Temperature effect on enzymes

Cano, M.P., Hernandez, A., and De Ancos, B. 1997. High pressure and temperature effects on enzyme inactivation in strawberry and orange products. J. Food Sci. 62, 85-88. 

Selected entries from Methods in Enzymology [vol, page(s)] Theory, 63, 340-352 measurement, 63, 365 cryosolvent [catalytic effect, 63, 344-346 choice, 63, 341-343 dielectric constant, 63, 354 electrolyte solubility, 63, 355, 356 enzyme stability, 63, 344 pH measurements, 63, 357, 358 preparation, 63, 358-361 viscosity effects, 63, 358] intermediate detection, 63, 349, 350 mixing techniques, 63, 361, 362 rapid reaction techniques, 63, 367-369 temperature control, 63, 363-367 temperature effect on catalysis, 63, 348, 349 temperature effect on enzyme structure, 63, 348. 

Effect of Temperature Effect on Enzyme Affinity, Reactivity and Stability... 

It is unlikely that under normal conditions, temperature will exercise any role in modulating enzymic activity. However, temperature effects on enzymes may achieve some importance in poikilothermic species and possibly also during the decrease in body temperature that occurs during hibernation. More importantly temperature may have been an important factor in determining the nature of binding interactions for specific enzymes which have evolved under different thermal environments, a fascinating possibility which has been elaborated by Somero and Low (1976). 

Many of the investigations are carried out at low temperatures and/or at pH values deviating somewhat from neutrality. It has earlier been emphasized that the influence from factors such as temperature, pressure, pH, concentrations, ionic strength, and salt effects must be considered when pressure effects are discussed. This is because conditions that are optimal to one enzyme may be intolerable to another. After all, we are dealing with enzymes from microorganisms, cold-blooded, and warm-blooded animals. Such complications make comparison of pressure effects on enzymes nearly meaningless. 

The increase in energy content of an atom, ion, or molecular entity or the process that makes an atom, ion, or molecular entity more active or reactive. In enzymology, activation often refers to processes that result in increased enzyme activity. For example, increasing temperature often can have a positive effect on enzyme activity (See Arrhenius Equation). Other examples of enzyme activation include (1) proteolysis of zymogens (2) alterations in ionic strength (3) alterations due to pH changes (4) activation in cooperative systems (5) lipid or membrane interface activation (6) metal ion effects (7) autocatalysis and (8) covalent modification. 

The study of temperature effects on the reactivation of an enzyme that has been completely unfolded allows one to distinguish between reactivation (referring to kinetic analysis exclusively) and renaturation, the latter of which would reflect both the refolding transition and the formation of misfolded or aggregated byproducts. 

Dixon and Webb provided a useful list of various causes for the shape of the temperature effect seen in enzyme-catalyzed reactions (1) effect on enzyme stability (2) effect on the actual velocity of the reaction (especially on kcat) (3) effect on affinity(ies) of the substrate(s)... 

Table 2 presents the results obtained in the statistical modeling. Temperature and reduced density had a pronounced effect on enzyme activity loss, both showing a positive effect. At this point, it is important to mention that the cross-interaction temperature-exposure time had a significant negative effect. In the range investigated (10-200 kg/[m3-min]), the decompression rate had a weak negative effect on loss of enzyme activity. The same effect was observed with the exposure time (60-360 min). 

The most common enzymatic reactions are those with two or more substrates and as many products. But many of the simpler single-substrate schemes are valuable for the development of kinetic ideas concerning effects of pH, temperature, etc., on enzyme reaction rates. Although the mechanisms of multisubstrate reactions are complicated, their kinetics can often be described by an equation of the form ... 

Clark, K.J., F.W. Chaplin, and S.W. Harcum. 2004. Temperature effects on product-quality-related enzymes in batch CHO cell cultures producing recombinant tPA. Biotechnol Prog 20 1888-1892. 

McNiel, B. Kristiansan, B. Temperature effects on polysaccharide formation by Aureobasidium pullulans in stirred tank. Enzyme Microb. Tech-nol. 1990, 12, 521-526. 

The presence of non-ionic detergents (Tween 20, Triton X-100) in the substrate solution is uncommon, but may have a beneficial effect on enzyme activity (Section 10.1.1.4.2). These detergents delay inactivation of the enzyme and increase the optimum temperature... 

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