Solubilization and affinity labeling of a dihydropyridine binding site from skeletal muscle: effects of temperature and diltiazem on [3H]dihydropyridine binding to transverse tubules.
Effects of temperature and d-cis-diltiazem (DTZ) on [3H]nitrendipine (NTD) and [3H]nimodipine (NIM) binding to skeletal muscle t-tubular membranes were studied. A decrease in temperature from 37 degrees C to 10 degrees C decreased KD and increased Bmax slightly. DTZ increased binding by increasing Bmax under all conditions and also decreased KD for NTD at 37 degrees C. The binding protein labeled with [3H]isothiocyanate dihydropyridine revealed a molecular weight of 36,000. The binding site for NTD was solubilized by deoxycholate and dihydropyridine binding was still stimulated by DTZ in the solubilized form.
D000345:Affinity Labels / Q000494:pharmacology; D000818:Animals; D001552:Benzazepines / Q000494:pharmacology*; D002118:Calcium / Q000378:metabolism; D002121:Calcium Channel Blockers / Q000378:metabolism*; D015220:Calcium Channels; D002462:Cell Membrane / Q000378:metabolism; D004110:Diltiazem / Q000494:pharmacology*; D007425:Intracellular Membranes / Q000378:metabolism; D007700:Kinetics; D008861:Microsomes / Q000378:metabolism; D008870:Microtubules / Q000378:metabolism; D009132:Muscles / Q000378:metabolism*; D009539:Nicotinic Acids / Q000378:metabolism*; D009543:Nifedipine / Q000031:analogs & derivatives* / Q000378:metabolism; D009553:Nimodipine; D009568:Nitrendipine; D011817:Rabbits; D011978:Receptors, Nicotinic / Q000302:isolation & purification / Q000378:metabolism*; D013696:Temperature
D000345:Affinity Labels; D001552:Benzazepines; D002121:Calcium Channel Blockers; D015220:Calcium Channels; D009539:Nicotinic Acids; D011978:Receptors, Nicotinic; D009553:Nimodipine; D009568:Nitrendipine; D004110:Diltiazem; D009543:Nifedipine; D002118:Calcium