Mechanism Of Enzymatic Hydrolysis Research Articles

Kinetics and Mechanism of Enzymatic Hydrolysis of Pivampicillin Monolayers

A study of the enzymatic hydrolysis of pivampicillin (an insoluble penicillin) extended as a monolayer on the aqueous interface at a constant surface pressure has been performed. Penicillinase promotes intensive hydrolysis of the pivampicillin monolayers, inducing their solubility. However, no action was observed with dog liver esterase. The hydrolytic process, which was dependent on the film surface pressure and on the quantity of the injected enzyme, is of the Michaelis-Menten type in two dimensions.

Studies on the mechanism of enzymatic hydrolysis of cellulosic substances.

Most cellulosic substances contain appreciable amounts of cellulose and hemicellulose, which on enzymatic hydrolysis mainly yield a mixture of glucose, cellobiose, and xylose. In this paper, studies on the mechanisms of hydrolysis of bagasse (a complex native cellulosic waste left after extraction of juice from cane sugar) by the cellulase enzyme components are described in light of their adsorption characteristics. Simultaneous adsorption of exo- and endoglucanases on hydrolyzable cellulosics is the causative factor of the hydrolysis that follows immediately after. It supports the postulate of synergistic enzyme action proposed by Eriksson. Xylanase pretreatment enhanced the hydrolysis of bagasse owing to the creation of more accessible cellulosic regions that are readily acted upon by exo- and endoglucanases. The synergistic action of the purified exoglucanase, endoglucanase, and xylanse has been found to be most effective for hydrolysis of bagasse but not for pure cellulose. Significant quantities of glucose are produced in beta-glucosidase-free cellulase action on bagasse. Individual and combined action of the purified cellulase components on hydrolysis of native and delignified bagasse are discussed in respect to the release of sugars in the hydrolysate.

On the mechanism of enzymatic hydrolysis of carbamyl phosphate

As indicated, reaction 1 leads to the simultaneous production of ammonia, CO*, and inorganic phosphate, while reaction 2 yields cyanate and phosphate. The half-life of cyanate is reported to be ‘~7-8 times that of carbamyl phosphate [l] ; therefore, reaction 2 results in initial accumulation of cyanate and as the cyanate decomposes, ammonia is produced. Thus at low pH the rates of ammonia and phosphate liberation are equal, while at pH 6 the release of ammonia is % 15% the rate of phosphate formation [2]. This seemingly paradoxical rapid appearance of inorganic phosphate and delayed appearance of ammonia led to the earlier postulation that a carbamyl phosphate derivative of acetyl glutamate was the intermediate in citrulline synthesis [2] In spite of the fact that acyl phosphatase (an enzyme which is highly specific for acyl phosphates such as carbamyl phosphate and 1,3-diphosphoglycerate) has been purified extensively from a number of sources [3] , no attempts have been carried out to determine whether the enzymatic hydrolysis of carbamyl phosphate involves the production of cyanate. The pH optimum for muscle acyl phosphatase is 5.4-S .6 [3,4]

MECHANISM OF ENZYMATIC HYDROLYSIS OF ADENOSINETRIPHOSPHATE

MECHANISM OF ENZYMATIC HYDROLYSIS OF ADENOSINETRIPHOSPHATE

リパーゼに依る油脂分解の機構に關する研究(第1報)

リパーゼに依る油脂分解の機構に關する研究(第1報)