Sequence analysis and antigenic identification of mimic epitopes of peptidoglycan
10.3969/j.issn.1000-484X.2017.08.014
- VernacularTitle:模拟肽聚糖表位的序列分析及其抗原性鉴定
- Author:
Yiguo CHEN
;
Xiaorui HOU
;
Ping ZHU
;
Beiyi LIU
- Keywords:
PGN;
Peptide mimics;
Phage peptide library;
S.aureus
- From:
Chinese Journal of Immunology
2017;33(8):1191-1196
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To analysis the Mimotopes of the peptide mimics to PGN using online softwares.Methods: Mimotopes of PGN were screened from 12-mers linear phage display peptide library by using anti-PGN McAb and the antigenicity of selected clones was identified by ELISA.The B cell epitopes,T cell epitopes of ′GRWxHxVxWAGL′ were estimated by DNAstar and online softwares.Results: 16 phage clones that bound with anti-PGN McAb were screened from 12-mers linear phage display peptide library.Among these positive clones,phage clones No.39 shared the conserved sequence:WxHx……AGL found in previous clone No.31(ATWxHxLxSAGL),which provoked an effective protective immunity against infection with S.aureus.To enhance the stability of the conformation as well as adding biotin on the N-ter-minal as a tag,the sequences ′39′ were redesigned and synthesized by adding S(serine)A(alanine) and GG(glycine)on the C-terminal of origin sequence(named SP39).Next,we estimated or predicted antigenic epitopes,T cell epitopes and scores binding to MHC of these peptides by using DNASTAR and online softwares(http://bio.dfci.harvard.edu/Tools/antigenic.pl,www.syfpeithi.de,http://www.darrenflower.info/mhcpred),indicating that SP39 contains sites bound both mice and human MHC.The sequences ′WxHxVxW-′ may be antigenic epitope as SP39,which contains a T cell epitope.Our results showed that both SP39 could bind to both anti-PGN McAb and a polyclonal antibody against S.aureus.Moreover PGN could inhibit the binding of SP39 to the anti-PGN McAb.These data indicated that SP39 mimic to epitopes on PGN.Conclusion: SP39(GRWxHxVxWAGLAGGS) probably display the mimotopes of PGN.
