kluyver's contributions to microbiology and biochemistry 



able that the same enzyme can promote several different conversions' 



(P- 95-96). 



He then pointed out that catalysis involves the formation of a loose 

 compound between catalyst and substrate, resulting in an activation 

 of the latter. Thus specificity might be conditioned either by config- 

 urational patterns or by the degree of activation which depends on 

 the electrostatic properties of the catalyst. Hydrolases would tend to 

 exhibit the former kind of specificity, whereas the oxido-reductases, 

 acting on relatively small molecules and causing reactions with 

 pronounced energetic effects, should display specificity largely be- 

 cause of differences in the intensity of their electric fields. Kluyver 

 concluded with the statement: 'Ignoring all this, the experimen- 

 tal material gathered with hydrolases has led biochemists to extend 

 unconsciously the doctrine of great specificity to the whole field 

 of enzymes . . . For every biochemical oxido-reduction . . . the ex- 

 istence of a special "ase" has been postulated. In this way biochem- 

 ical youth is nowadays poisoned by the necessity for learning nu- 

 merous names of the barbaric succinofumarase and quercito-pyro- 

 gallase type. 



'However, such a procedure is only practicable as long as the num- 

 ber of substrates which are liable to dehydrogenation under the in- 

 fluence of one and the same specific cell is limited. But when we think 

 of the bewildering diversity of compounds which are able to act as 

 dehydrogenation substrates for the cells of Pseudomonas putida, ... it 

 will be generally agreed that here the doctrine of extreme spe- 

 cificity becomes untenable. For it can scarcely be conceived that 

 the cells of the bacterium in question contain as many dehydrases* 

 as there are suitable oxidation substrates for these cells. And, more- 

 over, we should be obliged to assume that these cells have at their 

 disposal specific catalysts for substrates such as bromo-succinic 

 acid and bromopropionic acid which do not occur in nature, and 

 which are only made by the conscious operations of the organic 

 chemist. 



'So in this case there is not the slightest doubt that one and the 

 same catalyst is capable of acting upon different substrates and 

 very probably even on a large number of these. Once accepting 

 the presence of such dehydrogenating "master keys" in bacterial 

 * Ed. note: meant is obviously dehydrogenases. 



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