An Exploration of Multiple Component Peptide Assemblies by Enzyme-Instructed Self-Assembly

Based on the motifs (RNISY (M) and DEEVELILGDT (D)) in the protein crystal structures of Merlin and CRL4^DCAF−1, we phosphorylated the tyrosine residue in M and conjugated M to a self-assembling motif to produce a phosphopeptide (1P) and examined enzyme-instructed self-assembly (EISA) of 1P with and without the presence of D (4). Our results show that EISA of 1P forms a hydrogel at exceedingly low volume fraction (∼0.03 %) even with the presence of the hydrophilic peptide, 4. Unlike 1P, 2P (a diastereomer of 1P) or 3P (the enantiomer of 1P) forms a hydrogel via EISA when their concentration is four or three times that of 1P, respectively. Circular dichroism (CD) spectra show that increasing the concentration of the phosphopeptides lowers the CD signals of the mixtures, and the magnitudes of the CD signals depends on the interaction between M and D. This work provides insight for understanding multi-component hydrogels formed by self-assembly, which involves both specific intermolecular interaction and enzymatic reactions.