Libraries at University of Nebraska-Lincoln


Document Type


Date of this Version



Thesis (M.S.)—University of Nebraska—Lincoln, 1962. Department of Chemistry.


Copyright 1962, the author. Used by permission.


The purpose of this investigation was to obtain additional information about the specificity and hydrolytic reactions of ficin, in particular the thiol esterase activity of this proteolytic enzyme and the relationship of this activity to the basic mechanism of action of this enzyme.

Investigation of the ficin-catalyzed hydrolysis of the thiol ester BGTEE has contributed to the understanding of the mechanism of action of this enzyme. Optimum concentrations of crude and crystalline ficin have been determined for the BGTEE, the pH optimum has been determined for the enzyme, several activators and inhibitors have been found for this enzyme, and calculation of the Michaelis constant and the energy of activation of ficin for BGTEE has aided in the understanding of the mechanism of action of the enzyme.The results obtained support the postulation that a thiol ester may be an intermediate in the mechanism of action of ficin.

Advisor: Robert B. Johnston