Time-dependent inhibition of enzymes by active-site-directed reagents a theoretical treatment of the kinetics of affinity labelling
✍ Scribed by Robert E. Childs; William G. Bardsley
- Publisher
- Elsevier Science
- Year
- 1975
- Tongue
- English
- Weight
- 622 KB
- Volume
- 53
- Category
- Article
- ISSN
- 0022-5193
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✦ Synopsis
Time-dependent inhibition of enzymes by active-site-directed reagents is usually assumed to be a pseudo-first order process. However, we have noticed that the semilogarithmic plots reported by many workers and obtained by ourselves (for the inhibition of diamine oxidase by carbonyl group reagents) are actually non-linear. This suggested a reappraisal of the usual model and the results of this investigation are now reported.
Limitations in the various approximate mathematical models for timedependent inhibition are discussed. In particular, it is shown that the usual models cannot actually give linear functions of In [(E + EI)/Eo] with time as is generally claimed. However, under some circumstances, apparently pseudo-first order kinetics may result. A rigorous mathematical formulation of the problem is presented which should help towards more critical interpretation of experimental results in the future.