INTERACTION OF ORGANIC MOLECULES WITH PROTEINS 



113 



NHJ0OCCCI3 



Fig. la 



cated. The effect of a positive center is quite complex. We had occasion to meas- 

 ure the binding to serum albumin of some substances containing positive groups. 

 Let us take the two haptens which I described previously which were used for 

 determining the charge interaction or the closest approach of the positive charge 

 to the specific region of the antibody. You will recall, they were the following: 



(a) Ho H 



N O 



' ^>C(CH3)3 



-03S 



(b) 



H2 



N 



H 



O 



-O3S 



SO3 



NN 

 SO3 



N+(CH3)3 



(a) binds very strongly to albumin and it is a negative ion. If the tertiary Butyl 

 group is replaced by a carboxylate group, i.e. 



