Soliman A, Nordlund S
Department of Biochemistry, Arrhenius Laboratories for Natural Sciences, University of Stockholm, Sweden.
Arch Microbiol. 1992;157(5):431-5. doi: 10.1007/BF00249100.
The effect of NAD(P) and analogs of this nucleotide on nitrogenase activity in Rhodospirillum rubrum has been studied. Addition of NAD+ to nitrogen fixing Rsp. rubrum leads to inhibition of nitrogenase. NADP+ has the same effect but NADH or analogs modified in the nicotinamide portion do not cause inhibition. In contrast to ammonium ions, addition of NAD+ leads to inhibition of nitrogenase in cells that have been N-starved under argon. The inhibitory effect of NAD+ is more pronounced at lower light intensities. Addition of NAD+ also leads to inhibition of glutamine synthetase, a phenomenon also occurring when "switch-off" is produced by the addition of effectors such as ammonium ions or glutamine. It is also shown that NAD+ is taken up by Rsp. rubrum cells.
已研究了NAD(P)及其核苷酸类似物对深红红螺菌中固氮酶活性的影响。向固氮的深红红螺菌中添加NAD⁺会导致固氮酶受到抑制。NADP⁺也有相同作用，但NADH或在烟酰胺部分修饰的类似物不会引起抑制。与铵离子不同，向在氩气中进行氮饥饿处理的细胞中添加NAD⁺会导致固氮酶受到抑制。NAD⁺的抑制作用在较低光照强度下更为明显。添加NAD⁺还会导致谷氨酰胺合成酶受到抑制，当通过添加铵离子或谷氨酰胺等效应物产生“关闭”时也会出现这种现象。还表明深红红螺菌细胞会摄取NAD⁺。
