{"title":"通过突变去除假定的必需组氨酸残基而使羧基肽酶Y失活。","authors":"L M Bech, K Breddam","doi":"10.1007/BF02904470","DOIUrl":null,"url":null,"abstract":"<p><p>Carboxypeptidase Y is a serine carboxypeptidase assumed to contain a catalytic triad similar to the serine endopeptidases. On the basis of the homology between various serine carboxypeptidases His-397 is suspected to be part of the catalytic triad. To test this it was exchanged with Ala and Arg by site-directed mutagenesis of the cloned PRC1 gene. The catalytic efficiency of the mutant enzymes were reduced by a factor of 2 X 10(4) and 7 X 10(2), respectively, confirming the key role of His-397 in catalysis. Treatment of Ala-397-CPD-Y with Hg++ or CNBr, hence modifying Cys-341 located in the vicinity of the active site abolished the residual activity of the enzyme, indicating an additional involvement of this residue in catalysis.</p>","PeriodicalId":9616,"journal":{"name":"Carlsberg Research Communications","volume":null,"pages":null},"PeriodicalIF":0.0000,"publicationDate":"1989-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/BF02904470","citationCount":"24","resultStr":"{\"title\":\"Inactivation of carboxypeptidase Y by mutational removal of the putative essential histidyl residue.\",\"authors\":\"L M Bech, K Breddam\",\"doi\":\"10.1007/BF02904470\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<p><p>Carboxypeptidase Y is a serine carboxypeptidase assumed to contain a catalytic triad similar to the serine endopeptidases. On the basis of the homology between various serine carboxypeptidases His-397 is suspected to be part of the catalytic triad. To test this it was exchanged with Ala and Arg by site-directed mutagenesis of the cloned PRC1 gene. The catalytic efficiency of the mutant enzymes were reduced by a factor of 2 X 10(4) and 7 X 10(2), respectively, confirming the key role of His-397 in catalysis. Treatment of Ala-397-CPD-Y with Hg++ or CNBr, hence modifying Cys-341 located in the vicinity of the active site abolished the residual activity of the enzyme, indicating an additional involvement of this residue in catalysis.</p>\",\"PeriodicalId\":9616,\"journal\":{\"name\":\"Carlsberg Research Communications\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":0.0000,\"publicationDate\":\"1989-01-01\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"https://sci-hub-pdf.com/10.1007/BF02904470\",\"citationCount\":\"24\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Carlsberg Research Communications\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"https://doi.org/10.1007/BF02904470\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"\",\"JCRName\":\"\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Carlsberg Research Communications","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.1007/BF02904470","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
Inactivation of carboxypeptidase Y by mutational removal of the putative essential histidyl residue.
Carboxypeptidase Y is a serine carboxypeptidase assumed to contain a catalytic triad similar to the serine endopeptidases. On the basis of the homology between various serine carboxypeptidases His-397 is suspected to be part of the catalytic triad. To test this it was exchanged with Ala and Arg by site-directed mutagenesis of the cloned PRC1 gene. The catalytic efficiency of the mutant enzymes were reduced by a factor of 2 X 10(4) and 7 X 10(2), respectively, confirming the key role of His-397 in catalysis. Treatment of Ala-397-CPD-Y with Hg++ or CNBr, hence modifying Cys-341 located in the vicinity of the active site abolished the residual activity of the enzyme, indicating an additional involvement of this residue in catalysis.