Acid triacylglycerol lipase from bovine thyroid gland.
An acid lipase has been detected in bovine thyroid tissue using triolein as a substrate. The activity, probably associated with the lysosomes, displays a rather broad pH-optimum in the pH 4 to pH 6.5 range. The lipase activity can be partially purified by cosedimentation with lysosomes followed by solubilization through detergent and chromatography on Sephadex G-200 and carboxymethyl cellulose. The elution profile on Sephadex G-200 shows one peak (moleculare weight 67,000 +/- 2,000). In the final CM-cellulose step, two lipase peaks (lipase LA and lipase LB) are found. Sulhydryl reagents (iodoacetate, iodoacetamide, and N-ethylmaleimide) as well as mercuric ions markedly reduce both enzyme activities. Calcium ions, EDTA, and heparin have no effect. Sodium fluoride and diisopropylfluorophosphate are only slightly inhibitory. Sodium chloride causes a slight increase in both lipase activities. Anionic phospholipids such as cardiolipin and phosphatidylserine are not essential for enzyme activity.
D000818:Animals; D002417:Cattle; D006358:Hot Temperature; D007700:Kinetics; D008049:Lipase / Q000302:isolation & purification / Q000378:metabolism*; D008247:Lysosomes / Q000201:enzymology; D008928:Mitochondria / Q000201:enzymology; D013347:Subcellular Fractions / Q000201:enzymology; D013961:Thyroid Gland / Q000201:enzymology*; D014280:Triglycerides
D014280:Triglycerides; D008049:Lipase