740 



14. EFFECTS OF pH ON ENZYME INHIBITION 



as n becomes larger, the inflection shifts to higher vahies of pH^. The slopes 

 in the high pH^ range, however, are always + 1. 



Case II: depletion is caused by penetration into the cell and to binding to 

 nonenzymic material. If it is assumed that the ionic form binds to some 

 cell component, a new equilibrium must be introduced: 



Ho + lo :;^ HIo 



(14-180) 



Fig. 14-27. Effect of tlie depletion of the inhibitor due to its penetration into the 



cells (Eq. 14-177) for different values of n, the cellular fraction of the total reaction 



volume. A'„ = 10-^ (H),- = 1.6 x 10"' M, and (I), = 1 mM. 



The expression for I^ now has an additional term: 



[I.) = (I), 



(H), (H), 



n H h (1 - n) 



n{-Pt)i 



K„ 



(H), (I), + K, 



(14-181) 



