Nicotinamide-adenine nucleotides of Mycobacterium tuberculosis H37Rv

Abstract

The concentrations of the oxidized and reduced nicotinamide-adenine nucleotides were determined in the virulent strain of M. tuberculosis H37Rv. Nicotinamide-adenine dinucleotide (NAD) was present in almost double the concentration of nicotinamide-adenine dinucleotide phosphate (NADP), whereas the reverse is true for the corresponding reduced compounds. The total concentrations of the oxidized nicotinamide-adenine nucleotides of the virulent and avirulent strains were almost the same, and in the avirulent strain also the concentration of NAD was substantially higher than that of NADP. The concentrations of nicotinamide -adenine nucleotides were increased by the addition of nicotinamide and decreased by the addition of nicotinic acid to the growth medium. The presence of a powerful dihydronicotin-amide-adenine dinucleotide oxidase, a less powerful dihydronicotinamide-adenine dinucleotide phosphate oxidase, and a heat-stable nicotinamide -adenine dinucleotide glycohydrolase that is associated with a heat-labile inhibitor, are reported in the cell-free extracts. The significance of this inhibitor is discussed in relation to the survival and multiplication of tubercle bacilli in host tissues.