Premium
Identification of putative calcium channels in skeletal muscle microsomes
Author(s) -
Ferry David R.,
Glossmann Hartmut
Publication year - 1982
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(82)80835-1
Subject(s) - diltiazem , dihydropyridine , skeletal muscle , chemistry , calcium , nimodipine , guinea pig , microsome , differential centrifugation , ouabain , isradipine , binding site , biophysics , biochemistry , endocrinology , in vitro , biology , sodium , organic chemistry
Saturable binding sites for the labelled calcium antagonist (±)[ 3 H]nimodipine were found in guinea‐pig hind limb skeletal muscle homogenates. Binding sites were enriched in a microsomal pellet by differential centrifugation of the homogenate. [ 3 H]Nimodipine binding ( K d = 1.5±0.03 nM, B max = 2.1 ± 0.25 pmol/protein, at 37°C) copurified (6‐fold) in this fraction with [ 3 H]ouabain binding (6.6‐fold) and 125 I‐α‐bungarotoxin binding (5‐fold). d‐ cis ‐Diltiazem (but not 1‐ cis ‐diltiazem) stimulated (±) [ 3 H]nimodipine binding ( ED 50 1 μM) by increasing the B max . Binding sites discriminated between the optical enantiomers of 1,4‐dihydropyridine calcium antagonists and the optically pure enantiomers of D‐600. The data confirm, with biochemical techniques, the presence of 1,4‐dihydropyridine and (±)D‐600 inhibitable calcium channels in skeletal muscle, previously found with electrophysiological techniques.