Department of Biochemistry, Faculty of Life Sciences, Aligarh Muslim University, Aligarh 202002, U.P., India.
Department of Biochemistry, Faculty of Life Sciences, Aligarh Muslim University, Aligarh 202002, U.P., India.
Int J Biol Macromol. 2024 Mar;261(Pt 2):129845. doi: 10.1016/j.ijbiomac.2024.129845. Epub 2024 Feb 1.
Numerous neurodegenerative disorders are characterized by protein misfolding and aggregation. The mechanism of protein aggregation is intricate, and it is very challenging to study at cellular level. Inhibition of protein aggregation by interfering with its pathway is one of the ways to prevent neurodegenerative diseases. In the present work, we have evaluated the protective effect of a polyphenol compound chlorogenic acid (CGA) on the native and molten globule state of horse heart cytochrome c (cyt c). A molten globule state of this heme protein was achieved in the presence of fluorinated alcohol 1,1,1,3,3,3-hexafluoroisopropanol (HFIP) at physiological pH, as studied by UV-Vis absorption, circular dichroism, intrinsic and ANS fluorescence. We found that at 50 % (v/v) HFIP, the native cyt c transformed into a molten globule state. The same techniques were also used to analyze the protective effect of CGA on the molten globule state of cyt c, and the results show that the CGA prevented the molten globular state and retained the protein close to the native state at 1:1 protein:CGA sub molar ratio. Molecular dynamics study also revealed that CGA retains the stability of cyt c in HFIP medium by preserving it in an intermediate state close to native conformation.
许多神经退行性疾病的特征是蛋白质错误折叠和聚集。蛋白质聚集的机制很复杂，在细胞水平上研究起来极具挑战性。通过干扰其途径来抑制蛋白质聚集是预防神经退行性疾病的方法之一。在本工作中，我们评估了多酚化合物绿原酸（CGA）对马心细胞色素 c（cyt c）天然状态和变性状态的保护作用。通过紫外可见吸收、圆二色性、内源和 ANS 荧光研究，在生理 pH 下，用氟化醇 1,1,1,3,3,3-六氟异丙醇（HFIP）使这种血红素蛋白达到变性状态。结果发现，在 50%（v/v）HFIP 下，天然 cyt c 转变成变性状态。同样的技术也被用于分析 CGA 对 cyt c 变性状态的保护作用，结果表明，CGA 可防止变性球状状态，并在 1:1 蛋白：CGA 亚摩尔比下使蛋白接近天然状态。分子动力学研究还表明，CGA 通过将 cyt c 保持在接近天然构象的中间状态，在 HFIP 介质中保持其稳定性。
