蛋白质和肽自组装成纤维状淀粉样蛋白聚集体是定义下一代功能性纳米材料的非常有前途的途径。淀粉样纤维,传统上与神经退行性疾病相关,提供卓越的构象和化学稳定性以及机械性能,和抗降解。这里,我们报告了催化淀粉样纳米材料的发展,通过小型化的人工过氧化物酶(FeMC6*a)与自组装的淀粉样肽衍生自人类运甲状腺素蛋白,TTR(105-115),其序列是YTIAALLSPYS。我们的合成方法依赖于对肽和FeMC6*a进行适当修饰后的快速和选择性点击连接,导致TTRLys108@FeMC6*a。将未修饰的TTR(105-115)与TTRLys108@FeMC6*a混合,可以生成负载酶的淀粉样原纤维,即,FeMC6*a@原纤维。催化研究,在接近中性pH的水溶液中进行,使用ABTS作为模型底物和H2O2作为氧化剂表明,该酶保留了其催化活性。此外,发现活性取决于TTRLys108@FeMC6*a/未修饰的TTR(105-115)肽比率。特别是,在筛选的纳米缀合物中,与自由扩散的酶相比,具有2:100比率的那些在初始速率和底物转化率方面显示出最高的活性。最后,新开发的纳米材料被整合到基于聚偏氟乙烯膜过滤器的流动系统中。在这个流动反应器中,进行了多个反应循环,展示催化淀粉样蛋白在较长时间内的可重用性和稳定性,因此,与分离的FeMC6*a相比,在许多实际应用场景中提供了显着改善的特性。
The self-assembly of proteins and peptides into fibrillar amyloid aggregates is a highly promising route to define the next generation of functional nanomaterials. Amyloid fibrils, traditionally associated with neurodegenerative diseases, offer exceptional conformational and chemical stability and mechanical properties, and resistance to degradation. Here, we report the development of catalytic amyloid nanomaterials through the conjugation of a miniaturized artificial peroxidase (FeMC6*a) to a self-assembling amyloidogenic peptide derived from human transthyretin, TTR(105-115), whose sequence is YTIAALLSPYS. Our synthetic approach relies on fast and selective click ligation upon proper modification of both the peptide and FeMC6*a, leading to TTRLys108@FeMC6*a. Mixing unmodified TTR(105-115) with TTRLys108@FeMC6*a allowed the generation of enzyme-loaded amyloid fibrils, namely, FeMC6*a@fibrils. Catalytic studies, performed in aqueous solution at nearly neutral pH, using ABTS as a model substrate and H2O2 as the oxidizing agent revealed that the enzyme retains its catalytic activity. Moreover, the activity was found to depend on the TTRLys108@FeMC6*a/unmodified TTR(105-115) peptide ratio. In particular, those with the 2:100 ratio showed the highest activity in terms of initial rates and substrate conversion among the screened nanoconjugates and compared to the freely diffusing enzyme. Finally, the newly developed nanomaterials were integrated into a flow system based on a polyvinylidene difluoride membrane filter. Within this flow-reactor, multiple reaction cycles were performed, showcasing the reusability and stability of the catalytic amyloids over extended periods, thus offering significantly improved characteristics compared to the isolated FeMC6*a in the application to a number of practical scenarios.