Ca2+ dependence of inositol 1,4,5-trisphosphate 3-kinase activity in the cytosol fraction of pig coronary artery

Koji Yamaguchi, Masato Hirata, Toyohiro Ishimatsu, Hirosi Kuriyama

Research output: Contribution to journalArticle

1 Citation (Scopus)

Abstract

1. The activity of inositol 1,4,5-trisphosphate 3-kinase in subcellular fractions of smooth muscles of the pig coronary artery was examined. 2. Incubation of [3H]inositol 1,4,5-trisphosphate (IP3) with muscle homogenates produced more polar 3H-radioactivity (probably as inositol 1,3,4,5-tetrakisphosphate, IP4) than IP3, in the Mg2+- and ATP-dependent manner, thereby indicating the presence of IP3 3-kinase activity in homogenates of the muscle. 3. Most of the kinase activity was present in the cytosol fraction. The enzyme activity was reversibly activated by Ca2+ with a half-maximal effective concentration of 2.5 × 10-7 M. 4. The calmodulin antagonists, W-7 and chlorpromazine inhibited the Ca2+-activated enzyme activity.

Original languageEnglish
Pages (from-to)163-166
Number of pages4
JournalComparative Biochemistry and Physiology. Part C, Comparative
Volume92
Issue number1
DOIs
Publication statusPublished - 1989

All Science Journal Classification (ASJC) codes

  • Immunology
  • Pharmacology

Fingerprint Dive into the research topics of 'Ca<sup>2+</sup> dependence of inositol 1,4,5-trisphosphate 3-kinase activity in the cytosol fraction of pig coronary artery'. Together they form a unique fingerprint.

  • Cite this