Jump to ContentJump to Main Navigation

Biological Chemistry

Editor-in-Chief: Brüne, Bernhard

Editorial Board Member: Buchner, Johannes / Ludwig, Stephan / Sies, Helmut / Turk, Boris / Wittinghofer, Alfred

12 Issues per year

VolumeIssuePage

Issues

The PPIase Active Site of Legionella pneumophila Mip Protein Is Involved in the Infection of Eukaryotic Host Cells

J.H. Helbig / B. König / H. Knospe / B. Bubert / C. Yu / C.P. Lück / A. Riboldi-Tunnicliffe / R. Hilgenfeld / E. Jacobs / J. Hacker / G. Fischer

Citation Information: Biological Chemistry. Volume 384, Issue 1, Pages 125–137, ISSN (Print) 1431-6730, DOI: 10.1515/BC.2003.013, June 2005

Publication History

Published Online:
2005-06-01

Abstract

We analysed eight monoclonal antibodies (mAbs) directed against the Mip (macrophage infectivity potentiator) protein, a virulence factor of the intracellular pathogen Legionella pneumophila. Mip belongs to the FK506-binding proteins (FKBPs) and exhibits peptidyl prolyl cis/trans isomerase (PPIase) activity. Five of the mAbs recognised epitopes in the Cterminal, FKBP-homologous domain of Mip, which is highly conserved among all Legionella species. Upon immunological binding to Mip, all but one of these mAbs caused inhibition of the PPIase activity in vitro. mAb binding to the N-terminal domain of Mip did not influence its enzymatic activity. All but one of the PPIase inhibiting mAbs were able to significantly inhibit the early establishment and initiation of an intracellular infection of the bacteria in Acanthamoeba castellanii, the natural host, and in the human phagocytic cell line U937. These data demonstrate for the first time that for the virulence-enhancing property of the L. pneumophila Mip protein, an intact active site of the enzyme is an essential requirement.

Comments (0)

Please log in or register to comment.
Users without a subscription are not able to see the full content. Please, subscribe or login to access all content.