S-nitrosation versus S-glutathionylation of protein sulfhydryl groups by S-nitrosoglutathione.
S-Nitrosation of protein sulfhydryl groups is an established response to oxidative/nitrosative stress. The transient nature and reversibility of S-nitrosation, as well as its specificity, render this posttranslational modification an attractive mechanism of regulation of protein function and signal transduction, in analogy to S-glutathionylation. Several feasible mechanisms for protein S-nitrosation have been proposed, including transnitrosation by S-nitrosothiols, such as S-nitrosoglutathione (GSNO), where the nitrosonium moiety is directly transferred from one thiol to another. The reaction between GSNO and protein sulfhydryls can also produce a mixed disulfide by S-glutathionylation, which involves the nucleophilic attack of the sulfur of GSNO by the protein thiolate anion. In this study, we have investigated the possible occurrence of S-glutathionylation during reaction of GSNO with papain, creatine phosphokinase, glyceraldehyde-3-phosphate dehydrogenase, alcohol dehydrogenase, bovine serum albumin, and actin. Our results show that papain, creatine phosphokinase, and glyceraldehyde-3-phosphate dehydrogenase were significantly both S-nitrosated and S-glutathionylated by GSNO, whereas alcohol dehydrogenase, bovine serum albumin, and actin appeared nearly only S-nitrosated. The susceptibility of the modified proteins to denitrosation and deglutathionylation by reduced glutathione was also investigated.
Giustarini
Daniela
D
Department of Neuroscience, Pharmacology Unit, University of Siena, Siena, Italy.
Milzani
Aldo
A
Aldini
Giancarlo
G
Carini
Marina
M
Rossi
Ranieri
R
Dalle-Donne
Isabella
I
D000818:Animals; D004220:Disulfides / Q000378:metabolism; D005978:Glutathione / Q000378:metabolism*; D009584:Nitrogen / Q000378:metabolism*; D011506:Proteins / Q000378:metabolism*; D011817:Rabbits; D026422:S-Nitrosoglutathione / Q000737:chemistry / Q000378:metabolism*; D021241:Spectrometry, Mass, Electrospray Ionization; D013438:Sulfhydryl Compounds / Q000378:metabolism*
D004220:Disulfides; D011506:Proteins; D013438:Sulfhydryl Compounds; D026422:S-Nitrosoglutathione; D005978:Glutathione; D009584:Nitrogen