title: NaDNA-bipyridyl-(ethylenediamine)platinum (II) complex: structure in oriented wet-spun films and fibers.
abstract: Complexes of NaDNA with bipyridyl-(ethylenediamine)platinum(II) (abbreviated [(bipy)Pt(en)](2+)) in solid, oriented films, prepared with a wet-spinning method, have been studied using x-ray diffraction, elastic neutron scattering, two-dimensional magic-angle-spinning nuclear magnetic resonance (NMR), infrared (IR) linear dichroism, and IR absorption. All of these experiments indicate that the DNA in this complex is in the B conformation. The neutron diffraction experiments reveal that the rise per residue is 3.31 A, indicating that the [(bipy)Pt(en)](2+) molecular ion causes a small distortion of the B conformation. The neutron data in the direction perpendicular to the helical axis are consistent with a centered orthorhombic unit cell with a=22.65 A and b=32.2 A. The NMR and IR experiments show that the orientation of phosphate groups in the DNA small middle dot[(bipy)Pt(en)](2+) complex is the same as that observed for pure DNA in the B conformation. The IR experiments also show that the [(bipy)Pt(en)](2+) molecular ion stabilizes the B conformation of DNA down to 59% relative humidity, a low water activity. Mechanochemical experiments on wet-spun NaDNA fibers in 68% ethanol with and without [(bipy)Pt(en)](2+) reveal a 9% elongation of the DNA fibers as the complex is formed.
authors: Department of Physics & Astronomy, University of Toledo, Toledo, Ohio 43606, USA.
authors: S A
authors: SA
authors: Lee
authors: H
authors: H
authors: Grimm
authors: W
authors: W
authors: Pohle
authors: W
authors: W
authors: Scheiding
authors: L
authors: L
authors: van Dam
authors: Z
authors: Z
authors: Song
authors: M H
authors: MH
authors: Levitt
authors: N
authors: N
authors: Korolev
authors: A
authors: A
authors: Szabó
authors: A
authors: A
authors: Rupprecht
mesh_terms: D015082:2,2'-Dipyridyl / Q000031:analogs & derivatives* / Q000737:chemistry* / Q000378:metabolism; D000818:Animals; D004247:DNA / Q000737:chemistry* / Q000378:metabolism; D000431:Ethanol / Q000378:metabolism; D009682:Magnetic Resonance Spectroscopy; D009502:Neutrons; D009690:Nucleic Acid Conformation; D009942:Organometallic Compounds / Q000737:chemistry* / Q000378:metabolism; D017671:Platinum Compounds / Q000737:chemistry* / Q000378:metabolism; D012542:Scattering, Radiation; D013055:Spectrophotometry, Infrared; D014961:X-Ray Diffraction
chemical_list: D009942:Organometallic Compounds; D017671:Platinum Compounds; D000431:Ethanol; D015082:2,2'-Dipyridyl; D004247:DNA