Pancreatic triacylglycerol lipase (PTL) (PTL)

Pancreatic triacylglycerol lipase (PTL) is the principal enzyme responsible for the hydrolysis of dietary triglycerides into absorbable free fatty acids and monoglycerides within the small intestine [UniProt]. Secreted by the exocrine pancreas, its catalytic activity is highly dependent on the presence of colipase, a protein cofactor that anchors the enzyme to the lipid-water interface in the presence of inhibitory bile salts [Wikipedia, NIH]. In clinical medicine, PTL is a major therapeutic target for the management of obesity; pharmacological inhibitors like orlistat work by covalently binding to the enzyme's active site, thereby preventing fat absorption and promoting weight loss [PubMed]. Conversely, in conditions such as exocrine pancreatic insufficiency (EPI) or cystic fibrosis, pancreatic enzyme replacement therapy (PERT) is used to provide exogenous lipase to restore fat digestion [StatPearls]. Additionally, elevated serum levels of this enzyme serve as a primary diagnostic biomarker for acute pancreatitis and other forms of pancreatic injury [Cleveland Clinic]. Therapeutic challenges include managing the gastrointestinal side effects associated with fat malabsorption, such as steatorrhea and deficiencies in fat-soluble vitamins [NIH].

Other names

Pancreatic lipasePNLIPSteapsinTriacylglycerol acylhydrolaseIntestinal lipase

Covalent inhibition of the active site serine residue (for inhibitors like orlistat); enzymatic hydrolysis of dietary triglycerides into monoglycerides and free fatty acids (for replacement therapies like pancrelipase).