VI. ESTIMATION 



631 



CH3 



CHsC-CHOH-C-N-CHjCHjC- 

 CH. 



J 



B 



NHCH2CH2SH 



or -S-SR 



linkage 2 



Diagram giving suggested formula for coenzyme A. 



of which coenzyme A and its various degradation products are quanti- 

 tatively the most important.-^ Our present knowledge of the relationships 

 of these products is summarized in the diagram, which gives a suggested 

 formula for coenzyme A.-^ • -^ This formula will serve to illustrate the types 

 of linkages that must be broken to liberate pantothenic acid. 



A variety of different products containing pantothenic acid are possible, 

 depending upon whether one hydrolyzes linkages 1, 2, or 3, or various 

 combinations of these. Hydrolysis of linkage 1 yields one or more forms of 

 the growth factor, LBF, closely related to or identical with synthetic 

 pantetheine, A.^ "^^" This growth factor, and coenzyme A itself, exist in a 

 variety of forms, depending upon whether their — SH group is free or 



24 N. O. Kaplan and F. Lipmann, ./. Biol. Chem. 174, 37 (1948). 



" J. Baddiley and E. M. Thain, J. Chem. Soc. 1951, 2253. 



26 T. p. Wang, L. Shuster, and N. O. Kaplan, J. Am. Chem. Soc. 74, 3204 (1952). 



" G. M. Brown, J. A. Craig, and E. E. Snell, Arch. Biochem. 27, 473 (1950). 



28 E. E. Snell, G. M. Brown, V. J. Peters, J. A. Craig, E. I. Wittle, J. A. Moore, V. M. 

 McGlohon, and O. D. Bird, /. Am. Chem.. Soc. 72, 5349 (1950). 



29 J. A. Craig and E. E. Snell, J. Bacleriol. 61, 283 (1951). 



29° E. E. Snell and G. M. Brown, Advances in EnzTjmol. 14, 49 (1953). 



