RELATIONSHIP BETWEEN FUNCTIONAL-PROPERTIES AND STRUCTURE OF OVALBUMIN

The effects of ovalbumin (OVA) denaturation using urea, guanidinium ch loride (GdnHC1), sodium dodecyl sulphate (SDS), cetylpyridinium chlori de (CPC), 3-[(3-cholamidopropyl)dimethylammonio]-1-propa (CHAPS), and 5 different cationic detergents with various side chains, HC1, and CH3 COOH were observed. Progressive unfolding in ovalbumin was measured as a function of fluorescent light intensity, peak response and shift in the maximum of emission. Kinetic measurements demonstrated that the r ate of denaturation usually followed a double exponential decay patter n, but at small concentrations of urea and acids first-order reaction was indicated. The reversibility of the unfolding-folding transitions was confirmed from tryptophan fluorescence and circular dichroism (CD) measurements. Differences in secondary structure were observed and ch anges of alpha-helical content were calculated. Polyacrylamide gel ele ctrophoresis (PAGE) with and without sodium dodecyl sulphate (SDS-PAGE ) showed differences in the structure of native and denatured ovalbumi n. Native protein samples in PAGE demonstrated smaller number and larg er mobilities of subunits than denatured ones with different reductant s, such as SDS and 2-mercaptoethanol (2 ME). Scanning of SDS protein p atterns showed the appearance of aggregated forms in region of 45 kD.