Epitope mapping of Burkholderia pseudomallei serine metalloprotease: identification of serine protease epitope mimics.
Filamentous phage random peptide libraries were used to identify the epitopes of Burkholderia pseudomallei protease by panning against IgG polyclonal sera that exhibited protease neutralizing properties. The isolated fusion peptides presented a consensus peptide sequence, TKSMALSG, which closely resembles part of the active site sequence, 435GTSMATPHVAG445, of B. pseudomallei serine metalloprotease. By comparing the consensus sequence, TKSMALSG, with the predicted three-dimensional molecular model of B. pseudomallei serine metalloprotease, it appears that the potential antibody binding epitope was buried within the molecule. This active site was conformational whereby one continuous sub-region (SMA) was located between two discontinuous sub-regions, supplied by the flanking residues in the same polypeptide. All phages selected from the biopanning with IgG polyclonal sera showed good binding towards the polyclonal antibodies when compared to the negative control. In addition, these peptide-bearing phages showed competitive inhibition of B. pseudomallei serine metalloprotease binding to the polyclonal IgG.
Chan
Shzu-Wei
SW
Centre for Gene Analysis and Technology, School of Biosciences and Biotechnology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor D.E., Malaysia.
Nathan
Sheila
S
D000595:Amino Acid Sequence / Q000235:genetics; D000907:Antibodies, Bacterial / Q000276:immunology; D001665:Binding Sites / Q000235:genetics; D001667:Binding, Competitive; D016957:Burkholderia pseudomallei / Q000201:enzymology* / Q000276:immunology; D018604:Epitope Mapping; D007074:Immunoglobulin G / Q000276:immunology; D008958:Models, Molecular; D019151:Peptide Library; D011487:Protein Conformation; D012697:Serine Endopeptidases / Q000737:chemistry / Q000276:immunology*
D000907:Antibodies, Bacterial; D007074:Immunoglobulin G; D019151:Peptide Library; D012697:Serine Endopeptidases