Department of Clinical Laboratory Sciences, College of Applied Medical Sciences, University of Hail, Hail, Saudi Arabia.
IIRC-5, Clinical Biochemistry and Natural Product Research Lab, Department of Biosciences, Integral University, Lucknow, 226026, UP, India.
Int J Biol Macromol. 2022 Jul 31;213:663-674. doi: 10.1016/j.ijbiomac.2022.05.198. Epub 2022 Jun 2.
The robust use of osmolytes (i.e., polyols and sugars) in the key therapeutic regimens/formulations has questioned their impact beyond the stability of therapeutic proteins as these osmolytes trigger structural alterations into proteins including misfolding and subsequent aggregation into amyloid fibrils. Therefore, the current study is the first to delineate the inhibitory effect of carvacrol (CRV) on the carbonyl osmolyte-induced aggregation as well as structural alterations to the bovine serum albumin (BSA) via a set of physicochemical as well as artificial intelligence (AI)-based molecular docking studies. Our initial findings from physicochemical investigations revealed that CRV exhibits substantial protection to BSA under carbonyl osmolyte stress as evident by the compromised hyperchromicity, Schiff's bases, carbonyl and hydroxymethyl furfural content, reduced fluorescent signals, low Rayleigh scattering and prevention of covalent modifications at Lys and Arg residues. The protection against aggregate formation by CRV was further confirmed through the reduced amyloid-specific congo red absorbance as well as fluorescent signals recorded after adding the fibril-specific extrinsic fluorophore probes (i.e., ThT and ANS). The AI-based molecular docking analysis further revealed that CRV (ΔG: -4.96 kcal/mol) competes with d-fructose (ΔG: -4.40 kcal/mol) to mask the Lys and Arg residues to restrict the osmolyte-mediated protein modifications. In conclusion, CRV exhibits substantial protective impact against carbonyl osmolyte-induced structural alterations and protein misfolding and aggregation.
渗透剂（即多元醇和糖）在关键治疗方案/配方中的大量使用引发了人们的质疑，因为这些渗透剂除了对治疗性蛋白质的稳定性产生影响外，还会引发蛋白质的结构改变，包括错误折叠和随后聚集形成淀粉样纤维。因此，本研究首次通过一系列物理化学和基于人工智能（AI）的分子对接研究，描绘了香芹酚（CRV）对羰基渗透剂诱导的聚集以及对牛血清白蛋白（BSA）结构改变的抑制作用。我们从物理化学研究中获得的初步发现表明，CRV 在羰基渗透剂应激下对 BSA 表现出显著的保护作用，这表现在色氨酸的吸光度值降低、席夫碱、羰基和羟甲基糠醛含量降低、荧光信号降低、瑞利散射降低以及赖氨酸和精氨酸残基的共价修饰减少。CRV 对聚集形成的保护作用进一步通过减少纤维特异性外源性荧光探针（即 ThT 和 ANS）添加后淀粉样蛋白特异性刚果红吸收和荧光信号得到证实。基于 AI 的分子对接分析进一步表明，CRV（ΔG：-4.96 kcal/mol）与 d-果糖（ΔG：-4.40 kcal/mol）竞争，以掩盖赖氨酸和精氨酸残基，从而限制渗透剂介导的蛋白质修饰。总之，CRV 对羰基渗透剂诱导的结构改变、蛋白质错误折叠和聚集表现出显著的保护作用。
