Studies on Catalytic Properties of Purified High Molecular Weight Pancreatic Lipase 1

Abstract

Summary

The properties of the 500-fold purified high-molecular-weight lipase have been studied. The rate of hydrolysis of the triglycerides decreases with increasing fatty acid chain length. The lipolytic activity also increases with increase in unsaturation in the fatty acyl moiety. Diglycerides are hydro-lyzed at more than twice the rate for triglycerides while monoglycerides are not hydro-lyzed. Methyl esters are generally hydrolyzed at a higher rate which increases with increasing chain length of the fatty acid but the enzyme does not act on phospholipids. Emulsifying agents such as Tween 20, gum arabic, and albumin increase the rate of hydrolysis. Metal ions such as Hg²⁺, Zn²⁺, Cu²⁺, and Fe²⁺ strongly inhibit the lipolytic activity of the high-molecular-weight lipase while Ca²⁺ or Mg²⁺ by themselves show no stimulating effect. Treatment of the high-molecular-weight lipase with P-chloromer-curybenzoate inhibits hydrolytic activity by 70 % while iodoacetic acid has no effect.