RAMAN-SPECTROSCOPY IN ENZYMOLOGY - THE FIRST 25 YEARS

In principle, Raman spectroscopy has the potential to answer many of t he questions pertaining to the chemical detail of enzyme mechanisms. H owever, its application has been held back by the twin difficulties of lack of sensitivity and selectivity for large macromolecular complexe s. This review addresses the development of the technique over the pas t 25 years to overcome these handicaps. Due to technical innovations, the field stands at the brink of being applicable to a much wider rang e of enzyme systems; high-throughput spectrographs coupled with red ex citation are improving sensitivity and eliminating many of the problem s formerly encountered with the interfering fluorescence background. T he advantages and disadvantages of resonance Raman and Raman differenc e spectroscopy for studying enzyme complexes are outlined. For a relat ively few systems, unique information has been obtained in the areas o f precise substrate geometries in functioning intermediates, on active site-to-substrate hydrogen bonds and on probing the strong electrosta tic forces that can drive catalysis. These studies are detailed, with emphasis on how they provide powerful insight on enzyme mediated catal ysis. With the improvements due to technical advances, the impact of t hese kinds of insights will soon be felt across the whole field of enz ymology. (C) 1998 John Wiley & Sons, Ltd.