Supramolecular multiplexes from collagen mimetic peptide-PNA(GGG)3conjugates and C-rich DNA: pH-induced reversible switching from triplex–duplex to triplex-i-motifElectronic supplementary information (ESI) available: HPLC, MALDI-TOF, CD spectra, gel electrophoresis, TEM images and fluorescence spectra of collagen peptide, PNA conjugate and their assemblies. See DOI: https://doi.org/10.1039/d4bm00955j

Autor: More, Shahaji H., Schmutz, Marc, Jierry, Loïc, Ganesh, Krishna N.
Zdroj: Biomaterials Science; 2024, Vol. 13 Issue: 1 p261-274, 14p
Abstrakt: Peptides are well known for forming nanoparticles, while DNA duplexes, triplexes and tetraplexes create rigid nanostructures. Accordingly, the covalent conjugation of peptides to DNA/RNA produces hybrid self-assembling features and may lead to interesting nano-assemblies distinct from those of their individual components. Herein, we report the preparation of a collagen mimetic peptide incorporating lysine in its backbone, with alkylamino side chains radially conjugated with G-rich PNA [collagen-(PNA-GGG)3]. In the presence of complementary C-rich DNA (dCCCTTTCCC) at neutral pH, the collagen mimetic triplexes were interconnected by PNA-GGG : DNA-CCC duplexes, leading to the formation of larger assemblies of nanostructures. Upon decreasing the pH to 4.5, the dissociation of the triplex–duplex assembly released the protonated C-rich DNA, which immediately folded into an i-motif. With an increase in the pH to 7.2 (neutral), the i-motif unfolded into linear DNA, which reformed the PNA-GGG : DNA-CCC duplex interconnecting the collagen triplexes. The pH-induced switching of the assembly and disassembly was reversible over a few cycles. The hybrid collagen-(PNAGGG)3 : DNA-C3T3C3triplex–duplex and the individual components of the assembly including the i-motif were characterized by UV and CD melting, fluorescence, TEM and gel electrophoresis. The pH-induced reversible switching was established by the changes in the CD and fluorescence properties. Peptide-DNA conjugates have wide applications in both biology and materials science, ranging from therapeutics and drug delivery to diagnostics and molecular switches. Thus, the prototype ensemble of the triplex peptide-PNA conjugate and its duplex with DNA described herein has potential for elaboration into rationally designed systems by varying the PNA/DNA sequences to trap functional ligands/drugs for release in pH-controlled environments.
Databáze: Supplemental Index