title: Inhibition of Adhesion of Enteropathogenic Escherichia coli to HEp-2 Cells by Binding of a Novel Peptide to EspB Protein.
abstract: Enteropathogenic Escherichia coli (EPEC) is a major cause of infantile diarrhea in developing countries. The translocator EspB is a key virulence factor in the process of the attaching and effacing effect of EPEC and plays a critical role in the pathogenesis of the bacteria. In this study, we aimed to select the peptides binding to EspB protein by phage display library and further investigate whether these peptides can decrease the extent of invasion and virulence of EPEC on host cells by targeting to EspB protein. The expression and purification of EspB protein from E. coli was demonstrated by Western blotting. The Ph.D. 12-mer peptide phage display library was used to screen the candidate peptides binding specifically to EspB protein. Furthermore, the affinity of these candidate peptides bound to EspB was identified by enzyme-linked immunosorbent assay (ELISA). Moreover, we investigated whether these screened peptides could decrease the adherence ratio of EPEC to HEp-2 cells with increasing concentration. Successful purification of EspB protein from pET21b-EspB-transformed E. coli was identified by Western blotting. Then, the candidate peptides including phages 6, 7, 8, and 12 were screened by the Ph.D. 12-mer peptide phage display library and ELISA test demonstrated that their affinity binding to EspB protein was high compared with the control. Functional analysis indicated that synthetic peptide-6 (YFPYSHTSPRQP) significantly decreased the adherence ratio of EPEC to HEp-2 cells with increasing concentration (P < 0.01). Peptide-6 (100 µg/mL) could lead to a 40 % decrease in the adherence ratio of EPEC to HEp-2 cells compared with control (P < 0.01). However, the other three peptides at different concentrations showed only a slight ability to block the adherence of EPEC to host cells. Our data provided a potential strategy to inhibit the adhesion of EPEC to epithelial cells by a candidate peptide targeted toward EspB protein.
authors.affiliation: Department of Infectious Diseases and Shenzhen Key Lab for Endogenous Infection, The Affiliated Shenzhen Nanshan Hospital, Guangdong Medical College, No 89 Taoyuan Road, Nanshan District, Shenzhen, 518052, China.
authors.forename: Duoyun
authors.initials: D
authors.lastname: Li
authors.affiliation: Department of Infectious Diseases and Shenzhen Key Lab for Endogenous Infection, The Affiliated Shenzhen Nanshan Hospital, Guangdong Medical College, No 89 Taoyuan Road, Nanshan District, Shenzhen, 518052, China.
authors.forename: Zhong
authors.initials: Z
authors.lastname: Chen
authors.affiliation: Department of Infectious Diseases and Shenzhen Key Lab for Endogenous Infection, The Affiliated Shenzhen Nanshan Hospital, Guangdong Medical College, No 89 Taoyuan Road, Nanshan District, Shenzhen, 518052, China.
authors.forename: Hang
authors.initials: H
authors.lastname: Cheng
authors.affiliation: Department of Infectious Diseases and Shenzhen Key Lab for Endogenous Infection, The Affiliated Shenzhen Nanshan Hospital, Guangdong Medical College, No 89 Taoyuan Road, Nanshan District, Shenzhen, 518052, China.
authors.forename: Jin-Xin
authors.initials: JX
authors.lastname: Zheng
authors.affiliation: Department of Infectious Diseases and Shenzhen Key Lab for Endogenous Infection, The Affiliated Shenzhen Nanshan Hospital, Guangdong Medical College, No 89 Taoyuan Road, Nanshan District, Shenzhen, 518052, China.
authors.forename: Wei-Guang
authors.initials: WG
authors.lastname: Pan
authors.affiliation: Department of Infectious Diseases and Shenzhen Key Lab for Endogenous Infection, The Affiliated Shenzhen Nanshan Hospital, Guangdong Medical College, No 89 Taoyuan Road, Nanshan District, Shenzhen, 518052, China.
authors.forename: Wei-Zhi
authors.initials: WZ
authors.lastname: Yang
authors.affiliation: Department of Infectious Diseases and Shenzhen Key Lab for Endogenous Infection, The Affiliated Shenzhen Nanshan Hospital, Guangdong Medical College, No 89 Taoyuan Road, Nanshan District, Shenzhen, 518052, China. yuzhijiansmu@163.com.
authors.forename: Zhi-Jian
authors.initials: ZJ
authors.lastname: Yu
authors.affiliation: Department of Infectious Diseases and Shenzhen Key Lab for Endogenous Infection, The Affiliated Shenzhen Nanshan Hospital, Guangdong Medical College, No 89 Taoyuan Road, Nanshan District, Shenzhen, 518052, China. qiwendeng@hotmail.com.
authors.forename: Qi-Wen
authors.initials: QW
authors.lastname: Deng
mesh_terms: D000595:Amino Acid Sequence; D001422:Bacterial Adhesion / Q000187:drug effects*; D001425:Bacterial Outer Membrane Proteins / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D054308:Enteropathogenic Escherichia coli / Q000187:drug effects / Q000235:genetics / Q000502:physiology*; D004847:Epithelial Cells / Q000382:microbiology*; D004927:Escherichia coli Infections / Q000382:microbiology*; D029968:Escherichia coli Proteins / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D056945:Hep G2 Cells; D006801:Humans; D008969:Molecular Sequence Data; D010455:Peptides / Q000737:chemistry / Q000494:pharmacology*
chemical_list: D001425:Bacterial Outer Membrane Proteins; C087863:EaeB protein, E coli; D029968:Escherichia coli Proteins; D010455:Peptides