Abstract
Pantothenate kinase (ATP: pantothenate 4'- phosphotransferase, EC 2. 7. 1. 33) was purified about 200-fold from the cell extract of Brevibacterium ammoniagenes IFO 12071 by ammonium sulfate fractionation, DEAE-cellulose chromatography, and Sephadex G-150 gel filtration. The purified enzyme gave a single band on polyacrylamide gel electrophoresis. The molecular weight was calculated approximately 45, 000. The enzyme catalyzed the formation of pantothenic acid 4'-phosphate and ADP from pantothenate and ATP in the presence of Mg2+ ATP could be substituted for, partly, by ITP, GTP, and UTP. The enzyme phosphorylated not only pantothenate, but also pantothenoylcysteine, pantetheine, and pantothenyl alcohol. Apparent Km values were 6.7×10-5M for pantothenate, 3.5×10-5M for ATP, and 10-3M for Mg2+. The reaction was inhibited by the intermediates of CoA biosynthesis, of which CoA itself was a most effective inhibitor. Other properties of the enzyme were also investigated.
