Abbreviations

brightness and spectral properties of the fluorophore-labelled molecule affect the measurement of the signal significantly. This resolution directly yields kinetic information, for example, when measuring: (a) diffusion coefficients with respect to changes in the position of molecule (b) timelapse experiments to analyse the systematic change in the brightness of fluorogenic substrate turnover with time or (c) temporal changes in molecule conformation or configuration when

The microscopic validity of chemical master equation (CME) has also been tested and verified by molecular dynamics for dilute chemical systems and using Brownian dynamics simulations for non-dilute crowded systems. The major assumption underlying the CME is that reactions are occurring in well-mixed environments. The characteristics of reactivity fluctuations in individual enzyme molecules relate to the second moment of turnover time statistics which can be defined by the randomness parameter R and time statistics. The randomness parameter R tends to become 1, when the waiting time distribution is a single exponential decay function. Any deviation of R from this predicted value is an indication of dynamic disorder [121]. When this is applied for the inhibition reaction, the expressions for the waiting time distributions for inhibition reactions became cumbersome. If more than one intermediate steps are present in the given set of reactions, then the chemical master equations become more and more complex. To avoid such complications, Chaudhary has used a simple analytical model based on the first passage time distribution between successive catalytic turnover events. This probability distribution function (PDF) is the moment of one monitored transition. If ϕ(t)dt is the probability of observing the next monitored transition between time t and (t+ dt) after this time moment. The assumption made is that there is formation of product molecules with regeneration of the free enzyme. Such events are actually detectable in single-molecule fluorescence experiments [126]. These experiments have given the final expression for competitive inhibition can be given as

observing changes in FRET between a judiciously placed donor-acceptor pair.

〈tcompetitive〉 <sup>¼</sup> <sup>½</sup>S�þ½I�

plistic equations.

114 Enzyme Inhibitors and Activators

8. Conclusion

〈tuncompetitive〉 <sup>¼</sup> <sup>½</sup>S�þ½I�½S� <sup>k</sup><sup>3</sup>

Various researchers are applying various approaches to derive rate expression for the enzymatic reaction, which are under continuous evaluation to finalize more generalized and sim-

Biocatalysis has evolved as a promising lead to make the chemical process more sustainable, green and environment friendly. The main challenge in biocatalysed reactions is their industrial viability and economical aspects. The advancement in genetic engineering, medium engineering and immobilization technology has made them more robust to sustain the industrial environment. To transform the lab scale process to industrial scale, the understanding of the

k3ðk�1þk2Þ

<sup>k</sup>1k�<sup>3</sup> <sup>þ</sup> <sup>ð</sup>k�1þk2<sup>Þ</sup> k1

> <sup>k</sup>�<sup>3</sup> <sup>þ</sup> <sup>ð</sup>k�1þk2<sup>Þ</sup> k1

<sup>k</sup>2½S� (76)

<sup>k</sup>2½S� (77)


