de Souza Joelma M, Freire Paulo T C, Bordallo Heloisa N, Argyriou Dimitri N
J Phys Chem B. 2007 May 17;111(19):5034-9. doi: 10.1021/jp070366z. Epub 2007 Apr 18.
A first study of possible changes instigated by deuteration in amino acids was carried out using neutron diffraction, inelastic neutron scattering, and Raman scattering in l-alanine, C2H4(NH2)COOH. Careful analysis of the structural parameters shows that deuteration of l-alanine engenders significant geometric changes as a function of temperature, which can be directly related to the observation of new lattice vibration modes in the Raman spectra. The combination of the experimental data suggests that C2D4(ND2)COOD undergoes a structural phase transition (or a structural rearrangement) at about 170 K. Considering that this particular amino acid is a hydrogen-bonded system with short hydrogen bonds (O...H approximately 1.8 A), we evoke the Ubbelohde effect to conclude that substitution of hydrogen for deuterium gives rise to changes in the hydrogen-bonding interactions. The structural differences suggest distinct relative stabilities for the hydrogenous and deuterated l-alanine.
利用中子衍射、非弹性中子散射和拉曼散射对l-丙氨酸（C2H4(NH2)COOH）中氘化引发的可能变化进行了首次研究。对结构参数的仔细分析表明，l-丙氨酸的氘化会导致显著的几何变化，且这种变化是温度的函数，这与拉曼光谱中观察到的新晶格振动模式直接相关。实验数据的综合表明，C2D4(ND2)COOD在约170 K时经历结构相变（或结构重排）。考虑到这种特定的氨基酸是一个具有短氢键（O...H约1.8 Å）的氢键体系，我们援引乌贝洛德效应得出结论，氢被氘取代会导致氢键相互作用发生变化。结构差异表明含氢和氘化的l-丙氨酸具有不同的相对稳定性。
