Purification and some properties of a bovine milk lipase

Abstract

A low molecular weight lipase was isolated from clarifier slime. The enzyme was precipitated from a water extract of an acetone powder prepared from clarifier slime at 20-45% of saturation with (NHâ‚„)â‚‚ SOâ‚„. The enzyme was purified by ultrafiltration, and Sephadex G-75 was utilized for the final isolation of the lipase. An estimated molecular weight of 8,500 was determined for the enzyme which contained 7.6% carbohydrate. The lipase hydrolyzed a simple short chain fatty acid triglyceride faster than long chain fatty acid triglycerides, but had little specificity for natural oil emulsions. Complete inactivation of the enzyme was observed after 1 hr at 45 C. A rapid decrease in activity occurred at 37 C and only 16% of the original activity could be detected after 5 hr. Storage for 48 hr at 23 and 4 C caused a decrease in lipase activity of 74 and 28%, respectively. A 280/260 absorbency ratio of 0.43 was observed for the enzyme.