Abstract
1. Methods have been described for reducing protein S-S groups, for oxidizing protein SH groups, and for estimating protein S-S and SH groups. 2. It has been found necessary in estimating the cystine content of proteins by the Folin-Marenzi method to take into account any cysteine that may be present. 3. A method for estimating the cysteine content of proteins has been described. 4. With these methods, estimations have been made of the S-S and SH groups and of the cystine and cysteine contents of a number of proteins. 5. In a denatured, but unhydrolyzed protein, the number of S-S and SH groups is equivalent to the quantity of cystine and cysteine found in the protein after hydrolysis.
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Selected References
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- Lugg J. W. The application of phospho-18-tungstic acid (Folin's reagent) to the colorimetric determination of cysteine, cystine and related substances: The determination of sulphydryl compounds and disulphides already existing in solution. Biochem J. 1932;26(6):2160–2165. doi: 10.1042/bj0262160. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Walker E. A Colour Reaction for Disulphides. Biochem J. 1925;19(6):1082–1084. doi: 10.1042/bj0191082. [DOI] [PMC free article] [PubMed] [Google Scholar]