Rational Design of Responsive Self-Assembling Peptides from Native Protein Sequences

This study used identified functional native domains from spider flagelliform silk protein and the Ca2+ binding domain of lipase Lip A from Serratia marcescens. After carefully comparing the primary structures of both sequences, we rationally designed a newly sequenced eD(2) by "hiding" the ion binding sequence in the silk structure sequence. This helped avoid redundancy, and the new sequence had properties of both model sequences. In water, eD(2) formed uniform spherical agglomerates with a beta-spiral structure. Triggered by Ca2+, eD(2) formed nanofibers with higher compliance and thermal stability. We demonstrated the specialties of this novel peptide design by changing the pH, using other metal ions, and mutating the model sequence.