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Updated: Feb 7, 2026
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Defining Substrate Specificities for Lipase and Phospholipase Candidates
Published on: November 23, 2016
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Lysosomal phospholipase A2.
James A Shayman1, John J G Tesmer2
1Department of Internal Medicine, University of Michigan Medical School, University of Michigan, Ann Arbor, MI, USA.
Summary
Lysosomal phospholipase A2 (PLA2G15) is an enzyme found in lysosomes. It plays a role in breaking down oxidized phospholipids and may be involved in pulmonary surfactant catabolism and host defense.
Area of Science:
- Biochemistry
- Cell Biology
- Enzymology
Background:
- Lysosomal phospholipase A2 (PLA2G15) is a key enzyme localized to lysosomes and late endosomes.
- It exhibits unique characteristics, including an acidic pH optimum and calcium independence.
- Recent structural and functional studies have elucidated its catalytic mechanism and inhibition by certain drugs.
Purpose of the Study:
- To summarize the known functions and characteristics of Lysosomal phospholipase A2 (PLA2G15).
- To highlight recent advancements in understanding PLA2G15's catalytic activity and substrate specificity.
- To explore the potential roles of PLA2G15 in physiological processes such as surfactant metabolism and immune responses.
Main Methods:
- Analysis of crystal structure to understand catalytic mechanism and drug inhibition.
- Biochemical assays to determine enzyme activity, pH optimum, and substrate specificity.
- Studies using PLA2G15 null mice to investigate in vivo functions.
Main Results:
- PLA2G15 functions as a transacylase and hydrolyzes short-chain oxidized phospholipids.
- Its activity is independent of calcium and optimal at acidic pH.
- PLA2G15 null mice exhibit impaired pulmonary surfactant catabolism, suggesting a role in this process.
- Potential roles in host defense and lipid antigen processing for CD1 presentation were identified.
Conclusions:
- PLA2G15 is a multifunctional enzyme with significant roles in lipid metabolism within the lysosome.
- Its involvement extends to pulmonary surfactant breakdown and potentially immune system functions.
- Further research into PLA2G15's novel functions is warranted.
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