Dimerization and the effectiveness of ICAM-1 in mediating LFA-1-dependent adhesion.

ABSTRACT: Dimeric intercellular adhesion molecule-1 (ICAM-1) binds more efficiently to lymphocyte function-associated antigen-1 (LFA-1) than monomeric ICAM-1. However, it is unknown whether dimerization enhances binding simply by providing two ligand-binding sites and thereby increasing avidity, or whether it serves to generate a single "fully competent" LFA-1-binding surface. Domain 1 of ICAM-1 contains both the binding site for LFA-1, centered on residue E34, and a homodimerization interface. Whether the LFA-1-binding site extends across the homodimerization interface has not been tested. To address this question, we constructed four different heterodimeric soluble forms of ICAM-1 joined at the C terminus via an alpha-helical coiled coil (ACID-BASE). These heterodimeric ICAM-1 constructs include,

SUBMITTER: Jun CD 

PROVIDER: S-EPMC34438 | biostudies-literature | 2001 Jun

REPOSITORIES: biostudies-literature