ACYL CARRIER PROTEIN. IV. THE IDENTIFICATION OF 4'-PHOSPHOPANTETHEINE AS THE PROSTHETIC GROUP OF THE ACYL CARRIER PROTEIN.

by elution 400 ml ammonium formate a linear gradient, 0-0.3 M, in 0.6 M formic acid. total phosphate and Pi32 Fractions 26-38, comprising the major organic phosphate peak, were pooled and passed through a Dowex-50-H + column to remove the ammonium ions, and the resulting solution was lyophilized to remove the formic acid. There was 0.58 Xtmole of organic phosphate in this fraction. The other peaks were not studied further. Enzymatic synthesis of CoA: Hog liver dephospho CoA pyrophosphorylase was purified by the method of Novelli'9 through the calcium phosphate gel step. This enzyme preparation which also contains dephospho CoA kinase, catalyzes the synthesis of CoA from 4'-phosphopantetheine and ATP. CoA was assayed by the phosphotransacetylase assay.20