A Metaphosphate-dependent Nicotinamide Adenine Dinucleotide Kinase from Brevibacterium ammoniagenes

Abstract

The enzyme utilizing metaphosphate for nicotinamide adenine dinucleotide phosphorylation was purified 500-fold from B. ammoniagenes and its properties were studied. The isolated enzyme appeared homogeneous on disc gel electrophoresis; its molecular weight was determined to be 9.0×10⁴ by gel filtration. This enzyme specifically phosphorylated nicotinamide adenine dinuc-leotide at the optimum pH at 6.0. Of phosphoryl donors tested, metaphosphate was most effective for the reaction, and adenosine-5'-triphosphate was less effective. The activity was inhibited by adenosine-5'-monophosphate, adenosine-5'-diphosphate or reduced pyridine nucleotides. The enzyme did not exhibit catalytic activity in the absence of a divalent cation. We concluded that the enzyme phosphorylating nicotinamide adenine dinucleotide in the presence of metaphosphate is distinct from adenosine-5'-triphosphate-dependent nicotinamide adenine dinucleotide kinase, and tentatively designated it metaphosphate-dependent nicotinamide adenine dinucleotide kinase.