Spectrofluorometric determination of lipase activity

Area of Science:

• Biochemistry
• Analytical Chemistry
• Enzyme Assays

Background:

• Pancreatic lipase is a key enzyme in dietary fat digestion.
• Accurate measurement of lipase activity is crucial for diagnosing pancreatic disorders.
• Current lipase assays often require complex sample preparation, such as fatty acid extraction.

Purpose of the Study:

• To develop a novel fluorescent substrate for direct, real-time monitoring of pancreatic lipase activity.
• To establish a simplified assay for pancreatic lipase that circumvents the need for product extraction.

Main Methods:

• Synthesis of a fluorescent triglyceride: 1(3)-pyrenylbutanoyl-2,3(1,2)-dipalmitoyl-sn-glycerol.
• Characterization of the synthesized substrate using Nuclear Magnetic Resonance (NMR) and mass spectrometry.
• Incorporation of the substrate into a lipid emulsion.
• Monitoring changes in fluorescence (excimer and monomer) upon enzymatic hydrolysis by pancreatic lipase.

Main Results:

• The synthesized fluorescent triglyceride served as an effective substrate for pancreatic lipase.
• Hydrolysis of the substrate by pancreatic lipase released pyrene butyric acid.
• The release of pyrene butyric acid into the aqueous phase caused a measurable decrease in excimer fluorescence and an increase in monomer fluorescence.
• These fluorescence changes correlated with enzyme activity, providing a direct assay method.

Conclusions:

• A novel fluorescent triglyceride substrate enables a simplified and direct assay for pancreatic lipase activity.
• The fluorescence-based method eliminates the need for cumbersome fatty acid extraction steps.
• This approach offers a sensitive and efficient tool for enzyme activity determination in biochemical and clinical settings.