The hemolytic equivalence of human, guinea pig and canine complement proteins

The ability of functionally pure human, guinea pig and canine complement proteins to fulfill the hemolytic function of a substituted analagous component in an otherwise totally homogeneous complement sequence was investigated by means of conventional hemolytic assays. A striking feature was the observation that for hemolysis to occur, differing requirements for enzyme-substrate homology were exhibited by each of the three species of C3 and C5 convertases (C3 and C5 CVA). The results suggest that different strategies of molecular interaction evolved in complement systems of different species.