Phospholipase C in rat liver plasma membranes

FEBS Letters

Melin, Per-Martin¹  Jergil, Bengt¹  Sundler, Roger² 

[1] >Biochemistry, Chemical Centre, Box 124, University of Lund, Box 94, S-221 00 Lund, Sweden;Medical and Physiological Chemistry, University of Lund, Box 94, S-221 00 Lund, Sweden

关键词: Ca2+;    Guanine nucleotide;    Inositol trisphosphate;    Phosphatidylinositol bisphosphate;    Phospholipase C (Rat liver plasma membrane);    GMP-PCP;    guanylyl (β;    γ-methylene)diphosphonate;    IP2;    myo-inositol bisphosphate;    IP3;    myo-inositol trisphosphate;    PI;    phosphatidylinositol;    PIP;    phosphatidylinositol 4-phosphate;    PIP2;    phosphatidylinositol 4;    5-bisphosphate;   

DOI  :  10.1016/0014-5793(86)81189-9

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Phospholipase C activity against phosphoinositides in isolated rat liver plasma membranes has been examined using exogenous substrates. The enzyme hydrolyzed phosphatidylinositol 4,5-bisphosphate 30–40-times faster than phosphatidylinositol 4-monophosphate, while phosphatidylinositol was not a substrate. Maximum activity was observed with 1.1 mM phosphatidylinositol 4,5-bisphosphate at pH 5.0. The enzyme was stimulated by micromolar concentrations of Ca²⁺. The GTP analogue guanylyl (β,γ-methylene)diphosphonate enhanced phospholipase C activity at and above 0.3 μM Ca²⁺, but was inhibitory at 0.1 μM Ca²⁺. This supports the suggestion that plasma membrane phospholipase C is regulated by guanine nucleotide-binding protein, but indicates a regulatory mechanism different from that of other enzymes regulated by such proteins.

【 授权许可】

Unknown