INHIBITION AND INACTIVATION OF HYDROLASES

Mohammed Taleb H. AKSAMAWATY

 The Synthesis of 1,4-dideoxy-1,4-imino-L-threitol has been improved. Compound has been tested together with 1,4-dideoxy-1,4-imino-L-arabinitol as inhibitors of α-L-arabinofuranosidase AFIII of Monilinia Fructigena. Both compounds were competitive inhibitors of AFIII. 1,4-dideoxy-1,4-imino-L-arabinitol was approximately 1200 fold tighter binding than the 1,4-dideoxy-1,4-imino-L-threitol.

The pH variation of the affinity (1/K_j) of both compounds, with dissociation constant, pK_a, well above that of the acid catalytic group of the enzyme, were not likely to be transition state analogues for the α -L-arabinofuranosidase.

Aryl and Alkyl n-butyl ethyl diazoacetato borinate derivatives were synthesized as inactivators of serine proteases. Attempted inactivation of α-chymotrypsin by phenyl n-butyl ethyl diazoacetato borinate was not successful and the compound decomposed with the time of addition.

Attempted acid catalyzed enzyme catalyzed hydrolysis of n-butyl ethyl diazoacetato borinate was not successful. Decomposition of the compound occurred very quickly. n-Butyl ethyl diazoacetato borinates were air and moisture sensitive and thermally unstable compounds.