I-Arginin

Pufahl and Marietta82, with the /VG-hydroxy-i.-arginine that they had synthesized, gave the outline of the scheme presented in Figure 10. 

Using a spectrophotometric method, McMillan and Masters93 obtained evidence that bNOS contained a heme group that reacted with L-arginine and with iVG-hydroxy-L-arginine (an intermediate) and /VG-rncthyl-i.-arginine (an inhibitor). They therefore concluded that the heme was an oxygen donor. 

Of potentially greater consequence are the observations of HNO production during oxidation of L-arginine, by NOS under low cofactor conditions (97-100), or of the NOS intermediate M -hydroxy-i-arginine, either uncoupled (101, 102) or coupled to NOS (97, 103). These processes would convert the enzyme from an NO to an HNO synthase, and would thus provide a condition-dependent, alternative signaling mechanism. Although this is an intriguing possibility, based upon biochemical analysis, it is at present hypothetical in vivo. 

C7H,N204 616-79-5) see Afloqualone nitro-i.-arginine methyl ester hydrochloride (C7H 6CIN504 51298-62-5) see Angiotensinainide... 

Nitric oxide is synthesized from the amino acid arginine in a reaction catalysed by NOS I-arginine + 02 + NADPH — citrulline + NADP+ + NO (thiol, tetrahydrobiopterin, FMN and FAD being requisite cofactors in this process). NO subsequently acts by activating soluble GC, thereby successively causing elevation of cGMP and PKG activation. NO can also act by activating Ca2 1 -dependent K+ channels. 

A -Methyi-I,-arginine Synthetic cNOS, iNOS (28), nNOS... 

Trdzl, L., Rusznak, 1., Naray-Szabo, G., Szarva.s, T., Csiba, A., and Ludanyi, A Essential differences in spontaneous reactions of i.-lysine and i.-arginine with formaldehyde, Period. Polytech. Chem. Eng. Budapest.. 32, 251, 1988 Chem. Abstr.. 112, 99170, 1990,... 

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