title: Sunflower seed lipase: extraction, purification, and characterization.
abstract: A simple procedure for the extraction of the lipolytic activity from sunflower seed has been developed. Various conditions of extraction have been optimized in order to obtain maximum yield of lipase. A new lipase enzyme was purified by the fractional salt precipitation from the supernatant, dialysis on a cellulose membrane, and gel column chromatography on Sephadex G-75. The lipase was monomeric, with an apparent Mr of 22 kDa and a pI of 8, with the electrophoretic analysis. Kinetics of the enzyme activity versus substrate concentration showed typical lipase behavior, with Km and Vmax, values of 1.33 mM and 555 U/mg. All triglycerides were efficiently hydrolyzed by the enzyme, but this showed a preference towards triglycerides of natural mono unsaturated fatty acids. The optimum temperature, pH, and incubation time for lipolytic activity were 50 degrees C, 7.5, and 5 min, respectively. The stability of the sunflower lipase was investigated under operational and storage conditions. It was found that this enzyme preserved its lipolytic activity at temperatures between at 35-50 degrees C, alkaline pH, and for a period of about four months.
authors.affiliation: Department of Chemistry, Faculty of Science and Letters, Trakya University, 22030, Edirne, Turkey. aytensa@hotmail.com
authors.forename: Ayten
authors.initials: A
authors.lastname: Sagiroglu
authors.forename: Nilay
authors.initials: N
authors.lastname: Arabaci
mesh_terms: D005591:Chemical Fractionation / Q000379:methods*; D002850:Chromatography, Gel / Q000379:methods*; D003911:Dextrans; D004356:Drug Storage; D004789:Enzyme Activation; D004795:Enzyme Stability; D006368:Helianthus / Q000201:enzymology*; D006863:Hydrogen-Ion Concentration; D008049:Lipase / Q000737:chemistry* / Q000302:isolation & purification*; D012639:Seeds / Q000201:enzymology*; D013696:Temperature
chemical_list: D003911:Dextrans; C025614:sephadex; D008049:Lipase