Hierarchical self-assembly of a collagen mimetic peptide (PKG) n (POG)2n (DOG) n via electrostatic interactions

A new type of collagen mimetic peptide, (PKG) n (POG)2n (DOG) n , with charged-domain ends had been designed and successfully prepared in this work, which self-assembled into collagen-like triple helices homotrimers. The collagen-like homotrimers underwent higher level of self-assembly via static electrical interaction between positive and negative domains. Transmission electron microscope (TEM) examinations showed three typical morphologies of homotrimer assembly, which were defined as film, bicontinuous and fibril morphology in this paper. The film was formed in the initial stage and gradually transformed to bicontinuous or fibril morphology to improve stability of the assemblies or decrease surface energy. Furthermore, mechanism of assembly process was proposed based on TEM observations and theoretical analyses of packing equation.