Akademik Veri Yönetim Sistemi
JAOCS, Journal of the American Oil Chemists' Society, cilt.87, sa.6, ss.659-665, 2010 (SCI-Expanded, Scopus)
Lipase (E.C. 3.1.1.3) from walnut seed was purified 28.6-fold with 31% yield using Sephadex G-100 gel chromatography. Olive oil served as good substrate for the enzyme. The optimum pH and temperature were 9.0 and 70 °C, respectively. The lipase was stable between 30 and 80 °C for 5 min. K m and V max values were determined as 48 mM and 23.06 × 10-3 U/min mg for triolein as substrate. Lipase activity was slightly reduced by Cu2+, Ca2+,Hg2+,Mn2+, and Ni2+ ions, while Mg2+ and Zn2+ had no effects. Anionic surfactant sodium dodecyl sulfate stimulated lipase activity while non-ionic surfactants Tween-80 and Triton X-100 had negligible effects on enzymatic activity. The enzyme activity was not affected by 50 mM urea and thioacetamide. Potassium ferricyanide, n-bromosuccinamide and potassium cyanide reduced the enzyme activity. The enzyme showed a good stability in organic solvents, the best result being in n-hexane (113% residual activity). The activity of dialysate was maintained approximately 80% for 1 year at -20 °C. © 2010 AOCS.