title: Binding ability of a thymine-functionalized oligolysine towards nucleic acids.
abstract: In this Letter, we investigated the binding properties towards nucleic acids of a thymine-functionalized oligolysine, composed of nucleobase-bearing amino acid moieties and underivatized l-lysine residues alternate in the backbone. The basic nucleopeptide proved to be well soluble in water and able to interact with both DNA and RNA, as suggested by circular dichroism, UV and surface plasmon resonance studies performed on the thymine-containing oligomer with both adenine-containing DNA (dA12) and RNA (rA12 and poly rA) molecules. In both cases the thymine-functionalized oligolysine was proven to form complexes characterized by a 1:1 T/A stoichiometric ratio, as evidenced by CD titration. UV melting experiments revealed that the complex formed between the homothymine oligolysine and rA12 RNA was more stable than the complex with dA12 DNA probably due to the additional H-bonding of the 2'-OH groups in RNA, that reinforces the overall interaction with the nucleopeptide. Finally, human serum stability assays were conducted on the thymine-bearing nucleopeptide which showed a half-life of 45min.
authors.affiliation: Istituto di Biostrutture e Bioimmagini-CNR, Via Mezzocannone 16, 80134 Napoli, Italy. Electronic address: giovanni.roviello@cnr.it.
authors.forename: Giovanni N
authors.initials: GN
authors.lastname: Roviello
authors.affiliation: Dipartimento di Scienze Chimiche, Università di Napoli 'Federico II', 80126 Napoli, Italy.
authors.forename: Domenica
authors.initials: D
authors.lastname: Musumeci
authors.affiliation: Istituto di Biostrutture e Bioimmagini-CNR, Via Mezzocannone 16, 80134 Napoli, Italy.
authors.forename: Cristian
authors.initials: C
authors.lastname: D'Alessandro
authors.affiliation: Dipartimento delle Scienze Biologiche, Università di Napoli 'Federico II', 80134 Napoli, Italy.
authors.forename: Carlo
authors.initials: C
authors.lastname: Pedone
mesh_terms: D002942:Circular Dichroism; D004247:DNA / Q000737:chemistry / Q000378:metabolism*; D006207:Half-Life; D006801:Humans; D008239:Lysine / Q000737:chemistry*; D010455:Peptides / Q000737:chemistry* / Q000378:metabolism*; D012313:RNA / Q000737:chemistry / Q000378:metabolism*; D044967:Serum / Q000737:chemistry; D012995:Solubility; D020349:Surface Plasmon Resonance; D013941:Thymine / Q000737:chemistry*
chemical_list: D010455:Peptides; D012313:RNA; D004247:DNA; D008239:Lysine; D013941:Thymine
keywords: CD studies; DNA/RNA binding; Enzymatic stability; Nucleopeptide; Oligo-l-lysine