The esterification of Ac-Tyr-OH was carried out in one-phase system containing ethanol by a¡©chymotrypsin. The results of the esterification reaction are as follows. Chitin-a--chymotrypsin complex was found to be an effective catalyst for the esterification of Ac-Tyr-0H in ethanol organic solvent. The optimal conditions for the esterification were chitn/a-chymotrypsin ratio, 20(w/w) ; reaction temp., 35C ; reaction pH, 8.0 ; reaction time, 24 hrs. Also, addition of chitin in water/water-miscible organic solvent was effective for the stability of the enzyme. The esterification yield, Km and Vmax under optimal conditions were 93%, 3.093mM and 1.088mM/mg/hr, respectively.
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