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Peptide Library (peptide + library)
Kinds of Peptide Library Selected AbstractsBroad T cell immunity to the LcrV virulence protein is induced by targeted delivery to DEC-205/CD205-positive mouse dendritic cellsEUROPEAN JOURNAL OF IMMUNOLOGY, Issue 1 2008Yoonkyung Do Abstract There is a need for a more efficient vaccine against the bacterium Yersinia pestis, the agent of pneumonic plague. The F1-LcrV (F1-V) subunit vaccine in alhydrogel is known to induce humoral immunity. In this study, we utilized DC to investigate cellular immunity. We genetically engineered the LcrV virulence protein into the anti-DEC-205/CD205 mAb and thereby targeted the conjugated protein directly to mouse DEC-205+ DC in situ. We observed antigen-specific CD4+ T cell immunity measured by intracellular staining for IFN-, in three different mouse strains (C57BL/6, BALB/c, and C3H/HeJ), while we could not observe such T cell responses with F1-V vaccine in alhydrogel. Using a peptide library for LcrV protein, we identified two or more distinct CD4+ T cell mimetopes in each MHC haplotype, consistent with the induction of broad immunity. When compared to nontargeted standard protein vaccine, DC targeting greatly increased the efficiency for inducing IFN-,-producing T cells. The targeted LcrV protein induced antibody responses to a similar extent as the F1-V subunit vaccine, but Th1-dependent IgG2a and IgG2c isotypes were observed only after anti-DEC-205:LcrV mAb immunization. This study sets the stage for the analysis of functional roles of IFN-,-producing T cells in Y.,pestis infection. [source] Decreased specific CD8+ T,cell cross-reactivity of antigen recognition following vaccination with Melan-A peptideEUROPEAN JOURNAL OF IMMUNOLOGY, Issue 7 2006Victor Appay Abstract The aim of T,cell vaccines is the expansion of antigen-specific T,cells able to confer immune protection against pathogens or tumors. Although increase in absolute cell numbers, effector functions and TCR repertoire of vaccine-induced T,cells are often evaluated, their reactivity for the cognate antigen versus their cross-reactive potential is rarely considered. In fact, little information is available regarding the influence of vaccines on T,cell fine specificity of antigen recognition despite the impact that this feature may have in protective immunity. To shed light on the cross-reactive potential of vaccine-induced cells, we analyzed the reactivity of CD8+ T,cells following vaccination of HLA-A2+ melanoma patients with Melan-A peptide, incomplete Freund's adjuvant and CpG-oligodeoxynucleotide adjuvant, which was shown to induce strong expansion of Melan-A-reactive CD8+ T,cells in vivo. A collection of predicted Melan-A cross-reactive peptides, identified from a combinatorial peptide library, was used to probe functional antigen recognition of PBMC ex vivo and Melan-A-reactive CD8+ T,cell clones. While Melan-A-reactive CD8+ T,cells prior to vaccination are usually constituted of widely cross-reactive naive cells, we show that peptide vaccination resulted in expansion of memory T,cells displaying a reactivity predominantly restricted to the antigen of interest. Importantly, these cells are tumor-reactive. [source] Characterization of a novel NCAM ligand with a stimulatory effect on neurite outgrowth identified by screening a combinatorial peptide libraryEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 9 2002Lars C. B. Rųnn Abstract The neural cell adhesion molecule, NCAM, plays a key role in neural development and plasticity mediating cell adhesion and signal transduction. By screening a combinatorial library of synthetic peptides with NCAM purified from postnatal day 10 rat brains, we identified a nonapeptide, termed NCAM binding peptide 10 (NBP10) and showed by nuclear magnetic resonance analysis that it bound the NCAM IgI module of NCAM. NBP10 modulated cell aggregation as well as neurite outgrowth induced specifically by homophilic NCAM binding. Moreover, both monomeric and multimeric forms of NBP10 stimulated neurite outgrowth from primary hippocampal neurons. The neurite outgrowth response to NBP10 was inhibited by a number of compounds previously shown to inhibit neurite outgrowth induced by homophilic NCAM binding, including voltage-dependent calcium channel antagonists, suggesting that NBP10 induced neurite outgrowth by activating a signal transduction pathway similar to that activated by NCAM itself. Moreover, an inhibitor of intracellular calcium mobilization, TMB-8, prevented NBP10-induced neurite outgrowth suggesting that NCAM-dependent neurite outgrowth also requires mobilization of calcium from intracellular calcium stores in addition to calcium influx from extracellular sources. By single-cell calcium imaging we further demonstrated that NBP10 was capable of inducing an increase in intracellular calcium in PC12E2 cells. Thus, the NBP10 peptide is a new tool for the study of molecular mechanisms underlying NCAM-dependent signal transduction and neurite outgrowth, and could prove to be a useful modulator of regenerative processes in the peripheral and central nervous system. [source] Identification of calreticulin as a ligand of GABARAP by phage display screening of a peptide libraryFEBS JOURNAL, Issue 21 2007Jeannine Mohrlüder 4-Aminobutyrate type A (GABAA) receptor-associated protein (GABARAP) is a ubiquitin-like modifier implicated in the intracellular trafficking of GABAA receptors, and belongs to a family of proteins involved in intracellular vesicular transport processes, such as autophagy and intra-Golgi transport. In this article, it is demonstrated that calreticulin is a high affinity ligand of GABARAP. Calreticulin, although best known for its functions as a Ca2+ -dependent chaperone and a Ca2+ -buffering protein in the endoplasmic reticulum, is also localized to the cytosol and exerts a variety of extra-endoplasmic reticulum functions. By phage display screening of a randomized peptide library, peptides that specifically bind GABARAP were identified. Their amino acid sequences allowed us to identify calreticulin as a potential GABARAP binding protein. GABARAP binding to calreticulin was confirmed by pull-down experiments with brain lysate and colocalization studies in N2a cells. Calreticulin and GABARAP interact with a dissociation constant Kd = 64 nm and a mean lifetime of the complex of 20 min. Thus, the interaction between GABARAP and calreticulin is the strongest so far reported for each protein. [source] Modeling an active conformation for linear peptides and design of a competitive inhibitor for HMG-CoA reductaseJOURNAL OF MOLECULAR RECOGNITION, Issue 4 2008Valeriy V. Pak Abstract This study presents an approach that can be used to search for lead peptide candidates, including unconstrained structures in a recognized sequence. This approach was performed using the design of a competitive inhibitor for 3-hydroxy-3-methylglutaryl CoA reductase (HMGR). In a previous design for constrained peptides, a head-to-tail cyclic structure of peptide was used as a model of linear analog in searches for lead peptides with a structure close to an active conformation. Analysis of the conformational space occupied by the peptides suggests that an analogical approach can be applied for finding a lead peptide with an unconstrained structure in a recognized sequence via modeling a cycle using fixed residues of the peptide backbone. Using the space obtained by an analysis of the bioactive conformations of statins, eight cyclic peptides were selected for a peptide library based on the YVAE sequence as a recognized motif. For each cycle, the four models were assessed according to the design criterion ("V" parameter) applied for constrained peptides. Three cyclic peptides (FGYVAE, FPYVAE, and FFYVAE) were selected as lead cycles from the library. The linear FGYVAE peptide (IC50,=,0.4,µM) showed a 1200-fold increase the inhibitory activity compared to the first isolated LPYP peptide (IC50,=,484,µM) from soybean. Experimental analysis of the modeled peptide structures confirms the appropriateness of the proposed approach for the modeling of active conformations of peptides. Copyright © 2008 John Wiley & Sons, Ltd. [source] Analysis of the CD2 and spliceosomal Sm B/B, polyproline-arginine motifs defined by a monoclonal antibody using a phage-displayed random peptide libraryJOURNAL OF MOLECULAR RECOGNITION, Issue 6 2006Dimitri Monos Abstract The cytoplasmic region of the CD2 receptor of lymphocytes contains proline-rich motifs, which are involved in T cell activation and interleukin-2 production. An intracellular CD2 binding protein, CD2BP2, interacts with two tandem PPPPGHR segments of the CD2 tail. CD2BP2 contains a GYF (glycine-tyrosine-phenylalanine) domain that confers binding to these proline-rich sequences. Monoclonal antibody 3E10 that was previously raised against a peptide containing the CD2 PPPPGHR segment reacts with the native CD2 molecule and spliceosomal Sm B/B, proteins. To identify the exact epitope on the CD2 peptide recognized by 3E10, a phage-displayed combinatorial peptide library was used. Analysis of the selected clones revealed that the mAb 3E10 binds preferentially to the motif PxxPPGxR. Experiments using amino acid substitutions with synthetic peptides confirmed the reactivity of mAb 3E10 with this motif. In addition, we show that several similarities exist between this motif and the CD2BP2-GFY recognition motif PPGxR/K. Binding of antibody 3E10 indicates some degree of degeneracy, which is consistent with its ability to recognize structurally related polyproline,arginine motifs found in intracellular proteins including Sm B/B, proteins and other RNA binding proteins. Thus, mAb 3E10 can be used to specifically identify a sub-class of proline-rich motifs, and as such can be used to study the potential role of these proline-rich sequences in mediating protein-protein interactions. Copyright © 2006 John Wiley & Sons, Ltd. [source] Cyclic peptides selected by phage display mimic the natural epitope recognized by a monoclonal anti-colicin A antibodyJOURNAL OF PEPTIDE SCIENCE, Issue 11 2004Stephane Coulon Abstract A 10-mer random peptide library displayed on filamentous bacteriophage was used to determine the molecular basis of the interaction between the monoclonal anti-colicin A antibody 1C11 and its cognate epitope. Previous studies established that the putative epitope recognized by 1C11 antibody is composed of amino acid residues 19,25 (RGSGPEP) of colicin A. Using the phage display technique it was confirmed that the epitope of 1C11 antibody was indeed restricted to residues 19,25 and the consensus motif RXXXPEP was identified. Shorter consensus sequences (RXXPEP, RXXEP, KXXEP) were also selected. It was also demonstrated that the disulfide bond found in one group of the selected peptides was crucial for 1C11 antibody recognition. It was shown that cyclization of the peptides by disulfide bond formation could result in a structure that mimics the natural epitope of colicin A. Copyright © 2004 European Peptide Society and John Wiley & Sons, Ltd. [source] Structural requirements of nociceptin antagonist Ac-RYYRIK-NH2 for receptor bindingJOURNAL OF PEPTIDE SCIENCE, Issue 10 2002Michiaki Kawano Abstract Ac-RYYRIK-NH2 is a peptide isolated from the peptide library as an antagonist that inhibits the biological activities of nociceptin, a hyperalgesic neuropeptide. In order to clarify the structural requirements of this peptide for binding to the nociceptin receptor ORL1, systematic structure,activity studies were carried out. The result of Ala-scanning indicated that the N -terminal tripeptide RYY(=Arg-Tyr-Tyr) is crucially important for binding to the ORL1 receptor. Residual truncations from the N - or C -terminus revealed the special importance of the N -terminal Arg residue. The removal of protecting groups indicated that the N -terminal acetyl group is essential, but the C -terminal amide group is insignificant. These results indicated the conspicuous importance of acetyl-Arg at position 1 of Ac-RYYRIK-NH2 as a key structure allowing binding to the receptor. To investigate the binding site of this peptide in the ORL1 receptor, we synthesized and assayed a series of analogues of the nociceptin dibasic repeat region, residues 8,13 of RKSARK. None of the derivatives were active. Ac-RYYRIK-NH2 was inactive for the µ opioid receptor to which nociceptin binds with considerable strength. All the results suggested that the mode of binding between Ac-RYYRIK-NH2 and the ORL1 receptor is different to that between the ORL1 receptor and nociceptin, and that it may consist of interaction with the receptor site to which nociceptin(1,7) or -(14,17) binds. Copyright © 2002 European Peptide Society and John Wiley & Sons, Ltd. [source] Phage display identifies novel peptides that bind extracellular-regulated protein kinase 2 to compete with transcription factor binding,JOURNAL OF PHYSICAL ORGANIC CHEMISTRY, Issue 6-7 2004Mark A. Rainey Abstract Extracellular-regulated protein kinase 2 (ERK2) is a serine/threonine-specific protein kinase capable of phosphorylating multiple protein substrates within a cell. In an attempt to identify novel peptides that bind and inhibit the function of an active form of ERK2, phage display was carried out using a disulfide-constrained peptide library (X2CX14CX2). Several phage clones were identified by an enzyme-linked immunosorbent assay (ELISA) that competed with both a protein substrate and adenosine triphosphate (ATP) for immobilized ERK2. A chemically synthesized peptide derived from these experiments, NH2 -KKKIRCIRGWTKDIRTLADSCQY-COOH, inhibited ERK2 phosphorylation of the protein substrate Ets,138, exhibiting competitive and mixed inhibition towards Ets,138 and MgATP2,, respectively. Surprisingly, the same peptide displayed equally potent inhibition towards the phosphorylation of ATF2 by p38 MAPK,, another MAP kinase that has ,46% sequence similarity to ERK2. This study indicates that active ERK2 can be targeted by phage display to find novel antagonists to kinase function and suggests that protein-binding sites within the MAPK family may contain conserved features that render them susceptible to ligand binding. Copyright © 2004 John Wiley & Sons, Ltd. [source] Toward the development of new medicinal leads with selectivity for protein kinase C isozymesTHE CHEMICAL RECORD, Issue 4 2005Kazuhiro Irie Abstract Tumor promoters such as phorbol esters bind strongly to protein kinase C (PKC) isozymes to induce their activation. Since each PKC isozyme is involved in diverse biological events in addition to tumor promotion, the isozymes serve as promising therapeutic targets. Tumor promoters bind to the C1A and/or C1B domain of conventional (,, ,I, ,II, and ,) and novel PKC isozymes (,, ,, ,, and ,). As these C1 domains play differential roles in PKC activation and their translocation in cells, the development of agents with binding selectivity for individual C1 domains is a pressing need. For this purpose, we established a synthetic C1 peptide library of all PKC isozymes. The library enabled us to identify indolactam-V (1) as a promising lead compound. Our diverse structure,activity studies on 1 indicated that the position of the hydrophobic substituent on the indole ring dominates the PKC isozyme- and C1 domain-selective binding rather than conformation of the nine-membered lactam. Moreover, we suggested that the indole ring of 1 could be involved in the CH/, interaction with Pro-11 of the C1B domain of PKC,. This invaluable information will lead to the structural optimization of the PKC, ligand as exemplified by the design and synthesis of naphtholactam-V8 (21). © 2005 The Japan Chemical Journal Forum and Wiley Periodicals, Inc. Chem Rec 5: 185,195; 2005: Published online in Wiley InterScience (www.interscience.wiley.com) DOI 10.1002/tcr.20044 [source] Pharmacokinetics, biodistribution, and antitumor efficacy of a human glandular kallikrein 2 (hK2)-activated thapsigargin prodrugTHE PROSTATE, Issue 4 2006Samuel Janssen Abstract BACKGROUND Prostate cancer cells secrete unique proteases such as prostate-specific antigen (PSA) and human glandular kallikrein 2 (hK2) that represent targets for the activation of prodrugs as systemic treatment of metastatic prostate cancer. Previously, a combinatorial peptide library was screened to identify a highly active peptide substrate for hK2. The peptide was coupled to an analog of the potent cytotoxin thapsigargin, L12ADT, to generate an hK2-activated prodrug that was efficiently hydrolyzed by purified hK2, stable to hydrolysis in human and mouse plasma in vitro and selectively toxic to hK2 producing prostate cancer cells in vitro. METHODS In the current study, toxicology, pharmacokinetics, prodrug biodistribution, and antitumor efficacy studies were performed to evaluate the hK2-activated prodrug in vivo. RESULTS The single intravenous maximally tolerated dose of prodrug was 6 mg/kg (i.e., 3.67 µmole/kg) which produced peak serum concentration of ,36 µM and had a half-life of ,40 min. In addition, over a 24 hr period <0.5% of free L12ADT analog was observed in plasma. The prodrug demonstrated significant antitumor effect in vivo while it was being administered, but prolonged intravenous administration was not possible due to local toxicity to tail veins. Subcutaneous administration of equimolar doses produced lower plasma AUC compared to intravenous dosing but equivalent intratumoral levels of prodrug following multiple doses. CONCLUSIONS The hK2-activated prodrug was stable in vivo. The prodrug, however, was rapidly cleared and difficult to administer over prolonged dosing interval. Additional studies are underway to assess antitumor efficacy with prolonged administration of higher subcutaneous doses of prodrug. Second-generation hK2-activated thapsigargin prodrugs with increased half-lives and improved formulations are also under development. © 2005 Wiley-Liss, Inc. [source] Stimulation of the HIV-1 integrase enzymatic activity and cDNA integration by a peptide derived from the integrase proteinBIOPOLYMERS, Issue 8 2010Aviad Levin Abstract Here we describe the features of a peptide that was selected from the human immunodeficiency virus Type 1 (HIV-1) Integrase (IN) peptide library which interacts with both, the viral Rev and IN proteins. Because of its ability to stimulate the IN enzymatic activity this peptide was designated INS (IN stimulatory). Modification of its amino acid sequence revealed that replacement of its C-terminal lysine by glutamic acid (INS K188E) converts it from a stimulatory peptide to an inhibitory one. Both peptides promoted the dissociation of a previously described complex formed between Rev and IN whose formation results in IN inactivation. INS and INS K188E penetrated HIV-1-infected cells and caused stimulation and inhibition of viral genome integration, respectively. Using cultured cells infected with a ,Rev HIV revealed that INS can directly activate the viral IN. These results suggest that the stimulatory effect of INS in wild-type virus-infected cells is due to a dual effect: it dissociates the inactive Rev-IN complex and directly activates the free IN. © 2010 Wiley Periodicals, Inc. Biopolymers 93: 740,751, 2010. This article was originally published online as an accepted preprint. The "Published Online" date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com [source] Identification of a ligand for IgG-Fc derived from a soluble peptide library based on fusion proteins secreted by S. cerevisiaeBIOTECHNOLOGY JOURNAL, Issue 6 2007Christa Mersich Abstract Biological libraries are important tools in the development of new peptide-based compounds. Here, we describe the use of a soluble peptide library system as a complementary tool in the field of ligand development. Random peptides were expressed in S. cerevisiae as carboxy-terminal extensions of the eukaryotic initiation factor 5a (eIF5a) and secreted into the culture supernatant. Expression and screening of this library were performed in a microwell format. As an example of this versatile approach, we describe the identification of a ligand for the human IgG-Fc fragment. Ligands binding IgG-Fc show great potential in a wide variety of applications including development of therapeutics, streamlining the large-scale purification of antibodies, and applications in diagnostic tests. We demonstrated the utility of this system. After screening only 6160 clones, we identified a ligand with the peptide sequence of TRRRTCSPPTWPRARARSTPSGCSSTGPSANRG. An affinity constant of 3.9 x 105 M -1 was determined by a biosensor method. Handling and maintenance of this library is conceptually simple and highly applicable for automated high-throughput systems. [source] Eyes Absent Proteins: Characterization of Substrate Specificity and Phosphatase Activity of Mutants Associated with Branchial, Otic and Renal AnomaliesCHEMBIOCHEM, Issue 14 2008Amna Musharraf Abstract The eyes absent (Eya) genes encode a family of proteins that combine the functions of transcriptional cofactors, signal transducers and enzymes, namely protein tyrosine phosphatases. The latter activity resides in the highly conserved C-terminal Eya domain (ED). Here, we investigated the substrate specificity of the Arabidopsis thaliana homologue (AtEya) by using low-molecular-weight compounds and synthetic phosphotyrosine (pY)-containing peptides that correspond either to phosphorylation sites in proteins or to peptides that were selected through the screening of a combinatorial peptide library. AtEya displayed modest peptide substrate specificity and was sensitive to charges adjacent to pY. In general, the presence of acidic residues on the N-terminal side of the phosphorylation site was critical for catalysis, whereas basic amino acids seemed to be preferred with respect to high-affinity binding. We also detected significant acyl phosphatase activity of AtEya; this suggests that Eya proteins might have further substrates in vivo. In addition, we analysed the phosphatase activity of a number of variants of the mouse Eya1 protein that harbours single point mutations that were associated with branchio,oto,renal syndrome (BOR), branchio,oto syndrome (BO) and ocular defects, respectively, in humans. While BOR mutations led to a significantly reduced phosphatase activity, BO mutants as well as those that are associated with ocular defects only displayed activity that was similar to wild-type levels. [source] Selection of D -Amino-Acid Peptides That Bind to Alzheimer's Disease Amyloid Peptide A,1,42 by Mirror Image Phage DisplayCHEMBIOCHEM, Issue 8 2003Katja Wiesehan Dr. Abstract A mirror image phage display approach was used to identify novel and highly specific ligands for Alzheimer's disease amyloid peptide A,(1,42). A randomized 12-mer peptide library presented on M13 phages was screened for peptides with binding affinity for the mirror image of A,(1,42). After four rounds of selection and amplification the peptides were enriched with a dominating consensus sequence. The mirror image of the most representative peptide (D -pep) was shown to bind A,(1,42) with a dissociation constant in the submicromolar range. Furthermore, in brain tissue sections derived from patients that suffered from Alzheimer's disease, amyloid plaques and leptomeningeal vessels containing A, amyloid were stained specifically with a fluorescence-labeled derivative of D -pep. Fibrillar deposits derived from other amyloidosis were not labeled by D -pep. Possible applications of this novel and highly specific A, ligand in diagnosis and therapy of Alzheimer's disease are discussed. [source] Cover Picture: ChemBioChem 1/2003CHEMBIOCHEM, Issue 1 2003Sachdev S. Sidhu Dr. The cover picture shows a highly diverse peptide library displayed on cylindrical bacteriophage particles that also contain the cognate DNA. Libraries such as this can be used to identify specific ligands for essentially any protein of interest. Here, phage particles displaying peptides that bind vascular endothelial growth factor are selected from amongst a sea of billions of random sequences. Further information can be found in the Review by Sidhu and co-workers on p. 14 ff. (We thank David Wood and Christian Wiesmann for help in the preparation of the cover picture.) [source] Novel Peptide Ligands of RGS4 from a Focused One-Bead, One-Compound LibraryCHEMICAL BIOLOGY & DRUG DESIGN, Issue 2 2008Rebecca A. Roof Regulators of G protein signaling accelerate GTP hydrolysis by G, subunits and profoundly inhibit signaling by G protein-coupled receptors. The distinct expression patterns and pathophysiologic regulation of regulators of G protein signaling proteins suggest that inhibitors may have therapeutic potential. We previously reported the design, mechanistic evaluation, and structure,activity relationships of a disulfide-containing cyclic peptide inhibitor of RGS4, YJ34 (Ac -Val-Lys-c[Cys-Thr-Gly-Ile-Cys]-Glu- NH2, S-S) (Roof et al., Chem Biol Drug Des, 67, 2006, 266). Using a focused one-bead, one-compound peptide library that contains features known to be necessary for the activity of YJ34, we now identify peptides that bind to RGS4. Six peptides showed confirmed binding to RGS4 by flow cytometry. Two analogs of peptide 2 (Gly-Thr-c[Cys-Phe-Gly-Thr-Cys]-Trp- NH2, S-S with a free or acetylated N -terminus) inhibited RGS4-stimulated G,o GTPase activity at 25,50 ,m. They selectively inhibit RGS4 but not RGS7, RGS16, and RGS19. Their inhibition of RGS4 does not depend on cysteine-modification of RGS4, as they do not lose activity when all cysteines are removed from RGS4. Peptide 2 has been modeled to fit in the same binding pocket predicted for YJ34 but in the reverse orientation. [source] A hexamer peptide ligand that binds selectively to staphylococcal enterotoxin B: isolation from a solid phase combinatorial libraryCHEMICAL BIOLOGY & DRUG DESIGN, Issue 2 2004G. Wang Abstract:, By screening a solid-phase combinatorial peptide library, a short peptide ligand, YYWLHH, has been discovered that binds with high affinity and selectivity to staphylococcal enterotoxin B (SEB), but only weakly to other SEs that share sequence and structural homology with SEB. Using column affinity chromatography with an immobilized YYWLHH stationary phase, it was possible to separate SEB quantitatively from Staphylococcus aureus fermentation broth, a complex mixture of proteins, carbohydrates and other biomolecules. The immobilized peptide was also used to purify native SEB from a mixture containing denatured and hydrolyzed SEB, and showed little cross-reactivity with other SEs. To our knowledge this is the first report of a highly specific short peptide ligand for SEB. Such a ligand is a potential candidate to replace antibodies for detection, removal and purification strategies for SEB. [source] Identification of peptides specific for antibodies in vitiligo using a phage libraryCLINICAL & EXPERIMENTAL DERMATOLOGY, Issue 6 2005Z. Jadali Summary Patients with vitiligo produce specific autoantibodies that can be detected in their sera. These antibodies are believed to play a role in the pathogenesis of this disease. A random peptide library displayed on phage is a technique that can be used to identify the epitopes that react with monoclonal and polyclonal antibodies. We used this technique to identify the epitopes that react specifically with the vitiligo autoantibodies. By screening the random peptide phage library and using ELISA, two clones that showed a higher frequency of reactivity with the antibodies in the sera of patients with vitiligo were identified. The peptides do not show any similarity with the autoantigens so far implicated in vitiligo, indicating that these epitopes may mimic conformational epitopes in proteins. [source] | ||||||||||||||||