Protein glutathiolation in human blood.
Glutathione (GSH) exists in both free and protein-bound (glutathiolated) forms (GSSP). Protein glutathiolation may represent an important post-translational regulatory mechanism for proteins. However, there are little data regarding the regulation of glutathiolation in blood. Our objectives were to examine GSSP levels of human blood by determining the distribution and variability of blood GSSP, as well as its relationship to free GSH and hemoglobin in healthy adults. To this end, we used a newly modified method allowing for rapid analysis of both GSH and GSSP in blood. GSSP was found in red cells with levels ranging from 4 to 27% of total (free+bound) GSH (mean+/-SD: 12.1+/-4.5%) with a concentration of 0.13+/-0.05 microEq GSH/mL (mean+/-SD). No correlations were observed between GSSP and either GSH (r=-0.085) or hemoglobin (r=0.086). Together these results suggest that the extent of protein glutathiolation in blood is substantial ( approximately 0.1 mmol/L). While the interindividual variation in GSSP is large (34%), its levels are apparently not regulated by GSH content.
Kleinman
Wayne A
WA
Division of Epidemiology and Cancer Suceptibility, American Health Foundation, 1 Dana Road, Valhalla, NY 10595, USA.
Komninou
Despina
D
Leutzinger
Yvonne
Y
Colosimo
Stephen
S
Cox
Julie
J
Lang
Calvin A
CA
Richie
John P
JP
D000328:Adult; D000367:Age Factors; D000368:Aged; D001798:Blood Proteins / Q000378:metabolism*; D005260:Female; D005978:Glutathione / Q000378:metabolism*; D006801:Humans; D008297:Male; D008875:Middle Aged; D012737:Sex Factors
D001798:Blood Proteins; D005978:Glutathione