Phosphorylation of CMP by the Released CMP Kinase System from a Yeast: Saccharomyces carlsbergensis

Abstract

During our studies on fermentative production of CDP-choline by dried cells of yeasts, CMP kinase system was found to be released into supernatant of the reaction mixture, while pyrophosphorylase remained bound to cells. The supernatant phosphorylated CMP to CDP and further to CTP. The phosphorylation was inhibited by glucose. However, the inhibition was reversed by addition of small amount of ATP. Addition of inorganic orthophosphate accelerated the phosphorylation by the supernatants of early stages of the reaction, for inorganic phosphate was deficient in the supernatants.