Assay and distribution of bound forms of pantothenic acid.

The distribution of CoA (I), pantetheine (2, 3), and pantothenic acid (4) among a variety of natural materials is well established. However, until now, the relative amounts of these compounds present in any one substance has not been determined. Also, data on the distribution of P-pantothenic1 acid and P-pantetheine, both of which are intermediates in the biosynthesis of CoA (5), is rather meager. This lack of information can be attributed largely to the absence of accurate methods for the determination of any one of the compounds mentioned above in the presence of the others. A method suitable for this purpose has now been developed and is described in the present publication. This method depends on the differential enzymatic degradation of CoA and P-pantetheine to yield pantetheine and the degradation of P-pantothenic acid to pantothenic acid. The amounts of each of these products thus produced can then be measured separately by the use of specific microbiological assays. Values obtained with this method show that CoA is the major pantothenic acid-containing compound present in microorganisms and animal tissues. However, small amounts of pantetheine and P-pantothenic acid and considerably larger amounts of P-pantetheine were also found.