Motta A, Picone D, Temussi P A, Marastoni M, Tomatis R
Biopolymers. 1989 Jan;28(1):479-86. doi: 10.1002/bip.360280142.
The synthetic peptide of sequence H-Ala-Ser-Thr-Thr-Thr-Asn-Tyr-Thr-OH, termed peptide T, a competitor of the Human Immunodeficiency Virus in the binding to human T cells, and its C-terminal pentapeptide fragment, were studied by 1H-nmr in DMSO solution to determine conformational preferences. The observation of nuclear Overhauser enhancements (NOEs) for both peptides, and unusual finding for small linear peptides, allowed complete sequence-specific resonance assignments. Long-range NOEs, ring-current shifts, and the very small temperature coefficient of the Thr8 NH chemical shift suggest, for the zwitterionic form of peptide T, the presence in solution of a beta-turn involving Thr5, Asn6, Tyr7 and Thr8. This conformational feature is consistent with previous structure-activity relationship studies indicating the invariance of the same residues in several potent pentapeptide analogues. The studied pentapeptide fragment, although less structured, shows some tendency to fold even in a polar solvent such as DMSO. Preliminary chemotaxis data on some pentapeptide analogues are consistent with our structural model.
序列为H-Ala-Ser-Thr-Thr-Thr-Asn-Tyr-Thr-OH的合成肽（称为肽T，是人类免疫缺陷病毒与人T细胞结合的竞争者）及其C端五肽片段，在DMSO溶液中通过1H-nmr进行研究以确定构象偏好。对这两种肽观察到核Overhauser增强效应（NOEs），这对小线性肽来说是不寻常的发现，从而实现了完整的序列特异性共振归属。长程NOEs、环电流位移以及Thr8 NH化学位移非常小的温度系数表明，对于肽T的两性离子形式，溶液中存在一个涉及Thr5、Asn6、Tyr7和Thr8的β-转角。这种构象特征与先前的构效关系研究一致，该研究表明在几种有效的五肽类似物中相同残基是不变的。所研究的五肽片段虽然结构较少，但即使在极性溶剂如DMSO中也显示出一些折叠倾向。一些五肽类似物的初步趋化性数据与我们的结构模型一致。
