Issue 62, 2015

Functionalization of nano-graphenes by chimeric peptide engineering

Abstract

Here, we report the non-covalent functionalization of reduced graphene oxide (rGO) nanosheets using chimeric peptides engineered to have a biologically functional sequence, a spacer sequence, and an rGO-binding sequence. As a model peptide with biological activity, the cell-penetrating peptide buforin IIb (Bu) was used. A stretch of seven consecutive phenylalanine residues (7F) was used as the rGO-binding sequence. The various effects of tetraglycine (4G) and tetra-aspartate (4D) as spacers between the biologically active Bu and the rGO-binding 7F sequences were compared. All the chimeric peptides had α-helical structures at the carboxyl-terminal sequence, showing a structural similarity to the α-helical structure of Bu alone. Free chimeric peptides composed of 7F-Bu, 7F4G-Bu, or 7F4D-Bu in solution exhibited cell-penetrating abilities similar to that of Bu alone. However, following attachment onto rGO nanosheets, the compositions of the chimeric peptides affected the biological activity of Bu. Following modification, the 7F4D-Bu chimeric peptide yielded a higher cellular uptake of the rGO nanosheets than the other chimeric peptides. The levels of cellular uptake of the rGO nanosheets modified with the chimeric peptides were further evaluated by measuring the photothermal effect after near-infrared laser irradiation. The cells treated with 7F4D-Bu-modified rGO showed the greatest increase in temperature upon irradiation, with the temperature reaching 58.3 °C. The 7F4D-Bu-modified rGO also exhibited the highest photothermal cell-killing activity upon near-infrared laser irradiation. Our results demonstrate the utility of chimeric peptide engineering for simple and facile one-step non-covalent modification of rGO. The chimeric peptide composed of 7F4D can be further used to tether various functional peptides onto rGO nanosheets.

Graphical abstract: Functionalization of nano-graphenes by chimeric peptide engineering

Article information

Article type
Paper
Submitted
19 Feb 2015
Accepted
08 May 2015
First published
08 May 2015

RSC Adv., 2015,5, 49905-49913

Author version available

Functionalization of nano-graphenes by chimeric peptide engineering

G. Shim, J. Lee, J. Kim, H. Lee, Y. B. Kim and Y. Oh, RSC Adv., 2015, 5, 49905 DOI: 10.1039/C5RA03080C

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements