title: Construction of peptide conjugates with peptide nucleic acids containing an anthracene probe and their interactions with DNA.
abstract: We designed and synthesized the peptide nucleic acid (PNA)-peptide conjugates having anthracene chromophores and investigated their interactions with calf thymus DNA, [d(AT)(10)](2), [d(GC)(10)](2), and [d(AT)(10)dA(6)](2). Considering the synthesis compatibility and expecting that a novel DNA analogue, PNA, can improve DNA binding properties of alpha-helix peptides, we attempted to attach thymine PNA oligomers at the C-terminus of a 14 amino acid alpha-helix peptide that contained a pair of artificial intercalators, anthracene, as a probe, and to examine their interactions with DNA using anthracene UV, fluorescence and circular dichroism properties. The results observed in this study showed that the designed peptide folded in an alpha-helix structure in the presence of calf thymus DNA, [d(AT)(10)](2), and [d(AT)(10)dA(6)](2) with the chromophores at the side-chain being fixed with a left-handed chiral-sense orientation. The alpha-helix and the anthracene signals were not observed for [d(GC)(10)](2). Incorporation of thymine PNA oligomers into the designed alpha-helix peptide increased the DNA binding ability to [d(AT)(10)dA(6)](2) with increasing the length of the PNA without changing the conformations of the peptide backbone and the anthracene side-chains.
authors.affiliation: Department of Bioengineering, Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, Nagatsuta, Yokohama 226-8501, Japan.
authors.forename: G
authors.initials: G
authors.lastname: Balasundaram
authors.forename: T
authors.initials: T
authors.lastname: Takahashi
authors.forename: A
authors.initials: A
authors.lastname: Ueno
authors.forename: H
authors.initials: H
authors.lastname: Mihara
mesh_terms: D000873:Anthracenes / Q000032:analysis / Q000737:chemistry*; D002942:Circular Dichroism; D004247:DNA / Q000737:chemistry*; D007364:Intercalating Agents / Q000032:analysis / Q000737:chemistry; D015335:Molecular Probes / Q000032:analysis / Q000737:chemistry*; D020135:Peptide Nucleic Acids / Q000138:chemical synthesis*; D010455:Peptides / Q000737:chemistry*; D017433:Protein Structure, Secondary; D013050:Spectrometry, Fluorescence / Q000379:methods; D013056:Spectrophotometry, Ultraviolet / Q000379:methods
chemical_list: D000873:Anthracenes; D007364:Intercalating Agents; D015335:Molecular Probes; D020135:Peptide Nucleic Acids; D010455:Peptides; D004247:DNA