title: Post-assembly functionalization of supramolecular nanostructures with bioactive peptides and fluorescent proteins by native chemical ligation.
abstract: Post-assembly functionalization of supramolecular nanostructures has the potential to expand the range of their applications. We report here the use of the chemoselective native chemical ligation (NCL) reaction to functionalize self-assembled peptide amphiphile (PA) nanofibers. This strategy can be used to incorporate specific bioactivity on the nanofibers, and as a model, we demonstrate functionalization with the RGDS peptide following self-assembly. Incorporation of bioactivity is verified by the observation of characteristic changes in fibroblast morphology following NCL-mediated attachment of the signal to PA nanofibers. The NCL reaction does not alter the PA nanofiber morphology, and biotinylated RGDS peptide was found to be accessible on the nanofiber surface after ligation for binding with streptavidin-conjugated gold nanoparticles. In order to show that this strategy is not limited to short peptides, we utilized NCL to conjugate yellow fluorescent protein and/or cyan fluorescent protein to self-assembled PA nanofibers. Förster resonance energy transfer and fluorescence anisotropy measurements are consistent with the immobilization of the protein on the PA nanofibers. The change in electrophoretic mobility of the protein upon conjugation with PA molecules confirmed the formation of a covalent linkage. NCL-mediated attachment of bioactive peptides and proteins to self-assembled PA nanofibers allows the independent control of self-assembly and bioactivity while retaining the biodegradable peptide structure of the PA molecule and thus can be useful in tailoring design of biomaterials.
authors.affiliation: Institute for BioNanotechnology in Medicine, Northwestern University 303 East Superior Avenue, Rm. 11-123, Chicago, Illinois 60611, United States.
authors.forename: Saahir
authors.initials: S
authors.lastname: Khan
authors.forename: Shantanu
authors.initials: S
authors.lastname: Sur
authors.forename: Patricia Y W
authors.initials: PY
authors.lastname: Dankers
authors.forename: Ricardo M P
authors.initials: RM
authors.lastname: da Silva
authors.forename: Job
authors.initials: J
authors.lastname: Boekhoven
authors.forename: Taylor A
authors.initials: TA
authors.lastname: Poor
authors.forename: Samuel I
authors.initials: SI
authors.lastname: Stupp
mesh_terms: D000818:Animals; D002470:Cell Survival; D002478:Cells, Cultured; D005347:Fibroblasts / Q000166:cytology; D008164:Luminescent Proteins / Q000737:chemistry* / Q000378:metabolism*; D046911:Macromolecular Substances / Q000138:chemical synthesis / Q000737:chemistry / Q000378:metabolism; D051379:Mice; D008958:Models, Molecular; D015394:Molecular Structure; D041681:NIH 3T3 Cells; D049329:Nanostructures / Q000737:chemistry*; D010316:Particle Size; D010455:Peptides / Q000737:chemistry* / Q000378:metabolism*; D013499:Surface Properties
chemical_list: D008164:Luminescent Proteins; D046911:Macromolecular Substances; D010455:Peptides