Abstract
The fragment of viral protein R (Vpr), Vpr13-33, plays an important role in regulating nuclear importing of HIV through ion channel formation with a leucine-zipper-like α-helical conformation. Herein we report an approach to reduce cytotoxicity of Vpr13-33 by graphene oxide induced conformation change and aggregation. Preferential adsorption of Vpr13-33 on graphene oxide accompanied by conformation change from α-helix to β-sheet structures has been observed by using atomic force microscopy (AFM) and circular dichroism (CD). The submolecular structures of the Vpr13-33 peptide assembly on graphite surface have been identified by using scanning tunneling microscopy (STM), which confirms the β-sheet structures of Vpr13-33 on graphene oxide surface. The reduced cytotoxicity of Vpr13-33 to neuroblastoma cells and T cells are detected by MTT assay, which could be associated with the conformation change and stimulated aggregation of Vpr13-33 upon addition of graphene oxide through hydrophobic interaction. Furthermore, fluorescent leakage assay by using large unilamellar vesicles (LUVs) indicated that the GO reduced Vpr13-33-induced cytotoxicity could be associated with the inhibited " pore forming" function of Vpr13-33 by conformation change and aggregation.
Original language | English (US) |
---|---|
Pages (from-to) | 1383-1390 |
Number of pages | 8 |
Journal | Biomaterials |
Volume | 34 |
Issue number | 4 |
DOIs | |
State | Published - Jan 2013 |
Externally published | Yes |
Keywords
- Aggregation
- Conformation change
- Cytotoxicity
- Graphene oxide
- Hydrophobic interaction
- Vpr13-33
ASJC Scopus subject areas
- Biophysics
- Bioengineering
- Ceramics and Composites
- Biomaterials
- Mechanics of Materials