Room G20, Department of Chemistry, Obafemi Awolowo University, Ile-Ife, Nigeria.
Eur Biophys J. 2024 Nov;53(7-8):465-472. doi: 10.1007/s00249-024-01727-7. Epub 2024 Oct 25.
In a bid to quantify the contribution of molecular structure to non-specific interactions leading to functionally important structural changes in cellular processes, the self-interaction of dextran-T70 (DT70) and its interaction with each of bovine serum albumin (BSA) and ovomucoid trypsin inhibitor (OVO) were studied at pH 7.4 between 5 and 37 °C. The dependences of the apparent molecular weight of each of BSA, OVO and DT70 on the concentration of DT70 were independent of temperature. The activity coefficient of the interaction of each species on DT70 concentration was also independent of temperature. The change in activity coefficient was however dependent on the molecular structure and size of the interacting species. The energy of insertion of each macromolecule in DT70 increased in the order DT70 > BSA > OVO. These findings show that although the enthalpic contribution is negligible, the extent of the entropic contribution to the macromolecular activity coefficient of interaction is chiefly the consequence of the exclusion volume of the interacting macromolecules.
为了量化分子结构对非特异性相互作用的贡献，从而导致细胞过程中功能重要的结构变化，在 pH 7.4 下，研究了葡聚糖-T70（DT70）的自相互作用及其与牛血清白蛋白（BSA）和卵类粘蛋白胰蛋白酶抑制剂（OVO）的相互作用，温度范围为 5 至 37°C。BSA、OVO 和 DT70 的表观分子量随 DT70 浓度的变化与温度无关。每种物质与 DT70 浓度相互作用的活度系数也与温度无关。然而，活度系数的变化取决于相互作用物质的分子结构和大小。每个大分子在 DT70 中的插入能按 DT70 > BSA > OVO 的顺序增加。这些发现表明，尽管焓贡献可以忽略不计，但对相互作用的大分子活度系数的熵贡献的程度主要是由于相互作用的大分子的排除体积的结果。
