title: A novel peptide can mimic extracellular fibrinogen-binding protein to block the activation of complement system.
abstract: Extracellular fibrinogen-binding protein (Efb) of Staphylococcus aureus (S. aureus) is a bi-functional protein, which can specifically bind fibrinogen with its N terminus and inhibit deposition of C3b on the surface of S. aureus with its C terminus. Here, we screened the epitopes of Efb using phage display. Four peptides with consensus motif were screened. This consensus motif was identical to C terminus (161-164) of Efb. In the further investigation, it was found the synthesized peptide EC1 (154-165aa of Efb) could specifically bind C3/C3b and subsequently to block the activation of complement. Meanwhile, EC1 could inhibit the interaction between Efb and C3/C3b. Moreover, the interaction between the mutant protein of EmC1 (Efb without EC1) and C3 was decreased. And, the effect on the complement system of the mutant protein was dramatically declined compared with Efb. Our finding suggested that the peptide EC1 could mimic Efb to block complement system activation via binding C3.
authors: Beijing Institute of Basic Medical Sciences, Beijing, China.
authors: Ya-ping
authors: YP
authors: Gao
authors: Jie
authors: J
authors: Dong
authors: Xin
authors: X
authors: Zhang
authors: Yu
authors: Y
authors: Liu
authors: Qiang
authors: Q
authors: Lu
authors: Jian-nan
authors: JN
authors: Feng
authors: Xiao-rong
authors: XR
authors: Tan
authors: Guang
authors: G
authors: Yang
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001426:Bacterial Proteins / Q000737:chemistry / Q000378:metabolism*; D016923:Cell Death / Q000187:drug effects; D003169:Complement Inactivator Proteins / Q000737:chemistry / Q000378:metabolism*; D003165:Complement System Proteins / Q000378:metabolism*; D004912:Erythrocytes / Q000166:cytology / Q000187:drug effects; D005110:Extracellular Space; D005340:Fibrinogen / Q000378:metabolism*; D006801:Humans; D018716:Molecular Mimicry; D009842:Oligopeptides / Q000737:chemistry / Q000494:pharmacology*; D013211:Staphylococcus aureus
chemical_list: D001426:Bacterial Proteins; D003169:Complement Inactivator Proteins; D009842:Oligopeptides; D005340:Fibrinogen; D003165:Complement System Proteins