Role of glutathione in the regulation of inorganic pyrophosphatase activity in Streptococcus faecalis.

When the thiol-oxidizing agent diamide was added to a batch culture of Streptococcus faecalis during exponential growth, the specific activity of inorganic pyrophosphatase (EC 3.6.1.1) decreased to the level observed in the stationary phase. The effect of diamide was completely reversed by reduced glutathione. Furthermore, the ratio of reduced to oxidized glutathione and the specific activity of inorganic pyrophosphatase changed in a very similar fashion during batch culture. These findings, together with our earlier results, suggest that the activity of inorganic pyrophosphatase in S. faecalis is regulated by glutathione via the ratio of reduced to oxidized glutathione.