Purification and Some Properties of S-Hemolysin Produced by Streptomyces sp. Strain No. A-6288

Abstract

A new cytolytic toxin, designated as S-Hemolysin, was found in the culture filtrate of Streptomyces sp. strain No. A-6288, isolated from a soil sample. The molecular weight of S-Hemolysin was estimated to be 10, 000 by SDS-polyacrylamide gel electrophoresis and to be 20, 000 by Sephadex G-100. S-Hemolysin is a glycoprotein that is composed of 102 amino acid residues with 11.6% glucose, and the isoelectric point is around pH 5.8. The phospholipase C activity of S-Hemolysin was specific for the following substrates in this order : sphingomyelin > lysophosphatidylethanolamine > lysophosphatidylcholine > phosphatidylethanolamine > phosphatidylcholine. S-Hemolysin had hemolytic activity against rabbit, human, and sheep erythrocytes, but did not cause aggregation of human platelets. These activities were accelerated with Mg²⁺, Mn²⁺, and Co²⁺ ions and inhibited by the addition of Ca<2+>, Cu²⁺, and Zn²⁺ ions. This enzyme was shown to be different from the known bacterial phospholipase C.