title: Purification and characterization of alpha-glucosidase complex from the intestine of the frog, Rana japonica.
abstract: The enzymes responsible for much of the isomaltase and maltase activities in the intestine of the frog, Rana japonica, were purified by detergent solubilization and affinity chromatography on Sephadex G-200 gel. The two activities paralleled each other during purification. The isomaltase, maltase and glucoamylase activities eluted in the same pattern on Sepharose 4B gel filtration as well as on Sephadex G-200 gel affinity chromatography. Anti-rabbit sucrase-isomaltase antibody inhibited the isomaltase activity but not the maltase or glucoamylase activity of the purified enzyme preparation, while the three activities were precipitated in parallel by the antibody. The isomaltase activity was more stable at 55 degrees C than the maltase and glucoamylase activities. On SDS-polyacrylamide gel electrophoresis under nondissociating conditions the purified enzyme preparation showed only one major band of 330 kDa, while under dissociating conditions it showed two bands of 116 and 212 kDa. These results suggest that isomaltase (apparently with no or minor maltase activity) is due to a protein domain (or protein) different from one which is responsible for maltase and glucoamylase activities. This implies that isomaltase is associated with maltase/glucoamylase to form alpha-glucosidase complex in the brush border membrane of the frog intestine.
authors.affiliation: Department of Chemistry, Faculty of General Education, Gifu University, Japan. takesue@cc.gifu-u.ac.jp
authors.forename: Y
authors.initials: Y
authors.lastname: Takesue
authors.forename: S
authors.initials: S
authors.lastname: Takesue
mesh_terms: D000818:Animals; D002846:Chromatography, Affinity; D002850:Chromatography, Gel; D003902:Detergents; D005260:Female; D005087:Glucan 1,4-alpha-Glucosidase / Q000037:antagonists & inhibitors / Q000302:isolation & purification; D065089:Glycoside Hydrolase Inhibitors; D006863:Hydrogen-Ion Concentration; D007140:Immunoglobulin Fab Fragments / Q000276:immunology / Q000494:pharmacology; D007422:Intestines / Q000201:enzymology* / Q000648:ultrastructure; D008871:Microvilli / Q000201:enzymology; D008970:Molecular Weight; D009097:Multienzyme Complexes / Q000737:chemistry / Q000302:isolation & purification*; D017830:Octoxynol; D009834:Oligo-1,6-Glucosidase / Q000037:antagonists & inhibitors / Q000302:isolation & purification; D011817:Rabbits; D011898:Ranidae / Q000378:metabolism*; D013379:Substrate Specificity; D013394:Sucrase-Isomaltase Complex / Q000276:immunology; D000520:alpha-Glucosidases / Q000737:chemistry / Q000302:isolation & purification*
chemical_list: D003902:Detergents; D065089:Glycoside Hydrolase Inhibitors; D007140:Immunoglobulin Fab Fragments; D009097:Multienzyme Complexes; D017830:Octoxynol; D013394:Sucrase-Isomaltase Complex; D009834:Oligo-1,6-Glucosidase; D000520:alpha-Glucosidases; D005087:Glucan 1,4-alpha-Glucosidase