Effect of testosterone and its aliphatic and aromatic dimers on DNA morphology.
Conjugation of DNA with testosterone and it aliphatic dimer (alip) and aromatic dimer (arom) was investigated in aqueous solution at pH 7.4. Multiple spectroscopic methods, transmission electron microscopy (TEM) and molecular modeling were used to characterize steroid-DNA binding and DNA morphology. Spectroscopic analysis showed that testosterone binds DNA via A7, A16, A17, T8, T15 and T18 nucleobases with overall binding constants Ktest-DNA=1.8 (±0.4)×104M-1, Ktest-dimeralip-DNA=5.7 (±0.7)×104M-1and Ktest-dimer-arom-DNA=7.3 (±0.9)×104M-1. The binding affinity increases in this order: testosterone dimer-aromatic>testosterone dimer-aliphatic>testosterone. The steroid loading efficacy was 40-50%. Transmission electron microscopy showed major changes in DNA morphology as testosterone-DNA interaction occurred with increase in the diameter of the DNA aggregate, indicating encapsulation of testosterone by DNA. Modeling showed the presence of several nucleobases attached to testosterone with the free binding energy of -4.93Kcal/mol.
Department of Chemistry-Biochemistry and Physics, University of Québec at Trois-Rivières C.P. 500, Trois-Rivières, Québec G9A 5H7, Canada.
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Chanphai
Department of Chemistry-Biochemistry and Physics, University of Québec at Trois-Rivières C.P. 500, Trois-Rivières, Québec G9A 5H7, Canada.
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Agudelo
Department of Chemistry-Biochemistry and Physics, University of Québec at Trois-Rivières C.P. 500, Trois-Rivières, Québec G9A 5H7, Canada.
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Vesper
Department of Chemistry-Biochemistry and Physics, University of Québec at Trois-Rivières C.P. 500, Trois-Rivières, Québec G9A 5H7, Canada.
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Bérubé
Department of Chemistry-Biochemistry and Physics, University of Québec at Trois-Rivières C.P. 500, Trois-Rivières, Québec G9A 5H7, Canada. Electronic address: heidar-ali.tajmir-riahi@uqtr.ca.
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Tajmir-Riahi
D004247:DNA / Q000737:chemistry* / Q000378:metabolism; D019281:Dimerization; D062105:Molecular Docking Simulation; D009690:Nucleic Acid Conformation; D013329:Structure-Activity Relationship; D013739:Testosterone / Q000737:chemistry* / Q000378:metabolism / Q000494:pharmacology*
D013739:Testosterone; D004247:DNA
Conjugation; DNA; Modeling; Spectroscopy; TEM; Testosterone; Testosterone dimers