Mazurov A A, Andronati S A
A. V. Bogatsky Physico-Chemical Institute, Ukrainian Academy of Sciences, Odessa.
Analyst. 1994 Apr;119(4):647-52. doi: 10.1039/an9941900647.
The conformational mobility of peptide molecules plays a significant role in peptide-receptor interactions and quantitative structure-activity relationships. As a receptor mimetic system, bis(2-ethylhexyl) sodium succinate (AOT) reversed micelles containing an aqueous solution of one of the melanotrophine inhibiting factor analogues prolyltyrosyl-glycinamide hydrochloride in the inner cavity have been used. Two-dimensional nuclear magnetic resonance spectroscopy (NOESY) and 13C spin-lattice relaxation time measurements have been used to establish that the peptide molecule assumes the biologically active beta II turn conformation when it is adsorbed at the surfactant-water border. This conformation is stabilized by intramolecular H-bonding between the proline carbonyl oxygen atom and amide protons. Moreover, it has been shown that the phenyl ring of tyrosine was inserted into the AOT intermolecular cavity, which is located between the polar AOT groups and the branches of iso-octane fragments. By and large, the phenyl ring acts as a hydrophobic anchor. Reversed micelles can be regarded as providing a realistic model of the receptor.
肽分子的构象流动性在肽-受体相互作用和定量构效关系中起着重要作用。作为一种受体模拟系统，已使用了双（2-乙基己基）琥珀酸钠（AOT）反胶束，其内腔含有促黑素抑制因子类似物之一的脯氨酰酪氨酸甘氨酰胺盐酸盐的水溶液。二维核磁共振光谱（NOESY）和¹³C自旋晶格弛豫时间测量已用于确定肽分子在吸附于表面活性剂-水界面时呈现生物活性的β II型转角构象。这种构象通过脯氨酸羰基氧原子与酰胺质子之间的分子内氢键得以稳定。此外，已表明酪氨酸的苯环插入到AOT分子间腔中，该腔位于极性AOT基团与异辛烷片段的支链之间。总的来说，苯环起到疏水锚的作用。反胶束可被视为提供了一个真实的受体模型。
