The effects of glycine, TMAO and osmolyte mixtures on the pressure dependent enzymatic activity of α-chymotrypsin.

High pressure is an important feature of certain natural environments, such as the deep sea where pressures up to about 1000 bar are encountered. Further, pressure effects on biosystems are of increasing interest for biotechnological applications, such as baroenzymology. We studied the effect of two different natural osmolyte mixtures, with major components being glycine and trimethylamine-N-oxide (TMAO), on the activity of α-chymotrypsin, using high-pressure stopped-flow methodology in combination with fast UV/Vis detection. We show that pressure is not only able to drastically enhance the catalytic activity and efficiency of the enzyme, but also that glycine has a significant and diverse effect on the enzymatic activity and volumetric properties of the reaction compared to TMAO. The results might not only help to understand the modulation of enzymatic reactions by natural osmolytes, but also elucidate ways to optimize enzymatic processes in biotechnological applications.