title: A model for triple helix formation on human telomerase reverse transcriptase (hTERT) promoter and stabilization by specific interactions with the water soluble perylene derivative, DAPER.
abstract: The promoter of human telomerase reverse transcriptase (hTERT) gene, in the region from -1000 to +1, contains two homopurine-homopyrimidine sequences (-835/-814 and -108/-90), that can be considered as potential targets to triple helix forming oligonucleotides (TFOs) for applying antigene strategy. We have chosen the sequence (-108/-90) on the basis of its unfavorable chromatin organization, evaluated by theoretical nucleosome positioning and nuclease hypersensitive sites mapping. On this sequence, anti-parallel triplex with satisfactory thermodynamic stability is formed by two TFOs, having different lengths. Triplex stability is significantly increased by specific interactions with the perylene derivative N,N'-bis[3,3'-(dimethylamino) propylamine]-3,4,9,10-perylenetetracarboxylic diimide (DAPER). Since DAPER is a symmetric molecule, the induced Circular Dichroism (CD) spectra in the range 400-600 nm allows us to obtain information on drug binding to triplex and duplex DNA. The drug-induced ellipticity is significantly higher in the case of triplex with respect to duplex and, surprisingly, it increases at decreasing of DNA. A model is proposed where self-stacked DAPER binds to triplex or to duplex narrow grooves.
authors.affiliation: Dipartimento di Genetica e Biologia Molecolare, Università di Roma La Sapienza, Piazzale Aldo Moro, 5, c.a.p. 00185, Roma, Italy.
authors.forename: Luigi
authors.initials: L
authors.lastname: Rossetti
authors.forename: Giuliana
authors.initials: G
authors.lastname: D'Isa
authors.forename: Clementina
authors.initials: C
authors.lastname: Mauriello
authors.forename: Michela
authors.initials: M
authors.lastname: Varra
authors.forename: Pasquale
authors.initials: P
authors.lastname: De Santis
authors.forename: Luciano
authors.initials: L
authors.lastname: Mayol
authors.forename: Maria
authors.initials: M
authors.lastname: Savino
mesh_terms: D001483:Base Sequence; D001665:Binding Sites; D006801:Humans; D007094:Imides / Q000737:chemistry* / Q000494:pharmacology; D009690:Nucleic Acid Conformation / Q000187:drug effects; D010569:Perylene / Q000031:analogs & derivatives* / Q000737:chemistry / Q000494:pharmacology; D011401:Promoter Regions, Genetic / Q000187:drug effects*; D012995:Solubility; D019098:Telomerase / Q000235:genetics*; D013816:Thermodynamics
chemical_list: D007094:Imides; C099239:N,N'-bis(3,3'-(dimethylamino)propylamine)-3,4,9,10-perylenetetracarboxylic diimide; D010569:Perylene; C509186:TERT protein, human; D019098:Telomerase