title: Protection of oligodeoxynucleotides against nuclease degradation through association with self-assembling peptides.
abstract: Aggregates of the self-assembling peptide EAK16II or EAK16IV and oligodeoxynucleotides (ODNs) were prepared, and their stability upon diluting the solution was investigated by UV-vis spectroscopy. The aggregates prepared at pH 4 and pH 7 did not dissociate after the solution was diluted 5- and 10-fold. The resistance against Escherichia coli exonuclease I of the ODN located in the EAK-ODN aggregates was studied by fluorescence resonance energy transfer (FRET) after the ODN had aggregated with EAK16II or EAK16IV at pH 4 or pH 7. The effect that the peptide sequence, peptide concentration, pH, and centrifugation had on protecting the aggregated ODN against nuclease degradation was investigated. Significant nuclease resistance was obtained after the EAK-ODN aggregates had been prepared at pH 4, with an EAK16IV concentration greater than a threshold value, and ensuring that the solution was not centrifuged immediately after sample preparation. Centrifuging the EAK16IV-ODN solution immediately after sample preparation resulted in the loss of this nuclease protection. However, if the solution of EAK-ODN aggregates was centrifuged 24 h after sample preparation, the nuclease protection afforded by the EAK16IV-ODN aggregates to the ODN was maintained even after being subject to a 10-fold dilution and up to 4 rounds of centrifugation over 4 days.
authors.affiliation: Department of Chemical Engineering, University of Waterloo, 200 University Avenue West, Waterloo, Ontario, Canada N2L 3G1.
authors.forename: M
authors.initials: M
authors.lastname: Wang
authors.forename: H V
authors.initials: HV
authors.lastname: Adikane
authors.forename: J
authors.initials: J
authors.lastname: Duhamel
authors.forename: P
authors.initials: P
authors.lastname: Chen
mesh_terms: D003851:Deoxyribonucleases / Q000737:chemistry*; D004926:Escherichia coli / Q000201:enzymology; D005090:Exodeoxyribonucleases / Q000737:chemistry; D031541:Fluorescence Resonance Energy Transfer; D006863:Hydrogen-Ion Concentration; D009838:Oligodeoxyribonucleotides / Q000737:chemistry* / Q000378:metabolism; D009842:Oligopeptides / Q000737:chemistry* / Q000378:metabolism; D011066:Poly C / Q000737:chemistry / Q000378:metabolism; D011068:Poly G / Q000737:chemistry / Q000378:metabolism; D011485:Protein Binding; D013056:Spectrophotometry, Ultraviolet
chemical_list: C098329:EAK16 peptide; D009838:Oligodeoxyribonucleotides; D009842:Oligopeptides; D011068:Poly G; C023826:poly(dC); C026628:poly(dG); D011066:Poly C; D003851:Deoxyribonucleases; D005090:Exodeoxyribonucleases; C028450:exodeoxyribonuclease I