Complestain, a potent anti-complement substance produced by streptomyces lavendulae. I. Fermentation, isolation and biological characterization

Abstract

A new potent inhibitor of complement system, named complestatin, was isolated from the mycelium of Streptomyces lavendulae SANK 60477. Complestatin (C61H45N7O15Cl6, MW 1,325) was a peptide compound having two unusual amino acids, d-(–)-4-hydroxyphenylglycine and d-(–)-3, 5-dichloro-4-hydroxyphenylglycine. This compound inhibited the hemolysis of sensitized sheep erythrocytes (EA) mediated by guinea pig and human complement 50% at concentrations of 0.4 and 0.7 μg/ml, respectively, but did not trypsin and α-chymotrypsin activities at 200 μg/ml. When complestatin was administered intravenously to the sensitized guinea pigs, it strongly inhibited the systemic anaphylactic shock elicited by the antigen probably by blocking generation of anaphylatoxins (C3a and C5a). © 1989, JAPAN ANTIBIOTICS RESEARCH ASSOCIATION. All rights reserved.