Ca2+-dependent formation of an L-arginine-derived activator of soluble guanylyl cyclase in bovine lung.
In a fraction of cytosolic proteins from bovine lung, soluble guanylyl cyclase was concentration-dependently stimulated by L-arginine but not by D-arginine. Stimulation was up to 20-fold with an EC50 of about 3 x 10(-5) M. Activation of guanylyl cyclase by L-arginine was dependent on NADPH (EC50 about 5 x 10(-7) M) and Ca2+ (EC50 about 1.4 x 10(-6) M). The activation by L-arginine was inhibited by NG-monomethyl-L-arginine and hemoglobin. The effect of L-arginine was dependent on the protein concentration and was not observed in preparations of purified gyanylyl cyclase. These results suggest that bovine lung contains a Ca2+-regulated enzyme or enzyme system which converts L-arginine into an activator of soluble guanylyl cyclase.
Mayer
B
B
Institut für Pharmakologie, Freie Universität Berlin, FRG.
Böhme
E
E
D000818:Animals; D001120:Arginine / Q000494:pharmacology*; D002118:Calcium / Q000494:pharmacology*; D002417:Cattle; D003600:Cytosol / Q000201:enzymology; D004305:Dose-Response Relationship, Drug; D004789:Enzyme Activation; D006162:Guanylate Cyclase / Q000037:antagonists & inhibitors / Q000378:metabolism*; D008168:Lung / Q000201:enzymology*; D009249:NADP / Q000494:pharmacology; D013237:Stereoisomerism
D009249:NADP; D001120:Arginine; D006162:Guanylate Cyclase; D002118:Calcium