278 



6. INTERACTIONS OF INHIBITORS WITH ENZYMES 



with the antibody, but it is probable that dipole-dipole effects do occur in 

 individual instances. The deviations for —OH, — NH2, and — NO2 in- 

 dicate that on the p-azophenylarsonate antibody there is a dipole with 

 positive end directed toward the surface of contact, whereas in the p-phen- 

 ylazobenzoate antibody there is a dipole with the opposite orientation. 



Table 6-19 



Group Dispersion Energies in Interactions of Haptens with Antibodies 



to p-azophenylarsonate and p-phenylazobenzoate "■ 



" The following molar refractions were used: R^ 

 1.65. The electron numbers were estimated to be: Z^ 



3.67, R^ = 15.84, and Rjj = 

 .jj - -, Z^ = 8, Zp^ = 8, and Z^ = 18 

 for NO, and COO", and 8 for the rest, leading to Z^=^ Z^= 12 for NO2 anc COO" 

 and 8 for the rest, and Z3 = Z4 — 4. The average radius of antibody groups was taken 

 as 1.8 A. Interaction of the hapten group with three water molecules was assumed. 

 The combining constants, Kg{\) were averages obtained from Pressman and Siegel 

 (1953) and were corrected for nonspecific binding to serum; the A'o'(2)'s were obtained 

 from Xisonoff and Pressman (1957). A'o'(l)'s are for antibody to p-azophenylarsonate 

 and A'o'(2)'s are for antibody to ^^-phenylazobenzoate. 



The procedure used in these calculations was developed by Pauling and 

 Pressman (1945) and the modifications introduced here were made to in- 

 corporate more accurate values of K^ (Pressman and Siegel, 1953) and i2 4, 

 as well as to apply the extended eciuations derived in the previous sections. 

 The agreement with experiment is gratifying and ])rovides a certain amount 

 of confidence in the equations and the assumptions upon which the treat- 

 ment is based. 



