On the identity of vitronectin and S-protein: immunological crossreactivity and functional studies.

摘要: Vitronectin (serum spreading factor), a major serum cell adhesion molecule, was compared with S-protein, the inhibitor of C5-9 membrane attack complex. Data from literature indicate that S-protein and vitronectin are alpha globulins same aminoterminal residues, amino acid compositions, concentrations in normal plasma (150 to 250 micrograms/mL). Both proteins have been reported interact thrombin-antithrombin The cDNA sequences were recently determined found be almost identical. In present studies, rabbit-anti-S-protein monoclonal antibody both recognized 65,000- 75,000-molecular weight (mol wt) polypeptides when or separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis transferred nitrocellulose paper. 65,000 75,000-mol wt bound more avidly than anti-vitronectin heparin coupled agarose. presence absence constituted difference between heparin-binding plasma. When complement-activated unactivated filtration, coeluted C9 high-mol-wt fractions activated but not serum. Purified promoted human skin fibroblasts. degraded thrombin. On basis immunological functional, as well biochemical, properties, therefore, same.