Grzonka Z, Mishra P K, Bothner-By A A
Int J Pept Protein Res. 1985 Apr;25(4):375-81. doi: 10.1111/j.1399-3011.1985.tb02188.x.
The 600 MHz proton n.m.r. spectra of (sarcosyl7)-oxytocin and (N-methylalanyl7) oxytocin in 2H2O solution have been recorded and completely assigned. In each case the spectrum indicates the presence of two slowly interconverting conformers, which are the cis-trans isomers about the peptide bond between residues six and seven. The trans isomer is energetically favored in both cases. When neurophysin is added to a solution of (N-methylalanyl7) oxytocin or (sacrosyl7)-oxytocin at pH 3.0, the proportion of minor conformer remains constant, indicating that the cis and trans conformers are equally tightly bound to the protein.
已记录并完全归属了（肌氨酸酐7）-催产素和（N-甲基丙氨酰7）催产素在重水溶液中的600兆赫质子核磁共振谱。在每种情况下，光谱表明存在两种缓慢相互转化的构象异构体，它们是残基6和7之间肽键的顺反异构体。在两种情况下，反式异构体在能量上更有利。当在pH 3.0时将神经垂体素添加到（N-甲基丙氨酰7）催产素或（肌氨酸酐7）-催产素溶液中时，次要构象异构体的比例保持恒定，表明顺式和反式构象异构体与蛋白质的结合紧密程度相同。
