CHARACTERIZATION OF STAPHYLOCOCCAL GAMMA-LYSIN

Gamma-Lysin was purifed from Staphylococcus aureus strains Smith 5R and PG23 (a toxic shock syndrome isolate) by a combination of heparin-agarose and hydroxylapatite chromatography. Both strains produced two haemolytic components, designated gamma-1 and gamma-2. Though each component was weakly haemolytic they acted synergistically to potentiate haemolysis on rabbit, sheep and human blood. Rabbit and sheep erythrocytes were more sensitive to lysis by gamma-lysin than human erythrocytes. The molecular mass of gamma-1 was 32 kDa and its pl value was 9.4. Gamma-2 had a molecular mass of 36 kDa and a pI value of 9.3. While both trypsin and papain acted synergistically with gamma-2 to induce increased haemolysis, no such synergism was seen with gamma-1. Also, protease inhibitors acted to inhibit synergism between gamma-1 and gamma-2. These findings suggest that gamma-1 could be a protease.