Protonation states of the tryptophan synthase internal aldimine active site from solid-state NMR spectroscopy: direct observation of the protonated Schiff base linkage to pyridoxal-5'-phosphate.
Protonation states of the tryptophan synthase internal aldimine active site from solid-state NMR spectroscopy: direct observation of the protonated Schiff base linkage to pyridoxal-5'-phosphate.
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DOI：
10.1021/ja506267d
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发表时间：
2014-09-17
影响因子：
15
通讯作者：
Mueller, Leonard J.
中科院分区：
文献类型：
--
作者：
Caulkins, Bethany G.;Bastin, Baback;Yang, Chen;Neubauer, Thomas J.;Young, Robert P.;Hilario, Eduardo;Huang, Yu-ming M.;Chang, Chia-en A.;Fan, Li;Dunn, Michael F.;Marsella, Michael J.;Mueller, Leonard J.
自从最初鉴定出5 ′-磷酸吡哆醛（PLP）在这类广泛的酶中作为辅酶的作用以来，在PLP依赖性酶中驱动催化的酸碱化学一直是人们强烈兴趣和研究的主题。50多年前首次提出，催化循环的初始步骤由全酶的质子化希夫碱形式促进，其中共价结合辅酶的连接赖氨酸ε-亚胺氮被质子化。在这里，我们提供了第一个15 N NMR化学位移测量这样一个希夫碱连接在休息全酶的形式，色氨酸合酶的内部醛亚胺状态。双共振实验证实了席夫碱氮的分配，以及PLP辅酶上的位点的额外的13 C，15 N和31 P化学位移测量允许建立辅酶质子化状态的详细模型。
The acid–base chemistry that drives catalysis in pyridoxal-5′-phosphate (PLP)-dependent enzymes has been the subject of intense interest and investigation since the initial identification of PLP’s role as a coenzyme in this extensive class of enzymes. It was first proposed over 50 years ago that the initial step in the catalytic cycle is facilitated by a protonated Schiff base form of the holoenzyme in which the linking lysine ε-imine nitrogen, which covalently binds the coenzyme, is protonated. Here we provide the first 15N NMR chemical shift measurements of such a Schiff base linkage in the resting holoenzyme form, the internal aldimine state of tryptophan synthase. Double-resonance experiments confirm the assignment of the Schiff base nitrogen, and additional 13C, 15N, and 31P chemical shift measurements of sites on the PLP coenzyme allow a detailed model of coenzyme protonation states to be established.
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影响因子：
2.9
作者：
GOLDBERG, ME;BALDWIN, RL
通讯作者：
BALDWIN, RL
DOI：
10.1046/j.1432-1327.2000.01185.x
发表时间：
2000-03-01
期刊：
EUROPEAN JOURNAL OF BIOCHEMISTRY
影响因子：
--
作者：
Bazhulina, NP;Morozov, YV;Demidkina, TV
通讯作者：
Demidkina, TV
DOI：
10.1073/pnas.0900908106
发表时间：
2009-06-09
影响因子：
11.1
作者：
Bajaj, Vikram S.;Mak-Jurkauskas, Melody L.;Griffin, Robert G.
通讯作者：
Griffin, Robert G.
影响因子：
5.6
作者：
Kulik, V;Weyand, M;Schlichting, I
通讯作者：
Schlichting, I
影响因子：
56.9
作者：
Hall, DA;Maus, DC;Griffin, RG
通讯作者：
Griffin, RG