Sex hormone-binding globulin (SHBG) is a binding protein that regulates the availability of steroid hormones in the plasma. Although best known as a steroid carrier, recent studies have associated SHBG in modulating behavioral aspects related to sexual receptivity. Among steroids, estradiol (17β-estradiol, oestradiol or E2), documented as the most active endogenous female hormone, exerts important physiological roles in both reproductive and non-reproductive functions. In this framework, we employed molecular dynamics (MD) and docking techniques for quantifying the interaction energy between a complex aqueous solution, composed by different salts, SHBG and E2. As glucose concentration resembles measured levels in diabetes, special emphasis was devoted to analyzing the interaction energy between this carbohydrate, SHBG and E2 molecules. The calculations revealed remarkable interaction energy between glucose and SHBG surface. Surprisingly, a movement of solute components toward SHBG was observed, yielding clusters surrounding the protein. The high energy and short distance between glucose and SHBG suggests a possible scenario in favor of a detainment state between the sugar and the protein. In this context, we found that glucose clustering does not insert modification on binding site area nor over binding energy SHBG-E2 complex, in spite of protein superficial area increment. The calculations also point to a more pronounced interaction between E2 and glucose, considering the hormone immersed in the solution. In summary, our findings contribute to a better comprehension of both SHBG and E2 interplay with aqueous solution components.

中文翻译：

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水溶液与性激素结合球蛋白和雌二醇的相互作用：理论研究


性激素结合球蛋白 (SHBG) 是一种调节血浆中类固醇激素可用性的结合蛋白。尽管性激素结合球蛋白 (SHBG) 最出名的是类固醇载体，但最近的研究表明性激素结合球蛋白 (SHBG) 可以调节与性接受相关的行为方面。在类固醇中，雌二醇（17β-雌二醇、雌二醇或E2）被记录为最活跃的内源性女性激素，在生殖和非生殖功能中发挥重要的生理作用。在此框架中，我们采用分子动力学 (MD) 和对接技术来量化由不同盐、SHBG 和 E2 组成的复杂水溶液之间的相互作用能。由于葡萄糖浓度与糖尿病中测量的水平相似，因此特别强调分析这种碳水化合物、性激素结合球蛋白 (SHBG) 和 E2 分子之间的相互作用能。计算揭示了葡萄糖和性激素结合球蛋白表面之间显着的相互作用能。令人惊讶的是，观察到溶质成分向性激素结合球蛋白（SHBG）移动，在蛋白质周围产生簇。葡萄糖和性激素结合球蛋白之间的高能量和短距离表明一种可能的情况有利于糖和蛋白质之间的滞留状态。在这种情况下，我们发现，尽管蛋白质表面积增加，但葡萄糖聚集不会对结合位点区域插入修饰，也不会增加SHBG-E2复合物的结合能。考虑到激素浸入溶液中，计算还表明 E2 和葡萄糖之间存在更明显的相互作用。总之，我们的研究结果有助于更好地理解 SHBG 和 E2 与水溶液成分的相互作用。