Biomaterial Database

Mercury-induced transitions between right-handed and putative left-handed forms of poly[d(A-T).d(A-T)] and poly[d(G-C).d(G-C)]. 1989

D W Gruenwedel, and M K Cruikshank

Department of Food Science and Technology, University of California, Davis 95616.

Poly[d(A-T).d(A-T)] and poly[d(G-C).d(G-C)], each dissolved in 0.1 M NaClO4, 5 mM cacodylic acid buffer, pH 6.8, experience inversion of their circular dichroism (CD) spectrum subsequent to the addition of Hg(ClO4)2. Let r identical to [Hg(ClO4)2]added/[DNA-P]. The spectrum of the right-handed form of poly[d(A-T).d(A-T)] turns into that of a seemingly left-handed structure at r greater than or equal to 0.05 while a similar transition is noted with poly[d(G-C).(G-C)] at r greater than or equal to 0.12. The spectral changes are highly cooperative in the long-wavelength region above 250 nm. At r = 1.0, the spectra of the two polymers are more or less mirror images of their CD at r = 0. While most CD bands experience red-shifts upon the addition of Hg(ClO4)2, there are some that are blue-shifted. The CD changes are totally reversible when Hg(II) is removed from the nucleic acids by the addition of a strong complexing agent such as NaCN. This demonstrates that mercury keeps all base pairs in register.

UI	MeSH Term	Description	Entries
D008628	Mercury	A silver metallic element that exists as a liquid at room temperature. It has the atomic symbol Hg (from hydrargyrum, liquid silver), atomic number 80, and atomic weight 200.59. Mercury is used in many industrial applications and its salts have been employed therapeutically as purgatives, antisyphilitics, disinfectants, and astringents. It can be absorbed through the skin and mucous membranes which leads to MERCURY POISONING. Because of its toxicity, the clinical use of mercury and mercurials is diminishing.
D009690	Nucleic Acid Conformation	The spatial arrangement of the atoms of a nucleic acid or polynucleotide that results in its characteristic 3-dimensional shape.	DNA Conformation,RNA Conformation,Conformation, DNA,Conformation, Nucleic Acid,Conformation, RNA,Conformations, DNA,Conformations, Nucleic Acid,Conformations, RNA,DNA Conformations,Nucleic Acid Conformations,RNA Conformations
D010472	Perchlorates	Compounds that contain the Cl(	Perchloric Acid Derivatives,Perchloric Acids,Acids, Perchloric
D011067	Poly dA-dT	Polydeoxyribonucleotides made up of deoxyadenine nucleotides and thymine nucleotides. Present in DNA preparations isolated from crab species. Synthetic preparations have been used extensively in the study of DNA.	Poly(Deoxyadenylate-Thymidylate),Polydeoxyadenine Nucleotides-Polythymine Nucleotides,Poly dA dT,Poly(dA-dT),d(A(5)T(5))2,Nucleotides, Polydeoxyadenine Nucleotides-Polythymine,Nucleotides-Polythymine Nucleotides, Polydeoxyadenine,Polydeoxyadenine Nucleotides Polythymine Nucleotides,dA dT, Poly,dA-dT, Poly,dT, Poly dA
D011089	Polydeoxyribonucleotides	A group of 13 or more deoxyribonucleotides in which the phosphate residues of each deoxyribonucleotide act as bridges in forming diester linkages between the deoxyribose moieties.	Polydeoxyribonucleotide
D002942	Circular Dichroism	A change from planar to elliptic polarization when an initially plane-polarized light wave traverses an optically active medium. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)	Circular Dichroism, Vibrational,Dichroism, Circular,Vibrational Circular Dichroism
D017669	Mercury Compounds	Inorganic compounds that contain mercury as an integral part of the molecule.	Compounds, Mercury