School of Materials Science and Engineering, Qilu University of Technology (Shandong Academy of Sciences), Jinan, 250353, PR China.
School of Materials Science and Engineering, Qilu University of Technology (Shandong Academy of Sciences), Jinan, 250353, PR China.
Colloids Surf B Biointerfaces. 2021 Oct;206:111944. doi: 10.1016/j.colsurfb.2021.111944. Epub 2021 Jun 25.
The effect of various Hofmeister anions on the molecular conformation of gelatin in dilute solutions was investigated by viscosity, optical rotation and dynamic light scattering (DLS). The results showed that the intrinsic viscosity of gelatin decreased in the presence of the kosmotropic anions such as Citrate, SO, HPO and MeCOO, whereas it was increased with the addition of chaotropes such as Cl and KSCN. Furthermore, the intrinsic viscosity of gelatin was directly correlated to the hydration entropy of kosmotropic anions, suggesting that the decrease of the intrinsic viscosity was attributed to the strong hydration effect of kosmotropes. The strong dehydration of gelatin facilitated the folding of the polymer chains into helix bundles, validated by the results of optical rotation. On the contrary, the chaotropic anions could interact directly with polypeptide backbones, and the intrachain hydrogen bonds were destroyed. As a result, the polymer chains expanded, which was confirmed by DLS data, and the intrinsic viscosity was increased. These observations indicate that the molecular conformation of gelatin can be modulated by Hofmeister anions.
采用粘度、旋光度和动态光散射（DLS）研究了不同的Hofmeister 阴离子对稀溶液中明胶分子构象的影响。结果表明，在具有亲溶盐特性的阴离子（如柠檬酸盐、SO 、HPO 和 MeCOO ）存在下，明胶的特性粘度降低，而在加入具有疏溶盐特性的阴离子（如 Cl 和 KSCN）时，特性粘度增加。此外，明胶的特性粘度与亲溶盐阴离子的水合熵直接相关，表明特性粘度的降低归因于亲溶盐的强水合作用。明胶的强脱水作用促进了聚合物链折叠成螺旋束，这可以通过旋光度的结果得到验证。相反，疏溶盐阴离子可以直接与多肽主链相互作用，破坏链内氢键。结果，聚合物链展开，这可以通过 DLS 数据得到证实，并且特性粘度增加。这些观察结果表明，Hofmeister 阴离子可以调节明胶的分子构象。
