Purification of a Ca2+/calmodulin-dependent nitric oxide synthase from porcine cerebellum. Cofactor-role of tetrahydrobiopterin.
L-Arginine-derived nitric oxide acts as an inter- and intracellular signal molecule with cytosolic guanylyl cyclase as the effector system. Two NO synthase isoenzymes are postulated: a cytokine-inducible enzyme in macrophages and a constitutive, Ca2(+)-regulated enzyme in various other cells. An NO synthase was isolated from porcine cerebellum by ammonium sulfate precipitation and affinity chromatography on 2',5'-ADP-Sepharose. The enzyme was identified as an NO synthase with a specific NO-chemiluminescence method and with purified cytosolic guanylyl cyclase as an NO-sensitive detection system. The purified NO synthase was, besides Ca2+/calmodulin and NADPH, largely dependent on tetrahydrobiopterin as a cofactor.
Institut für Pharmakologie, Freie Universität Berlin, Germany.
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B
Mayer
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M
John
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Böhme
D000594:Amino Acid Oxidoreductases / Q000302:isolation & purification*; D000818:Animals; D001708:Biopterins / Q000031:analogs & derivatives / Q000378:metabolism; D002118:Calcium / Q000502:physiology; D002147:Calmodulin / Q000502:physiology; D002531:Cerebellum / Q000201:enzymology*; D002956:Citrulline / Q000378:metabolism; D006152:Cyclic GMP / Q000378:metabolism; D006162:Guanylate Cyclase / Q000378:metabolism; D008970:Molecular Weight; D019001:Nitric Oxide Synthase; D013552:Swine
D002147:Calmodulin; D001708:Biopterins; D002956:Citrulline; D019001:Nitric Oxide Synthase; D000594:Amino Acid Oxidoreductases; D006162:Guanylate Cyclase; C003402:sapropterin; D006152:Cyclic GMP; D002118:Calcium