The reaction of methyl mercury nitrate with the sulfhydryl groups of yeast glyceraldehyde-3-phosphate dehydrogenase.

The importance of two of the thiol groups of yeast triosephosphate dehydrogenase for its activity haa been shown by the abolition of activity and diphosphopyridine nucleotide binding by the addition of 2 equivalents of p-chloromercuribenzoate (PCMB) (1, 2). The reaction of methyl mercury nitrate with this enzyme has been found to be anomalous in the sense that this mercury compound, unlike PCMB, does not react first with the enzyme sulfhydryl groups which are required for activity. These results and some determinations of the total numbers of sulfhydryl groups available in the enzyme after various treatments are presented here.