{"title":"镉、铅和汞对肌浆网Ca(2+)- atp酶活性的抑制作用","authors":"S Hechtenberg, D Beyersmann","doi":"10.1159/000468875","DOIUrl":null,"url":null,"abstract":"<p><p>The effect of Cd2+, Pb2+ and Hg2+ on the Ca(2+)-ATPase activity of sarcoplasmic reticulum from rabbit muscle was studied. The concentration of relevant free and complex species for the assay conditions have been computed. As a result, ATP hydrolysis was found to be inhibited with an IC50 value of 950 nmol/l free Cd2+ or 95 nmol/l free Pb2+. Although calculation of the free Hg2+ was not possible, the comparison of the IC50 values for total metal ions show that Hg2+ is the strongest inhibitor of enzyme activity. The inhibition by Cd2+ seems to be independent of substrate concentration, whereas the inhibitory effect of Pb2+ is lowered in the presence of higher MgATP concentrations. Our data illustrate that the three heavy metals are potent inhibitors of the Ca2+ pump. Therefore low concentrations of these metal ions may disturb intracellular Ca2+ homeostasis and act on Ca(2+)-mediated cell functions.</p>","PeriodicalId":11933,"journal":{"name":"Enzyme","volume":null,"pages":null},"PeriodicalIF":0.0000,"publicationDate":"1991-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1159/000468875","citationCount":"84","resultStr":"{\"title\":\"Inhibition of sarcoplasmic reticulum Ca(2+)-ATPase activity by cadmium, lead and mercury.\",\"authors\":\"S Hechtenberg, D Beyersmann\",\"doi\":\"10.1159/000468875\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<p><p>The effect of Cd2+, Pb2+ and Hg2+ on the Ca(2+)-ATPase activity of sarcoplasmic reticulum from rabbit muscle was studied. The concentration of relevant free and complex species for the assay conditions have been computed. As a result, ATP hydrolysis was found to be inhibited with an IC50 value of 950 nmol/l free Cd2+ or 95 nmol/l free Pb2+. Although calculation of the free Hg2+ was not possible, the comparison of the IC50 values for total metal ions show that Hg2+ is the strongest inhibitor of enzyme activity. The inhibition by Cd2+ seems to be independent of substrate concentration, whereas the inhibitory effect of Pb2+ is lowered in the presence of higher MgATP concentrations. Our data illustrate that the three heavy metals are potent inhibitors of the Ca2+ pump. Therefore low concentrations of these metal ions may disturb intracellular Ca2+ homeostasis and act on Ca(2+)-mediated cell functions.</p>\",\"PeriodicalId\":11933,\"journal\":{\"name\":\"Enzyme\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":0.0000,\"publicationDate\":\"1991-01-01\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"https://sci-hub-pdf.com/10.1159/000468875\",\"citationCount\":\"84\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Enzyme\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"https://doi.org/10.1159/000468875\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"\",\"JCRName\":\"\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Enzyme","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.1159/000468875","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
Inhibition of sarcoplasmic reticulum Ca(2+)-ATPase activity by cadmium, lead and mercury.
The effect of Cd2+, Pb2+ and Hg2+ on the Ca(2+)-ATPase activity of sarcoplasmic reticulum from rabbit muscle was studied. The concentration of relevant free and complex species for the assay conditions have been computed. As a result, ATP hydrolysis was found to be inhibited with an IC50 value of 950 nmol/l free Cd2+ or 95 nmol/l free Pb2+. Although calculation of the free Hg2+ was not possible, the comparison of the IC50 values for total metal ions show that Hg2+ is the strongest inhibitor of enzyme activity. The inhibition by Cd2+ seems to be independent of substrate concentration, whereas the inhibitory effect of Pb2+ is lowered in the presence of higher MgATP concentrations. Our data illustrate that the three heavy metals are potent inhibitors of the Ca2+ pump. Therefore low concentrations of these metal ions may disturb intracellular Ca2+ homeostasis and act on Ca(2+)-mediated cell functions.
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