Competing rates: Partially rate-limiting proton transfer displayed by ent-copalyl diphosphate synthase, a class II diterpene cyclase, is explored by HPLC/MS analysis of competition experiments in D₂O and H₂O. The cyclization reaction, one of the most complex reactions in biochemistry, is associated with a large kinetic isotope effect that is independent of temperature, consistent with hydrogen tunneling.

中文翻译：

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通过隧道辅助的II类萜烯环化酶质子化引发的环化

竞争速率：通过HPLC / MS分析D ₂ O和H ₂ O中的竞争实验，探索了对戊基二磷酸合酶（一种II类二萜环化酶）显示的部分限速质子转移。生物化学中复杂的反应与大的动力学同位素效应有关，该效应与温度无关，与氢隧穿一致。