Differential effects of organic co-solvents on peptide synthesis and hydrolysis by thermolysin.

Thermolysin is an effective peptide synthetase in mixtures of buffer and water miscible solvents MeOH, EtOH and PrOH. Although the solvents are inhibitory, primarily through effects on kcat, synthetic reactions are much less affected than peptide hydrolysis. This may be of value in prevention of unwanted proteolytic cleavages, for example in protein semisynthesis.