title: Influence of detergents and pH on the isolation, purification and molecular properties of alpha-galactosidase-C2 from germinating guar (Cyamopsis tetragonolobus).
abstract: alpha-Galactosidase was isolated from germinating guar. The extract also contained small amounts of alpha-mannosidase and beta-mannosidase activities. The fractionation of the enzyme extract with ammonium sulphate (75% saturation) resulted in the appearance of all the three enzymes in a floating lipid complex. The inclusion of detergents such as Triton X-100 and sodium deoxycholate in the extraction medium failed to prevent the appearance of these enzymes in the floating lipid complex. However, by using acetone powder of the seedlings, alpha-galactosidase could be sedimented with ammonium sulphate. The presence of detergents in the extraction medium affected the molecular properties of the enzyme. Using a set of carefully selected conditions alpha-galactosidase was purified to apparent homogeneity. Analytical ultracentrifugation and gel filtration studies of the purified enzyme showed association-dissociation phenomenon as a function of pH and temperature. The effect of pH on the association-dissociation indicates the predominance of electrostatic interactions in the association of subunits.
authors.forename: B D
authors.initials: BD
authors.lastname: Shivanna
authors.forename: M
authors.initials: M
authors.lastname: Ramakrishna
authors.forename: V
authors.initials: V
authors.lastname: Prakash
authors.forename: C S
authors.initials: CS
authors.lastname: Ramadoss
mesh_terms: D055598:Chemical Phenomena; D002621:Chemistry; D003902:Detergents; D005696:Galactosidases / Q000302:isolation & purification*; D006863:Hydrogen-Ion Concentration; D010944:Plants / Q000201:enzymology*; D013501:Surface-Active Agents; D000519:alpha-Galactosidase / Q000302:isolation & purification*
chemical_list: D003902:Detergents; D013501:Surface-Active Agents; D005696:Galactosidases; D000519:alpha-Galactosidase