Extraction of an Egg-Membrane-Lysin from Sperm of the Giant Keyhole Limpet (Megathura Crenulata)

Abstract

A lytic agent having the property of dissolving the egg membrane was extracted from sperm of the giant keyhole limpet (Megathura crenulata). The lysin is non-dialyzable and readily inactivated by heat. It precipitates upon saturation of the extract with ammonium sulphate. The precipitate gives the usual protein tests and pure proteinases inactivate the lytic agent. Abalone (Haliotis cracherodii) sperm also yield a lysin which acts on the eggs of the same sp. Cross-lysis between limpet and abalone does not occur; nor does cross-fertilization. Limpet sperm extracts also contain a substance (anti-fertilizin) capable of neutralizing the sperm agglutinin (fertilizin) obtained from eggs. Heat inactivation of the lysin leaves the anti-fertilizin unaffected.