Binding of dihydro-alpha-lipoic acid (DHLA) to human serum albumin (HSA) was characterised in detail in this study. Binding process was monitored by spectroscopic methods and molecular docking approach. HSA binds DHLA with moderate affinity, 0.80 ± 0.007 × 104 M-1. Spectroscopic data demonstrated that the preferential binding site for DHLA on HSA is IIA (Sudlow I). Hydrogen bonds and electrostatic interactions were identified as the key binding interactions. DHLA binding thermally stabilized HSA, yet it had no effect on HSA structure and its susceptibility to trypsin digestion. Molecular docking confirmed that Sudlow I site accommodated DHLA in a certain conformation in order for binding to occur. Molecular dynamic simulation showed that formed complex is stable. Reported results offer future perspectives for investigations regarding the use of DHLA as a dietary intervention but also raise concerns about the effectiveness of alpha-lipoic acid and DHLA in treatment of patients with COVID-19.

中文翻译：

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二氢-α-硫辛酸在Sudlow I结合位点与人血清白蛋白结合

这项研究中详细描述了二氢-α-硫辛酸（DHLA）与人血清白蛋白（HSA）的结合。通过光谱法和分子对接法监测结合过程。HSA以0.80±0.007×104 M-1的中等亲和力结合DHLA。光谱数据表明，HSA上DHLA的优先结合位点是IIA（Sudlow I）。氢键和静电相互作用被确定为关键的结合相互作用。DHLA结合热稳定的HSA，但对HSA结构及其对胰蛋白酶消化的敏感性没有影响。分子对接证实Sudlow I位点以一定构象容纳DHLA，以便发生结合。分子动力学模拟表明所形成的配合物是稳定的。