Protease, oligopeptide synthesis

Basic to protease catalyzed oligopeptide synthesis is equilibrium- or thermodynamic control to direct reversal of proteolysis . Difficulties encountered include low reaction rates, high stoichiometric amounts of enzyme, and the need to apply direct approaches to shift the reactions towards formation of desired products. Reaction conditions that lead to product precipitation or extraction increase efficiency of the reverse reaction. Kinetically controlled syntheses has proved useful for serine and cysteine proteases that form activated acyl enzyme intermediates during catalysis. This approach generally involves use of activated acyl moieties, such as esters, as donor components which significantly accelerate the reaction rate. This study makes use of principles from both kinetic and thermodynamically controlled reactions in that, reactants are activated by formation of esters and products precipitate fi om reactions. 

Using the reverse of the hydrolytic reaction, proteases are capable of catalyzing the formation of peptide bonds. Thermolysin is a powerful enzyme in catalyzing the synthesis of various useful oligopeptides, either in a free form or in an immobilized form in organic solvent media [58]. Recently, the systematic study about the stability of immobilized thermolysin has been reported [59]. In this study, the authors described the mechanism and kinetics for the inactivation of immobilized thermolysin with respect to the effects of organic solvents, kinds of support, water content, and so on. The strategy and results of their approach are discussed next. 

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