Laboratoire de Chimie Physique Moleculaire, Ecole Polytechnique Federale de Lausanne, CH-1015 Lausanne, Switzerland.
J Am Chem Soc. 2010 Mar 31;132(12):4040-1. doi: 10.1021/ja910118j.
We have measured a vibrationally resolved UV spectrum of doubly protonated gramicidin S (GS) in the gas phase and, subsequently, a highly resolved, conformer-specific IR spectrum in the 6 mum fingerprint region, using a cold ion trap in combination with table-top lasers. The study has revealed at least three conformational states of GS populated under our experimental conditions, with the major one showing evidence of a symmetric three-dimensional structure similar to that in the condensed phase. The derived qualitative constraints, along with the measured vibrational frequencies, serve as a benchmark for computations of peptide structure.
我们已经测量了气相中双质子化的短杆菌肽 S（GS）的振动分辨的紫外光谱，并随后在 6 微米指纹区使用冷离子阱和台式激光器测量了具有高分辨率的构象特异性的红外光谱。该研究揭示了在我们的实验条件下存在至少三种构象状态的 GS，其中主要的一种状态表现出类似在凝聚相中的对称三维结构的证据。所得的定性约束条件以及测量的振动频率可作为肽结构计算的基准。
