title: Interactions of cationic porphyrins with double-stranded oligodeoxynucleotides: a study by electrospray ionisation mass spectrometry.
abstract: Electrospray ionisation mass spectrometry (ESI-MS), electrospray ionisation tandem mass spectrometry (ESI-MS/MS) and Ultraviolet-visible (UV-vis) spectroscopy were used to investigate the non-covalent interactions between small oligonucleotide duplexes with the GC motif and a group of cationic meso(N-methylpyridynium-4-yl)porphyrins (four free bases with one to four positive charges, and the zinc complex of the tetracationic free base). The results obtained point to outside binding of the porphyrins, with the binding strength increasing with the number of positive charges. Fragmentations involving losses from both chains were observed for the porphyrins with N-methylpyridinium-4-yl groups in opposite meso positions.
authors.affiliation: Mass Spectrometry Laboratory, Department of Chemistry, University of Aveiro, Campus de Santiago, 3810-193 Aveiro, Portugal.
authors.forename: Catarina I V
authors.initials: CI
authors.lastname: Ramos
authors.forename: Cristina M
authors.initials: CM
authors.lastname: Barros
authors.forename: Ana M
authors.initials: AM
authors.lastname: Fernandes
authors.forename: M G
authors.initials: MG
authors.lastname: Santana-Marques
authors.forename: A J Ferrer
authors.initials: AJ
authors.lastname: Correia
authors.forename: João P C
authors.initials: JP
authors.lastname: Tomé
authors.forename: Maria do Carmo T
authors.initials: Mdo C
authors.lastname: Carrilho
authors.forename: Maria Amparo F
authors.initials: MA
authors.lastname: Faustino
authors.forename: Augusto C
authors.initials: AC
authors.lastname: Tomé
authors.forename: M G P M S
authors.initials: MG
authors.lastname: Neves
authors.forename: J A S
authors.initials: JA
authors.lastname: Cavaleiro
mesh_terms: D001483:Base Sequence; D002412:Cations / Q000737:chemistry / Q000378:metabolism; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009838:Oligodeoxyribonucleotides / Q000737:chemistry* / Q000378:metabolism; D011166:Porphyrins / Q000737:chemistry* / Q000378:metabolism; D021241:Spectrometry, Mass, Electrospray Ionization
chemical_list: D002412:Cations; D009838:Oligodeoxyribonucleotides; D011166:Porphyrins