Flavones Suppress Aggregation and Amyloid Fibril Formation of Human Lysozyme under Macromolecular Crowding Conditions.

IF 2.9 3区 生物学 Q3 BIOCHEMISTRY & MOLECULAR BIOLOGY
Shabnam, Rajiv Bhat
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引用次数: 0

Abstract

The crowded milieu of a biological cell significantly impacts protein aggregation and interactions. Understanding the effects of macromolecular crowding on the aggregation and fibrillation of amyloidogenic proteins is crucial for the treatment of many amyloid-related disorders. Most in vitro studies of protein amyloid formation and its inhibition by small molecules are conducted in dilute buffers, which do not mimic the complexity of the cellular environment. In this study, we used PEGs to simulate macromolecular crowding and examined the inhibitory effects of flavones DHF, baicalein, and luteolin on human lysozyme (HuL) aggregation at pH 2. Naturally occurring flavones have been effective inhibitors of amyloid formation in some proteins. Our findings indicate that while flavones inhibit HuL aggregation and fibrillation in dilute buffer solutions, complete inhibition is observed with a combination of flavones and PEGs, as shown by ThT fluorescence, light scattering, TEM, and AFM studies. The species formed in the presence of PEG 8000 and flavones were less hydrophobic, less toxic, and α-helix-rich compared to control samples, which were hydrophobic and β-sheet-rich, as demonstrated by ANS hydrophobicity, MTT assay, and CD spectroscopy. Fluorescence titration studies of flavones with HuL showed a significant increase in binding constant values under crowding conditions. These findings highlight the importance of macromolecular crowding in modulating protein aggregation and amyloid inhibition. Further studies using disease-causing mutants of HuL and other amyloidogenic proteins are needed to explore the role of macromolecular crowding in small-molecule-mediated modulation and inhibition of protein aggregation and amyloid formation.

黄酮类化合物抑制大分子拥挤条件下人溶菌酶的聚集和淀粉样纤维的形成
生物细胞的拥挤环境会对蛋白质的聚集和相互作用产生重大影响。了解大分子拥挤对淀粉样蛋白聚集和纤维化的影响,对于治疗许多淀粉样蛋白相关疾病至关重要。大多数关于蛋白质淀粉样蛋白形成及其受小分子抑制的体外研究都是在稀释缓冲液中进行的,无法模拟细胞环境的复杂性。在这项研究中,我们使用 PEG 模拟大分子拥挤,并考察了黄酮类化合物 DHF、黄芩素和木犀草素在 pH 值为 2 时对人溶菌酶(HuL)聚集的抑制作用。我们的研究结果表明,黄酮类化合物能抑制稀释缓冲溶液中 HuL 的聚集和纤化,而黄酮类化合物和 PEG 的组合则能完全抑制这种聚集和纤化,ThT 荧光、光散射、TEM 和原子力显微镜研究均表明了这一点。ANS 疏水性、MTT 试验和 CD 光谱显示,与疏水性和富含 β 片层的对照样品相比,在 PEG 8000 和黄酮存在下形成的物种疏水性较低、毒性较低且富含 α-螺旋。黄酮与 HuL 的荧光滴定研究表明,在拥挤条件下,结合常数值显著增加。这些发现凸显了大分子拥挤在调节蛋白质聚集和抑制淀粉样蛋白方面的重要性。需要利用 HuL 和其他淀粉样蛋白的致病突变体开展进一步研究,以探索大分子拥挤在小分子介导的调节和抑制蛋白质聚集和淀粉样蛋白形成中的作用。
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来源期刊
Biochemistry Biochemistry
Biochemistry Biochemistry 生物-生化与分子生物学
CiteScore
5.50
自引率
3.40%
发文量
336
审稿时长
1-2 weeks
期刊介绍: Biochemistry provides an international forum for publishing exceptional, rigorous, high-impact research across all of biological chemistry. This broad scope includes studies on the chemical, physical, mechanistic, and/or structural basis of biological or cell function, and encompasses the fields of chemical biology, synthetic biology, disease biology, cell biology, nucleic acid biology, neuroscience, structural biology, and biophysics. In addition to traditional Research Articles, Biochemistry also publishes Communications, Viewpoints, and Perspectives, as well as From the Bench articles that report new methods of particular interest to the biological chemistry community.
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