Enzyme theory advantage

MULTISUBSTRATE SYSTEMS. Wong and Hanes were probably among the first to suggest that alternative substrates may be useful in mechanistic studies. Fromm s laboratory was the first to use and extend the theory of alternative substrate inhibition to address specific questions about multisubstrate enzyme kinetic mechanisms. Huang demonstrated the advantages of a constant ratio approach when dealing with alternative substrate kinetics. 

Selected entries from Methods in Enzymology [vol, page(s)] Theory, 63, 159-162 activation effect, 63, 174, 175 analysis, 63, 140, 159-183 burst, 64, 20, 203, 215 enzyme concentration, 63, 175-177 hysteresis, 64, 197, 200-204 limitations, 63, 181-183 plotting, 63, 177-180 practical methods, 63, 175-177 reversible inhibitor action, 63, 163-175 reversible reaction, 63, 171-175 simulation of, 63, 180 advantages and disadvantages, 249, 61-62 analysis, in kinetic models of inhibition, 249, 168-169 concave-down, 249, 156 concave-up, 249, 156 with enzyme-product complex instability, 249, 88 with enzyme-substrate instabil-... 

A Owen, The Diode-Array Advantage in UV/VIS Spectroscopy (1988), Hewlett-Packard Co Theory and practice of diode array spectroscopy K Peterman, K Lentz, and J Duncan,/ Chem. Educ. 75, 1283-1284 (1998) A I9F NMR Study of Enzyme Activity ... 

We have demonstrated for the first time that we could apply the theory of generalized Thiele modulus to an enzymatic reaction both in n-hexane and SC CO2. The comparison between the two reaction media is not so clear in n-hexane the real reaction velocity is higher than that obtained in SC C02. Nevertheless, the Thiele modulus values indicates a limitation due to the internal mass transfer rate g 1. Thus we observed, in the hexane case, a diffusional control, while in SC C02 an intermediate rate between the reactional and diffusional rates was apparent. It therefore, seems that SC CO2 should be the solvent of choice in reactions catalyzed by immobilized enzymes, since it reduces problems with internal mass transfer. An other advantage is that the value of the inhibition constant is 43 mM in n-hexane and 120 mM in SC CO2 [14], so SC CO2 should be more convenient if we have to work with higher ethanol concentration. The economic feasibility of an industrial scale lipase catalyzed reaction on C02 may depend upon possible costs for high-pressure equipment. 

T he fact that many pesticides inhibit enzymes in vitro has led to the introduction of various analytical methods for the detection and estimation of pesticide residues. This paper wiU not describe in detail all the enzymatic techniques used for pesticide residue analysis but rather will attempt to categorize and describe briefly the main types with reference to the theory behind their use, their practical application, and associated problems. This will be followed by a brief discussion on the advantages and disadvantages of these techniques. 

You might suppose that this was all that needed to be said about entropy-enthalpy compensation, but there is more, because to make a usable theory about biochemical optimization we have to be able to see some biological point in the property that is supposedly being optimized. What if the phenomenon in question were not just a mathematical artifact What if there really were a compensation temperature at which the enzymes from fishes living at different temperatures from one another (and different from the compensation temperature) all had the same activity What would be the advantage to a fish that spent its entire life in tropical waters at 40°C if its muscle enzymes, once removed from the killed fish, proved to have the same catalytic activity when cooled to 18°C as the corresponding warmed enzymes from a quite different fish that spent its life in the near-frozen waters of the Antarctic Why should such a correspondence have been selected by evolution I can see no reason, and so even if the phenomenon were based on a much firmer basis of experimental fact than it is, I should be deeply suspicious of it until some plausible advantage to the fishes had been identified. 

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