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.
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.
Rossetti
Luigi
L
Dipartimento di Genetica e Biologia Molecolare, Università di Roma La Sapienza, Piazzale Aldo Moro, 5, c.a.p. 00185, Roma, Italy.
D'Isa
Giuliana
G
Mauriello
Clementina
C
Varra
Michela
M
De Santis
Pasquale
P
Mayol
Luciano
L
Savino
Maria
M
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
D007094:Imides; C099239:N,N'-bis(3,3'-(dimethylamino)propylamine)-3,4,9,10-perylenetetracarboxylic diimide; D010569:Perylene; C509186:TERT protein, human; D019098:Telomerase