首页    期刊浏览 2024年12月15日 星期日
登录注册

文章基本信息

  • 标题:GTP is not required for calmodulin stimulation of bovine brain adenylate cyclase
  • 本地全文:下载
  • 作者:W Heideman ; B M Wierman ; D R Storm
  • 期刊名称:Proceedings of the National Academy of Sciences
  • 印刷版ISSN:0027-8424
  • 电子版ISSN:1091-6490
  • 出版年度:1982
  • 卷号:79
  • 期号:5
  • 页码:1462-1465
  • DOI:10.1073/pnas.79.5.1462
  • 语种:English
  • 出版社:The National Academy of Sciences of the United States of America
  • 摘要:The importance of guanyl nucleotides for calmodulin stimulation of bovine cerebral cortex adenylate cyclase [ATP pyrophosphate-lyase (cyclizing), EC 4.6.1.1 ] was examined by using a partially purified calmodulin-sensitive adenylate cyclase that was resolved from calmodulin-insensitive forms of the enzyme. By using 5'-adenylyl imidodiphosphate as a substrate, in the absence of an ATP-regenerating system, it was determined that GTP is not required for calmodulin stimulation of the enzyme. Maximal activation by 5'-guanylyl imidodiphosphate (p[NH]ppG) was 5.3-fold, whereas the combination of p[NH]ppG and calmodulin stimulated the enzyme 27-fold. Although GDP inhibited p[NH]ppG stimulation of the calmodulin-sensitive adenylate cyclase, it did not affect calmodulin stimulation. In addition, calmodulin did not alter the kinetics for activation of the enzyme by p[NH]ppG. It is concluded that GTP is not required for calmodulin stimulation of brain adenylate cyclase and that calmodulin regulation of this enzyme is probably not due to effects of calmodulin on the affinity of the guanyl nucleotide regulatory complex for guanyl nucleotides.
国家哲学社会科学文献中心版权所有