ANAPHYLATOXIC PEPTIDE C3A OF GUINEA-PIG COMPLEMENT .1. PURIFICATION, PHYSICOCHEMICAL AND ANTI-GENETIC PROPERTIES

Abstract

Highly purified guinea pig C3a [subunit of 3rd component of complement] was obtained after specific cleavage of isolated C3 by the alternative pathway enzyme VF-.hivin.B [cobra venom factor-activated factor B complex] in a 1 step procedure. It was a low MW peptide with basic character (MW 9500; isoelectric point above 9.4). C3a represents an antigenetic determinant of its own in the native C3 molecule, different from the B determinant. Guinea pig C3a is resistant to 100.degree. C for 10 minutes. Its smooth muscle contracting activity can be destroyed by trypsin and carboxypeptidase B. Guinea pig C3a is quite similar to human C3a.