino derivatives of aspartic acid was studied on various experimental models of depression. IEM-1770 (30 mg/kg) and IEM-1944 (20 mg/kg) exhibited antidepressant activity after single injection in the forced swimming and tail suspension tests. Antidepressant effect of 14-day administration of these compounds and reference drugs maprotiline (10 mg/kg) and citalopram (10 mg/kg) was confirmed on the model of learned helplessness. PMID:11550022

  2. Mechanism of antibacterial action of a synthetic peptide with an Ala-peptoid residue based on the scorpion-derived antimicrobial peptide IsCT.

    PubMed

    Lim, Shin Saeng; Yoon, Sang-Pil; Park, Yoonkyoung; Zhu, Wan Long; Park, Il-Seon; Hahm, Kyung-Soo; Shin, Song Yub

    2006-09-01

    A novel bacterial cell-selective antimicrobial peptide, IsCT-P (ILKKIWKPIKKLF-NH(2)), was designed based on the scorpion-derived alpha-helical antimicrobial peptide, IsCT. Here, we investigated the effect of substituting Pro(8) of IsCT-P with the Ala-peptoid residue (N-methylglycine) on the peptide's structure and mechanism of action. Circular dichroism analysis revealed that the modified peptide, IsCT-a, has a much lower alpha-helicity than IsCT-P in membrane mimicking conditions, suggesting the peptoid residue provides much more structural flexibility than the proline residue. IsCT-a was also much less effective than IsCT-P at causing leakage of fluorescent dye entrapped within negatively charged vesicles and at dissipating the membrane potential of Staphylococcus aureus. Collectively, our results suggest that the antibacterial action of IsCT-a is due to the inhibition of intracellular targets rather than the disruption and depolarization of bacterial cell membranes. PMID:16871429

  3. Suppression of coronary atherosclerosis by helix B surface Peptide, a nonerythropoietic, tissue-protective compound derived from erythropoietin.

    PubMed

    Ueba, Hiroto; Shiomi, Masashi; Brines, Michael; Yamin, Michael; Kobayashi, Tsutomu; Ako, Junya; Momomura, Shin-Ichi; Cerami, Anthony; Kawakami, Masanobu

    2013-01-01

    Erythropoietin (EPO), a type I cytokine originally identified for its critical role in hematopoiesis, has been shown to have nonhematopoietic, tissue-protective effects, including suppression of atherosclerosis. However, prothrombotic effects of EPO hinder its potential clinical use in nonanemic patients. In the present study, we investigated the antiatherosclerotic effects of helix B surface peptide (HBSP), a nonerythropoietic, tissue-protective compound derived from EPO, by using human umbilical vein endothelial cells (HUVECs) and human monocytic THP-1 cells in vitro and Watanabe heritable hyperlipidemic spontaneous myocardial infarction (WHHLMI) rabbits in vivo. In HUVECs, HBSP inhibited apoptosis (≈70%) induced by C-reactive protein (CRP), a direct mediator of atherosclerosis. By using a small interfering RNA approach, Akt was shown to be a key molecule in HBSP-mediated prevention of apoptosis. HBSP also attenuated CRP-induced production of tumor necrosis factor (TNF)-α and matrix metalloproteinase-9 in THP-1 cells. In the WHHLMI rabbit, HBSP significantly suppressed progression of coronary atherosclerotic lesions as assessed by mean cross-sectional stenosis (HBSP 21.3 ± 2.2% versus control peptide 38.0 ± 2.7%) and inhibited coronary artery endothelial cell apoptosis with increased activation of Akt. Furthermore, TNF-α expression and the number of M1 macrophages and M1/M2 macrophage ratio in coronary atherosclerotic lesions were markedly reduced in HBSP-treated animals. In conclusion, these data demonstrate that HBSP suppresses coronary atherosclerosis, in part by inhibiting endothelial cell apoptosis through activation of Akt and in association with decreased TNF-α production and modified macrophage polarization in coronary atherosclerotic lesions. Because HBSP does not have the prothrombotic effects of EPO, our study may provide a novel therapeutic strategy that prevents progression of coronary artery disease. PMID:23648638

  4. Interaction of jack bean (Canavalia ensiformis) urease and a derived peptide with lipid vesicles.

    PubMed

    Micheletto, Yasmine Miguel Serafini; Moro, Carlo Frederico; Lopes, Fernanda Cortez; Ligabue-Braun, Rodrigo; Martinelli, Anne Helene Souza; Marques, Carlos Manuel; Schroder, André Pierre; Carlini, Célia Regina; da Silveira, Nádya Pesce

    2016-09-01

    Ureases are metalloenzymes that catalyze the hydrolysis of urea to ammonia and carbon dioxide. Jack bean (Canavalia ensiformis) produces three isoforms of urease (Canatoxin, JBU and JBURE-II). Canatoxin and JBU display several biological properties independent of their ureolytic activity, such as neurotoxicity, exocytosis-inducing and pro-inflammatory effects, blood platelets activation, insecticidal and antifungal activities. The Canatoxin entomotoxic activity is mostly due to an internal peptide, named pepcanatox, released upon the hydrolysis of the protein by insect cathepsin-like digestive enzymes. Based on pepcanatox sequence, Jaburetox-2Ec was produced in Escherichia coli. JBU and its peptides were shown to permeabilize membranes through an ion channel-based mechanism. Here we studied the JBU and Jaburetox-2Ec interaction with platelet-like multilamellar liposomes (PML) using Dynamic Light Scattering and Small Angle X-ray Scattering techniques. We also analyzed the interaction of JBU with giant unilamellar vesicles (GUVs) using Fluorescence Microscopy. The interaction of vesicles with JBU led to a slight reduction of hydrodynamic radius, and caused an increase in the lamellar repeat distance of PML, suggesting a membrane disordering effect. In contrast, Jaburetox-2Ec decreased the lamellar repeat distance of PML membranes, while also diminishing their hydrodynamic radius. Fluorescence microscopy showed that the interaction of GUVs with JBU caused membrane perturbation with formation of tethers. In conclusion, JBU can interact with PML, probably by inserting its Jaburetox "domain" into the PML external membrane. Additionally, the interaction of Jaburetox-2Ec affects the vesicle's internal bilayers and hence causes more drastic changes in the PML membrane organization in comparison with JBU. PMID:27281243

  5. The FGF-2-Derived Peptide FREG Inhibits Melanoma Growth In Vitro and In Vivo

    PubMed Central

    Aguzzi, Maria S; Faraone, Debora; D'Arcangelo, Daniela; De Marchis, Francesco; Toietta, Gabriele; Ribatti, Domenico; Parazzoli, Alberto; Colombo, Paolo; Capogrossi, Maurizio C; Facchiano, Antonio

    2011-01-01

    Previous data report that fibroblast growth factor-2 (FGF-2)-derived peptide FREG potently inhibits FGF-2-dependent angiogenesis in vitro and in vivo. Here, we show that FREG inhibits up to 70% in vitro growth and invasion/migration of smooth muscle and melanoma cells. Such inhibition is mediated by platelet-derived growth factor-receptor-α (PDGF-Rα); in fact, proliferation and migration were restored upon PDGF-Rα neutralization. Further experiments demonstrated that FREG interacts with PDGF-Rα both in vitro and in vivo and stimulates its phosphorylation. We have previously shown that overexpressing PDGF-Rα strongly inhibits melanoma growth in vivo; we, therefore, hypothesized that PDGF-Rα agonists may represent a novel tool to inhibit melanoma growth in vivo. To support this hypothesis, FREG was inoculated intravenously (i.v.) in a mouse melanoma model and markedly inhibited pulmonary metastases formation. Immunohistochemical analyses showed less proliferation, less angiogenesis, and more apoptosis in metastasized lungs upon FREG treatment, as compared to untreated controls. Finally, in preliminary acute toxicity studies, FREG showed no toxicity signs in healthy animals, and neither microscopic nor macroscopic toxicity at the liver, kidney, and lungs level. Altogether, these data indicate that FREG systemic treatment strongly inhibits melanoma metastases development and indicate for the first time that agonists of PDGF-Rα may control melanoma both in vitro and in vivo. PMID:20924364

  6. Selection of Phage Display Peptides Targeting Human Pluripotent Stem Cell-Derived Progenitor Cell Lines.

    PubMed

    Bignone, Paola A; Krupa, Rachel A; West, Michael D; Larocca, David

    2016-01-01

    The ability of human pluripotent stem cells (hPS) to both self-renew and differentiate into virtually any cell type makes them a promising source of cells for cell-based regenerative therapies. However, stem cell identity, purity, and scalability remain formidable challenges that need to be overcome for translation of pluripotent stem cell research into clinical applications. Directed differentiation from hPS cells is inefficient and residual contamination with pluripotent cells that have the potential to form tumors remains problematic. The derivation of scalable (self-renewing) embryonic progenitor stem cell lines offers a solution because they are well defined and clonally pure. Clonally pure progenitor stem cell lines also provide a means for identifying cell surface targeting reagents that are useful for identification, tracking, and repeated derivation of the corresponding progenitor stem cell types from additional hPS cell sources. Such stem cell targeting reagents can then be applied to the manufacture of genetically diverse banks of human embryonic progenitor cell lines for drug screening, disease modeling, and cell therapy. Here we present methods to identify human embryonic progenitor stem cell targeting peptides by selection of phage display libraries on clonal embryonic progenitor cell lines and demonstrate their use for targeting quantum dots (Qdots) for stem cell labeling. PMID:25410289

  7. The Synthetic Parasite-Derived Peptide GK1 Increases Survival in a Preclinical Mouse Melanoma Model

    PubMed Central

    Vera-Aguilera, Jesús; Hernaiz-Leonardo, Juan Carlos; Moreno-Aguilera, Eduardo; Monteverde-Suarez, Diego; Vera-Aguilera, Carlos; Estrada-Bárcenas, Daniel

    2013-01-01

    Abstract Purpose The therapeutic efficacy of a synthetic parasite-derived peptide GK1, an immune response booster, was evaluated in a mouse melanoma model. This melanoma model correlates with human stage IIb melanoma, which is treated with wide surgical excision; a parallel study employing a surgical treatment was carried out as an instructive goal. Experimental Design C57BL/6 mice were injected subcutaneously in the flank with 2×105 B16-F10 murine melanoma cells. When the tumors reached 20 mm3, mice were separated into two different groups; the GK1 group, treated weekly with peritumoral injections of GK1 (10 μg/100 μL of sterile saline solution) and the control group, treated weekly with an antiseptic peritumoral injection of 100 μL of sterile saline solution without further intervention. All mice were monitored daily for clinical appearance, tumor size, and survival. Surgical treatment was performed in parallel when the tumor size was 20 mm3 (group A), 500 mm3 (group B), and >500 mm3 (group C). Results The GK1 peptide effectively increased the mean survival time by 9.05 days, corresponding to an increase of 42.58%, and significantly delayed tumor growth from day 3 to 12 of treatment. In addition, tumor necrosis was significantly increased (p<0.05) in the treated mice. The overall survival rates obtained with surgical treatment at 6 months were 83.33% for group A, 40% for group B, and 0% for group C, with significant differences (p<0.05) among the groups. Conclusions The GK1 peptide demonstrated therapeutic properties in a mouse melanoma model, as treatment resulted in a significant increase in the mean survival time of the treated animals (42.58%). The potential for GK1 to be used as a primary or adjuvant component of chemotherapeutic cocktails for the treatment of experimental and human cancers remains to be determined, and surgical removal remains a challenge for any new experimental treatment of melanoma in mouse models. PMID:23841709

  8. Prodynorphin-derived peptides are critical modulators of anxiety and regulate neurochemistry and corticosterone.

    PubMed

    Wittmann, Walter; Schunk, Eduard; Rosskothen, Iris; Gaburro, Stefano; Singewald, Nicolas; Herzog, Herbert; Schwarzer, Christoph

    2009-02-01

    Stress and anxiety are mainly regulated by amygdala and hypothalamic circuitries involving several neurotransmitter systems and providing physiological responses to peripheral organs via the hypothalamic-pituitary-adrenal axis and other pathways. The role of endogenous opioid peptides in this process is largely unknown. Here we show for the first time that anxiolytic parameters of explorative behavior in mice lacking prodynorphin were increased 2-4-fold in the open field, the elevated plus maze and the light-dark test. Consistent with this, treatment of wild-type mice with selective kappa-opioid receptor antagonists GNTI or norbinaltorphimine showed the same effects. Furthermore, treatment of prodynorphin knockout animals with U-50488H, a selective kappa-opioid receptor agonist, fully reversed their anxiolytic phenotype. These behavioral data are supported by an approximal 30% reduction in corticotropin-releasing hormone (CRH) mRNA expression in the hypothalamic paraventricular nucleus and central amygdala and an accompanying 30-40% decrease in corticosterone serum levels in prodynorphin knockout mice. Although stress-induced increases in corticosterone levels were attenuated in prodynorphin knockout mice, they were associated with minor increases in depression-like behavior in the tail suspension and forced swim tests. Taken together, our data suggest a pronounced impact of endogenous prodynorphin-derived peptides on anxiety, but not stress coping ability and that these effects are mediated via kappa-opioid receptors. The delay in the behavioral response to kappa-opioid receptor agonists and antagonist treatment suggests an indirect control level for the action of dynorphin, probably by modulating the expression of CRH or neuropeptide Y, and subsequently influencing behavior. PMID:18800067

  9. A Novel Cell-Penetrating Peptide Derived from Human Eosinophil Cationic Protein

    PubMed Central

    Fang, Shun-lung; Fan, Tan-chi; Fu, Hua-Wen; Chen, Chien-Jung; Hwang, Chi-Shin; Hung, Ta-Jen; Lin, Lih-Yuan; Chang, Margaret Dah-Tsyr

    2013-01-01

    Cell-penetrating peptides (CPPs) are short peptides which can carry various types of molecules into cells; however, although most CPPs rapidly penetrate cells in vitro, their in vivo tissue-targeting specificities are low. Herein, we describe cell-binding, internalization, and targeting characteristics of a newly identified 10-residue CPP, denoted ECP32–41, derived from the core heparin-binding motif of human eosinophil cationic protein (ECP). Besides traditional emphasis on positively charged residues, the presence of cysteine and tryptophan residues was demonstrated to be essential for internalization. ECP32–41 entered Beas-2B and wild-type CHO-K1 cells, but not CHO cells lacking of cell-surface glycosaminoglycans (GAGs), indicating that binding of ECP32–41 to cell-surface GAGs was required for internalization. When cells were cultured with GAGs or pre-treated with GAG-digesting enzymes, significant decreases in ECP32–41 internalization were observed, suggesting that cell-surface GAGs, especially heparan sulfate proteoglycans were necessary for ECP32–41 attachment and penetration. Furthermore, treatment with pharmacological agents identified two forms of energy-dependent endocytosis, lipid-raft endocytosis and macropinocytosis, as the major ECP32–41 internalization routes. ECP32–41 was demonstrated to transport various cargoes including fluorescent chemical, fluorescent protein, and peptidomimetic drug into cultured Beas-2B cells in vitro, and targeted broncho-epithelial and intestinal villi tissues in vivo. Hence this CPP has the potential to serve as a novel vehicle for intracellular delivery of biomolecules or medicines, especially for the treatment of pulmonary or gastrointestinal diseases. PMID:23469189

  10. Peptide-Modulated Activity Enhancement of Acidic Protease Cathepsin E at Neutral pH

    PubMed Central

    Komatsu, Masayuki; Biyani, Madhu; Ghimire Gautam, Sunita; Nishigaki, Koichi

    2012-01-01

    Enzymes are regulated by their activation and inhibition. Enzyme activators can often be effective tools for scientific and medical purposes, although they are more difficult to obtain than inhibitors. Here, using the paired peptide method, we report on protease-cathepsin-E-activating peptides that are obtained at neutral pH. These selected peptides also underwent molecular evolution, after which their cathepsin E activation capability improved. Thus, the activators we obtained could enhance cathepsin-E-induced cancer cell apoptosis, which indicated their potential as cancer drug precursors. PMID:23365585

  11. Elastin-Derived Peptides Promote Abdominal Aortic Aneurysm Formation by Modulating M1/M2 Macrophage Polarization.

    PubMed

    Dale, Matthew A; Xiong, Wanfen; Carson, Jeffrey S; Suh, Melissa K; Karpisek, Andrew D; Meisinger, Trevor M; Casale, George P; Baxter, B Timothy

    2016-06-01

    Abdominal aortic aneurysm is a dynamic vascular disease characterized by inflammatory cell invasion and extracellular matrix degradation. Damage to elastin in the extracellular matrix results in release of elastin-derived peptides (EDPs), which are chemotactic for inflammatory cells such as monocytes. Their effect on macrophage polarization is less well known. Proinflammatory M1 macrophages initially are recruited to sites of injury, but, if their effects are prolonged, they can lead to chronic inflammation that prevents normal tissue repair. Conversely, anti-inflammatory M2 macrophages reduce inflammation and aid in wound healing. Thus, a proper M1/M2 ratio is vital for tissue homeostasis. Abdominal aortic aneurysm tissue reveals a high M1/M2 ratio in which proinflammatory cells and their associated markers dominate. In the current study, in vitro treatment of bone marrow-derived macrophages with EDPs induced M1 macrophage polarization. By using C57BL/6 mice, Ab-mediated neutralization of EDPs reduced aortic dilation, matrix metalloproteinase activity, and proinflammatory cytokine expression at early and late time points after aneurysm induction. Furthermore, direct manipulation of the M1/M2 balance altered aortic dilation. Injection of M2-polarized macrophages reduced aortic dilation after aneurysm induction. EDPs promoted a proinflammatory environment in aortic tissue by inducing M1 polarization, and neutralization of EDPs attenuated aortic dilation. The M1/M2 imbalance is vital to aneurysm formation. PMID:27183603

  12. Activity of Bisnaphthalimidopropyl Derivatives against Trypanosoma brucei.

    PubMed

    Graça, Nuno A G; Gaspar, Luis; Costa, David M; Loureiro, Inês; Thoo-Lin, Paul Kong; Ramos, Isbaal; Roura, Meritxell; Pruvost, Alain; Pemberton, Ian K; Loukil, Hadjer; MacDougall, Jane; Tavares, Joana; Cordeiro-da-Silva, Anabela

    2016-04-01

    Current treatments for African trypanosomiasis are either toxic, costly, difficult to administer, or prone to elicit resistance. This study evaluated the activity of bisnaphthalimidopropyl (BNIP) derivatives againstTrypanosoma brucei BNIPDiaminobutane (BNIPDabut), the most active of these compounds, showedin vitroinhibition in the single-unit nanomolar range, similar to the activity in the reference drug pentamidine, and presented low toxicity and adequate metabolic stability. Additionally, using a murine model of acute infection and live imaging, a significant decrease in parasite load in BNIPDabut-treated mice was observed. However, cure was not achieved. BNIPDabut constitutes a new scaffold for antitrypanosomal drugs that deserves further consideration. PMID:26787703

  13. Anti-inflammatory effect of a human prothrombin fragment-2-derived peptide, NSA9, in EOC2 microglia

    SciTech Connect

    Kim, Ji Yeon; Kim, Tae Hyong; Kim, Soung Soo

    2008-04-11

    Pro-inflammatory mediators, such as nitric oxide (NO), prostaglandin E{sub 2} (PGE{sub 2}), and several cytokines (tumor necrosis factor (TNF)-{alpha}, interleukin (IL)-1{beta}, and IL-6) are responsible for central nervous system (CNS) injuries that include ischemia, Alzheimer's disease, and neural death. Inhibition of these pro-inflammatory mediators would be an effective therapy to reduce the progression of neurodegenerative diseases. In this study, we examined the anti-inflammatory effects of a human prothrombin fragment-2-derived peptide, NSA9 (NSAVQLVEN), on the production of pro-inflammatory mediators in lipopolysaccharide (LPS)-activated brain microglia. NSA9 significantly inhibited the release of NO, PGE{sub 2}, and pro-inflammatory cytokines in a dose-dependent manner. Furthermore, NSA9 reduced the expression of inducible NO synthase (iNOS) and cyclooxygenase (COX)-2 mRNA and protein, which control the production of NO and PGE{sub 2}, respectively. Moreover, NSA9 suppressed the LPS-induced nuclear translocation and activation of nuclear factor-{kappa}B (NF-{kappa}B). These results suggest that NSA9 strongly inhibits the pro-inflammatory responses of microglia through the modulation of NF-{kappa}B activity.

  14. Antifungal effect and pore-forming action of lactoferricin B like peptide derived from centipede Scolopendra subspinipes mutilans.

    PubMed

    Choi, Hyemin; Hwang, Jae-Sam; Lee, Dong Gun

    2013-11-01

    The centipede Scolopendra subspinipes mutilans has been a medically important arthropod species by using it as a traditional medicine for the treatment of various diseases. In this study, we derived a novel lactoferricin B like peptide (LBLP) from the whole bodies of adult centipedes, S. s. mutilans, and investigated the antifungal effect of LBLP. LBLP exerted an antifungal and fungicidal activity without hemolysis. To investigate the antifungal mechanism of LBLP, a membrane study with propidium iodide was first conducted against Candida albicans. The result showed that LBLP caused fungal membrane permeabilization. The assays of the three dimensional flow cytometric contour plot and membrane potential further showed cell shrinkage and membrane depolarization by the membrane damage. Finally, we confirmed the membrane-active mechanism of LBLP by synthesizing model membranes, calcein and FITC-dextran loaded large unilamellar vesicles. These results showed that the antifungal effect of LBLP on membrane was due to the formation of pores with radii between 0.74nm and 1.4nm. In conclusion, this study suggests that LBLP exerts a potent antifungal activity by pore formation in the membrane, eventually leading to fungal cell death. PMID:23896552

  15. Pegylation of Antimicrobial Peptides Maintains the Active Peptide Conformation, Model Membrane Interactions, and Antimicrobial Activity while Improving Lung Tissue Biocompatibility following Airway Delivery

    PubMed Central

    Morris, Christopher J.; Beck, Konrad; Fox, Marc A.; Ulaeto, David; Clark, Graeme C.

    2012-01-01

    Antimicrobial peptides (AMPs) have therapeutic potential, particularly for localized infections such as those of the lung. Here we show that airway administration of a pegylated AMP minimizes lung tissue toxicity while nevertheless maintaining antimicrobial activity. CaLL, a potent synthetic AMP (KWKLFKKIFKRIVQRIKDFLR) comprising fragments of LL-37 and cecropin A peptides, was N-terminally pegylated (PEG-CaLL). PEG-CaLL derivatives retained significant antimicrobial activity (50% inhibitory concentrations [IC50s] 2- to 3-fold higher than those of CaLL) against bacterial lung pathogens even in the presence of lung lining fluid. Circular dichroism and fluorescence spectroscopy confirmed that conformational changes associated with the binding of CaLL to model microbial membranes were not disrupted by pegylation. Pegylation of CaLL reduced AMP-elicited cell toxicity as measured using in vitro lung epithelial primary cell cultures. Further, in a fully intact ex vivo isolated perfused rat lung (IPRL) model, airway-administered PEG-CaLL did not result in disruption of the pulmonary epithelial barrier, whereas CaLL caused an immediate loss of membrane integrity leading to pulmonary edema. All AMPs (CaLL, PEG-CaLL, LL-37, cecropin A) delivered to the lung by airway administration showed limited (<3%) pulmonary absorption in the IPRL with extensive AMP accumulation in lung tissue itself, a characteristic anticipated to be beneficial for the treatment of pulmonary infections. We conclude that pegylation may present a means of improving the lung biocompatibility of AMPs designed for the treatment of pulmonary infections. PMID:22430978

  16. Recombinant vascular basement-membrane-derived multifunctional peptide inhibits angiogenesis and growth of hepatocellular carcinoma

    PubMed Central

    Wu, You-Hua; Cao, Jian-Guo; Xiang, Hong-Lin; Xia, Hong; Qin, Yong; Huang, A-Ji; Xiao, Di; Xu, Fang

    2009-01-01

    AIM: To investigate the anti-angiogenic and anti-tumor activities of recombinant vascular basement membrane-derived multifunctional peptide (rVBMDMP) in hepatocellular carcinoma (HCC). METHODS: HepG2, Bel-7402, Hep-3B, HUVE-12 and L-02 cell lines were cultured in vitro and the inhibitory effect of rVBMDMP on proliferation of cells was detected by MTT assay. The in vivo antitumor efficacy of rVBMDMP on HCC was assessed by HepG2 xenografts in nude mice. Distribution of rVBMDMP, mechanism by which the growth of HepG2 xenografts is inhibited, and microvessel area were observed by proliferating cell nuclear antigen (PCNA) and CD31 immunohistochemistry. RESULTS: MTT assay showed that rVBMDMP markedly inhibited the proliferation of human HCC (HepG2, Bel-7402, Hep-3B) cells and human umbilical vein endothelial (HUVE-12) cells in a dose-dependent manner, with little effect on the growth of L-02 cells. When the IC50 was 4.68, 7.65, 8.96, 11.65 and 64.82 μmol/L, respectively, the potency of rVBMDMP to HepG2 cells was similar to 5-fluorouracil (5-FU) with an IC50 of 4.59 μmol/L. The selective index of cytotoxicity to HepG2 cells of rVBMDMP was 13.8 (64.82/4.68), which was higher than that of 5-FU [SI was 1.9 (8.94/4.59)]. The VEGF-targeted recombinant humanized monoclonal antibody bevacizumab (100 mg/L) did not affect the proliferation of HepG2, Bel-7402, Hep-3B and L-02 cells, but the growth inhibitory rate of bevacizumab (100 mg/L) to HUVE-12 cells was 87.6% ± 8.2%. Alternis diebus intraperitoneal injection of rVBMDMP suppressed the growth of HepG2 xenografts in a dose-dependent manner. rVBMDMP (1, 3, 10 mg/kg) decreased the tumor weight by 12.6%, 55.9% and 79.7%, respectively, compared with the vehicle control. Immunohistochemical staining of rVBMDMP showed that the positive area rates (2.2% ± 0.73%, 4.5% ± 1.3% and 11.5% ± 3.8%) in rVBMDMP treated group (1, 3, 10 mg/kg) were significantly higher than that (0.13% ± 0.04%) in the control group (P < 0.01). The positive

  17. Isolation and identification of renal cell carcinoma-derived peptides associated with GP96.

    PubMed

    Li, H-Z; Li, C-W; Li, C-Y; Zhang, B-F; Li, L-T; Li, J-M; Zheng, J-N; Chang, J-W

    2013-08-01

    We determined the possible associated determinants and analyzed whether gp96-_associated antigenic peptides can be found in renal cell carcinoma (RCC). The gp96-peptide complexes were chromatographically purified from resected tumor tissue of RCC patients. SDS-PAGE and Western blot analysis confirmed gp96 using the gp96 monoclonal antibody, and its concentration was measured using BCA. Approximately 20 to 50 μg gp96-peptide complexes was obtained from 1 g RCC tissue. The mass spectrometry (MS) analysis of the eluted peptides included the initial profiling using matrix-assisted laser desorption/ionization time-of-flight MS. Quadrupole time-of-flight MS combined with the Mascot search engine was used to identify the peptides and find proteins from primary sequence databases. MS analysis results demonstrated that the mass range of peptide associated with gp96 was from 1046.48 to 3501.56 Da. Further research confirmed the sequences of two gp96-associated peptides, namely, LVPLEGWGGNVM and PPVYYVPYVVL. However, the original protein of the two peptides could not be found. The results demonstrated that the gp96-associated peptides are small molecular peptides, and the two peptides are deduced to be RCC-associated peptides. The identified peptides were confirmed to be associated with gp96 using the protocols described above. However, the specificity and relevance of the association to the immunogenicity of gp96 remains to be examined. Further analysis must be accomplished before the findings can be applied in peptide vaccine. PMID:23448575

  18. Induction and antimicrobial activity of platelet basic protein derivatives in human monocytes.

    PubMed

    Schaffner, Andreas; King, Charles C; Schaer, Dominik; Guiney, Donald G

    2004-11-01

    The antimicrobial activity of a number of chemokines has recently come into focus of research about innate immunity. We have previously shown that platelet basic protein (PBP), which gives rise to several antimicrobial peptides of platelets, is also expressed in human monocytes. In the present studies, we show that exposure of human monocytes to bacteria or microbial components (lipopolysaccharide and zymosan) induces a several-fold greater expression of derivates of PBP. Also, activation of proteinase-activated receptors (PARs) by thrombin or the synthetic peptide ligand SFLLRN of PAR-1 significantly increased PBP expression, presumably on the transcriptional level, as evidenced by higher mRNA levels. Derivates of PBP appeared to reach phago-lysosomes, as higher concentration was found in latex phagosomes isolated by a flotation method. By the gel-overlay technique, two bactericidal derivatives of PBP could be visualized, which were immunoreactive with anti-PBP antibody in Western blots. By matrix-assisted laser desorption/ionization time of flight and surface-enhanced laser desorption and ionization techniques, it was confirmed that the bands corresponded to PBP derivates. After immunofixation with a monoclonal antibody to PBP, the major peptide in zymosan-stimulated monocytes was identified to correspond by molecular weight to connective tissue-activating peptide III, which has been reported to be a major antimicrobial PBP derivate also in platelets. Our observations indicate that PBP and its derivates are constituents of the antimicrobial arsenal of human monocytes. Their increased expression after exposure to microorganisms allows a rapid host response to pathogens. PMID:15316029

  19. Amyloidogenic amyloid-β-peptide variants induce microbial agglutination and exert antimicrobial activity.

    PubMed

    Spitzer, Philipp; Condic, Mateja; Herrmann, Martin; Oberstein, Timo Jan; Scharin-Mehlmann, Marina; Gilbert, Daniel F; Friedrich, Oliver; Grömer, Teja; Kornhuber, Johannes; Lang, Roland; Maler, Juan Manuel

    2016-01-01

    Amyloid-β (Aβ) peptides are the main components of the plaques found in the brains of patients with Alzheimer's disease. However, Aβ peptides are also detectable in secretory compartments and peripheral blood contains a complex mixture of more than 40 different modified and/or N- and C-terminally truncated Aβ peptides. Recently, anti-infective properties of Aβ peptides have been reported. Here, we investigated the interaction of Aβ peptides of different lengths with various bacterial strains and the yeast Candida albicans. The amyloidogenic peptides Aβ1-42, Aβ2-42, and Aβ3p-42 but not the non-amyloidogenic peptides Aβ1-40 and Aβ2-40 bound to microbial surfaces. As observed by immunocytochemistry, scanning electron microscopy and Gram staining, treatment of several bacterial strains and Candida albicans with Aβ peptide variants ending at position 42 (Aβx-42) caused the formation of large agglutinates. These aggregates were not detected after incubation with Aβx-40. Furthermore, Aβx-42 exerted an antimicrobial activity on all tested pathogens, killing up to 80% of microorganisms within 6 h. Aβ1-40 only had a moderate antimicrobial activity against C. albicans. Agglutination of Aβ1-42 was accelerated in the presence of microorganisms. These data demonstrate that the amyloidogenic Aβx-42 variants have antimicrobial activity and may therefore act as antimicrobial peptides in the immune system. PMID:27624303

  20. Developments in the synthesis and biological activity of glycyl-L-histydyl- L-lysine derivatives.

    PubMed

    Kukowska, M; Dzierzbicka, K

    2014-01-01

    Three decades of extensive research on biological activity of natural tripeptide Gly-His-Lys has established the substructure for development of its novel derivatives which give hope for widening the application in the field of medicine and dermatology. Synthetic approaches to obtain Gly-His-Lys and its modifications provide both classical solution method and solid phase peptide synthesis, usage of different protecting groups and methods of peptide bond formation. In our present review, we emphasize on the methods of the synthesis described in the literature and present the aspects of Gly-His-Lys structure modifications that played a key role in scientific research. PMID:24350846