{"title":"Intact cell and cell-free phosphorylation and concomitant activation of a low Km, cAMP phosphodiesterase found in human platelets.","authors":"C H Macphee, D H Reifsnyder, T A Moore, J A Beavo","doi":"","DOIUrl":null,"url":null,"abstract":"<p><p>A monoclonal antibody (CGI-5) directed against the cGMP-inhibited phosphodiesterase isolated from bovine heart was used to examine the phosphorylation of this isozyme in human platelets. PGE1 promoted the phosphorylation of this isozyme, identified as a 110 kDa peptide following SDS-gel electrophoresis. Phosphorylation resulted in approximately a 40% increase in the cGMP-inhibited phosphodiesterase activity. Cell-free experiments demonstrated that cAMP-dependent protein kinase phosphorylated the cGMP-inhibited phosphodiesterase, and that this could be blocked by the heat stable inhibitor peptide (PKI). Phosphorylation of the cGMP-inhibited phosphodiesterase increases the Vmax for cAMP hydrolysis approximately 50%, but does not affect the Km for cAMP (0.12 microM).</p>","PeriodicalId":15406,"journal":{"name":"Journal of cyclic nucleotide and protein phosphorylation research","volume":null,"pages":null},"PeriodicalIF":0.0000,"publicationDate":"1986-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of cyclic nucleotide and protein phosphorylation research","FirstCategoryId":"1085","ListUrlMain":"","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 0
Abstract
A monoclonal antibody (CGI-5) directed against the cGMP-inhibited phosphodiesterase isolated from bovine heart was used to examine the phosphorylation of this isozyme in human platelets. PGE1 promoted the phosphorylation of this isozyme, identified as a 110 kDa peptide following SDS-gel electrophoresis. Phosphorylation resulted in approximately a 40% increase in the cGMP-inhibited phosphodiesterase activity. Cell-free experiments demonstrated that cAMP-dependent protein kinase phosphorylated the cGMP-inhibited phosphodiesterase, and that this could be blocked by the heat stable inhibitor peptide (PKI). Phosphorylation of the cGMP-inhibited phosphodiesterase increases the Vmax for cAMP hydrolysis approximately 50%, but does not affect the Km for cAMP (0.12 microM).
求助内容：
应助结果提醒方式：
京公网安备 11010802042870号
