Institut für Biophysik, Johann Wolfgang Goethe-Universität Frankfurt, Max-von-Laue-Str. 1, 60438 Frankfurt am Main, Germany.
Chembiochem. 2013 Feb 11;14(3):372-80. doi: 10.1002/cbic.201200659. Epub 2013 Jan 16.
CO(2)-consuming reactions, in particular carboxylations, play important roles in technical processes and in nature. Their kinetic behavior and the reaction mechanisms of carboxylating enzymes are difficult to study because CO(2) is inconvenient to handle as a gas, exists in equilibrium with bicarbonate in aqueous solution, and typically yields products that show no significant spectroscopic differences from the reactants in the UV/Vis range. Here we demonstrate the utility of 3-nitrophenylacetic acid and related compounds (caged CO(2)) in conjunction with infrared spectroscopy as widely applicable tools for the investigation of such reactions, permitting convenient measurement of the kinetics of CO(2) consumption. The use of isotopically labeled caged CO(2) provides a tool for the assignment of infrared absorption bands, thus aiding insight into reaction intermediates and mechanisms.
CO(2)-消耗反应，特别是羧化反应，在技术过程和自然界中都起着重要作用。由于 CO(2)作为气体处理不方便，在水溶液中与碳酸氢盐处于平衡状态，并且通常生成的产物在紫外/可见范围内与反应物没有明显的光谱差异，因此研究其动力学行为和羧化酶的反应机制具有一定的难度。在这里，我们展示了 3-硝基苯乙酸及其相关化合物（笼状 CO(2))与红外光谱相结合的实用性，将其作为广泛适用的工具来研究此类反应，从而方便地测量 CO(2)消耗的动力学。使用同位素标记的笼状 CO(2)提供了一种分配红外吸收带的工具，从而有助于深入了解反应中间体和机制。
