## Abstract The extent and modes of binding of the divalent metal ions Mn^2+^ and Co^2+^ to DNA and the effects of salt on the binding have been studied by measurements of the effects of these paramagnetic metal ions on the longitudinal and transverse relaxation rates of the protons of the solvent
Interactions of DNA with divalent metal ions. III. Extent of metal binding: Experiment and theory
β Scribed by Joseph Granot; David R. Kearns
- Publisher
- Wiley (John Wiley & Sons)
- Year
- 1982
- Tongue
- English
- Weight
- 766 KB
- Volume
- 21
- Category
- Article
- ISSN
- 0006-3525
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β¦ Synopsis
Abstract
DNA with Mn^2+^ as the only counterion has been prepared, and the extent of the Mn^2+^ binding was determined under a variety of conditions through measurements of the proton relaxation enhancement of water. The total extent of Mn^2+^ binding per DNA phosphate is found to be 0.43 Β± 0.04, independent of the metal ion concentration in the experimental range of 2.8 Γ 10^β5^ to 2.1 Γ 10^β3^M. The predictions of Manning's condensation theory and those obtained from solution of the generalized PoissonβBoltzmann equation regarding the extent of divalent ion binding to polyelectrolytes, in the presence and absence of monovalent counterions, are compared with one another and with the experimental results. Good agreement between the two theoretical approaches is found, with less than 14% variance in the predicted extent of binding over a large range of monoβ and divalent ion concentrations. While the predictions of both theoretical approaches generally agree with the experimental results, some discrepancies are noted and their possible origins discussed.
π SIMILAR VOLUMES
## Abstract It has been inferred from previous studies that Mn^2+^ ions bind preferentially to GΒ·C base pairs in DNA, and it has even been suggested that this preference for GΒ·C pairs might be responsible for some of the Mn^2+^ specific effects observed in various biochemical reactions. In this pap
Polyadenylic acid is degraded into niononncleotides and low molecular might, oligoniicleotides in a 20 hr. period at 64Β°C. by the action of ;\In (II), Co (11), Xi (11), and Cri (11) ions, and in a 2 hr. period by Zn (11) ions. The latter also degrade poly C, poly U, and RNA at approsimately the same
## Abstract Changes in the conformation of poly(G), poly(C), poly(U), and poly(I) in the presence of divalent metal ions Mg^2+^, Ca^2+^, Mn^2+^, Co^2+^, Ni^2+^, Cu^2+^, Cd^2+^, and Zn^2+^ have been measured by means of ORD and u.v. spectra. Mg^2+^ and Ca^2+^ ions stabilize helical structures of all
The polarographically determined binding constants of Cu++ and Cd++ to DNA were found to decrease with the degree of binding. The binding causes a reduction in the electrostatic potential $ on the DNA molecule. The binding constant conforms to the relation K = KO exp ( -z e $ / k T ) . The binding c
The polyrihonucleotides of adenylic, cytidylic, and uridylic acids are degraded in a 2-hr. period at 64Β°C. into low molecular weight oligoniicleot,ides and mononncleotides through the action of lanthanum ( 111) or other trivalent inner transition met,al ions. Polyinosinic arid is degraded somewhat m