title: Characterization of D-myo-inositol 1,4,5-trisphosphate phosphatase in rat brain.
abstract: Rat brain homogenates contain significant amounts of inositol 1,4,5-trisphosphate phosphatase in both 180,000xg (60 min) particulate and supernatant fractions. As other membrane-bound enzymes (e.g. guanylate cyclase), particulate inositol 1,4,5-trisphosphate phosphatase activity is highly sensitive to low concentrations of Triton X-100 (0.03%). Higher concentrations of detergent (1%) partially solubilized the enzyme. Thiol blocking agents (e.g. p-hydroxymercuribenzoate) inactivate inositol 1,4,5-trisphosphate phosphatase activity (an effect reversed with 2-mercaptoethanol). It is thus suggested that enzymatic activity requires the presence of -SH groups.
mesh_terms: D000818:Animals; D001921:Brain / Q000201:enzymology*; D002104:Cadmium / Q000494:pharmacology; D004228:Dithionitrobenzoic Acid / Q000494:pharmacology; D004229:Dithiothreitol / Q000494:pharmacology; D004910:Erythrocyte Membrane / Q000201:enzymology; D005033:Ethylmaleimide / Q000494:pharmacology; D005978:Glutathione / Q000031:analogs & derivatives / Q000494:pharmacology; D019803:Glutathione Disulfide; D006902:Hydroxymercuribenzoates / Q000494:pharmacology; D015544:Inositol 1,4,5-Trisphosphate; D007295:Inositol Phosphates / Q000378:metabolism; D010744:Phosphoric Monoester Hydrolases / Q000378:metabolism*; D051381:Rats
chemical_list: D006902:Hydroxymercuribenzoates; D007295:Inositol Phosphates; D002104:Cadmium; C030601:4-hydroxymercuribenzoate; D015544:Inositol 1,4,5-Trisphosphate; D004228:Dithionitrobenzoic Acid; D010744:Phosphoric Monoester Hydrolases; C043422:myo-inositol 1,4,5-triphosphate phosphatase; D005978:Glutathione; D005033:Ethylmaleimide; D004229:Dithiothreitol; D019803:Glutathione Disulfide