Studies on the Egg-Membrane Lysin of Tegula Pfeifferi: Quantitative Assay of the Lytic Activity

An egg-membrane lysin was partially purified from the sperm extract of Tegula pfeifferi. A turbidimetric and a chemical method with the use of isolated egg membrane as the substrate have been proposed for the quantitative assay of the lysin. The methods are shown to be valid over a limited range of lysin concentration. The pH optimum for the lytic activity is at about 8.3. The lysin shows considerable thermo-instability and is highly sensitive to PCMB and heavy metals. The reduction in turbidity of egg-membrane suspensions during lysis is accompanied by the release of a substance(s) containing neutral sugar. The possibility that the lytic process is composed of two steps is discussed.