On the Micro-determination of Sulfhydryl Group in Denatured Proteins

In 1941 it was reported by P. ZIMA that the sulfhdryl group in cysteine or glutathione molecules may be calculated by treating with aneurin disulfide and then estimating the micro-amount (0.2_??_0.5γ) of aneurin in the obtained solution with the thiochrome method. Recently the present authors have carried out a few micro analytical experiments of SH group determination in denatured proteins by this O. ZIMA's aneurin disulflde method. The results are briefly summarized as follows: 1) Studies on the estimation of the SH group in egg-albumin denatured by urea were successfully completed. 2) But, on the other hand, no accruated results were obtained in the experiments with egg-albumin denatured by guanidine hydrochloride.