S-nitrosation of serum albumin: spectrophotometric determination of its nitrosation by simple S-nitrosothiols.
The transfer of nitroso groups from S-nitroso-L-cysteine (1) and six other simple S-nitrosothiols to Cys 34 of bovine serum albumin (2) has been followed using Ellman's reagent, 5,5'-dithio-bis (2-nitrobenzoate) (3), to detect the resulting thiols. The described method utilizes the low reactivity of (3) with (2) and the high extinction coefficient of 2-nitro-5-thiobenzoate produced upon its reaction with thiols to follow the transfer of nitroso moieties at low concentrations where other procedures are not feasible. A second-order rate constant of 6400 M-1 s-1 obtained for the reaction of (2) with S-nitrosomercaptoethylamine is approximately 10 times faster than that for its reaction with (1), approximately 40 times faster than that for its reaction with S-nitrosoglutathione, and consistent with Cys 34 being located in a narrow crevice in close proximity to an anionic charge.
Zhang
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Department of Biochemistry, Ohio State University, 484 West 12th Avenue, Columbus, Ohio, 43210, USA.
Means
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GE
D000818:Animals; D002417:Cattle; D003545:Cysteine / Q000031:analogs & derivatives* / Q000378:metabolism; D004228:Dithionitrobenzoic Acid / Q000378:metabolism; D005978:Glutathione / Q000031:analogs & derivatives* / Q000378:metabolism; D009603:Nitroso Compounds / Q000378:metabolism*; D026422:S-Nitrosoglutathione; D026403:S-Nitrosothiols; D012709:Serum Albumin / Q000378:metabolism*; D013053:Spectrophotometry
D009603:Nitroso Compounds; D026403:S-Nitrosothiols; D012709:Serum Albumin; D026422:S-Nitrosoglutathione; C021315:S-nitrosocysteine; D004228:Dithionitrobenzoic Acid; D005978:Glutathione; D003545:Cysteine