Esterases in mycobacteria

Abstract

Esterases ofMycobacterium phlei isolated by means of Sephadex G-100 chromatography could be temporarily activated by adding calcium ions. This activation could not be brought about in crude enzyme preparations from cells or in crude extracts from the culture filtrate. It was demonstrated that compounds (or a compound) without the esterase activity isolated after the separation of crude enzyme preparations on Sephadex G-100 (peak C) are responsible for the above difference. It was found that the suppression by compounds from the “C peak” of the temporary activation of esterases with calcium ions depends most probably on the ratio of these compounds to the quantity of the enzyme rather than on their concentration. In addition, the compounds of the C peak themselves were found to activate esterases. The activation was lower than the temporary activation with calcium ions. The possible mechanisms of the temporary activation of esterases and the importance of these findings, from the point of view of regulation of the activity of esterases during submerged cultivation ofMycobacterium phlei, are discussed.