title: Purification and some important characters of extracellular inulinase of Alternaria alternata (Fr.) Keissler.
abstract: Protein precipitate of cell-free dialysate of extracellular inulinase (2,1-beta-fructan fructanohydrolase, EC 3.2.1.7) of A. alternata was maximally obtained by methanol. Such protein was fractionated by using 2-step column chromatography on Sephadex G150 and DEAE-cellulose. The partially purified enzyme had activity of 81 x 10(3) U/mg protein, with a yield of 69% of the original activity and the fold of purification was 62. Optimum temperature and pH for the activity of the purified enzyme were found to be 55 degrees C and 4.5, respectively. The enzyme was found to be stable up to 55 degrees C and in pH range of 4 to 5. Ba2+ and Ca2+ were found to stimulate the enzyme activity while Cu2+, Fe3+, Hg2+, and iodoacetate were recorded as strong inhibitors. T(1/2) of the enzyme was estimated to be two weeks and its apparent Km was calculated to be 0.066 M. The enzyme recorded hydrolyzing activity against sucrose and raffinose recording I/S ratio of 0.50. Molecular mass of the enzyme preparation was estimated by gel filtration and found to be 115 +/- 5 kDa.
authors.affiliation: Biological Sciences & Geology Department, Faculty of Education, Ain Shams University, Roxy, Heliopolis, Cairo, 11757, Egypt. hossamhamdy@yahoo.com
authors.forename: Hossam S
authors.initials: HS
authors.lastname: Hamdy
mesh_terms: D000528:Alternaria / Q000201:enzymology*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004795:Enzyme Stability; D006863:Hydrogen-Ion Concentration; D007339:Insulysin / Q000037:antagonists & inhibitors / Q000302:isolation & purification* / Q000378:metabolism; D013696:Temperature
chemical_list: D004791:Enzyme Inhibitors; D007339:Insulysin