Modification of creatine kinase by S-nitrosothiols: S-nitrosation vs. S-thiolation.
Creatine kinase is reversibly inhibited by incubation with S-nitrosothiols. Loss of enzyme activity is associated with the depletion of 5,5'-dithiobis (2-nitrobenzoic acid)-accessible thiol groups, and is not due to nitric oxide release from RSNO. Full enzymatic activity and protein thiol content are restored by incubation of the S-nitrosothiol-modified protein with glutathione. S-nitroso-N-acetylpenicillamine, which contains a more sterically hindered S-nitroso group than S-nitrosoglutathione, predominantly modifies the protein thiol to an S-nitrosothiol via a transnitrosation reaction. In contrast, S-nitrosoglutathione modifies creatine kinase predominantly by S-thiolation. Both S-nitroso-N-acetylpenicillamine and S-nitrosoglutathione modify bovine serum albumin to an S-nitroso derivative. This indicates that S-thiolation and S-nitrosation are both relevant reactions for S-nitrosothiols, and the relative importance of these reactions in biological systems depends on both the environment of the protein thiol and on the chemical nature of the S-nitrosothiol.
Konorev
E A
EA
Biophysics Research Institute, Medical College of Wisconsin, Milwaukee WI 53226, USA.
Kalyanaraman
B
B
Hogg
N
N
D000818:Animals; D002417:Cattle; D003402:Creatine Kinase / Q000037:antagonists & inhibitors* / Q000737:chemistry*; D004791:Enzyme Inhibitors / Q000737:chemistry / Q000494:pharmacology; D005609:Free Radicals / Q000737:chemistry; D005978:Glutathione / Q000031:analogs & derivatives / Q000737:chemistry / Q000494:pharmacology; D066298:In Vitro Techniques; D009603:Nitroso Compounds / Q000737:chemistry / Q000494:pharmacology*; D010396:Penicillamine / Q000031:analogs & derivatives / Q000737:chemistry / Q000494:pharmacology; D011817:Rabbits; D026423:S-Nitroso-N-Acetylpenicillamine; D026422:S-Nitrosoglutathione; D012710:Serum Albumin, Bovine / Q000737:chemistry; D013438:Sulfhydryl Compounds / Q000737:chemistry / Q000494:pharmacology*
D004791:Enzyme Inhibitors; D005609:Free Radicals; D009603:Nitroso Compounds; D013438:Sulfhydryl Compounds; D012710:Serum Albumin, Bovine; D026422:S-Nitrosoglutathione; D026423:S-Nitroso-N-Acetylpenicillamine; D003402:Creatine Kinase; D005978:Glutathione; D010396:Penicillamine