No prokaryotic expression of integrin alpha v beta 3 has been reported so f
ar. We report here the expression of C-terminally truncated alpha v beta 3
receptors in E. coli considering the known features required for dimerizati
on and ligand binding. The expressed protein was insoluble despite of the a
ddition of 'solubilizers' to the culture medium. Osmotic stress conditions
combined with added exogenous solutes resulted in a small part of soluble r
eceptor. The alpha v beta 3 variants were purified from inclusion bodies or
from soluble cytoplasmic maltose binding protein fusions. Heterodimerizati
on of the subunits was proved by immunoprecipitation assays. Receptor-ligan
d binding was found to depend on the concentration. A competition assay wit
h RGD peptides referred to unspecific receptor-ligand interaction. The latt
er fact was consistent with the finding that soluble receptors did not bind
on RGD peptide-coupled sepharose (GRGDSPK sepharose).