Outer membrane protein I of Pseudomonas aeruginosa is a target of cationic antimicrobial peptide/protein.

Journal Article (Journal Article)

Cationic antimicrobial peptides/proteins (AMPs) are important components of the host innate defense mechanisms against invading microorganisms. Here we demonstrate that OprI (outer membrane protein I) of Pseudomonas aeruginosa is responsible for its susceptibility to human ribonuclease 7 (hRNase 7) and alpha-helical cationic AMPs, instead of surface lipopolysaccharide, which is the initial binding site of cationic AMPs. The antimicrobial activities of hRNase 7 and alpha-helical cationic AMPs against P. aeruginosa were inhibited by the addition of exogenous OprI or anti-OprI antibody. On modification and internalization of OprI by hRNase 7 into cytosol, the bacterial membrane became permeable to metabolites. The lipoprotein was predicted to consist of an extended loop at the N terminus for hRNase 7/lipopolysaccharide binding, a trimeric alpha-helix, and a lysine residue at the C terminus for cell wall anchoring. Our findings highlight a novel mechanism of antimicrobial activity and document a previously unexplored target of alpha-helical cationic AMPs, which may be used for screening drugs to treat antibiotic-resistant bacterial infection.

Full Text

Duke Authors

Cited Authors

  • Lin, Y-M; Wu, S-J; Chang, T-W; Wang, C-F; Suen, C-S; Hwang, M-J; Chang, MD-T; Chen, Y-T; Liao, Y-D

Published Date

  • March 19, 2010

Published In

Volume / Issue

  • 285 / 12

Start / End Page

  • 8985 - 8994

PubMed ID

  • 20100832

Pubmed Central ID

  • PMC2838320

Electronic International Standard Serial Number (EISSN)

  • 1083-351X

Digital Object Identifier (DOI)

  • 10.1074/jbc.M109.078725


  • eng

Conference Location

  • United States