Multiple Self‐Assembly Functional Structures Based on Versatile Binding Sites of β ‐Lactoglobulin

In recent years, research in the field of protein‐based fibrils gained a great attention due to use of these materials as building blocks for construction of functional synthetic biofilms. Yet, efficient and general methodology for preparation of orderly‐doped fibrils with desired properties, made of protein‐dopant/ligand complexes, still remains a significant challenge. In this manuscript, it is demonstrated that the β ‐lactoglobulin ( β ‐Lg) protein can form stable and well‐defined complexes with linear retinoic acid, discotic protoporphyrine IX and spherical carboxyfullerene ligands (dopants). Upon heating these β ‐Lg complexes under acidic conditions, formation of orderly‐doped fibrils, which partially preserved ligand‐specific stoichiometries and modes of binding (of the parent protein‐dopant complexes), is observed. These results present a new synthetic methodology, which complements other reported approaches for preparation of the protein‐based doped fibrils, by surface functionalization and by post‐assembly modulation techniques. A combination of ordered self‐assembly nano‐structures, with chemical versatility of the orderly‐doped protein‐based fibrils, represents a new method for construction of novel multifunctional materials in a bottom‐up fashion. Preparation of composite β ‐Lg‐complex fibrils by the co‐assembly process, using β ‐Lg building blocks that already incorporate various organic ligands inside, is unprecedented.