SATURATED FATTY ACIDS 15 



ham lectures.*^ A considerable part of the historical development in this 

 field has been reported by Lipmann^^ and by Lynen.^" 



The first indication that a coenzyme existed was afforded by an experi- 

 ment of Nachmansohn and Machado^^ which involved the acetylation of 

 choline in nerve. It was found that, when adenosine triphosphate (ATP) 

 and a brain extract were added to the preparation, a vigorous acetylation 

 occurred. The same system was found by Lipmann^^ to be effective in pro- 

 moting the acetylation of aromatic amines. Lipmann^^ concluded that a 

 pigeon liver preparation also provided a coenzyme. It was simultaneously 

 observed by a number of investigators^ *~^^ that an activator was needed 

 in the acetylation of choline. Lipmann and co-workers^^ were the first to 

 purify this coenzyme, isolated from hog liver, and to discover that it con- 

 tained a pantothenic acid residue. It was named "coenzyme A" and will 

 be abbreviated as CoA. It is also referred to as S-acetylpantetheine and 

 as acetyl LBF {Lactobacillus hulgaricus factor). It was proved shortly 

 thereafter that CoA functions not only in the acetylation process but also 

 in the synthesis of acetoacetate'*'' and in that of citrate. ^^-^^ 



Through the work of Lipmann, ^^-^^ it is becoming increasingly evident 

 that the probable "active acetate," which is recognized as the fundamental 

 building block in the metabolic patterns of animals, plants, and micro- 

 organisms, is a combination of the acetyl group with CoA; this unit is 

 referred to as "acetyl-CoA," and it is considered to be identical with 

 active acetate in animal systems. The wide application of this com- 

 pound is demonstrated by the fact that the acetyl-CoA prepared from 

 yeast was shown to function^^ in the acetyl donor system (acetate, adeno- 

 sinetriphosphate (ATP), CoA) in pigeon liver required for the acetylation 

 of sulfanilamide.^^ 



There are two mechanisms which can activate acetate.^^ xhe first of 



^' R. Schoenheimer, The Dynamic State of Body Constituents, Harvard Univ. Press, 

 Cambridge, 1942. 



«F. Lynen, Harvey Lectures, 48, 210-244 (1952-1953). 



^1 D. Nachmansohn and A. L. Machado, /. Neurophysiol, 6, 397-403 (1943). 



«F. Lipmann, /. Biol. Chem., 160, 173-190 (1945). 



" W. Feldberg and T. Mann, J. Physiol, 104, 411-425 (1946). 



" D. Nachmansohn and M. Berman, /. Biol. Chem., 165, 551-563 (1946). 



« M. A. Lipton and E. S. G. Barron, /. Biol. Chem., 166, 367-380 (1946). 



« F. Lipmann, N. 0. Kaplan, G. D. Novelli, L. C. Tuttle, and B. M. Guirard, /. Biol. 

 Chem., 186, 235-243 (1950). 



^' M. Soodak and F. Lipmann, J. Biol. Chem., 175, 999-1000 (1948). 



« J. R. Stern and S. Ochoa, /. Biol. Chem., 179, 491-492 (1949). 



" G. D. NoveUi and F. Lipmann, /. Biol. Chem., 182, 213-228 (1950). 



^0 F. Lynen, E. Reichert, and L. Rueff, Ann., 574, 1-32 (1951). 



" N. O. Kaplan and F. Lipmann, J. Biol. Chem., 174, 37-44 (1948). 



" A. D. Welch and C. A. Nichol, Ann. Rev. Biochem., 21, 633-686 (1952). 



