[The role of sulfhydryl groups in functioning of components of adenylate cyclase signal system in smooth muscles of the mollusk Anodonta cygnea (effect of N-ethylmaleimide and p-chloromercuribenzoic acid)].
The alkylating agent N-ethylameimide and the sulfhydryl group blocker p-chloromercuribenzoic acid (CPMA) inhibited in dose-dependent manner both basal activity of adenylyl cyclase (AC) and its activity stimulated by non-hormonal substances (forskolin, sodium fluoride, guanylilimidodiphosphate) in smooth muscles of the freshwater bivalve mollusk Anodonta cygnea. The double increase (from 30 to 60 min) in the time of preincubation of a sarcolemmal membrane fraction with ethylmaleimide and CPMA led to an essential increase in enzyme inhibition (especially for CPMA). 50 mM SH-containing reagent beta-mercaptoethanol (ME) partially restored the AC activity, inhibited by N-ethylmaleimide and CPMA, except when these two latter reagents were in high concentrations (1-10 and 0.5 mM, respectively). The data obtained point to the key role of cysteine SH-groups in regulation of the functional activity of proteins, components of the adenylyl cyclase system--AC and heterotrimeric G-proteins.
Shpakov
A O
AO
Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, St. Petersburg.
Derkach
K V
KV
D000067956:Adenylyl Cyclase Inhibitors; D000262:Adenylyl Cyclases / Q000096:biosynthesis; D000595:Amino Acid Sequence; D000818:Animals; D004790:Enzyme Induction; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D005033:Ethylmaleimide / Q000494:pharmacology*; D008969:Molecular Sequence Data; D008974:Mollusca / Q000201:enzymology; D009130:Muscle, Smooth / Q000201:enzymology; D013439:Sulfhydryl Reagents / Q000494:pharmacology*; D020245:p-Chloromercuribenzoic Acid / Q000494:pharmacology*
D000067956:Adenylyl Cyclase Inhibitors; D004791:Enzyme Inhibitors; D013439:Sulfhydryl Reagents; D020245:p-Chloromercuribenzoic Acid; D000262:Adenylyl Cyclases; D005033:Ethylmaleimide