116 



A SYMPOSIUM ON RESPIRATORY ENZYMES 



units is more complete for cozymase than for codehydrogenase II; 

 investigations on the latter have been less numerous, since it is 

 difficult to obtain in quantity. 



10 



MOLE 



300 



320 



340 



7V< 



360 



360 



Figure 2. — Absorption spectnim of nicotinamide nucleoside 



Our knowledge of the structure of cozymase is based on the 

 following findings: Besides the isolation of nicotinamide and adenine 

 (6, 9), the isolation of pentosephosphoric acid was attained by acid 

 hydrolysis (17). By means of the periodate method it was showni 

 that the phosphoric acid is linked to the fifth carbon atom of the 

 pentose molecules, as is indicated in formula 6. 



CONH 



^ 



2 Mol. 



FORMULA 6 



N 



I 

 HC 



II II 

 N C 



C-NH, 

 I 2 



C — N 





OH 



OH OH OH 



III / 



OHC-C-C-C-CH 0-P=0 

 III 2 \ 



H H H OH 



