SPECIFIC INTERACTIONS BETWEEN HUMAN INTEGRIN ALPHA(V)BETA(3) AND CHIMERIC HEPATITIS-B VIRUS CORE PARTICLES BEARING THE RECEPTOR-BINDING EPITOPE OF FOOT-AND-MOUTH-DISEASE VIRUS

Purified integrin alpha(v) beta(3) was used in solid-phase binding stu dies with chimeric hepatitis B cores which carry the RGD-containing lo op of VP1 protein of the foot-and-mouth disease Virus (FMDV). High lev els of specific binding between the integrin and the particles were de tected by enzyme-linked immunosorbent assays. The binding was Mn2+ cat ion dependent and could be competed with fibronectin, vitronectin, and the peptide GRGDSPK. Particles in which the RGD motif had been mutate d to RGE failed to hind, indicating that the chimeric cores bound spec ifically to the ligand binding site of integrin alpha(v) beta(3). Eiec tron micrographs showed several individual alpha(v) beta(3) molecules hound to the surface of each chimeric particle. Collectively, these da ta constitute firm evidence that the RGD-containing loop of FMDV is cr itical for binding to alpha(v) beta(3) and provide support for identif ication of alpha(v) beta(3) a potential cellular receptor for FMDV. (C ) 1997 Academic Press.