854 



15. EFFECTS OF VARIOUS FACTORS ON INHIBITION 



by pressure. Studies on cyanide, azide, ;p-chloromercuribenzoate, iodo- 

 acetate, the naphthoquinones, and other more specific inhibitors on kimi- 

 nescence might be quite informative. 



1.0 



0.8- 



0.6- 



0.4- 



2 - 



n - h e xy I 



2000 

 PRESSURE - 



4000 



6000 



8000 . 

 lbs/Inch' 



Fig. 15-27. Effects of pressure on the inhibition of lu- 

 minescence in Photohacterium by a series of carbamate 

 analogs. The concentrations of the inhibitors were such 

 as to give approximately 50% inhibition at standard 

 pressure, the relative positions of the curves being 

 unimportant. (From Johnson et al., 1951.) 



EFFECTS OF EXTRANEOUS BINDING AND IMPURITIES 



It was briefly discussed in Chapter 3 how the ])inding of an inhil^itor to 

 extraneous sites could have important consequences in mutual depletion 

 systems and it was i^ointed out that the over-all specific concentration of 

 binding sites is critical in the determination of the boundary conditions. 

 By extraneous binding sites is meant all the sites and substances, aside 

 from the enzyme active center or immediately adjacent regions, capable of 

 complexing with the inhibitor. In other words, the inhibitor can be bound 

 to noncatalytic groups on the enzyme, or to other proteins present in the 

 enzyme preparation, or to any other substances present (such as nucleic 



