Picone D, Temussi P A, Marastoni M, Tomatis R, Motta A
Dipartimento di Chimica, Università di Napoli, Italy.
FEBS Lett. 1988 Apr 11;231(1):159-63. doi: 10.1016/0014-5793(88)80723-3.
Peptide T, an octapeptide of sequence ASTTTNYT that binds to human T cells, was studied as a zwitterion in DMSOd6 solution by means of proton NMR spectroscopy at 500 MHz. The unusual dispersion of the resonances of residues of the same type (T) makes it possible to assign all resonances to specific residues by means of several 2D techniques. The non-random nature of the conformation is substantiated by the observation of sequential nuclear Overhauser enhancements (NOEs). The low value of the temperature coefficient of the chemical shift of the NH of T8 and a diagnostic NOE between the NHs of T7 and T8 hint that a beta-turn including T5, N6, Y7 and T8 is a prominent conformational feature in solution. The ring current high field shifts of the methyl group and of the NH of T8 are consistent with an interaction with the side-chain of Y7, favoured by the beta-turn.
肽T是一种序列为ASTTTNYT的八肽，可与人T细胞结合。在500兆赫下，通过质子核磁共振光谱法，将其作为两性离子在DMSOd6溶液中进行了研究。相同类型残基（T）共振的异常分散使得通过几种二维技术能够将所有共振归属于特定残基。通过观察序列核Overhauser效应（NOE）证实了构象的非随机性。T8的NH化学位移温度系数较低，以及T7和T8的NH之间的诊断性NOE表明，包含T5、N6、Y7和T8的β-转角是溶液中一个突出的构象特征。T8的甲基和NH的环电流高场位移与与Y7侧链的相互作用一致，这种相互作用受β-转角的促进。
