Roth Justine P
Department of Chemistry, Johns Hopkins University, 3400 North Charles Street, Baltimore MD 21218, USA.
Curr Opin Chem Biol. 2007 Apr;11(2):142-50. doi: 10.1016/j.cbpa.2007.01.683. Epub 2007 Feb 16.
Metalloenzymes catalyze reactions of molecular oxygen and its reduced forms through the controlled formation of metal-bound, activated oxygen intermediates. These intermediates have been a challenge to characterize and new experimental approaches capable of relating structure to reactivity under physiologically relevant conditions are needed. The application of a competitive isotope fractionation technique has enabled changes in O-O bonding to be probed during enzyme-catalyzed reactions. The derived isotope effects provide insights into the reaction mechanisms of O2 and O2*-, which probably could not have been obtained using more conventional methods.
金属酶通过可控地形成金属结合的活性氧中间体来催化分子氧及其还原形式的反应。这些中间体的表征颇具挑战，因此需要新的实验方法来在生理相关条件下将结构与反应活性关联起来。竞争性同位素分馏技术的应用使得在酶催化反应过程中能够探测O - O键的变化。由此得出的同位素效应为O₂和O₂⁻的反应机制提供了见解，这可能是使用更传统的方法无法获得的。
