Methionine and Selenomethionine as Energy Transfer Acceptors for Biomolecular Structure Elucidation in the Gas Phase.
Methionine and Selenomethionine as Energy Transfer Acceptors for Biomolecular Structure Elucidation in the Gas Phase.
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蛋氨酸和硒代蛋氨酸作为气相生物分子结构阐明的能量转移受体。
DOI：
10.1007/s13361-019-02262-y
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发表时间：
2019
影响因子：
3.2
通讯作者：
Julian,RyanR
中科院分区：
文献类型：
--
作者：
Talbert,LanceE;Julian,RyanR
质谱法提供快速和灵敏的肽和蛋白质分析。耦合光谱与质谱允许新方法的发展，以提高生物分子结构的测定。在这里，我们展示了两个新的能量受体，可用于行动激发能量转移实验。在第一个系统中，甲硫氨酸中的C-S键充当来自天然发色团（包括酪氨酸、色氨酸和苯丙氨酸）的能量受体。发色团之间的比较表明，酪氨酸在266 nm处最有效地转移能量，但苯丙氨酸和色氨酸也以相当的效率转移能量。总的来说，能量转移后的C-S键解离产率对于甲硫氨酸是低的，这导致了对硒代甲硫氨酸的研究，硒代甲硫氨酸是在许多天然存在的蛋白质中发现的常见类似物。硫和硒的化学性质相似，但C-Se键比C-S键弱，并且具有较低的σ* 反键轨道。含有酪氨酸和色氨酸的肽的激发导致有效的能量转移到硒代甲硫氨酸和丰富的C-Se键解离。一系列的螺旋肽进行了检查，其中供体或受体的位置进行了系统的扫描，以探讨距离和螺旋取向的能量转移的影响。距离被认为是影响能量转移效率的主要因素，这表明硒代蛋氨酸可能是一个有用的受体，用于探测蛋白质结构的气相。
Mass spectrometry affords rapid and sensitive analysis of peptides and proteins. Coupling spectroscopy with mass spectrometry allows for the development of new methods to enhance biomolecular structure determination. Herein, we demonstrate two new energy acceptors that can be utilized for action-excitation energy transfer experiments. In the first system, C–S bonds in methionine act as energy acceptors from native chromophores, including tyrosine, tryptophan, and phenylalanine. Comparison among chromophores reveals that tyrosine transfers energy most efficiently at 266 nm, but phenylalanine and tryptophan also transfer energy with comparable efficiencies. Overall, the C–S bond dissociation yields following energy transfer are low for methionine, which led to an investigation of selenomethionine, a common analog that is found in many naturally occurring proteins. Sulfur and selenium are chemically similar, but C–Se bonds are weaker than C–S bonds and have lower lying σ* anti-bonding orbitals. Excitation of peptides containing tyrosine and tryptophan results in efficient energy transfer to selenomethionine and abundant C–Se bond dissociation. A series of helical peptides were examined where the positions of the donor or acceptor were systematically scanned to explore the influence of distance and helix orientation on energy transfer. The distance was found to be the primary factor affecting energy transfer efficiency, suggesting that selenomethionine may be a useful acceptor for probing protein structure in the gas phase.