《Biomolecular Kinetics：A Step-by-Sep Guide》Clive R. Bagshaw 著
Chemical kinetics of biological systems has a long history. Brewing is often
cited as an early example of applied biochemistry and timing is clearly a key
part of the fermentation process to generate the desired alcohol concentration.
But even in terms of modern biochemical investigations, kinetic measurements
represent a long-standing methodology. Many of the key concepts were derived
more than a century ago [1]. For these reasons and their continued under-pinning
role in biochemical assays, the fundamentals of steady-state enzyme kinetics are
introduced in most first-year undergraduate biochemistry courses, including
the practical measurement of enzyme activity. In parallel, the principles of firstand
second-order reactions are taught in first-year supplementary chemistry
courses, but often with few biochemical examples. In subsequent years, the
teaching of biomolecular kinetics has been squeezed out of the curriculum by the
incredible expansion in knowledge across the biochemical sciences that must be
accommodated within a three- or four-year period. Unfortunately, this has led to
a situation where kinetics is often seen as “old hat,” and any later course option
with “kinetics” in the title is likely to be met with low registration. Actually, this is
not a new phenomenon. More than 30 years ago, Engel [2] likened the attitude
toward kinetics being on par with Latin and cold showers: “character-building
perhaps, but otherwise to be forgotten as quickly as possible.” It is at and beyond
the graduate level, where the deficiency in understanding kinetics often becomes
apparent. One does not have to look far in the current biological literature to find
examples of lax wording or elementary errors in kinetic analysis that potentially
lead to erroneous conclusions (e.g., see Goody’s commentary “How not to do
kinetics” [3]).
To be fair, kinetics has never been out of fashion with subpopulations of scientists.
Every decade has brought advances to the field that has catalyzed interest and new
developments. For example, from the 1980s, the increasing availability of commercial
instrumentation opened up many of the key techniques to a wider audience. Around
the same time, the ability to express proteins on the milligram scale by molecular
cloning opened up new problems that became amenable to transient-kinetic analysis.
From the 1990s, impressive advances in detection techniques allowed reactions
to be studied at the single-molecule level. This approach is particularly valuable
in illustrating the probabilistic nature of chemical reactions, as well as providinginformation that is masked in ensemble methods. Single-molecule measurements
also require very small amounts of material compared with traditional transientkinetic
methods, again opening the field to a wider audience. In parallel, advances in
microfluidics are revealing new approaches to studying ensemble reaction kinetics
on the femtomole scale, which complement single-molecule methods. Kinetics is
alive and well, even if its teaching has become rather fragmented.
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