Weers J G, Maki A H
Biochemistry. 1986 May 20;25(10):2897-904. doi: 10.1021/bi00358a024.
Triplet-singlet energy transfer has been studied in the complex formed between auramine O (AO) and horse liver alcohol dehydrogenase with optically detected magnetic resonance (ODMR) spectroscopy. The results show that Trp-15 and Tyr residues transfer triplet energy mainly by a trivial process, whereas Trp-314 transfers triplet energy by a Förster process with two observed lifetimes at 77 K of 170 and 50 ms. The different Förster energy-transfer lifetimes are ascribed either to quenching of the two Trp-314 residues of the dimer by a single asymmetrically bound AO or to two distinct conformations of the enzyme-dye complex with differing separations and/or orientations of donor and acceptor. Individual spin sublevel transfer rate constants are reported for the major decay component with the 170-ms Trp triplet-state lifetime; these are found to be highly selective with kxtr much greater than kytr and kztr.
利用光探测磁共振（ODMR）光谱研究了金胺O（AO）与马肝醇脱氢酶形成的复合物中的三重态-单重态能量转移。结果表明，Trp-15和Tyr残基主要通过一个平凡的过程转移三重态能量，而Trp-314通过Förster过程转移三重态能量，在77 K下观察到的两个寿命分别为170和50 ms。不同的Förster能量转移寿命要么归因于单个不对称结合的AO对二聚体的两个Trp-314残基的猝灭，要么归因于酶-染料复合物的两种不同构象，其供体和受体的间距和/或取向不同。报告了具有170 ms Trp三重态寿命的主要衰变组分的各个自旋子能级转移速率常数；发现这些常数具有高度选择性，kxtr远大于kytr和kztr。
