Kinetics of α-chymotrypsin action. III. Mechanisms of inhibition

1967 ◽  
Vol 45 (5) ◽  
pp. 559-565 ◽  
Author(s):  
Harvey Kaplan ◽  
Keith J. Laidler
Keyword(s):  
Experimental Study ◽  
Ethyl Ester ◽  
Free Enzyme ◽  
General Mechanism ◽  
Competitive Behavior ◽  
Mechanism Of Inhibition ◽  
Quantitative Manner ◽  
Order Sequence ◽  
Kinetics Of ◽  
Hydrolysis Of

An experimental study was made of the α-chymotrypsin-catalyzed hydrolysis of N-acetyl-l-tyrosine ethyl ester, inhibited by indole and phenol. Indole inhibits noncompetitively, and analysis of the behavior shows that it binds to the enzyme and the acyl enzyme but not to the Michaelis complex; by binding to the acyl enzyme, it blocks deacylation. Phenol exhibits competitive behavior, two molecules of phenol being bound to the free enzyme in a forced-order sequence. It is concluded from the kinetics that there is either no binding of phenol to the acyl enzyme, or binding which does not affect the rate of deacylation. A general mechanism of inhibition is shown, to explain in a quantitative manner these and other inhibition results.

The effect of ethanol on the kinetics of lipase-mediated enantioselective esterification of 4-methyloctanoic acid and the hydrolysis of its ethyl ester

2001 ◽  
Vol 76 (3) ◽  
pp. 193-199 ◽  
Author(s):  
Nicole W. J. T. Heinsman ◽  
Ana M. Valente ◽  
Henry G. F. Smienk ◽  
Albert van der Padt ◽  
Maurice C. R. Franssen ◽  
...  
Keyword(s):  
Ethyl Ester ◽  
Kinetics Of ◽  
Hydrolysis Of

Studies on Chymotrypsin-P. II. Kinetics

1972 ◽  
Vol 50 (7) ◽  
pp. 846-847 ◽  
Author(s):  
M. C. Shaw ◽  
T. Viswanatha
Keyword(s):  
Ethyl Ester ◽  
Catalytic Properties ◽  
Feature Characteristic ◽  
Catalyzed Reactions ◽  
A Chain ◽  
Kinetics Of ◽  
Hydrolysis Of ◽  
Chymotrypsin A

A comparison of the kinetics of chymotrypsin-P catalyzed hydrolysis of N-acetyl-L-tyrosine ethyl ester and cinnamoylimidazole with those of the chymotrypsin Aα catalyzed reactions revealed the two enzymes to possess very similar catalytic properties. The deletion of the three C-terminal residues from the A-chain of chymotrypsin Aα, a feature characteristic of chymotrypsin-P, does not lead to significant changes in the function of the enzyme.

Immobilized Nanoparticles-Mediated Enzymatic Hydrolysis of Cellulose for Clean Sugar Production: A Novel Approach

2019 ◽  
Vol 15 (3) ◽  
pp. 296-303 ◽  
Author(s):  
Swapnil Gaikwad ◽  
Avinash P. Ingle ◽  
Silvio Silverio da Silva ◽  
Mahendra Rai
Keyword(s):  
Catalytic Activity ◽  
Enzymatic Hydrolysis ◽  
Immobilized Enzyme ◽  
Free Enzyme ◽  
Magnetic Nanomaterials ◽  
Sugar Production ◽  
Cellulase Enzyme ◽  
Enzymatic Hydrolysis Of Cellulose ◽  
Hydrolysis Of Cellulose ◽  
Hydrolysis Of

Background: Enzymatic hydrolysis of cellulose is an expensive approach due to the high cost of an enzyme involved in the process. The goal of the current study was to apply magnetic nanomaterials as a support for immobilization of enzyme, which helps in the repeated use of immobilized enzyme for hydrolysis to make the process cost-effective. In addition, it will also provide stability to enzyme and increase its catalytic activity. Objective: The main aim of the present study is to immobilize cellulase enzyme on Magnetic Nanoparticles (MNPs) in order to enable the enzyme to be re-used for clean sugar production from cellulose. Methods: MNPs were synthesized using chemical precipitation methods and characterized by different techniques. Further, cellulase enzyme was immobilized on MNPs and efficacy of free and immobilized cellulase for hydrolysis of cellulose was evaluated. Results: Enzymatic hydrolysis of cellulose by immobilized enzyme showed enhanced catalytic activity after 48 hours compared to free enzyme. In first cycle of hydrolysis, immobilized enzyme hydrolyzed the cellulose and produced 19.5 ± 0.15 gm/L of glucose after 48 hours. On the contrary, free enzyme produced only 13.7 ± 0.25 gm/L of glucose in 48 hours. Immobilized enzyme maintained its stability and produced 6.15 ± 0.15 and 3.03 ± 0.25 gm/L of glucose in second and third cycle, respectively after 48 hours. Conclusion: This study will be very useful for sugar production because of enzyme binding efficiency and admirable reusability of immobilized enzyme, which leads to the significant increase in production of sugar from cellulosic materials.

Influence of medium on alkaline hydrolysis of succinic acid monomethyl and monopropyl esters

1980 ◽  
Vol 45 (11) ◽  
pp. 2873-2882
Author(s):  
Vladislav Holba ◽  
Ján Benko
Keyword(s):  
Succinic Acid ◽  
Kinetic Parameters ◽  
Alkaline Hydrolysis ◽  
Specific Interactions ◽  
Nonaqueous Media ◽  
The Media ◽  
Kinetics Of ◽  
Hydrolysis Of

The kinetics of alkaline hydrolysis of succinic acid monomethyl and monopropyl esters were studied in mixed aqueous-nonaqueous media at various temperatures and ionic strengths. The results of measurements are discussed in terms of electrostatic and specific interactions between the reactants and other components of the reaction mixture. The kinetic parameters in the media under study are related to the influence of the cosolvent on the solvation sphere of the reactants.

Belousov–Zhabotinskii type oscillation reaction with glycerol and kinetics of reactions between the system components

1987 ◽  
Vol 52 (10) ◽  
pp. 2375-2382 ◽  
Author(s):  
Ľubica Adamčíková ◽  
Peter Ševčík
Keyword(s):  
Oscillation System ◽  
Chemical Oscillations ◽  
Oscillation Reaction ◽  
Reaction Solution ◽  
System Components ◽  
Probable Source ◽  
Belousov Zhabotinskii Reaction ◽  
Kinetics Of ◽  
Hydrolysis Of ◽  
Type Oscillation

Glycerol causes chemical oscillations in Belousov-Zhabotinskii reaction in a closed system as well as in a reaction solution bubbled with nitrogen. Since the oxidation of glycerol with bromate ions does not proceed autocatalytically and bromine in the oxidation state 0 or +1 in the absence of light does not react with glycerol, hydrolysis of bromine is the probable source of bromide ions in the studied oscillation system.

Kinetics of hydrolysis of peroxodisulphate ions in acidic medium to peroxomonosulphuric acid

1981 ◽  
Vol 46 (5) ◽  
pp. 1229-1236 ◽  
Author(s):  
Jan Balej ◽  
Milada Thumová
Keyword(s):  
Ionic Strength ◽  
Rate Constants ◽  
Acidic Medium ◽  
Measured Data ◽  
Molar Ratios ◽  
Starting Solution ◽  
Kinetics Of Hydrolysis ◽  
Rate Of Hydrolysis ◽  
Kinetics Of ◽  
Hydrolysis Of

The rate of hydrolysis of S2O82- ions in acidic medium to peroxomonosulphuric acid was measured at 20 and 30 °C. The composition of the starting solution corresponded to the anolyte flowing out from an electrolyser for production of this acid or its ammonium salt at various degrees of conversion and starting molar ratios of sulphuric acid to ammonium sulphate. The measured data served to calculate the rate constants at both temperatures on the basis of the earlier proposed mechanism of the hydrolysis, and their dependence on the ionic strength was studied.

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