Department of Chemistry, Texas A&M University, 3255 TAMU, College Station, Texas 77843, USA.
J Am Chem Soc. 2009 Oct 28;131(42):15188-93. doi: 10.1021/ja9040785.
The lower critical solution temperature (LCST) of elastin-like polypeptides (ELPs) was investigated as a function of ELP chain length and guest residue chemistry. These measurements were made in both D(2)O and H(2)O. Differences in the LCST values with heavy and light water were correlated with secondary structure formation of the polypeptide chains. Such structural information was obtained by circular dichroism and infrared measurements. Additional thermodynamic data were obtained by differential scanning calorimetry. It was found that there is a greater change in the LCST value between H(2)O and D(2)O for those polypeptides which form the greatest amount of beta-turn/beta-aggregate structure. Moreover, these same molecules were the least hydrophobic ELPs. Therefore, hydrogen bonding rather than hydrophobicity was the key factor in the stabilization of the collapsed state of ELPs in D(2)O compared with H(2)O.
弹性蛋白样多肽 (ELP) 的下临界溶液温度 (LCST) 作为 ELP 链长和客体残基化学性质的函数进行了研究。这些测量在 D(2)O 和 H(2)O 中进行。重水和轻水中 LCST 值的差异与多肽链的二级结构形成有关。这种结构信息通过圆二色性和红外测量获得。通过差示扫描量热法获得了其他热力学数据。结果发现，在 H(2)O 和 D(2)O 之间，那些形成最大量β-转角/β-聚集结构的多肽的 LCST 值变化更大。此外，这些分子也是疏水性最小的 ELP。因此，与 H(2)O 相比，氢键而不是疏水性是在 D(2)O 中稳定 ELP 塌陷状态的关键因素。
