Colipase interaction with pancreatic lipase

Pancreatic lipase is one of the mammalian key digestive enzymes. It completes the dietary triacylglycerol breakdown initiated by preduode-nal lipases, including lingual and gastric enzymes, (see below). The enzyme is inhibited in the intestine by bile salts, but the activity is restored in the presence of colipase (CLP), a relatively short (95 residues) heat-stable polypeptide secreted by the pancreas (Semeriva and Desnuelle, 1979 Borgstrbm and Erlanson-Albertsson, 1984). The structural details of the interaction of colipase with lipase are described in Section III,C. 

Soluble substrates are available which are cleaved by carboxylester lipase in the absence of bile salts, such as the not quite specific para-nitrophenylacetate [40] or the dilaurate ester of fluorescein [51,52] (Fig. 9). However, bile salts not only protect the enzyme, but interact specifically with the enzyme, affecting approximately 7- to 10-fold the activity on water-soluble substrates like para-nitrophenylacetate. When water-insoluble esters like triolein or cholesterol oleate are selected as the substrate, the enzyme is virtually inactive without bile salts, which gives them the character of essential activators [53]. In contrast to pancreatic lipase, carboxylester lipase needs no cofactor like colipase and is not activated by an oilAvater interface. Purified carboxylester lipase loses the majority of its activity by lyophylization but can be stored frozen at -20°C [46]. 

P. Canioni, R. Julien, J. Rat helot, and L. Sarda. Pancreatic and microbial lipases a comparison of the interaction of pancreatic colipase with lipases of various origins. Upids 12 393 (1977). 

---