The effects of amino acid-reactive reagents on the functioning of the inositol 1,4,5-trisphosphate-sensitive calcium channel from rat cerebellum.
Covalent modification of arginine residues with phenylglyoxal and lysine residues with 4,4'-diisothiocyano-2,2'-disulphonic acid stilbene (DIDS) was carried out in preparations of rat cerebellar microsomes, as was the interaction of silver ions (silver nitrate) with cysteine residues. The effects of these amino acid-reactive agents on [3H]inositol 1,4,5-trisphosphate (InsP3) binding and InsP3-induced calcium release were assessed. Both phenylglyoxal and DIDS inhibited [3H]InsP3 binding and InsP3-induced calcium release (IC50 = 2.0 mM and 18 microM, respectively). Silver ions inhibited InsP3-induced Ca2+ release alone (IC50 approximately 1 microM). These results suggest that arginine and lysine residues may be located at or close to the InsP3 binding site of the InsP3 receptor, while cysteine residues are important in channel opening.
Michelangeli
F
F
School of Biochemistry, University of Birmingham, Edgbaston, U.K.
D017878:4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid; D012856:4-Acetamido-4'-isothiocyanatostilbene-2,2'-disulfonic Acid / Q000031:analogs & derivatives* / Q000494:pharmacology; D000255:Adenosine Triphosphate / Q000502:physiology; D000818:Animals; D001120:Arginine / Q000187:drug effects*; D001665:Binding Sites; D001693:Biological Transport, Active / Q000187:drug effects; D000001:Calcimycin / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism; D015220:Calcium Channels / Q000187:drug effects* / Q000502:physiology; D002531:Cerebellum / Q000378:metabolism*; D003545:Cysteine / Q000187:drug effects*; D015544:Inositol 1,4,5-Trisphosphate / Q000502:physiology*; D008239:Lysine / Q000187:drug effects*; D008861:Microsomes / Q000378:metabolism; D010658:Phenylglyoxal / Q000494:pharmacology*; D051381:Rats; D012430:Ruthenium Red / Q000494:pharmacology; D015398:Signal Transduction / Q000187:drug effects; D012835:Silver Nitrate / Q000494:pharmacology*; D014638:Vanadates / Q000494:pharmacology
D015220:Calcium Channels; D012430:Ruthenium Red; D012856:4-Acetamido-4'-isothiocyanatostilbene-2,2'-disulfonic Acid; D000001:Calcimycin; D014638:Vanadates; D015544:Inositol 1,4,5-Trisphosphate; D000255:Adenosine Triphosphate; D001120:Arginine; D012835:Silver Nitrate; D008239:Lysine; D003545:Cysteine; D010658:Phenylglyoxal; D017878:4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid; D002118:Calcium