Fischer and the specificity of enzyme action

The same decade saw the development of a modem concept of enzyme action. Fischer published his studies of the hydrolyses of the a- and )S-glycosides of d- and L-glucose in 1894 (Boyde, 1980 Teich and Needham, 1992). The active agents which he used to catalyse these reactions were the soluble ferments separated from S. cerevisiae and other microoiganisms, the so-called enzymes , as he described them, using the term which Kiihne had introduced in 1878 (Boyde, 1980). Some of these preparations catalysed a range of hydrolyses which do, in fact, reflect the action of several enzymes (Boyde, 1980) nevertheless, their specifications were sufiiciently clear cut to allow him to propose 

The biochemistry of the period was in no position to acknowledge the complexity of these preparations of enzymes. Some years before. Brown (1886b) had even queried whether an individual cell of B. xylinum could both oxidize glucose to gluconate and at the same time assimilate it into cellulose. No more could Buchner, in 1897, imagine the nature of the cell-free system with which he converted sucrose into alcohol (Boyde, 1980). 

These views, and the research on which they were based, were part of the mainstream of organic chemistry. The nature of enzyme action was also by this time an important topic for research in its own right. The developments which eventually led to the Michaelis-Menten theory were ones in which Adrian Brown, his elder brother Horace, and others from the group at Burton-on-Trent all played a major part (Boyde, 1980 Teich and Needham, 1992). Curiously, in their publications, the word catalysis itself is conspicuous by its absence. 

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