Probing the stereochemistry of E. coli 3-deoxy-D-arabino-heptulosonate 7-phosphate synthase (phenylalanine-sensitive)-catalyzed synthesis of KDO 8-P analogues.
Probing the stereochemistry of E. coli 3-deoxy-D-arabino-heptulosonate 7-phosphate synthase (phenylalanine-sensitive)-catalyzed synthesis of KDO 8-P analogues.
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探究大肠杆菌 3-脱氧-D-阿拉伯-庚酮酸 7-磷酸合酶（苯丙氨酸敏感）催化合成 KDO 8-P 类似物的立体化学。
DOI：
10.1021/jo991529l
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发表时间：
2000
期刊：
影响因子：
--
通讯作者：
Woodard,RW
中科院分区：
文献类型：
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作者：
Sundaram,AK;Woodard,RW
五碳磷酸化单糖类似物，d-阿拉伯糖5-磷酸、d-核糖5-磷酸和2-脱氧-d-核糖5-磷酸，分别与（Z）-和（E）-[3- 2 H]-磷酸烯醇式丙酮酸（PEP）在土乙酰基3-脱氧-d-阿拉伯庚酮糖酸7-磷酸（DAH 7-P）合酶（phe）存在下缩合，得到（Z）-[3- 2 H]-PEP（3S）-[3 - 2 H]-3-脱氧-d-甘露-辛酮糖酸8-磷酸、（3S）-[3- 2 H]-3-脱氧-d-阿卓-辛酮糖酸8-磷酸和（3S）-[3- 2 H]-3，5-双脱氧-d-阿卓-辛酮糖酸8-磷酸，而与（E）-[3- 2 H]-PEP孵育得到相应的（3R）-单糖。这些结果与观察到的DAH 7-P合成酶对正常底物4-磷酸赤藓糖和PEP的表面选择性完全一致，并提供了直接证据，证明DAH 7-P合成酶（phe）催化PEP的C3表面加成到所测试的磷酸化单糖的C1表面。首次对DAH 7-P合酶（phe）催化的（Z）-和（E）-[3-F]-PEP与E4-P缩合产物进行了1H和19 F NMR分析。我们的研究结果表明，PEP的C2和C3之间的双键的消失和PEP的C3和所测试的磷酸化单糖的C1之间的键的形成在DAH 7-P糖苷酶催化的缩合反应中同时发生。
The five-carbon phosphorylated monosaccharide analogues,d-arabinose 5-phosphate,d-ribose 5-phosphate, and 2-deoxy-d-ribose 5-phosphate, were separately condensed with (Z)- and (E)-[3-2H]-phosphoenolpyruvate (PEP) in the presence ofEscherichiacoli3-deoxy-d-arabino-heptulosonate 7-phosphate (DAH 7-P) synthase (phe) to give in the case of (Z)-[3-2H]-PEP (3S)-[3-2H]-3-deoxy-d-manno-octulosonate 8-phosphate, (3S)-[3-2H]-3-deoxy-d-altro-octulosonate 8-phosphate, and (3S)-[3-2H]-3,5-dideoxy-d-altro-octulosonate 8-phosphate, respectively, whereas incubation with (E)-[3-2H]-PEP gives the corresponding (3R)-monosaccharides. These results are in complete agreement with the observed facial selectivity of DAH 7-P synthase for its normal substratesd-erythrose 4-phosphate and PEP and provide direct evidence that DAH 7-P synthase (phe) catalyzes thesiface addition of the C3 of PEP to thereface of C1 of the phosphorylated monosaccharides tested. Products formed by DAH 7-P synthase (phe)-catalyzed condensation of (Z)- and (E)-[3-F]-PEP with E 4-P were completely characterized by1H and19F NMR analysis for the first time. Results of our studies suggest that disappearence of the double bond between C2 and C3 of PEP and formation of a bond between C3 of PEP and C1 of the phosphorylated monosaccharide tested occur in concert during the DAH 7-P synthase-catalyzed condensation reaction.