Stabilization of enzymes by dormancy autoinducers as a possible mechanism of resistance of resting microbial forms

Alkyl-substituted hydroxybenzenes (AHBs), autoinducers of microbial dormanc y (or dl factors), were found to stabilize the structure of protein macromo lecules, making them metabolically less active and more resistant to stress es. In vitro experiments with the Bacillus intermedius ribonuclease and chy motrypsin showed that the degree of the physical and chemical stability of these enzymes treated with AHBs depends on their concentration and incubati on time. Experiments with RNase, which is capable of refolding, i.e., renat uration after heat denaturation, revealed that AHBs efficiently interact wi th both intact and denatured proteins. The data obtained allow the inferenc e to be made that dr factors may play the role of natural chemical chaperon s, blocking metabolism in dormant cells through the formation of catalytica lly inactive thermostable complexes with enzymes.