Coupling enzyme, soluble

Ad values) (4) effect on the pH function of any or all components of the reactions (including the buffer) (5) effect on the affinity(ies) of enzyme effector(s) (6) an alteration in the rate determining (or rate contributing) step(s) (7) effect on the coupling enzymes of the assay and (8) effect on physical properties e.g., solubility of substrates, particularly gas substrates such as O2 and N2, dielectric constant of the solvent, etc.). 

To achieve true homogeneous catalysis, enzyme solubility may be increased by coupling polyethyleneglycol to its surface1871. The coupling may alter the stability, activity and selectivity of the enzyme. 

Modificatimi of Enzymes and Uses of Modified En rmes a-Amylase.—Bacillus amyloliquefaciens a-amylase has been modified by covalent coupling with soluble dextran cyclic imidocarbonate and the stability of the resulting complex investigated. ... 

Because of the fairly conclusive evidence that malate synthesized by dark CO2 fixation is not in equilibrium with malate synthesized in the mitochondria, it seems reasonable to conclude that the soluble malate dehydrogenase functions to a large extent in the dark CO2 fixation pathway. We also would predict, that insofar as P-enolpyruvate carboxylase-mediated synthesis of malate takes place in chloroplasts, the NADP malate dehydrogenase would be the coupling enzyme. 

This is a crucial point because (as we will see) proton transport is coupled with ATP synthesis. Oxidation of one FADHg in the electron transport chain results in synthesis of approximately two molecules of ATP, compared with the approximately three ATPs produced by the oxidation of one NADH. Other enzymes can also supply electrons to UQ, including mitochondrial 5w-glyc-erophosphate dehydrogenase, an inner membrane-bound shuttle enzyme, and the fatty acyl-CoA dehydrogenases, three soluble matrix enzymes involved in fatty acid oxidation (Figure 21.7 also see Chapter 24). The path of electrons from succinate to UQ is shown in Figure 21.8. 

As with organic solvents, proteins are not soluble in most of the ionic liquids when they are used as pure solvent. As a result, the enzyme is either applied in immobilized form, coupled to a support, or as a suspension in its native form. For production processes, the majority of enzymes are used as immobilized catalysts in order to facilitate handling and to improve their operational stability [24—26]. As support, either inorganic materials such as porous glass or different organic polymers are used [27]. These heterogeneous catalyst particles are subject to internal and external... 

Many interesting biocatalytic reactions involve organic components that are poorly water-soluble. When using organic-aqueous biphasic bioreactor, availability of poorly water-soluble reactants to cells and enzymes is improved, and product extraction can be coupled to the bioreaction. Many applications in two-phase media can use the existing standard-type bioreactors, such as stirred-tank, fluidized-bed, and column reactors with minor adjustments. 

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