Synthesis and amino acid composition of basic proteins in mammalian sperm nuclei☆
[摘要] Thebasicchromosomalproteins(SCP)ofhuman,mouse,rabbitandguineapigspermnucleiwerecharacterizedbypolyacrylamidegelelectrophoresisandaminoacidanalysis.Spermatozoaweredecapitatedwith1%SDSandthenucleirecoveredbydensitygradientcentrifugation.ExaminationbyNomarskiandelectronmicroscopyrevealedthenucleitobeintactand99%pure.Thebasicproteinswereextractedfromnuclei,aminoethylatedandpurifiedbyionexchangechromatographyandgelfiltrationchromatography.TheSCPofhuman,rabbitandguineapiggavesingleproteinbandswithsimilarmobilitieswhensubjectedtopolyacrylamidegelelectrophoresis.Incontrast,aminoethylatedmouseSCPconsistedoftwoproteins,SCP·AE1andSCP·AE2,whichhaddifferentelectrophoreticmobilities.TheSCPofthesemammalianspecieswerecharacteristicallyrichinarginine(47–54.4%)andcysteine(7.7–12.2%).Majordifferencesexistedintheaminoacidcompositionsoftheseproteins.MouseandhumanSCPwererichinhistidine(12.2and7.7%,respectively)andguineapigwashighintyrosine(11.7%)andphenylalanine(3.5%).ValinewasdetectedonlyinrabbitSCPandprolineinhumanandguineapig.Asparticacid,methionineandtryptophanwerenotdetectedinallfourspecies.Studiesontheincorporationof[3H]arginineintomouseSCPdemonstratedthatthesebasicproteinsaresynthesizedduringtheterminalstagesofspermatogenesisandaresubsequentlyconserved.
[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]
