Dephospho-CoA pyrophosphorylase

DIETHYL PYROCARBONATE DEPHOSPHO-CoA KINASE Dephospho-CoA pyrophosphorylase, PANTETHEINE-RHOSRHATE ADENYLYL-TRANSFERASE DEPOLARIZATION ACTION ROTENTIAL HYPERROLARIZATION DEPOLYMERIZATION PROCESSIVITY... 

Dephospho-CoA pyrophosphorylase. 4-phosphopanto-thenate was prepared from dephospho-CoA by incubation with commercial nucleotide pyrophosphatase, and isolated by affinity chromatography with Thiopropy1-Sepharose followed by preparative paper chromatography. Dephospho-CoA pyrophosphorylase was estimated at pH 8.5, in a system similar to that used for dephospho-CoA kinase. 

Dephospho-CoA pyrophosphorylase was also found to have a previously unrecognized mitochondrial pool (8). Pantothenate kinase, on the other hand, could not be detected in mitochondria (9). 

Pantothenic acid is not synthesized by the body and therefore must be obtained from the diet. It is condensed with a molecule of cysteine and the resulting pseudopeptide is decarboxylated to form a compound of pantothenic acid and thioethanolamine, pantetheine. The latter, in the presence of ATP and a phosphokinase, becomes phosphopantatheine, which, in the presence of ATP and a pyrophosphorylase, is converted to dephospho-CoA, which, in turn, is phosphorylated on the 3 position of ribose in the presence of ATP and a phosphokinase to form CoA (Fig. 78). 

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