Ronen Maria, Kalanoor Basanth S, Oren Ziv, Ron Izhar, Tischler Yaakov R, Gerber Doron
Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University Ramat-Gan 5290002 Israel
Bar-Ilan Institute for Nanotechnology and Advanced Materials, Bar-Ilan University Ramat-Gan 5290002 Israel.
RSC Adv. 2018 Apr 30;8(29):16161-16170. doi: 10.1039/c8ra01232f. eCollection 2018 Apr 27.
Low Frequency Vibrational (LFV) modes of peptides and proteins are attributed to the lattice vibrations and are dependent on their structural organization and self-assembly. Studies taken in order to assign specific absorption bands in the low frequency range to self-assembly behavior of peptides and proteins have been challenging. Here we used a single stage Low Frequency Raman (LF-Raman) spectrometer to study a series of diastereomeric analogue peptides to investigate the effect of peptides self-assembly on the LF-Raman modes. The structural variation of the diastereomeric analogues resulted in distinct self-assembly groups, as confirmed by transmission electron microscopy (TEM) and dynamic light scattering (DLS) data. Using LF-Raman spectroscopy, we consistently observed discrete peaks for each of the self-assembly groups. The correlation between the spectral features and structural morphologies was further supported by principal component analysis (PCA). The LFV modes provide further information on the degrees of freedom of the entire peptide within the higher order organization, reflecting the different arrangement of its hydrogen bonding and hydrophobic interactions. Thus, our approach provides a simple and robust complementary method to structural characterization of peptides assemblies.
肽和蛋白质的低频振动（LFV）模式归因于晶格振动，并且取决于它们的结构组织和自组装。为了将低频范围内的特定吸收带与肽和蛋白质的自组装行为相关联而进行的研究一直具有挑战性。在这里，我们使用单级低频拉曼（LF-拉曼）光谱仪来研究一系列非对映体类似物肽，以研究肽自组装对LF-拉曼模式的影响。如透射电子显微镜（TEM）和动态光散射（DLS）数据所证实的，非对映体类似物的结构变化导致了不同的自组装组。使用LF-拉曼光谱，我们始终观察到每个自组装组的离散峰。主成分分析（PCA）进一步支持了光谱特征与结构形态之间的相关性。LFV模式提供了关于高阶组织内整个肽的自由度的进一步信息，反映了其氢键和疏水相互作用的不同排列。因此，我们的方法为肽组装体的结构表征提供了一种简单而可靠的补充方法。
