..'V 



92 



A. I. EIXGER 



In this reaction two glycocoll molecules are allowed to interact. The 

 basic ammo radical of II unites with the acid carboxyl radical of I, giving 

 rise to the glycyl-glycin peptid HI. This compound, while larger and more 

 complex than the original glycocoll, still possesses one free ]STII 2 and one 

 free COOII at either end, which again makes it capable of uniting with 

 other amino acids at either end or with other peptids. 



Ill 



H 

 CIL N 



! \ 



I 



CO N C 



./ i 



H COOII 



Glycyl-glycin 



H 



CIL N 



\ 



H 



+ HOOC 



Glycocoll 



IV 



CH 9 



II 



CH.,~ N OC 



I 

 CO N CH 2 



/ I 



H COOH 



Glycyl-glycyl-glycin 



H 



'H 



C 



III 



CH 2 X 



. 



CO - X CH 2 



/ I 



H COOH 



Glycyl-glycin 



III 



HOOC CH 2 



oc CH 



Glycyl-glycin 



H 

 H 



H 



OC CIL 



CO - N CI 

 / 



H 



H 



OC CH 



COOH 

 Tetra-glycyl-glycin 



H 

 H 



