Partial amino acid sequence of a novel 40-kDa human aortic protein, with vitronectin-like, fibrinogen-like, and calcium binding domains: aortic aneurysm-associated protein-40 (AAAP-40) [human MAGP-3, proposed].

A microfibrillar protein (40 kDa) purified from the adventitia of the human abdominal aorta is immunoreactive with IgG harvested from the wall of abdominal aortic aneurysms. We have partially sequenced this protein and found that it has fibrinogen alpha-, beta-, and gamma-like domains, a vitronectin-like domain, and a possible site for binding calcium. Because of homologies with other microfibril-associated glycoproteins and because it is the third member of the family to be characterized in man, we suggest the name MAGP-3.