Changes in the Substrate Specificities of Farnesyl Diphosphate Synthase by a Single Amino Acid Substitution

法尼基二磷酸(FPP)合成酶催化异戊烯基二磷酸(IPP)与烯丙基底物缩合，得到最终产物FPP。猪肝FPS已成功应用于生物活性化合物的合成。脂肪嗜热芽孢杆菌耐热FPS基因的克隆和表达，使其产生足量的FPS成为可能。但它很难接受链上含有氧原子的底物类似物，而这些底物很容易被猪的肝脏酶所接受。耐热酶在有机合成中的应用可能存在一定的局限性。本研究以嗜热脂肪芽孢杆菌为原料，用丝氨酸(S)、精氨酸(R)、天冬氨酸(D)或甘氨酸(G)取代酪氨酸-81，构建了FPP合成物(FPS)。有趣的是，突变酶的底物特异性已经发生了显着的变化。它们可以很容易地接受含有氧原子的底物类似物。这些结果表明戊基转移酶在有机合成中的应用更为有效。

Farnesyl diphosphate (FPP) synthase catalyze the condensation of isopentenyl diphosphate (IPP) with allylic primer to give FPP as final product. The FPS from pig liver has been successfully applied to syntheses of bioactive compounds. Molecular cloning and expression of the gene for thermostable FPS from Bacillus stearothermophilus made it possible to produce sufficient amounts of the enzyme. However it can hardly accept the substrate analogs having oxygen atom in their chain, which are easily accepted by the pig the liver enzyme. There may be some limitations in the thermostable enzyme for applying to organic synthesis. We constructed the FPP syntheses (FPSs) from Bacillus stearothermophilus, in which Tyr-81 was substituted with Ser (S), Arg (R), Asp (D), or Gly (G). Interestingly the substrate specificities of the mutated enzymes have been dramatically altered. They can easily accept the substrate analogs having oxygen atom. These results may suggest the application of the prenyltransferases to organic synthesis is more available.