1. Irreversible inhibition of Ca2+ release in saponin-treated macrophages by the photoaffinity derivative of inositol-1, 4, 5-trisphosphate.
- Author
-
Hirata M, Sasaguri T, Hamachi T, Hashimoto T, Kukita M, and Koga T
- Subjects
- Animals, Cell Membrane Permeability, Dose-Response Relationship, Drug, Guinea Pigs, In Vitro Techniques, Macrophages metabolism, Photochemistry, Saponins, Structure-Activity Relationship, Affinity Labels, Calcium metabolism, Inositol Phosphates pharmacology, Macrophages drug effects, Sugar Phosphates pharmacology
- Abstract
D-myo-inositol-1,4,5-trisphosphate (InsP3) is a putative intracellular second messenger for the mobilization of Ca2+ from intracellular stores, in particular, the endoplasmic reticulum. Specific binding sites on the endoplasmic reticulum may participate in the InsP3-induced release of Ca2+ from the Ca2+ pool. To examine the specific binding sites on the endoplasmic reticulum, we synthesized an arylazide derivative of InsP3 for photoaffinity labelling; InsP3 coupled to p-azidobenzoic acid (InsP3-pAB) using N,N'-carbonyldiimidazole (CDI) was obtained at a 9-11% yield. Here, we report that InsP3-pAB, but not an arylazide derivative of inositol-1,4-bisphophate (Ins(1,4)P2), causes the irreversible inhibition of InsP3-induced release of Ca2+ in saponin-permeabilized photo-irradiated macrophages. The irreversible inhibition by InsP3-pAB after photo-irradiation was prevented by a 10-fold excess of unmodified InsP3.
- Published
- 1985
- Full Text
- View/download PDF