| Autor: |
S V, Kornilova, L E, Kapinos, Iu P, Blagoĭ |
| Rok vydání: |
1995 |
| Předmět: |
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| Zdroj: |
Molekuliarnaia biologiia. 29(3) |
| ISSN: |
0026-8984 |
| Popis: |
DNA complexes with Ca2+ ions formed in films at various relative humidities were studied by IR-spectroscopy for molar concentration ratio of calcium ions and DNA phosphate groups [Ca2+]/[P] = 0.4-20. It is shown that the transition of DNA complexed with Ca2+ ions into B-form occurs at higher average numbers (n) of water molecules absorbed per nucleotide: n18 at the ratio [Ca2+]/[P] = 10, n24 at [Ca2+]/[P] = 20 and n12 in the absence of Ca2+ ions. This shows stronger binding of water molecules in the hydrate shell of DNA-Ca2+ if compared with free DNA. The results confirm a model proposed earlier. Ca2+ ions interact with phosphate oxygens of DNA and with N(7) nitrogens of guanine forming chelated complexes. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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