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Thermo induced endothermic phase transitions of phospholipids

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Thermo induced endothermic phase transitions of phospholipids

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  1. THE EXPERIMENTAL MODELS OF FIRST LIFE OBJECTS. THE ACTIONS OF BIOLOGICAL ACTIVE SUBSTANCES TO THESE MODELS.1Yagolnik E.A., 2Alekseeva O.M., 3Kim Yu. A.1Tula State University, Tula,2N.M.Emmanuel Institute of Biochemical Physics, RAS, Moscow, 3 Institute of Cell Biophysics, Russian Academy of Sciences, Pushchino, Moscow region E-mails: yea_88@mail.ru;olgavek@yandex; yuk01@rambler.ru

  2. 2 Model phospholipids membranes imitated the main components of bio-objects. We formed the multilammelar liposomes with aid of hydration of phospholipids thin films under the shacking at warm phosphate buffer. Biological active substances actions to these experimental objects were tested. Multilammelar liposomes that were artificially formed from phospholipids bilayer membranes were the adequate model of some intracellular organelles.

  3. 3 • The liposomes are fairly interesting model for research of primary bio-similar structures formation and action of different materials on their organization, biologically active substances (BAS). Among them were ions, simple non organic and organic substances. • Liposomes are organized due to the spontaneous process of self-assembly of amphiphilic phospholipids molecules. Hydrophobic and hydrophilic interactions stimulate the liposomes formation with different structures in dependent of hydration degree. • Cell organelles are imitated by bilayer and multilayer liposomes. • Restructuring of cell compartments are simulated by means of hexagonal and stack lipid structures. • With the help of differential scanning microcalorimetry (DSC) method we described any actions of some organic (Melafen and phenozan and its derivatives) biologically active substance on such model membranes. Multulammelar liposomes that were formed from artificial individual phospholipid - dimyristoilphosphatidylcholine (DMPC) were used for DSC experiments. Liposomes were treated under the Melafen presence from 10-17 M to-10-3 M).

  4. 4 Thermo induced endothermic phase transitions of phospholipids Heat absorbtion (DSC) test. Multilammelar liposomes of DMPS T Main transition Pre - transition Lipid packing from more rankorder to free Gel phase Ripple-phase Liquid crystal phase

  5. speed of heat supplied (1 degree/min; 0,5 degree/min; 0,25 degree/min; 0,125 degree/min one-eighth of degree) to cells with control and experimental samples 5 Melafen influence to DMPC thermo inducted parameters – enthalpy, T, cooperatives

  6. 6 The structural effects of ICHFANs to the multulammelar DMPC liposomes ICHFAN C16 formed the its own phase under the concentrations 10-5, 10-4М at the belayer. This phase has another thermo inductions parameters. The domains of ICHFANs have the great influencing to the rafts near the integral and associated receptors and enzymes at cellular membrane, by this its affect to the functional activities. ICHFANs С10 and С12 have the maximal effects, С8 and С16 have the less effect, probably the length of anchoring fatty acid residue С10, С12 is the optimal. Phenozan has not the fatty acid tail; by this its influence is weaker. Phenozan does not formed the own phase. Its effects were occurred under the biggest concentrations 10-4, 10-3М DMPC thermograms control Redundant heat absorbtion ICHFANs

  7. scheme of possible ways of liposomes and cell interactions 7 BAS Next step in bio-structural complicating may be the building of hydrophobic peptide molecules in such membranous liposomes, or else grabbing of hydrophilic ones to interior space. Some regions of big outer membranes may be drowning, in interior space, break away and so that form small internal liposome with mixed composition, as the organelles predecessors. The education of cell compartments led on creating of ionic and electrostatic gradients that was able to already emergence of some functions. Intracellular vesicle formed Membrane fusion and vesicle introducing, than it were cat and form internal vesicles

  8. 8 • As of experimental object we used the erythrocyte ghost.

  9. Melafen,ICHFAN-10,phenozan influence to the thermo induced protein domains denaturation of erythrocyte ghosts membranes suspension 9 phenozan Erythrocyte ghosts thermograms А- spektrin, actin; В1-ancyrin, demantin, Band 4,1, 4,2; В2- Band 3 cytoplasm fragment; С- Band 3 – ion channels; D – membrane’s blabbing control 2 ICHFAN-10 10-6 М ICHFAN-1010-5 М J /K ethanol Melafen control

  10. 10 Conclusions: • Certain small and large structural changes of lipid and protein components of cell membrane when biological active substances presence at medium are being revealed by DSC test. • So that, on first the making up stages of living cells, some materials (as organic, and non organic) changed the cellular structure and the interaction of their components.

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