Pilch P F, Somerville R L
Biochemistry. 1976 Nov 30;15(24):5315-20. doi: 10.1021/bi00669a018.
The phosphoenolpyruvate analogue (Z)-phosphoenol-3-fluoropyruvate is a substrate for phenylalanine-inhibitable 3-deoxy-D-arabino-heptulosonic acid-7-phosphate synthase from Escherichia coli. In the presence of excess erythrose 4-phosphate, apparent KM values of 65 and 38 muM were observed for phosphoenol-3-fluoropyruvate and phosphoenolpyruvate, respectively. Because the apparent Vmax for phosphoenol-3-fluoropyruvate is only 1.17% of that for phosphoenolpyruvate, one can study the former as an inhibitor of 3-deoxy-arabino-heptulosonic acid-7-phosphate synthase. Kinetic experiments showed phosphoenol-3-fluoropyruvate to be competitive with respect to phosphoenolpyruvate. Two distinguishable Ki values of 8 and 48 muM were obtained. The product (3S)-3-deoxy--3-fluoro-arabino-heptulosonic acid 7-phosphate was purified, characterized, and shown to act as a substrate for 5-dehydroquinate synthase. 3-Deoxy-3-fluoro-arabino-heptulosonic acid 7-phosphate, in contrast to 3-deoxy-arabino-heptulosonic acid 7-phosphate reacts slowly or not at all with reagents specific for 2-keto-3-deoxy sugars and is relatively resistant to oxidative cleavage by sodium periodate. The expected product of periodate oxidation, 3-fluoro-3-formylpyruvate, cannot be detected. This observation was clarified by studies with model compounds.
磷酸烯醇丙酮酸类似物（Z）-磷酸烯醇-3-氟丙酮酸是来自大肠杆菌的苯丙氨酸可抑制的3-脱氧-D-阿拉伯庚酮糖酸-7-磷酸合酶的底物。在过量的4-磷酸赤藓糖存在下，磷酸烯醇-3-氟丙酮酸和磷酸烯醇丙酮酸的表观KM值分别为65和38μM。由于磷酸烯醇-3-氟丙酮酸的表观Vmax仅为磷酸烯醇丙酮酸的1.17%，因此可以将前者作为3-脱氧阿拉伯庚酮糖酸-7-磷酸合酶的抑制剂进行研究。动力学实验表明，磷酸烯醇-3-氟丙酮酸与磷酸烯醇丙酮酸具有竞争性。获得了8和48μM两个可区分的Ki值。产物（3S）-3-脱氧-3-氟阿拉伯庚酮糖酸7-磷酸被纯化、表征，并显示为5-脱氢奎尼酸合酶的底物。与3-脱氧阿拉伯庚酮糖酸7-磷酸相比，3-脱氧-3-氟阿拉伯庚酮糖酸7-磷酸与2-酮-3-脱氧糖特异性试剂反应缓慢或根本不反应，并且对高碘酸钠的氧化裂解相对抗性。高碘酸氧化的预期产物3-氟-3-甲酰丙酮酸无法检测到。通过对模型化合物的研究阐明了这一观察结果。
