Engineering pH-responsive switching of donor-π-acceptor chromophore alignments along a peptide nanotube scaffold

Yuki Tabata; Yusuke Kamano; Shunsaku Kimura; Hirotaka Uji

doi:10.1039/d0ra00231c

Engineering pH-responsive switching of donor-π-acceptor chromophore alignments along a peptide nanotube scaffold

RSC Adv. 2020 Jan 22;10(6):3588-3592. doi: 10.1039/d0ra00231c. eCollection 2020 Jan 16.

Authors

Yuki Tabata¹, Yusuke Kamano¹, Shunsaku Kimura¹, Hirotaka Uji¹

Affiliation

¹ Department of Material Chemistry, Graduate School of Engineering, Kyoto University Kyoto-Daigaku-Katsura, Nishikyo-ku Kyoto 615-8246 Japan [email protected].

Abstract

A cyclic tri-β-peptide cyclo(β-Ala-β-Ala-β-Lys) having diethylaminonaphthalimide at the β-Lys side chain (CP3Npi) self-assembled into a peptide nanotube in a solution of HFIP and water. CD spectra of the CP3Npi nanotubes show a negative Cotton effect at 441 nm and a positive Cotton effect at 393 nm, indicating that D-π-A naphthalimide chromophores are aligned in a left-handed chiral way along the nanotube. The CP3Npi nanotubes bear positive charges under acidic conditions retaining the nanotube structure but pH-responsive switching of D-π-A naphthalimide alignments along the nanotube between a left-handed chiral and random arrangement was observed. The peptide nanotube is a stable scaffold for attaining pH-responsive alignment switching of side-chain chromophores.