Misset-Smits M, van Ophem P W, Sakuda S, Duine J A
Department of Microbiology and Enzymology, Delft University of Technology, The Netherlands.
FEBS Lett. 1997 Jun 9;409(2):221-2. doi: 10.1016/s0014-5793(97)00510-3.
Two different NAD/coenzyme-dependent formaldehyde dehydrogenases exist, the well-known NAD/GSH-dependent (EC 1.2.1.1) and the more recently discovered NAD/Factor-dependent enzyme. The GSH-dependent one has been found in eukaryotes and Gram-negative bacteria, the Factor-dependent one in two different Gram-positive bacteria. Previous work also showed that Factor and GSH are not interchangeable in the enzymatic reactions. Here it is revealed that the Factor is identical to mycothiol (MySH), 1-O-(2'-[N-acetyl-L-cysteinyl]-amido-2'-deoxy-alpha-D-glucopyranosyl)-D- myo-inositol, a thiol compound which has recently been detected in Actinomycetes. Thus, MySH is GSH's companion as it is the coenzyme for the enzyme which henceforth can be indicated as NAD/MySH-dependent formaldehyde dehydrogenase.
存在两种不同的NAD/辅酶依赖性甲醛脱氢酶，即著名的NAD/GSH依赖性（EC 1.2.1.1）和最近发现的NAD/因子依赖性酶。GSH依赖性酶存在于真核生物和革兰氏阴性细菌中，因子依赖性酶存在于两种不同的革兰氏阳性细菌中。先前的研究还表明，因子和GSH在酶促反应中不可互换。在此揭示，因子与肌醇硫醇（MySH）相同，即1-O-(2'-[N-乙酰-L-半胱氨酰]-氨基-2'-脱氧-α-D-吡喃葡萄糖基)-D-肌醇，一种最近在放线菌中检测到的硫醇化合物。因此，MySH是GSH的伙伴，因为它是该酶的辅酶，此后该酶可称为NAD/MySH依赖性甲醛脱氢酶。
