Frequency of cysteine residue in proteins

Range 2.4-2.7 %
Organism Human Homo sapiens
Reference 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.PubMed ID19122143
Method 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. Quantification of PSH, PSox, and Total PS was performed with 4-DPS and BH using a modification of the HPLC method described by Hansen, et al.
Comments Low and high values for Hek and HeLa cells respectively
Entered by Uri M
ID 103538