Effects of Organic Solvents on Streptomyces griseus Protease I with Transfer Action

The protease I from Streptomyces griseus var. alcalophilus strongly catalyzed the transfer reaction forming hydroxamic acids of various amino acids, especially aromatic and hydrophobic amino acids. Dimethyl sulfoxide (DMSO), 1,4-butane diol, and glycerol protected this enzyme from heat denaturation. Moreover, only DMSO strongly activated the transfer action of protease I and the velocity of reaction was accelerated three times in the presence of 50% DMSO. The yield of transfer product strongly depended on reaction time and the concentrations of enzyme and substrates in the presence of DMSO. The velocity of the transfer reaction was faster than that of the hydrolysis reaction under the conditions of 0.1 M Phe-OEt, 0.75 M NH2OH, and 50% DMSO.