Umerani Mehran J, Pratakshya Preeta, Chatterjee Atrouli, Cerna Sanchez Juana A, Kim Ho Shin, Ilc Gregor, Kovačič Matic, Magnan Christophe, Marmiroli Benedetta, Sartori Barbara, Kwansa Albert L, Orins Helen, Bartlett Andrew W, Leung Erica M, Feng Zhijing, Naughton Kyle L, Norton-Baker Brenna, Phan Long, Long James, Allevato Alex, Leal-Cruz Jessica E, Lin Qiyin, Baldi Pierre, Bernstorff Sigrid, Plavec Janez, Yingling Yaroslava G, Gorodetsky Alon A
Department of Materials Science and Engineering, University of California, Irvine, CA 92697.
Department of Chemistry, University of California, Irvine, CA 92697.
Proc Natl Acad Sci U S A. 2020 Dec 29;117(52):32891-32901. doi: 10.1073/pnas.2009044117. Epub 2020 Dec 15.
Naturally occurring and recombinant protein-based materials are frequently employed for the study of fundamental biological processes and are often leveraged for applications in areas as diverse as electronics, optics, bioengineering, medicine, and even fashion. Within this context, unique structural proteins known as reflectins have recently attracted substantial attention due to their key roles in the fascinating color-changing capabilities of cephalopods and their technological potential as biophotonic and bioelectronic materials. However, progress toward understanding reflectins has been hindered by their atypical aromatic and charged residue-enriched sequences, extreme sensitivities to subtle changes in environmental conditions, and well-known propensities for aggregation. Herein, we elucidate the structure of a reflectin variant at the molecular level, demonstrate a straightforward mechanical agitation-based methodology for controlling this variant's hierarchical assembly, and establish a direct correlation between the protein's structural characteristics and intrinsic optical properties. Altogether, our findings address multiple challenges associated with the development of reflectins as materials, furnish molecular-level insight into the mechanistic underpinnings of cephalopod skin cells' color-changing functionalities, and may inform new research directions across biochemistry, cellular biology, bioengineering, and optics.
天然存在的和基于重组蛋白的材料经常被用于基础生物学过程的研究，并且常常被应用于电子、光学、生物工程、医学甚至时尚等多个不同领域。在此背景下，一种名为反射蛋白的独特结构蛋白最近因其在头足类动物迷人的变色能力中所起的关键作用以及作为生物光子和生物电子材料的技术潜力而备受关注。然而，对反射蛋白的理解进展一直受到其非典型的富含芳香族和带电荷残基的序列、对环境条件细微变化的极端敏感性以及众所周知的聚集倾向的阻碍。在此，我们在分子水平上阐明了一种反射蛋白变体的结构，展示了一种基于简单机械搅拌的方法来控制该变体的分级组装，并建立了该蛋白的结构特征与其固有光学性质之间的直接关联。总之，我们的研究结果解决了与将反射蛋白开发为材料相关的多个挑战，提供了对头足类动物皮肤细胞变色功能的机制基础的分子水平见解，并可能为生物化学、细胞生物学、生物工程和光学等领域的新研究方向提供参考。
