NR ATHB
AU Hianik,T.; Ponikova,S.; Antalik,M.
TI Study of the mechanisms of interaction of polyanions with proteins and biomembranes contained lipid rafts
QU International Conference - Prion 2005: Between fundamentals and society's needs - 19.10.-21.10.2005, Congress Center Düsseldorf - Poster Session: Cell Biology of PrPc and PrPsc CELL-07
PT Konferenz-Poster
AB The study of the mechanisms of interaction of polyanions with proteins and biomembranes has great significance for molecular biology and medicine. For example the protein-DNA complexes are responsible for transcription of DNA, gene expression as well as for formation of specific structures of chromosomes and viruses. On the other hand several polyanions, such are e.g. dextran sulfate (DS), heparin (HEP), pentosan polysulfat reveal certain therapeutic action against development of transmissible spongiform encephalopaties (TSE). It has been shown, that these polyanions bind to the prion proteins and prevent their accumulation in animals and cells. Polyanions and their complexes with proteins may interacts also with cell membranes. It is assumed that the lipid rafts play important role in this interaction. In this work we used ultrasound velocimetry, densitometry and precise differential scanning calorimetry (DSC) to study the mechanisms of interaction of HEP and DS with human serum albumin (HSA) as well as with large unilamellar liposomes contained lipid rafts composed of cholesterol and sphingomyelin. We showed that at presence of HEP and DS the adiabatic compressibility of HSA decreases with increasing concentration of polyanions. Changes of compressibility of HSA can be caused by increase of the hydration due formation of the HSA-polyanion complexes and due to partial unfolding of HSA. The unfolding of the HSA has been confirmed also by DSC method. We showed strong interaction of the HSA-heparin complexes with the liposomes contained lipid rafts, that was accompanied by decrease of volume compressibility of the lipid bilayer. The mechanisms of the interactions of polyanions with proteins and membranes are discussed.
AD T.Hianik, S.Ponikova1, Comenius University, Slovakia; M.Antalik, Institute of Experimental Physics, SAS, Slovakia
SP englisch
PO Deutschland