||Human Homo sapiens
||Hansen RE, Roth D, Winther JR. Quantifying the global cellular thiol-disulfide status. Proc Natl Acad Sci U S A. 2009 Jan 13 106(2):422-7. Table 2PubMed ID19122143
||Differential labeling of protein thiols and disulfides, followed by chromatographic or electrophoretic separation of cellular proteins. Then, cysteine containing proteins are identified by mass spectrometry and in some cases information of the thiol–disulfide status of peptides are also determined. Cells from a 95% confluent 10-cm dish were harvested by trypsinization, washed in PBS, and directly quenched by addition of 10% TCA.Total GS were quantified by reducing disulfides with TCEP followed by thiol derivatization with NPM. For quantification of GSSG, free thiols were first blocked by NEM followed by TCEP reduction and NPM derivatization. GSH equivalents were calculated by subtracting GS in GSSG from total GS.
||In terms of distribution of glutathione equivalents there were no significant differences between HEK and HeLa cells with GSSG levels constituting ˜4.5% of the total GS equivalents (Table 2). However, the absolute levels of glutathione were ˜30% higher in HeLa cells than in HEK cells (Fig. 3B).