Cyclo[Gln-Trp-Phe-Gly-Leu-Met] (1) is a selective peptide antagonist of NK-2 receptors. The conformational analysis of this peptide was conducted using nuclear magnetic resonance (NMR) and molecular dynamics. This study improves understanding of the neurokinin ligand-receptor interactions. Two-dimensional Homonuclear Hartmann-Hahn (2D-HOHAHA) and rotating frame Overhauser enhancement spectroscopy (2D-ROESY) were used to assign all the protons and to obtain through-space proton-proton interactions. ROE (rotating frame Overhauser enhancement) constraints molecular dynamics were done to find the conformation which is consistent with the NMR data. Two beta I (or beta V') turns around Trp-2-Phe-3 and around Leu-5-Met-6 are found in this peptide which are represented by models. The conformation of this peptide is also compared with the non-peptide NK-2 antagonist SR-48968 (2).

中文翻译：

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通过NMR和分子动力学研究作为NK-2拮抗剂的环[Gln-Trp-Phe-Gly-Leu-Met]的构象研究。

环[Gln-Trp-Phe-Gly-Leu-Met]（1）是NK-2受体的选择性肽拮抗剂。使用核磁共振（NMR）和分子动力学对该肽进行了构象分析。这项研究提高了对神经激肽配体-受体相互作用的理解。二维Homonuclear Hartmann-Hahn（2D-HOHAHA）和旋转框架Overhauser增强光谱法（2D-ROESY）用于分配所有质子并获得空间质子-质子相互作用。进行了ROE（旋转框架Overhauser增强）约束分子动力学研究，以发现与NMR数据相符的构象。在该肽中发现了两个围绕Trp-2-Phe-3和围绕Leu-5-Met-6的beta I（或beta V'），它们由模型表示。