Exploiting terminal charged residue shift for wide bilayer nanotube assembly

• Published in: Journal of colloid and interface science 2023-01, Vol.629, p.1-10
• Main Authors: Zhao, Yurong, Qi, Hao, Zhang, Limin, He, Chunyong, Wei, Feng, Wang, Dong, Li, Jie, Qi, Kai, Hu, Xuzhi, Wang, Jiqian, Ke, Yubin, Zhang, Chunqiu, Lu, Jian R., Xu, Hai
• Format: Article
• Language: English
• Subjects: Dimerization; Self-assembly; Short amphiphilic peptide; Terminal residue shift; Thin nanofibril; Wide nanotube
• ISSN: 0021-9797; 1095-7103
• DOI: 10.1016/j.jcis.2022.08.104

[Display omitted] Self-assembly of peptides is influenced by both molecular structure and external conditions, which dictate the delicate balance of different non-covalent interactions that driving the self-assembling process. The shifting of terminal charge residue is expected to influence the non-covalent interactions and their interplay, thereby affecting the morphologies of self-assemblies. Therefore, the morphology transition can be realized by shifting the position of the terminal charge residue. The structure transition from thin nanofibers to giant nanotubes is realized by simply shifting the C-terminal lysine of ultrashort Ac-I3K-NH2 to its N-terminus. The morphologies and detailed structure information of the self-assemblies formed by these two peptides are investigated systemically by a combination of different experimental techniques. The effect of terminal residue on the morphologies of the self-assemblies is well presented and the underlying mechanism is revealed. Giant nanotubes with a bilayer shell structure can be self-assembled by the ultrashort peptide Ac-KI3-NH2 with the lysine residue close to the N-terminal. The Ac-KI3-NH2 dimerization through intermolecular C-terminal H-bonding promotes the formation of a bola-form geometry, which is responsible for the wide nanotube assembly formation. The evolution process of Ac-KI3-NH2 nanotubes follows the “growing width” model. Such a morphological transformation with the terminal lysine shift is applicable to other analogues and thus provides a facile approach for the self-assembly of wide peptide nanotubes, which can expand the library of good template structures for the prediction of peptide nanostructures.