Kinetics cooperative

Rate-limiting enzymes may show cooperative kinetic. 

Pyruvate kinase (PK) from F. hepatica closely resembles L-type PK from mammalian liver (Behm and Bryant, 1980). It shows cooperative kinetics with PEP, but in the presence of... 

The SC state transition can be characterized as a non-adiabatic sudden increase of the cooperative kinetic effect at lattice energy stabilization (NASICKELES). It is exactly participation of the nuclear kinetic energy... 

For multisubstrate enzymatic reactions, the rate equation can be expressed with respect to each substrate as an m function, where n and m are the highest order of the substrate for the numerator and denominator terms respectively (Bardsley and Childs, 1975). Thus the forward rate equation for the random bi bi derived according to the quasi-equilibrium assumption is a 1 1 function in both A and B (i.e., first order in both A and B). However, the rate equation for the random bi bi based on the steady-state assumption yields a 2 2 function (i.e., second order in both A and B). The 2 2 function rate equation results in nonlinear kinetics that should be differentiated from other nonlinear kinetics such as allosteric/cooperative kinetics (Chapter 6, Bardsley and Waight, 1978) and formation of the abortive substrate complex (Dalziel and Dickinson, 1966 Tsai, 1978). 

In the very general form of Eq. (101), cooperative kinetics are very hard to deal with mathematically. However, a very strong (but also powerful) assumption of uniformity was introduced by Astarita and Ocone (1988) The functional F[ ] does not depend on the component label x, so that the continuous description of uniform cooperative kinetics is... 

Luchter-Wasylewska E (2001) Cooperative kinetics of human prostatic acid phosphatase. Biochim Biophys Acta 1548 257-264... 

Figure 6.20. An example of cooperative kinetics with a toe at low substrate levels.

The two-variable model for birhythmicity is built on the basis of eqns (2.7) by incorporating into them a term related to the transformation of product into substrate, in a reaction catalysed by an enzyme whose cooperative kinetics is described by a Hill equation, characterized by a degree of cooperativity n. The kinetic equations of the model thus take the form of eqns (3.1) where the various parameters remain defined as for eqns (2.7) and (2.11) ... 

The nonlinear 2 2 function kinetics should be differentiated from other nonlinear kinetics such as allosteric/cooperative kinetics (Bardsley and Waight, 1978) and the formation of the abortive substrate complex (Dalziel and Dickinson, 1966). The cooperative kinetics (of the double reciprocal plots) can either concave up (positive cooperativity) or... 

Simha, R., and Lacombe, R. H., One-dimensional cooperative kinetic model equilibrium solution for finite chins, J. Chem. Phys., 55, 2936-2939 (1971)... 

Simha, R., Lacombe, R. H., One-dimensional cooperative kinetic model. Equilibrium... 

W. Cooper, Kinetics of polymerization initiated by Ziegler-Natta and related catalysts, in Comprehensive Chemical Kinetics, Vol. 15 Non-radical Polymerization, C. H. Bamfordand C. F. H. Tipper (eds.), Elsevier, Amsterdam, 1976. 

Creation, motion, and destraction of holes are cooperative kinetic processes and may be slow. This leads to deviations from Eq. (1) if the measurement is carried out faster than the kinetics allows. Applied to the glass transition, one can write and solve a simple, first-order kinetics expression [40] based on the equilibrium expression, above ... 

The enzyme has been purified from a yeast, Schizosaccharomyces pombe, by Nagy [50a], It shows homotropic cooperative kinetics with the two substrates, PRPP and glutamine, and it differs in its inhibition patterns from those of bacteria in that IMP and GMP are strong inhibitors, and AMP is a weak inhibitor. Combinations of AMP with the other nucleotides are additive rather than synergistic. Genetic alteration of the enzyme was found in a mutant resistant to 8-azaguanine. Sensitivity of the mutant enzyme toward IMP and GMP is drastically reduced and binding kinetics of these nucleotides is altered. 

Two ideas have been considered to derive valid lumped models for systems with nonlinear kinetics. The first is the use of cooperative kinetics,which is applicable to catalytic reactions governed by Langmuir isotherm adsorption, and can be extended to other models if there is uniform catalytic surface coverage. The second is a transformation of the coordinates (such as nonlinear stretching of the time coordinate). ... 

Ainslie, G.R., Shill, J.P., and Neet, K. E., 1972, Transients and cooperativity A slow transition model for relating transients and cooperative kinetics of enzymes, /. Biol. Chem. 247 7088. 

Vessey, D. A., Goldenberg, J., and Zakim, D., 1973, Kinetic properties of microsomal UDP-glucuronyltransferase. Evidence for cooperative kinetics and activation by UDP-N-acetylglucosamine, Biochim. Biophys. Acta 309 58. 

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