Catalysis of S-nitrosothiols formation by serum albumin: the mechanism and implication in vascular control.
Nitric oxide (NO(.)) is a short-lived physiological messenger. Its various biological activities can be preserved in a more stable form of S-nitrosothiols (RS-NO). Here we demonstrate that at physiological NO(.) concentrations, plasma albumin becomes saturated with NO(.) and accelerates formation of low-molecular-weight (LMW) RS-NO in vitro and in vivo. The mechanism involves micellar catalysis of NO(.) oxidation in the albumin hydrophobic core and specific transfer of NO(+) to LMW thiols. Albumin-mediated S-nitrosylation and its vasodilatory effect directly depend on the concentration of circulating LMW thiols. Results suggest that the hydrophobic phase formed by albumin serves as a major reservoir of NO(.) and its reactive oxides and controls the dynamics of NO(.)-dependant processes in the vasculature.
Rafikova
Olga
O
Department of Biochemistry, New York University Medical Center, New York, NY 10016, USA.
Rafikov
Ruslan
R
Nudler
Evgeny
E
D000418:Albumins / Q000378:metabolism; D000818:Animals; D002384:Catalysis; D004305:Dose-Response Relationship, Drug; D005263:Femoral Artery / Q000378:metabolism*; D005268:Femoral Vein / Q000378:metabolism*; D008297:Male; D008823:Micelles; D008954:Models, Biological; D009569:Nitric Oxide / Q000737:chemistry / Q000378:metabolism*; D009573:Nitrites / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D026403:S-Nitrosothiols / Q000378:metabolism*; D013438:Sulfhydryl Compounds / Q000378:metabolism; D013997:Time Factors; D014867:Water / Q000737:chemistry
D000418:Albumins; D008823:Micelles; D009573:Nitrites; D026403:S-Nitrosothiols; D013438:Sulfhydryl Compounds; D014867:Water; D009569:Nitric Oxide