Characterization of the interaction of lipid A and lipopolysaccharide with human serum albumin: implications for an endotoxin carrier function for albumin

David, S. A. ; Balaram, P. ; Mathan, V. I. (1995) Characterization of the interaction of lipid A and lipopolysaccharide with human serum albumin: implications for an endotoxin carrier function for albumin Innate Immunity, 2 (2). pp. 99-106. ISSN 1753-4259

Full text not available from this repository.

Official URL: http://ini.sagepub.com/content/2/2/99.abstract

Related URL: http://dx.doi.org/10.1177/096805199500200204

Abstract

The interactions of lipid A and lipopolysaccharide (LPS) with human serum albumin (HSA) were examined using fluorescence methods. Lipid A binds HSA with a stoichiometry of 2:1 with dissociation constants of 1.0 μM and 6.0 μM for the high- and low-affinity interactions, respectively. Lipid A displaces HSA-bound dansylsarcosine competitively, but not HSA-bound warfarin, suggesting that domain III-A, and not domain 11-A, is a lipid A binding site. Domain I does not contribute a site for lipid A. Based on these data, and the structural similarity between subdomains III-A and III-B, it is proposed that these two regions of HSA represent the high- and low-affinity sites of interaction of lipid A. Whole LPS also binds HSA, displacing dansylsarcosine, and its lipid A moiety appears to be the interaction site. However, there are differences between LPS and free lipid A. Polymyxin B forms ternary complexes with LPS bound to HSA, suggesting that the regions on LPS recognized by HSA and polymyxin B are different. The observed affinity of lipid A for HSA and mass action effects due to its abundance in the circulation would imply a major LPS carrier function for HSA.

Item Type:Article
Source:Copyright of this article belongs to Sage Publications.
ID Code:4444
Deposited On:18 Oct 2010 07:52
Last Modified:16 May 2011 06:23

Repository Staff Only: item control page