Bociek S M, Darke A H, Welti D, Rees D A
Eur J Biochem. 1980 Aug;109(2):447-56. doi: 10.1111/j.1432-1033.1980.tb04814.x.
Complete assignments are given for the 13C NMR spectra of hyaluronate and chondroitin in deuterium oxide solution at 50.32 MHz. The assignments published earlier for chondroitin 4-sulphate and chondroitin 6-sulphate were largely confirmed but were found to need some revision in detail. Our conclusions for hyaluronate and the chondroitin sulphates were confirmed by off-resonance experiments based on the proton NMR assignments. The spectra for hyaluronate show line narrowing and chemical shift changes from neutral to alkaline solution which are consistent with, and clearer than, the effects reported earlier for the proton spectra. As before no such changes occur for the chondroitin sulphates. The suggested interpretation is in terms of a conformation change for hyaluronate which originates mainly in altered interaction energies across the 1 leads to 3 linkage with the results that motional freedom is enhanced above that of the parent hyaluronate and even above the chondroitin sulphates. This, and the evidence from a temperature effect, suggests that an additional potential energy minimum is made favourable in alkali so that the overall amplitudes of the bond oscillations are increased.
给出了在50.32兆赫兹下，透明质酸和软骨素在重水氧化氘溶液中的13C核磁共振谱的完整归属。早期发表的关于4-硫酸软骨素和6-硫酸软骨素的归属在很大程度上得到了证实，但发现细节上需要一些修订。基于质子核磁共振归属的非共振实验证实了我们关于透明质酸和硫酸软骨素的结论。透明质酸的谱图显示从中性溶液到碱性溶液谱线变窄和化学位移变化，这与早期报道的质子谱图效应一致且更清晰。和之前一样，硫酸软骨素没有发生这样的变化。所提出的解释是基于透明质酸的构象变化，这种变化主要源于跨越1到3键的相互作用能的改变，结果是运动自由度比母体透明质酸甚至比硫酸软骨素都有所增强。这一点以及温度效应的证据表明，在碱性条件下会形成一个额外的有利势能最小值，从而使键振动的整体振幅增加。
