Kasărov L B, Moat A G
J Bacteriol. 1972 May;110(2):600-3. doi: 10.1128/jb.110.2.600-603.1972.
A marked difference was found to exist between the nicotinamide adenine dinucleotide (NAD) glycohydrolase activity of human strains of Mycobacterium tuberculosis as compared with bovine strains. Human strains had from 6- to 20-fold higher NAD glycohydrolase activity than bovine strains. This finding explains the accumulation of free nicotinic acid in the culture medium by human strains and not by bovine strains. The biosynthetic intermediates nicotinic acid mononucleotide and deamido-NAD were not degraded by either human or bovine strains of M. tuberculosis; hence these nucleotides do not represent a source of the nicotinic acid accumulated by the human strains.
与牛型结核分枝杆菌菌株相比,发现人型结核分枝杆菌菌株的烟酰胺腺嘌呤二核苷酸(NAD)糖水解酶活性存在显著差异。人型菌株的NAD糖水解酶活性比牛型菌株高6至20倍。这一发现解释了人型菌株而非牛型菌株能使培养基中游离烟酸积累的原因。结核分枝杆菌的人型和牛型菌株均不会降解生物合成中间体烟酸单核苷酸和脱酰胺NAD;因此,这些核苷酸并非人型菌株积累的烟酸来源。