442 



2. ANALOGS OF ENZYME REACTION COMPONENTS 



pH 7.2 most of the amino groups are protonated and interfere with the 

 binding. HFj" may bind across two attachment points and its potency may 

 be related to the strong hydrogen bonds formed by fluorine. The nitrate 



Fig. 2-14. Scheme for the active site of 

 prostatic acid phosphatase showing two 

 cationic groups and two hydrogen -bonding 

 groups separated by a seam in the enzyme. 

 The unmarked circles represent various 

 enzyme groups and the stippled area 

 between them a lipophilic region. (Modi- 

 fied from London et al., 1958.) 



ion also can bridge two of the attachment points, one oxygen atom being 

 negatively charged and the other nucleophilic. 



Some of the results of Nigam et al. (1959), shown in the accompanying 

 tabulation, differ from those of London et al. (1958). These inhibitions were 



