title: Folic acid binds DNA and RNA at different locations.
abstract: We located multiple binding sites for folic acid on DNA and tRNA at physiological conditions, using FTIR, CD, fluorescence spectroscopic methods and molecular modeling. Structural analysis revealed that folic acid binds DNA and tRNA at multiple sites via hydrophilic, hydrophobic and H-bonding contacts with overall binding constants of Kfolic acid-DNA=1.1 (±0.3)×10(4) M(-1) and Kfolic acid-tRNA=6.4 (±0.5)×10(3) M(-1). Molecular modeling showed the participation of several nucleobases in folic acid complexes with DNA and tRNA, stabilized by H-bonding network. Two types of complexes were located for folic acid-tRNA adducts, one at the major groove and the other with TΨC loop, while acid binding occurs at major and minor grooves of DNA duplex. Folic acid complexation induced more alterations of DNA structure than tRNA.
authors.affiliation: Department of Chemistry-Biochemistry-Physics, University of Québec at Trois-Rivières, C.P. 500, Trois-Rivières, Québec G9A 5H7, Canada.
authors.forename: P
authors.initials: P
authors.lastname: Bourassa
authors.affiliation: Department of Chemistry-Biochemistry-Physics, University of Québec at Trois-Rivières, C.P. 500, Trois-Rivières, Québec G9A 5H7, Canada. Electronic address: tajmirri@uqtr.ca.
authors.forename: H A
authors.initials: HA
authors.lastname: Tajmir-Riahi
mesh_terms: D001665:Binding Sites; D002942:Circular Dichroism; D004247:DNA / Q000737:chemistry* / Q000378:metabolism; D005492:Folic Acid / Q000737:chemistry* / Q000378:metabolism; D008958:Models, Molecular; D008968:Molecular Conformation; D009690:Nucleic Acid Conformation; D012313:RNA / Q000737:chemistry* / Q000378:metabolism; D012343:RNA, Transfer; D013050:Spectrometry, Fluorescence; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: D012313:RNA; D004247:DNA; D012343:RNA, Transfer; D005492:Folic Acid
keywords: Binding site; DNA; Folic acid; Modeling; Spectroscopy; tRNA