Kyoto University.
Proc Jpn Acad Ser B Phys Biol Sci. 2021;97(8):479-498. doi: 10.2183/pjab.97.024.
Polyphosphate [poly(P)] is described as a homopolymer of inorganic phosphates. Nicotinamide adenine dinucleotide kinase (NAD kinase) catalyzes the phosphorylation of NAD to NADP in the presence of ATP (ATP-NAD kinase). Novel NAD kinase that explicitly phosphorylates NAD to NADP using poly(P), besides ATP [ATP/poly(P)-NAD kinase], was found in bacteria, in particular, Gram-positive bacteria, and the gene encoding ATP/poly(P)-NAD kinase was also newly identified in Mycobacterium tuberculosis H37Rv. Both NAD kinases required multi-homopolymeric structures for activity expression. The enzymatic and genetic results, combined with their primary and tertiary structures, have led to the discovery of a long-awaited human mitochondrial NAD kinase. This discovery showed that the NAD kinase is a bacterial type of ATP/poly(P)-NAD kinase. These pioneering findings, i.e., ATP/poly(P)-NAD kinase, NAD kinase gene, and human mitochondrial NAD kinase, have significantly enhanced research on the biochemistry, molecular biology, and evolutionary biology of NAD kinase, mitochondria, and poly(P), including some biotechnological knowledge applicable to NADP production.
多聚磷酸盐（poly(P)）被描述为无机磷酸盐的均聚物。烟酰胺腺嘌呤二核苷酸激酶（NAD 激酶）在存在 ATP 的情况下催化 NAD 磷酸化为 NADP（ATP-NAD 激酶）。在细菌中，特别是革兰氏阳性菌中发现了一种新型的 NAD 激酶，它可以使用多聚磷酸盐（poly(P)）而不是 ATP 将 NAD 明确磷酸化为 NADP [ATP/poly(P)-NAD 激酶]，并且在结核分枝杆菌 H37Rv 中也新鉴定了编码 ATP/poly(P)-NAD 激酶的基因。这两种 NAD 激酶都需要多同聚体结构才能表达活性。酶学和遗传学结果，结合其一级和三级结构，导致了人们期待已久的人类线粒体 NAD 激酶的发现。这一发现表明 NAD 激酶是一种细菌类型的 ATP/poly(P)-NAD 激酶。这些开创性的发现，即 ATP/poly(P)-NAD 激酶、NAD 激酶基因和人类线粒体 NAD 激酶，极大地促进了 NAD 激酶、线粒体和多聚磷酸盐的生物化学、分子生物学和进化生物学的研究，包括一些适用于 NADP 生产的生物技术知识。
