Short Peptides Derived from a Block Copolymer-like Barnacle Cement Protein Self-Assembled into Diverse Supramolecular Structures

Abstract

Peptides capable of self-assembling into different supramolecular structures have potential applications in a variety of areas. The biomimetic molecular design offers an important avenue to discover novel self-assembling peptides. Despite this, a lot of biomimetic self-assembling peptides have been reported so far; to continually expand the scope of peptide self-assembly, it is necessary to find out more novel self-assembling peptides. Barnacle cp19k, a key underwater adhesive protein, shows special block copolymer-like characteristics and diversified self-assembly properties, providing an ideal template for biomimetic peptide design. In this study, inspired by Balanus albicostatus cp19k (Balcp19k), we rationally designed nine biomimetic peptides (P1–P9) and systematically studied their self-assembly behaviors for the first time. Combining microscale morphology observations and secondary structure analyses, we found that multiple biomimetic peptides derived from the central region and the C-terminus of Balcp19k form distinct supramolecular structures via different self-assembly mechanisms under acidic conditions. Specifically, P9 self-assembles into typical amyloid fibers. P7, which resembles ionic self-complementary peptides by containing nonstrictly alternating hydrophobic and charged amino acids, self-assembles into uniform, discrete nanofibers. P6 with amphipathic features forms twisted nanoribbons. Most interestingly, P4 self-assembles to form helical nanofibers and novel ring-shaped microstructures, showing unique self-assembly behaviors. Apart from their self-assembly properties, these peptides showed good cytocompatibility and demonstrated promising applications in biomedical areas. Our results expanded the repertoire of self-assembling peptides and provided new insights into the structure–function relationship of barnacle cp19k.

Topics & Concepts