Figure 9.

(a) Chemoenzymatic synthesis of polypeptide prepolymers for step-growth polymerization of silk-mimetic polymers. First, amino acid esters are used as monomers for papain-catalyzed polymerization of rigid polyalanine and soft glycine-rich polypeptides. Polycondensation is then used to synthesize silk-mimetic multiblock polypeptides. (b) Self-assembly of these polymers results in silk-like supramolecular structure, including antiparallel β-sheets and nanofiber morphologies visible by AFM. Copyright 2017 American Chemical Society, adapted with permission from [117]. Article and further information regarding permissions can be accessed at this direct link: https://doi.org/10.1021/acsmacrolett.7b00006.