STAPHYLOCOCCAL TOXINS: II. FACTORS AFFECTING HEMOLYSIS BY δ-LYSIN

Abstract

The influence of a number of variables upon lysis of erythrocytes by staphylococcal δ-lysin has been examined. Hemolysis of human erythrocytes by δ-lysin has been found to be unaffected by the presence of α-lysin but is inhibited by a number of proteins, serum being the most active of those tested. Glucose, citrate, and magnesium ions were found to have no effect on hemolysis by δ-lysin. Hemoglobin and erythrocyte ghosts were inhibitory. Release of cell constituents during hemolysis is considered to be partly responsible for the change from a rapid to a slower rate of hemolysis in the early stages of the reaction.It was found that the extent of hemolysis of a 1% suspension of human erythrocytes is linearly related to lysin concentration provided lysis is not greater than 65% nor less than 30% of total hemolysis. A method of determining relative δ-lysin activity is described.