M V Lomonosov Moscow State University Faculty of

M. V. Lomonosov Moscow State University Faculty of Physics Charles University in Prague Faculty of Mathematics and Physics INTERACTIONS BETWEEN BIOMARKERS and MAIN BLOOD PROTEINS Gibizova V. V. , Petrova G. P. , Sergeeva I. A. , Fedorova K. V. E-mail: gibizova@physics. msu. ru Nowadays biophysics investigations are developing and are important for medicine applications. PHOTON CORRELATION SPECTROSCOPY Static Light Scattering Average scattering intensity is a function of the (particle) molecular weight and the 2 nd virial coefficient. M – Molecular weight, R 90 – Rayleigh ratio c – Concentration, H – Optical constant B – 2 nd Virial coefficient, NA – Avogadros number, ν 0 – excluded Volume, i. e. volume of the molecule which supersedes all other 2 nd virial coefficient is a thermodynamic property. describing the interaction strength between the molecule and the solvent. For samples where B>0, the molecules tend to stay in solution (protein molecules prefer contact with buffer). When B=0, the molecule-solvent interaction strength is equivalent to the molecule-molecule interaction strength – the solvent is described as being a theta solvent (protein doesn’t mind buffer). When B<0, the molecule will tend to fall out of solution or aggregate (protein doesn’t like buffer). RESULTS INVESTIGATED OBJECTS Gadopentetic acid C 14 H 20 Gd. N 3 O 10 Paramagnetic contrast agents for MRI: 1) for enhancing of picture contrast; 2) for the detection of tumors, including small and bad visualized. gamma-globulin globular protein, determines the immune properties of the body. The investigated water solution: bovine gamma-globulin; bovine gammaglobulin+gadopentetic acid PHOTOCOR COMPLEX Parameters of laser: wavelength - 647 nm, power P=25 m. W The conditions of experiment: temperature of investigated solutions T=20ºC, p. H~7, 0 CONCLUSIONS Our results show that the slope of the straight is positive for the pure solution of gamma-globulin, but the addition of gadopentetic acid changes the sigh of 2 nd virial coefficient of intermolecular interaction (positive slope becomes negative).