[Interaction of DNA with calcium ions by a vibrational spectroscopy].
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: n > 18 at the ratio [Ca2+]/[P] = 10, n > 24 at [Ca2+]/[P] = 20 and n > 12 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.
Kornilova
S V
SV
Kapinos
L E
LE
Blagoĭ
Iu P
IuP
D000818:Animals; D002118:Calcium / Q000737:chemistry*; D002412:Cations; D002417:Cattle; D004247:DNA / Q000737:chemistry*; D010100:Oxygen / Q000737:chemistry; D013055:Spectrophotometry, Infrared / Q000379:methods; D014867:Water / Q000737:chemistry
D002412:Cations; D014867:Water; D004247:DNA; D010100:Oxygen; D002118:Calcium
Izuchenie vzaimodeĭstviia DNK s ionami kal'tsiia metodom kolebatel'noĭ spektroskopii.