Wilson J C, Nielsen K J, McLeish M J, Craik D J
Victorian College of Pharmacy, Monash University, Parkville, Australia.
Biochemistry. 1994 Jun 7;33(22):6802-11. doi: 10.1021/bi00188a008.
The nonmammalian tachykinin eledoisin was investigated by use of CD and two-dimensional NMR techniques. In aqueous solution the peptide is conformationally averaged, but on addition of 50% trifluoroethanol (TFE) or sodium dodecyl sulfate (SDS) it adopts an alpha-helical structure. In TFE/H2O and SDS, residues 6-10 of eledoisin show more conformational order than the terminal regions, which undergo dynamic fraying. A possible turn in the N-terminal "address" region, the putative receptor recognition site of the peptide, is detected by NMR spectroscopy but appears to undergo substantial conformational averaging. The NMR data indicate that the helical central core of eledoisin is better defined in the micellar environment than in TFE; however, partial unfolding via 3(10) intermediates occurs in both cases. The conformational preference for SDS-bound eledoisin was examined by three-dimensional structure calculations using NMR-derived distance information in simulated annealing calculations.
利用圆二色光谱（CD）和二维核磁共振（NMR）技术对非哺乳动物速激肽eledoisin进行了研究。在水溶液中，该肽的构象呈平均化状态，但加入50%的三氟乙醇（TFE）或十二烷基硫酸钠（SDS）后，它会形成α-螺旋结构。在TFE/H₂O和SDS中，eledoisin的6-10位残基比末端区域具有更高的构象有序性，末端区域会发生动态磨损。通过核磁共振光谱在肽的假定受体识别位点N端“地址”区域检测到一个可能的转角，但它似乎经历了大量的构象平均化。核磁共振数据表明，eledoisin的螺旋中央核心在胶束环境中比在TFE中定义得更好；然而，在两种情况下都会通过3(10)中间体发生部分解折叠。使用模拟退火计算中基于核磁共振得出的距离信息，通过三维结构计算研究了SDS结合的eledoisin的构象偏好。
