磷酸葡萄糖酸脫氫酶 (脫羧)
磷酸葡萄糖酸脫氫酶 (脫羧)（英語：phosphogluconate dehydrogenase (decarboxylating)，EC 1.1.1.44 （頁面存檔備份，存於網際網路檔案館））是一種以NAD+或NADP+為受體、作用於供體CH-OH基團上的氧化還原酶,化學式為:C2376H3725O694N643S23[1]。這種酶能催化以下酶促反應：
在上述反應中，6-磷酸葡萄糖酸首先被氧化為3-酮-6-磷酸葡萄糖酸，同時NADPH形成並被釋放；然後，中間體被脫羧產生1,2-烯二醇式結構，最終互變異構化為核酮糖5-磷酸。[2]高濃度的NADPH對這種酶的活性有抑制性，而6-磷酸葡萄糖酸則能激活這種酶。[3]磷酸葡萄糖酸脫氫酶 (脫羧)主要參與核酮糖5-磷酸的產生，並為磷酸戊糖途徑提供主要的NADPH。[4]
參考文獻
[編輯]- ^ Expasy - ProtParam. web.expasy.org. [2025-07-08].
- ^ Chen YY, Ko TP, Chen WH, Lo LP, Lin CH, Wang AH. Conformational changes associated with cofactor/substrate binding of 6-phosphogluconate dehydrogenase from Escherichia coli and Klebsiella pneumoniae: Implications for enzyme mechanism. J Struct Biol. 2010, 169 (1): 25–35. PMID 19686854. doi:10.1016/j.jsb.2009.08.006.
- ^ Rippa M, Giovannini PP, Barrett MP, Dallocchio F, Hanau S. 6-Phosphogluconate dehydrogenase: the mechanism of action investigated by a comparison of the enzyme from different species. Biochim Biophys Acta. 1998, 1429 (1): 83–92. PMID 9920387. doi:10.1016/S0167-4838(98)00222-2.
- ^ He, W., Wang, Y., Liu, W. & Zhou, C.-Z. Crystal structure of Saccharomyces cerevisiae 6-phosphogluconate dehydrogenase Gnd1. BMC Struct. Biol. 2007,. 7, (38): 38. PMC 1919378
. PMID 17570834. doi:10.1186/1472-6807-7-38.
- DICKENS F, GLOCK GE. Direct oxidation of glucose-6-phosphate, 6-phosphogluconate and pentose-5-phosphates by enzymes of animal origin. Biochem. J. 1951, 50 (1): 81–95. PMC 1197610 . PMID 14904376.
- Bonsignore A and Horecker BL. Purification and properties of beta-L-hydroxy acid dehydrogenase II. Isolation of beta-keto-L-gluconic acid, an intermediate in L-xylulose biosynthesis. J. Biol. Chem. 1961, 236: 2975–2980.
- Scott DBM and Cohen SS. The oxidative pathway of carbohydrate metabolism in Escherichia coli. 1. The isolation and properties of glucose 6-phosphate dehydrogenase and 6-phosphogluconate dehydrogenase. Biochem. J. 1953, 55: 23–33.
- Scott DBM and Cohen SS. The oxidative pathway of carbohydrate metabolism in Escherichia coli. 5. Isolation and identification of ribulose phosphate produced from 6-phosphogluconate by the dehydrogenase of E. coli. Biochem. J. 1957, 65: 686–689.