III. BIOCHEMICAL SYSTEM 609 



CH, OH ^0 

 CH,-C— CH-C^ •CH.-CHt^ 

 I ^H N,^ Q;C-NH-CHe-CHrSH 



-0-P*0 

 I 







-o-p-*o 



I 

 



CHa-CH CH CH — CH — ADENINE 



6 OH 



"O-^^O 



-0 

 



I 



Fig. 5. The structure of coenzj'me A. 



For further details, the reader is referred to Novelli's review in the CoA 

 Symposium of the Federation Meeting, 1953.^^^ 



5. Preparation of CoA 



The early preparations of CoA were obtained from pig liver. ^^^ '*• ^^ In 

 view of the easy destruction of CoA by autolysis, only very fresh pig liver 

 can be used for the isolation. A rather complicated procedure was originally 

 used, involving metal precipitation and acetone fractionation.^* More 

 recently, in collaboration with Dr. Evans, Dr. Govier, and Mr. DeVries 

 of the Upjohn Research Laboratory, a simpler procedure was elaborated 

 for isolation of CoA from cultures of Streptomyces jradiae}^ The coenzyme 

 was repeatedly adsorbed from acid solution on charcoal and eluted with 

 acetone-ammonia . 



Final purification was worked out by Gregory after it had been observed 

 that a reduction step had to be included in the purification procedure to 

 remove cross-linking from sulfur compounds.'*^ The best preparation de- 

 scribed in the previous paragraph was obtained by following up the adsorp- 

 tion procedure with reduction with zinc and hydrochloric acid and mercury 

 precipitation.^^ After removal of mercury by hydrogen sulfide, the solution 

 was chromatographed over Duolite-CS 100. Most of the impurities were 

 removed by washing with hydrochloric acid, and the coenzyme was even- 

 tually eluted with water and freeze-dried. 



More recently, Green, Strong,^^ and their group at the University of 

 Wisconsin described a relatively simple, promising isolation procedure. 

 Yeast was used as the starting material, and preliminary purification was 



fiifr G. D. Novelli, Federation Proc. 12, 675 (1953). 



