820 



15. EFFECTS OF VARIOUS FACTORS ON INHIBITION 



When the ionic strength is changed from s^ to s^, the change in p^^ is then 

 given by: 



V Si Vs2 



ApK, = 1.02 



1 + 1.31 Vsi 1 + 1.31 V S2 



+ Ksois, - s,) (15-78) 



if the charges on the enzyme and inhibitor are of opposite sign. The ratios 

 of Kj to Kj at different ionic strengths are shown in Fig. 15-17 as calcu- 



FiG. 15-17. Variation of the ratio KJKi with the ionic strength, 







using the hmiting Debye-Hiickel equation (A) and the complete 

 Debye-Hiickel equation (B). 



lated from Eq. 15-77 and compared with the ratios calculated from the 

 simple Debye-Hiickel expression and Eq. 15-76. The deviation beyond an 

 ionic strength of 0.01 is easily observed and the difference between the two 

 treatments is very marked at higher ionic strengths. 



