Isolation and biological activity of the proteases released by sea urchin eggs following fertilization

摘要: Abstract The protease activity released from sea urchin egg cortical granules into the surrounding seawater at fertilization is involved in vitelline layer elevation and block to polyspermy. granule components were isolated by isoelectric precipitation affinity chromatography on p -aminobenzamidine-Sepharose columns. Elution profiles columns suggested heterogeneity of proteases, polyacrylamide-gel electrofocusing affinity-purified preparations established presence two proteins. Dramatically different biological activities resolved chromatography. Early-eluting fractions low specific delaminated plasma membrane; this termed delaminase. Late-eluting high modified surface such that sperm could not bind or fertilize them; referred as receptor hydrolase. proteases are apparently result limited action layer, unlike bovine trypsin which simply digests layer. lost specificity when stored 0°C pH 8.0. Esterase increased, preparation acquired ability digest Increase esterase was prevented storage pH. molecular weight both enzymes estimated sucrose gradient centrifugation be 47,000, whereas multiple with weights between 10 5 6 demonstrated gel filtration.