Schleicher Erik, Wenzel Ringo, Ahmad Margret, Batschauer Alfred, Essen Lars-Oliver, Hitomi Kenichi, Getzoff Elizabeth D, Bittl Robert, Weber Stefan, Okafuji Asako
Institut für Physikalische Chemie, Albert-Ludwigs-Universität Freiburg, Albertstr.21, 79104 Freiburg, Germany.
Institut für Experimentalphysik, Fachbereich Physik, Freie Universität Berlin, Arnimallee 14, 14195 Berlin, Germany.
Appl Magn Reson. 2010 Jan 1;37(1-4):339-352. doi: 10.1007/s00723-009-0101-8.
Electron-nuclear double resonance (ENDOR) spectroscopy provides useful information on hyperfine interactions between nuclear magnetic moments and the magnetic moment of an unpaired electron spin. Because the hyperfine coupling constant reacts quite sensitively to polarity changes in the direct vicinity of the nucleus under consideration, ENDOR spectroscopy can be favorably used for the detection of subtle protein-cofactor interactions. A number of pulsed ENDOR studies on flavoproteins have been published during the past few years; most of them were designed to characterize the flavin cofactor by means of its protonation state, or to detect individual protein-cofactor interactions. The aim of this study is to compare the pulsed ENDOR spectra from different flavoproteins in terms of variations of characteristic proton hyperfine values. The general concept is to observe limits of possible influences on the cofactor's electronic state by surrounding amino acids. Furthermore, we compare ENDOR data obtained from in vivo experiments with in vitro data to emphasize the potential of the method for gaining molecular information in complex media.
电子-核双共振（ENDOR）光谱提供了关于核磁矩与未成对电子自旋磁矩之间超精细相互作用的有用信息。由于超精细耦合常数对所考虑原子核紧邻区域的极性变化反应非常敏感，ENDOR光谱可有效地用于检测微妙的蛋白质-辅因子相互作用。在过去几年中已经发表了许多关于黄素蛋白的脉冲ENDOR研究；其中大多数旨在通过黄素辅因子的质子化状态来表征它，或者检测单个蛋白质-辅因子相互作用。本研究的目的是根据特征质子超精细值的变化比较不同黄素蛋白的脉冲ENDOR光谱。总体概念是观察周围氨基酸对辅因子电子态可能影响的限度。此外，我们将体内实验获得的ENDOR数据与体外数据进行比较，以强调该方法在复杂介质中获取分子信息的潜力。
