This paper reports an insight into the kinetic mechanism of activation and then inhibition in a thermolysin - catalyzed peptide synthesis of dipeptide N-(benzyloxycarbonyl)-L-phenylalanyl-L-phenylalanine methyl ester in aqueous - organic one phase system containing n-alcohols as activator. The jump in catalytic efficiency - as an effect of alcoholic solvents and the kinetic mode of activation are discussed.