scholarly journals Kinetic behaviour of zymogen activation processes in the presence of an inhibitor

1993 ◽  
Vol 290 (2) ◽  
pp. 463-470 ◽  
Author(s):  
R Varón ◽  
M C Manjabacas ◽  
M García-Moreno ◽  
E Valero ◽  
F Garcia-Canovas
Keyword(s):  
Data Analysis ◽  
Kinetic Analysis ◽  
General Model ◽  
Kinetic Data ◽  
Kinetic Equations ◽  
Zymogen Activation ◽  
Activation Model ◽  
Kinetic Behaviour ◽  
Irreversible Inhibition

A global kinetic analysis of a general zymogen activation model, where not only the activating but also the activated enzyme suffer an irreversible inhibition is presented. A reaction in which the enzyme acts upon a substrate is coupled to monitor the process. In addition, we determined the corresponding kinetic equations for a number of particular cases of the general model studied. Finally, a kinetic data analysis and a procedure to discriminate among the different mechanisms considered, which are based on the kinetic equations obtained, are suggested.

scholarly journals Kinetic analysis of the control through inhibition of autocatalytic zymogen activation

1992 ◽  
Vol 282 (2) ◽  
pp. 583-587 ◽  
Author(s):  
M C Manjabacas ◽  
E Valero ◽  
M García-Moreno ◽  
F García-Cánovas ◽  
J N Rodríguez ◽  
...  
Keyword(s):  
Steady State ◽  
Kinetic Analysis ◽  
Kinetic Equations ◽  
Enzyme Regulation ◽  
Activation Process ◽  
Transient Phase ◽  
Zymogen Activation ◽  
Irreversible Inhibitor ◽  
The One ◽  
The Complement System

A global kinetic analysis of a model of an autocatalytic zymogen-activation process in which an irreversible inhibitor competes with the zymogen for the active site of the proteinase is presented. Processes like the one here described are of great physiological interest because they are involved in the enzyme regulation of the gastrointestinal-tract enzymes, in blood coagulation, in fibrinolysis and in the complement system. The kinetic equations of both the transient phase and the steady state are derived for this mechanism. In addition, we have introduced a new parameter related to the kinetic behaviour of the system which allows us to predict whether the inhibition route or the activation route prevails in the steady state of the system. Finally, we extend the kinetic equations derived to different particular cases of the system studied.

scholarly journals Kinetic analysis of the transient phase and steady state of open multicyclic enzyme cascades.

2005 ◽  
Vol 52 (4) ◽  
pp. 765-780 ◽  
Author(s):  
Ramón Varón ◽  
Bent H Havsteen ◽  
Edelmira Valero ◽  
Milagros Molina-Alarcón ◽  
Francisco García-Cánovas ◽  
...  
Keyword(s):  
Steady State ◽  
Data Analysis ◽  
Kinetic Analysis ◽  
Kinetic Data ◽  
Time Course ◽  
Intrinsic Value ◽  
Transient Phase ◽  
Enzyme Cascade ◽  
Rapid Equilibrium ◽  
Enzyme Cascades

This paper presents a kinetic analysis of the whole reaction course, i.e. of both the transient phase and the steady state, of open multicyclic enzyme cascade systems. Equations for fractional modifications are obtained which are valid for the whole reaction course. The steady state expressions for the fractional modifications were derived from the latter equations since they are not restricted to the condition of rapid equilibrium. Finally, the validity of our results is discussed and tested by numerical integration. Apart from the intrinsic value of knowing the kinetic behaviour of any of the species involved in any open multicyclic enzyme cascade, the kinetic analysis presented here can be the basis of future contributions concerning open multicyclic enzyme cascades which require the knowledge of their time course equations (e.g. evaluation of the time needed to reach the steady state, suggestion of kinetic data analysis, etc.), analogous to those already carried out for open bicyclic cascades.

scholarly journals Kinetic analysis of a Michaelis-Menten mechanism in which the enzyme is unstable

1993 ◽  
Vol 294 (2) ◽  
pp. 459-464 ◽  
Author(s):  
C Garrido-del Solo ◽  
F García-Cánovas ◽  
B H Havsteen ◽  
R Varón-Castellanos
Keyword(s):  
Data Analysis ◽  
Experimental Design ◽  
Numerical Simulations ◽  
Kinetic Analysis ◽  
Kinetic Data ◽  
Time Course ◽  
Enzyme Concentration ◽  
Free Enzyme ◽  
Substrate Complex ◽  
Enzyme Substrate

A kinetic analysis of the Michaelis-Menten mechanism is made for the cases in which the free enzyme, or the enzyme-substrate complex, or both, are unstable, either spontaneously or as a result of the addition of a reagent. The explicit time-course equations of all of the species involved has been derived under conditions of limiting enzyme concentration. The validity of these equations has been checked by using numerical simulations. An experimental design and a kinetic data analysis allowing the evaluation of the parameters and kinetic constants are recommended.

A general model for non-autocatalytic zymogen activation in the presence of two different and mutually exclusive inhibitors. I. Kinetic analysis

2010 ◽  
Vol 48 (3) ◽  
pp. 617-634 ◽  
Author(s):  
J. Masiá-Pérez ◽  
J. Escribano ◽  
E. Valero ◽  
E. Arribas ◽  
M. García-Moreno ◽  
...  
Keyword(s):  
Kinetic Analysis ◽  
General Model ◽  
Zymogen Activation

Reesterification of ethyl acetate by propanol catalysed by glycidyl methacrylate copolymers containing sulphonic acid groups

1981 ◽  
Vol 46 (8) ◽  
pp. 1941-1946 ◽  
Author(s):  
Karel Setínek
Keyword(s):  
Liquid Phase ◽  
Ethyl Acetate ◽  
Kinetic Study ◽  
Gas Phase ◽  
Nonlinear Regression ◽  
Kinetic Data ◽  
Glycidyl Methacrylate ◽  
Kinetic Equations ◽  
Methacrylate Copolymers ◽  
Styrene Divinylbenzene

A series of differently crosslinked macroporous 2,3-epoxypropyl methacrylate-ethylenedimethacrylate copolymers with chemically bonded propylsulphonic acid groups were used as catalysts for the kinetic study of reesterification of ethyl acetate by n-propanol in the liquid phase at 52 °C and in the gas phase at 90 °C. Analysis of kinetic data by the method of nonlinear regression for a series of equations of the Langmuir-Hinshelwood type showed that kinetic equations which describe best the course of the reaction are the same as for the earlier studied sulphonated macroporous styrene-divinylbenzene copolymers. Compared types of catalysts differ, however, in the dependence of their activity on the degree of crosslinking of the copolymer used.

Analysis of the temperature curves in non-isothermal adsorption on compacted zeolites

1984 ◽  
Vol 49 (4) ◽  
pp. 911-919 ◽  
Author(s):  
Milan Kočiřík ◽  
Arkadii G. Bezus ◽  
Arlette Zikánová ◽  
Irina T. Erashko ◽  
Michail M. Dubinin ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Heat Transport ◽  
Kinetic Data ◽  
Kinetic Equations ◽  
Analytical Description ◽  
Isothermal Adsorption

An analytical description is presented of the temperature curves describing adsorption on thin zeolite plates. The solution, based on the model of simultaneous mass and heat transport was obtained by linearization of the kinetic equations. A method is proposed for verification of the plausibility of the model and for evaluation of the kinetic data by numerical simulation of the temperature curves.

Kinetic analysis of a general model of activation of aspartic proteinase zymogens involving a reversible inhibitor. I. Kinetic analysis

2007 ◽  
Vol 22 (2) ◽  
pp. 147-155
Author(s):  
A. Muñoz-López ◽  
A. Sotos-Lomas ◽  
E. Arribas ◽  
J. Masia-Perez ◽  
F. Garcia-Molina ◽  
...  
Keyword(s):  
Kinetic Analysis ◽  
General Model ◽  
Aspartic Proteinase ◽  
Reversible Inhibitor

scholarly journals Kinetic Modelling of Biodegradability Data of Commercial Polymers Obtained under Aerobic Composting Conditions

Eng ◽  
2021 ◽  
Vol 2 (1) ◽  
pp. 54-68
Author(s):  
Ilenia Rossetti ◽  
Francesco Conte ◽  
Gianguido Ramis
Keyword(s):  
Kinetic Data ◽  
Kinetic Modelling ◽  
Kinetic Equations ◽  
Second Order ◽  
Aerobic Biodegradation ◽  
First Order ◽  
First Order Kinetics ◽  
Plastic Materials ◽  
Partial Degradation ◽  
Commercial Polymers

Methods to treat kinetic data for the biodegradation of different plastic materials are comparatively discussed. Different samples of commercial formulates were tested for aerobic biodegradation in compost, following the standard ISO14855. Starting from the raw data, the conversion vs. time entries were elaborated using relatively simple kinetic models, such as integrated kinetic equations of zero, first and second order, through the Wilkinson model, or using a Michaelis Menten approach, which was previously reported in the literature. The results were validated against the experimental data and allowed for computation of the time for half degradation of the substrate and, by extrapolation, estimation of the final biodegradation time for all the materials tested. In particular, the Michaelis Menten approach fails in describing all the reported kinetics as well the zeroth- and second-order kinetics. The biodegradation pattern of one sample was described in detail through a simple first-order kinetics. By contrast, other substrates followed a more complex pathway, with rapid partial degradation, subsequently slowing. Therefore, a more conservative kinetic interpolation was needed. The different possible patterns are discussed, with a guide to the application of the most suitable kinetic model.

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