9780521516358book.pdf
(seven catalytic centres), pyruvate dehydrogenase (EC 2:7:1:99) (three catalytic centres) and DNA polymerase (EC 2:7:7:7) (three ...
whereVmaxis the limiting value of the initial rate when all the active sites are occupied, Kmis theMichaelis constantand [S] is ...
the maximum rate (Fig. 15.3) and has units of molarity. Values ofKmare usually in the range 10^2 to 10^5 M and are important b ...
It can be seen that whenKsis numerically large, the equilibrium is in favour of unbound E and S, i.e. of non-binding, whilst whe ...
A plot of 1/n 0 against 1/[S] gives a straight line of slopeKm/Vmax, with an intercept on the 1/ 0 axis of 1/Vmaxand an interce ...
Example 1PRACTICAL ENZYME KINETICS Question The enzymea-D-glucosidase isolated fromSaccharomyces cerevisiaewas studied using the ...
Example 1(cont.) Table B [S] (mM) 0.03 0.06 0.09 0.12 0.18 0.24 0.36 v 0 (mmol min^1 ) 0.054 0.096 0.138 0.168 0.210 0.251 0.29 ...
kcat¼ Vmax ½Et ð 15 : 8 Þ where [Et] is the total concentration of enzyme. The turnover number is the maximum number of moles o ...
Thus, when the substrate concentration is very large, equation 15.9 reduces to v 0 ¼kþ 2 [E], i.e. the initial rate is directly ...
value is obtained from a secondary plot (Fig. 15.6). The reaction is carried out for a range of substrate concentrations in the ...
Non-competitive reversible inhibition Anon-competitive reversible inhibitorcombines at a site distinct from that for the substra ...
kinetics are obtained. Mixed inhibition is characterised by a linear Lineweaver–Burk plot that does not fit any of the patterns ...
it gives an understanding of the possible ways by which metabolic activity may be controlledin vivo; it allows specific inhibit ...
a substrate to product as a function of the reaction coordinate that measures the time- related progress of the reaction. The nu ...
The observation is explained in terms ofenzyme-catalysed quantum tunnelling. Under this mechanism, rather than overcoming the po ...
15.2.4 Allosterism and cooperativity The discussion of the mechanism of enzyme action so far has been based on the assumption th ...
log v^0 Vmaxv 0 ¼hlog½SþlogK ð 15 : 17 Þ wherehis theHill constantorcoefficient, andKis anoverall binding constant related to ...
of protein conformations is the existence ofamino acid networksthat facilitate communication between the different sites and tha ...
15.3 Analytical methods for the study of enzyme reactions 15.3.1 General considerations Enzyme assays are undertaken for a varie ...
assay. It is essential that the substrate and product do not absorb at the same wavelength and that the Beer–Lambert law (Sectio ...
«
26
27
28
29
30
31
32
33
34
35
»
Free download pdf
