Development of truncated elastin-like peptide analogues with improved temperature-response and self-assembling properties

Functional peptides, which are composed of proteinogenic natural amino acids, are expected to be used as biomaterials with minimal environmental impact. Synthesizing a functional peptide with a shorter amino acid sequence while retaining its function is a easy and economical strategy. Furthermore, shortening functional peptides helps to elucidate the mechanism of their functional core region. Truncated elastin-like peptides (ELPs) are peptides consisting of repetitive sequences, derived from the elastic protein tropoelastin, that show the thermosensitive formation of coacervates. In this study, to obtain shortened ELP analogues, we synthesized several (Phe-Pro-Gly-Val-Gly)_n (FPGVG)_n analogues with one or two amino acid residues deleted from each repeat sequence, such as the peptide analogues consisting of FPGV and/or FPG sequences. Among the novel truncated ELP analogues, the 16-mer (FPGV)₄ exhibited a stronger coacervation ability than the 25-mer (FPGVG)₅. These results indicated that the coacervation ability of truncated ELPs was affected by the amino acid sequence and not by the peptide chain length. Based on this finding, we prepared Cd²⁺-binding sequence-conjugated ELP analogue, AADAAC-(FPGV)₄, and found that it could capture Cd²⁺. These results indicated that the 16-mer (FPGV)₄ only composed of proteinogenic amino acids could be a new biomaterial with low environmental impact.