Isolation and biological activity of the proteases released by sea urchin eggs following fertilization☆
[摘要] Theproteaseactivityreleasedfromseaurchineggcorticalgranulesintothesurroundingseawateratfertilizationisinvolvedinvitellinelayerelevationandtheblocktopolyspermy.Thecorticalgranuleproteasecomponentswereisolatedbyisoelectricprecipitationandaffinitychromatographyonp-aminobenzamidine-Sepharosecolumns.Elutionprofilesfromaffinitycolumnssuggestedheterogeneityoftheproteases,andpolyacrylamide-gelelectrofocusingofaffinity-purifiedpreparationsestablishedthepresenceoftwoproteins.Dramaticallydifferentbiologicalactivitieswereresolvedbyaffinitychromatography.Early-elutingfractionsoflowspecificactivitydelaminatedthevitellinelayerfromtheeggplasmamembrane;thisactivityistermedvitellinedelaminase.Late-elutingfractionsofhighspecificactivitymodifiedtheeggvitellinelayersurfacesuchthatspermcouldnotbindorfertilizethem;thisactivityisreferredtoasspermreceptorhydrolase.Thebiologicalactivitiesoftheseaurchinproteasesareapparentlytheresultoflimitedactiononthevitellinelayer,unlikebovinetrypsinwhichsimplydigeststhevitellinelayer.Thecorticalgranuleproteaseslostbiologicalspecificitywhenstoredat0°CatpH8.0.Esteraseactivityincreased,andthepreparationacquiredtheabilitytodigestthevitellinelayer.IncreaseoftheesteraseactivityinproteasepreparationswaspreventedbystorageatlowpH.Themolecularweightofbothenzymeswasestimatedbysucrosegradientcentrifugationtobe47,000,whereasmultiplecomponentswithmolecularweightsbetween105and106weredemonstratedbygelfiltration.
[发布日期] [发布机构]
[效力级别] [学科分类] 生物科学（综合）
[关键词] [时效性]
