Human gastric lipase. The N-terminal tetrapeptide is essential for lipid binding and lipase activity.
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Bernback S, Blackberg L
Human gastric lipase. The N-terminal tetrapeptide is essential for lipid binding and lipase activity.
Eur J Biochem. 1989 Jul 1;182(3):495-9.
- PubMed ID
- 2753032 [ View in PubMed]
- Abstract
Human gastric lipase subjected to limited tryptic proteolysis lost its ability to hydrolyze emulsified long-chain triacylglycerol. Activity against a water-soluble substrate was however retained, indicating that proteolysis did not affect the active site. Sequence analysis revealed that trypsin specifically cleaved the linkage between lysine-4 and leucine-5. This cleavage rendered the enzyme unable to bind to emulsified triacylglycerol particles, e.g. human milk fat globules. We suggest that the N-terminal tetrapeptide, in particular lysine-4, is essential for the binding of human gastric lipase to lipid/water interfaces, and hence, for its physiological function.