III. BIOCHEMICAL SYSTEM 



615 



LIVER 



• PA DEFICIENT 



a RIBOFLAVIN DERCIENT 



O NORMAL CONTROLS 



ADRENAL 



> 100 



KIDNEY 



HEART 



Fig. 6. Changes in the coenzyme A content of liver, adrenal, heart, and kidney 

 in rats on normal, riboflavin-deficient, and pantothenic acid-deficient diets. Coen- 

 zyme A content in units per gram of fresh weight of tissue plotted against the time on 

 the diet in weeks. Each point represents the mean value for pooled tissues from two 

 rats. 



2. Acetyl and Acyl Transfer 



CoA was discovered during a study which was essentially undertaken to 

 elucidate the nature of the active acetate.^ Isotope work had indicated a 

 great variety of synthetic reactions with the mysteriously reactive acetyl 

 as starting material.®^ This is illustrated by Fig. 7.®^ 



Then a connection of CoA with a great variety of primary processes in- 

 volved in acetyl transfer soon indicated that the coenzyme may act as an 

 acetyl carrier. ^^-^^ This view was substantiated through a separation of 



61 K. Bloch, Physiol. Revs. 27, 574 (1947). 



62 F. Lipmann, Harvey Lectures, Ser. XLIV, 99 (1948-1949). 



63 N. O. Kaplan and F. Lipmann, Federation Proc. 7, 163 (1948). 



6^ R. C. Millican, S. M. Rosenthal, and H. Tabor, /. Pharmacol. Exptl. Therop. 97, 



4 (1949). 

 65 G. D. Novell! and F. Lipmann, J. Biol. Chem. 182, 213 (1950). 



