Polymer Engineering Laboratory, School of Biomedical Engineering, Indian Institute of Technology (Banaras Hindu University), Varanasi, Uttar Pradesh, India.
Tissue Engineering and Biomaterials Laboratory, Department of Biotechnology, Bhupat and Jyoti Mehta School of Biosciences, Indian Institute of Technology Madras, Chennai, Tamil Nadu, India.
Biopolymers. 2020 Aug;111(8):e23383. doi: 10.1002/bip.23383. Epub 2020 Jun 30.
Amyloids are a group of proteins that are capable of forming aggregated amyloid fibrils, which is responsible for many neurodegenerative diseases including Alzheimer's disease (AD). In our previous study, synthesis and characterization of star-shaped poly(D,L-lactide)-b-gelatin (ss-pLG) have been reported. In the present work, we have extended our work to study ss-pLG against protein aggregation. To the best of our knowledge, this is the first report on the inhibition of amyloid fibrillation by protein grafted poly(D,L-lactide). Bovine serum albumin (BSA) was chosen as the model protein, which readily forms fibril under high temperature. We found that ss-pLG efficiently suppressed the fibril formation of BSA compared with gelatin (Gel), which was supported by Thioflavin T assay, circular dichroism (CD) spectroscopy and atomic force microscopy (AFM). In addition, ss-pLG significantly curtailed amyloid-induced hemolysis. We also found that incubation of ss-pLG with neuroblastoma cells (MC65) protected the cells from fibril-induced toxicity. The rescuing efficiency of ss-pLG was better than Gel, which could be attributed to the reduced lamella thickness in branched ss-pLG. These results suggest the significance of gelatin grafting, which probably allows gelatin to interact with the key residues of the amyloidogenic core of BSA effectively.
淀粉样蛋白是一组能够形成聚集态淀粉样纤维的蛋白质，这些纤维是包括阿尔茨海默病（AD）在内的许多神经退行性疾病的罪魁祸首。在我们之前的研究中，已报道了星形多聚（D，L-丙交酯）-b-明胶（ss-pLG）的合成和表征。在本工作中，我们将研究 ss-pLG 对蛋白质聚集的抑制作用扩展到了研究中。据我们所知，这是首次报道蛋白质接枝聚（D，L-丙交酯）抑制淀粉样蛋白纤维形成的研究。牛血清白蛋白（BSA）被选为模型蛋白，它在高温下容易形成纤维。我们发现 ss-pLG 与明胶（Gel）相比，能够有效地抑制 BSA 的纤维形成，这一点得到了 Thioflavin T 检测、圆二色性（CD）光谱和原子力显微镜（AFM）的支持。此外，ss-pLG 显著抑制了淀粉样蛋白诱导的溶血。我们还发现，ss-pLG 与神经母细胞瘤细胞（MC65）孵育可保护细胞免受纤维诱导的毒性。ss-pLG 的挽救效率优于 Gel，这可能归因于支化的 ss-pLG 中薄片厚度的减少。这些结果表明了明胶接枝的重要性，这可能使明胶能够有效地与 BSA 的淀粉样蛋白形成核心的关键残基相互作用。
