ULTRAVIOLET RESONANCE RAMAN-SPECTROSCOPY OF FLAVIN MONONUCLEOTIDE AND FLAVIN ADENINE-DINUCLEOTIDE
ULTRAVIOLET RESONANCE RAMAN-SPECTROSCOPY OF FLAVIN MONONUCLEOTIDE AND FLAVIN ADENINE-DINUCLEOTIDE
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DOI：
10.1021/j100283a011
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发表时间：
1986-12-04
影响因子：
--
通讯作者：
SPIRO, TG
中科院分区：
文献类型：
--
作者：
COPELAND, RA;SPIRO, TG
黄素作为氧化还原辅助因子在生物学中起着关键作用。图1是常见黄素辅助因子的结构图，所有这些辅助因子都基于异alloxazine发色团，它能够容易地进行单电子和双电子还原。该发色团的扩展ir电子系统在可见和紫外区域产生强烈的ir-rr*电子跃迁。在这些跃迁中的激光激发有望产生与异alloxazine振动模式相关的拉曼跃迁的共振增强。共振拉曼技术能够提供黄素辅助因子与蛋白质环境以及与底物或抑制剂相互作用的详细结构信息。在最长吸收波长~ 450 nm处激发的拉曼光谱受到强烈黄素荧光的干扰，这是常用的连续波激光器所能达到的。已经找到了各种减少这种干扰的方法，并通过同位素取代和正态分析对黄素的可见激发RR谱进行了很好的编目和分析。5·6这些方法包括CARS（相干）的应用
Flavins play a key role as redox cofactors in biology. 1 Figure1 is a structural diagram for the common flavin cofactors, all based on the isoalloxazine chromophore, which is capable of facile one-and two-electron reductions. The extended ir electronic system of this chromophore gives rise to strong ir-rr* electronic transitions in the visible and ultraviolet regions. 1 2 Laser excitation in these transitions is expected to produce resonance enhancement of Raman transitions associated with isoalloxazine vibrational modes. The resonance Raman technique is capable of providing detailed structural information about the interaction of flavin cofactors with their protein environment and with substrates or inhibitors. Raman spectra excited in the longest wavelength absorption,~ 450 nm, which is accessible to commonly available CW lasers, are subject to interference by intense flavin fluorescence. Various methods of reducing this interference have been found, and the visible-excitation RR spectrum of flavin has been well catalogued3 and analyzed via isotope substitution4 and normal-mode analysis. 5· 6 These methods include the application of the CARS (coherent