title: Kinetic properties and storage stability of catalase immobilized on to florisil.
abstract: The covalent immobilization of bovine liver catalase (CAT) on to florisil via glutaraldehyde was investigated. Optimum immobilization pH and temperature were determined as pH 6.0, 10 degrees C respectively, while the amount of initial CAT per g of carrier and immobilization time was determined as 5 mg g(-1) and 120 min, respectively. The Vmax values for free and immobilized CAT were found to be 1.7 x 10(5) and 2.0 x 10(4) micromol H2O2 min(-1) mg protein(-1), respectively, whereas KM values were 33.3 mM and 1722.0 mM respectively. Operational stability was determined by using a stirred batch-type column reactor. Immobilized CAT retained about 40% of its initial activity after 50 uses. It showed higher storage stability than free CAT at 4 degrees C and 25 degrees C. Its storage stability increased with increasing relative humidity (RH) from 0 to 20% of the medium. The highest storage stability was obtained in 20% RH, however, further increase in RH from 40 to 100% significantly decreased the storage stability.
authors: University of Mustafa Kemal, Faculty of Arts & Sciences, Department of Chemistry 31040 Hatay, Turkey. gozyilmaz@gmail.com
authors: Gul
authors: G
authors: Ozyilmaz
authors: S Seyhan
authors: SS
authors: Tukel
authors: Ozlem
authors: O
authors: Alptekin
mesh_terms: D000818:Animals; D002021:Buffers; D002374:Catalase / Q000737:chemistry / Q000378:metabolism*; D002417:Cattle; D004356:Drug Storage; D004795:Enzyme Stability; D004800:Enzymes, Immobilized / Q000737:chemistry / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D066298:In Vitro Techniques; D007700:Kinetics; D008099:Liver / Q000201:enzymology; D017633:Magnesium Silicates
chemical_list: D002021:Buffers; D004800:Enzymes, Immobilized; D017633:Magnesium Silicates; C005013:Florisil; D002374:Catalase