HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via CrossRef Citing Articles via Google Scholar Google Scholar Articles by Nomura, T. Articles by Mitsuyama, M. Search for Related Content PubMed Articles by Nomura, T. Articles by Mitsuyama, M. Agricola Articles by Nomura, T. Articles by Mitsuyama, M.

Irreversible loss of membrane-binding activity of Listeria-derived cytolysins in non-acidic conditions: a distinct difference from allied cytolysins produced by other Gram-positive bacteria

¹ Department of Microbiology, Kyoto University Graduate School of Medicine, Kyoto 606-8501, Japan
² Department of Microbiology and Immunology, Showa University School of Medicine, Tokyo 142-8555, Japan
³ Department of Infectious Diseases, Nagoya University School of Medicine, Nagoya 466-8550, Japan
⁴ Department of Respiratory Medicine, Kyoto University Graduate School of Medicine, Kyoto 606-8507, Japan

Correspondence
Takamasa Nomura
nomura{at}mb.med.kyoto-u.ac.jp

Listeriolysin O (LLO), a member of the cholesterol-dependent cytolysin (CDC) family, is a major virulence factor of Listeria monocytogenes and contributes to bacterial escape from intracellular killing of macrophages. LLO is activated under weakly acidic conditions; however, the molecular mechanism of this pH-dependent expression of cytolytic activity of LLO is poorly understood. In this study, CDCs including LLO, ivanolysin O (ILO), seeligeriolysin O (LSO), pneumolysin (PLY), streptolysin O (SLO) and perfringolysin O (PFO) were prepared as recombinant proteins and examined for their functional changes after treatment under various pH conditions. Haemolytic and membrane cholesterol-binding activities were not affected in PLY, SLO and PFO at any pH examined. By contrast, all the Listeria-derived cytolysins, LLO, ILO and LSO, were active only at an acidic pH and rapidly inactivated under neutral or alkaline conditions. Once inactivated, LLO could not be reactivated even by a downward pH shift. The hydrophobicity of LLO treated at neutral or alkaline pH was increased. These data suggested that the pH-dependent loss of cytolytic activity appeared to be due to irreversible structural changes of domain 4 that resulted in the loss of target membrane cholesterol binding.

This article has been cited by other articles:

				H. Hara, K. Tsuchiya, T. Nomura, I. Kawamura, S. Shoma, and M. Mitsuyama Dependency of Caspase-1 Activation Induced in Macrophages by Listeria monocytogenes on Cytolysin, Listeriolysin O, after Evasion from Phagosome into the Cytoplasm J. Immunol., June 15, 2008; 180(12): 7859 - 7868. [Abstract] [Full Text] [PDF]