scholarly journals Kinetic analysis of regeneration by dilution of a covalently modified protein

1990 ◽  
Vol 268 (3) ◽  
pp. 669-670 ◽  
Author(s):  
E T Rakitzis
Keyword(s):  
Reaction Time ◽  
Rate Constants ◽  
Constant Term ◽  
Covalent Modification ◽  
Regeneration Rate ◽  
Modifying Agent ◽  
Reaction Rate Constants ◽  
Enzyme Reactivation ◽  
Microscopic Reaction ◽  
Single Exponential

An analysis of regeneration by dilution of a covalently modified protein is presented. It is shown that, when protein regeneration is realized through the intermediacy of a protein-modifying agent adsorptive complex, the reaction is described by a summation of two exponential functions of reaction time plus a constant-term equation. The conditions whereby this equation reduces to a single-exponential equation are delineated. It is shown that, when protein regeneration is described by a single-exponential function of reaction time, the first-order protein-regeneration rate constant is a function of modifying-agent concentration and also of the microscopic reaction rate constants. Accordingly, the protein-modifying agent dissociation constant (Ki), as well as the protein-covalent-modification and -regeneration, rate constants (k+2 and K-2), may be determined by an analysis of dilution-induced protein-regeneration (or enzyme-reactivation) data obtained at different dilutions of the covalently modified protein-modifying agent preparation.

scholarly journals Kinetic analysis of protein modification reactions at equilibrium

1989 ◽  
Vol 263 (3) ◽  
pp. 855-859 ◽  
Author(s):  
E T Rakitzis
Keyword(s):  
Reaction Time ◽  
Kinetic Analysis ◽  
Protein Modification ◽  
Constant Term ◽  
Enzyme Inactivation ◽  
Exponential Functions ◽  
Kinetic Criterion ◽  
Single Exponential Function ◽  
Single Exponential ◽  
Reaction Schemes

A kinetic analysis is presented of reactions of protein modification, and/or of modification-induced enzyme inactivation, which can formally be described by a single exponential function, or by a summation of two exponential functions, of reaction time plus a constant term. The reaction schemes compatible with the kinetic formalism of these cases are given, and a simple kinetic criterion is described whereby the identification of one of these cases, strong negative protein modification co-operativity, may be carried out. The treatment outlined in this paper is applied to a case from the literature, the inactivation of glyceraldehyde-3-phosphate dehydrogenase by butane-2,3-dione [Asriyants, Benkevich & Nagradova (1983) Biokhimiya (Engl. Transl.) 48, 164-171].

scholarly journals Treatability of Biodiesel Wastewaters By Using KMnO4 And KMnO4/O3 Processes And Kinetic Analysis

2021 ◽  
Author(s):  
Pınar N. TANATTI
Keyword(s):  
Reaction Time ◽  
Potassium Permanganate ◽  
Rate Constants ◽  
Reaction Rate ◽  
Suitable Model ◽  
Order Kinetic ◽  
Optimum Conditions ◽  
Reaction Rate Constants ◽  
Order Kinetic Model ◽  
Removal Efficiencies

Abstract The purpose of this study is to investigate the treatability of electrocoagulated biodiesel wastewater (ECBD) by potassium permanganate (KMnO4) and potassium permanganate/ozone (KMnO4/O3) processes. The ECBD removal efficiencies of both combined method and KMnO4 methods were compared and the KMnO4/O3 process gave better results than the KMnO4 process. For the ECBD removal efficiencies, the experimental parameters including pH, potassium permanganate dose, ozone dose and reaction time parameters were optimized by changing the one parameter at a time. As a result of 6 h of KMnO4 oxidation, 91.74% of COD and 95.93% of MeOH removal was achieved under the optimum conditions (pH 2, 5 g/L KMnO4 dose). However, under optimum conditions (pH 13, 2 g/L KMnO4 dose, 3000 mg/L O3 dose, 6 h reaction time), the COD and MeOH removal efficiencies have been obtained for KMnO4/O3 as 97.79% and 98.30%, respectively. The second order kinetic model has been found to be the most suitable model for both processes and the regression coefficients (R2) has been found as 0.999 and 0.999 for KMnO4 and KMnO4/O3, respectively. The reaction rate constants (k) have been also calculated as 6x10-5 L/mg.min and 1.63x10-4 L/mg.min for COD and MeOH in KMnO4 oxidation, respectively. Furthermore, the reaction rate constants (k) have been also calculated as 6x10-5 L/mg.min and 1.6x10-4 L/mg.min for COD and MeOH in KMnO4/O3 oxidation, respectively.

Measurement of the OH Reaction Rate Constants for CF3CH2OH, CF3CF2CH2OH, and CF3CH(OH)CF3

1999 ◽  
Vol 103 (15) ◽  
pp. 2664-2672 ◽  
Author(s):  
Kazuaki Tokuhashi ◽  
Hidekazu Nagai ◽  
Akifumi Takahashi ◽  
Masahiro Kaise ◽  
Shigeo Kondo ◽  
...  
Keyword(s):  
Rate Constants ◽  
Reaction Rate ◽  
Reaction Rate Constants

scholarly journals PREDICTION OF REACTION RATE CONSTANTS OF HYDROXYL RADICAL WITH ORGANIC COMPOUNDS

2014 ◽  
Vol 59 (1) ◽  
pp. 2252-2259 ◽  
Author(s):  
ZHEN CHEN ◽  
XINLIANG YU ◽  
XIANWEI HUANG ◽  
SHIHUA ZHANG
Keyword(s):  
Hydroxyl Radical ◽  
Organic Compounds ◽  
Rate Constants ◽  
Reaction Rate ◽  
Reaction Rate Constants

scholarly journals Tunnelling dominates the reactions of hydrogen atoms with unsaturated alcohols and aldehydes in the dense medium

2018 ◽  
Vol 617 ◽  
pp. A25 ◽  
Author(s):  
V. Zaverkin ◽  
T. Lamberts ◽  
M. N. Markmeyer ◽  
J. Kästner
Keyword(s):  
Functional Groups ◽  
Rate Constants ◽  
Aldehyde Group ◽  
Dense Medium ◽  
Hydrogen Atoms ◽  
Hydrogen Addition ◽  
Reaction Rate Constants ◽  
Quantum Chemical Methods ◽  
Experimental Findings ◽  
Recombination Reactions

Hydrogen addition and abstraction reactions play an important role as surface reactions in the buildup of complex organic molecules in the dense interstellar medium. Addition reactions allow unsaturated bonds to be fully hydrogenated, while abstraction reactions recreate radicals that may undergo radical–radical recombination reactions. Previous experimental work has indicated that double and triple C–C bonds are easily hydrogenated, but aldehyde –C=O bonds are not. Here, we investigate a total of 29 reactions of the hydrogen atom with propynal, propargyl alcohol, propenal, allyl alcohol, and propanal by means of quantum chemical methods to quantify the reaction rate constants involved. First of all, our results are in good agreement with and can explain the observed experimental findings. The hydrogen addition to the aldehyde group, either on the C or O side, is indeed slow for all molecules considered. Abstraction of the H atom from the aldehyde group, on the other hand, is among the faster reactions. Furthermore, hydrogen addition to C–C double bonds is generally faster than to triple bonds. In both cases, addition on the terminal carbon atom that is not connected to other functional groups is easiest. Finally, we wish to stress that it is not possible to predict rate constants based solely on the type of reaction: the specific functional groups attached to a backbone play a crucial role and can lead to a spread of several orders of magnitude in the rate constant.

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