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R S Khusainova

Publications and source records attributed to R S Khusainova.

6 recordsLinked to original sources

Spin-dependent absorption of water molecules.

The effects of spin state of water molecules on its absorption on lyophilized DNA, lysozyme and some inorganic sorbents were studied. It was shown that the absorption rates of ortho and para water from vapor differ noticeably. The para isomer binding with preparations is distinctly faster than that of the ortho isomer in all cases. Clear-cut distinction in the sorption kinetics is determined by the difference in quantum statistics for spin isomers, which in its turn can give rise to remarkable differences in physico-chemical properties of ortho and para water. This finding opens a wide field of activity in studying fundamental and applied problems relating to the role of the spin state of water molecules in physics, chemistry, biology and medicine.

Absorption↗

Stoichiometry of dipalmitoylphosphatidylcholine-DNA interaction in the presence of Ca2+: a temperature-scanning ultrasonic study.

DNA-DPPC complexes can be prepared by means of a single step procedure of mixing DNA solution and aqueous lipid dispersion in the presence of calcium ions. Interaction between DPPC and DNA brings about a biphasic shape of melting curves corresponding to the free lipid and the strongly bound one. The amount of the strongly bound lipid is 5 molecules per nucleotide which is close to the size of the first lipid monolayer around DNA molecule.

1,2-Dipalmitoylphosphatidylcholine↗

DNA initiates polymorphic structural transitions in lecithin.

The inverted micellar phase, obtained by treating lecithin and Ca(2+)-DNA complex with chloroform, was used as an intermediate step in the preparation of DNA-Ca(2+)-lecithin complex. DSC analysis demonstrated the involvement of a large fraction of lipid in the interaction with DNA. Freeze-fracture electron microscopy revealed (i) rod-like structures on the hydrophobic fracture surface of membranes and (ii) regular bundles of fibrils with a repeat distance of about 6 nm, which were located free in solution. Similar regular bundles of fibrils were also revealed by staining the samples with uranyl acetate. According to the suggested model, the observed structures are hexagonally packed inverted lipid tubes, with DNA located in their central cores. The possible biological relevance of the capability of Ca(2+)-DNA to initiate polymorphic phase transitions of lecithin is discussed.

Animals↗