BIOGRAPHICAL MEMORANDA 



THE NATURE OF BIOCATALYSIS 



The developments mentioned in the last few pages show how firmly 

 our current notions of metabolic reactions are based on the general 

 concepts that Kluyver had advanced. 



Whenever a particular branch of science has reached the stage 

 where such a generalization has been achieved, further progress is 

 apt to result primarily from attempts to comprehend in an increasing- 

 ly refined manner the mechanism underlying those phenomena that 

 have been recognized as the most basic ones. Ultimately this approach 

 should permit an interpretation of the behaviour of inanimate as well 

 as animate systems in terms of the properties of the elementary par- 

 ticles of matter, or of whatever may eventually take their place as the 

 most fundamental constituents of the universe. 



Thus, when Kluyver had enunciated the main principles of bio- 

 chemistry, it was logical to anticipate that important new advances in 

 this field would come from studies aimed at acquiring a more pro- 

 found understanding of the nature and mechanism of biocatalysis. 

 Amongst the possible approaches that could be envisaged in 1930, one 

 was obviously directed at investigations of the biocatalysts themselves. 

 How much has been accomplished in this respect, owing to twenty- 

 five years of increasingly intensive enzymological research, need not 

 be discussed here. But Kluyver was reluctant to follow this line, with 

 the consequence that not until the last few years were enzyme-chemical 

 studies conducted in his institute. And it is pertinent to our subject to 

 examine into the reasons for this attitude. 



At the time when the principles of biochemistry were gradually 

 being developed, knowledge of enzyme chemistry was virtually non- 

 existent. To be sure, the hydrolysis of starch under the influence of 

 saliva had been known for about a century, and subsequently the 

 hydrolysis of other complex carbohydrates, of fats, and of proteins by 

 tissue extracts had been established. The agencies responsible for 

 these hydrolyses appeared to be catalysts produced and often ex- 

 creted by living cells; even if not excreted they could usually be 

 extracted with ease. They had been designated as 'ferments' or 'en- 

 zymes'; they seemed to exhibit a high degree of specificity ; but their 

 chemical nature and mode of action were completely unknown as late 

 as 1920. The inactivation of enzymatic activity by exposure to tern- 



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