Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.6.3.1 (Mg2+-ATPase)
 1,484 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Okadaic acid isolated from black sponge (Halichondria okadai), at the concentration of 10 mumol/l, caused contraction in saponin-treated skinned smooth muscle of guinea-pig taenia coli in the absence of Ca2+. In the presence of low concentration (0.3 mumol/l) of Ca2+, okadaic acid induced a greater contraction than in the absence of Ca2+. Okadaic acid potentiated the contractions induced by Ca2+ and pCa2+-tension curve was shifted to the left as well as upward by 1 mumol/l okadaic acid. Native actomyosin preparation (myosin B) containing calmodulinmyosin light chain kinase system and phosphatase was obtained from taenia coli. Okadaic acid (10 mumol/l) increased the actomyosin Mg2+-ATPase activity in the presence or absence of Ca2+. Okadaic acid (1-100 mumol/l) had no effect on calmodulin activity as monitored by Ca2+-calmodulin activated cyclic nucleotide phosphodiesterase activity and the (Ca2+ + Mg2+)-ATPase activity or erythrocyte membranes. These results suggest that okadaic acid directly activates contractile elements of smooth muscle.
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PMID:Direct activation by okadaic acid of the contractile elements in the smooth muscle of guinea-pig taenia coli. 303 85