Phospholipase

From WikiMD.com Medical Encyclopedia

(Redirected from Phospholipases)

Phospholipase[edit | edit source]

Diagram of phospholipase activity on phospholipids

Phospholipases are a group of enzymes that hydrolyze phospholipids into fatty acids and other lipophilic substances. They play a crucial role in the metabolism of phospholipids, which are essential components of cell membranes. Phospholipases are involved in various cellular processes, including membrane remodeling, signal transduction, and the generation of lipid mediators.

Types of Phospholipases[edit | edit source]

Phospholipases are classified into several types based on the site of hydrolysis on the phospholipid molecule:

Phospholipase A1 (PLA1)[edit | edit source]

Phospholipase A1 enzymes cleave the fatty acid at the sn-1 position of glycerophospholipids, releasing a free fatty acid and a lysophospholipid.

Phospholipase A2 (PLA2)[edit | edit source]

Phospholipase A2 enzymes specifically hydrolyze the fatty acid at the sn-2 position of glycerophospholipids. This reaction releases arachidonic acid, a precursor for the synthesis of eicosanoids, which are important signaling molecules.

Phospholipase B (PLB)[edit | edit source]

Phospholipase B enzymes have the ability to hydrolyze both the sn-1 and sn-2 acyl chains of phospholipids, acting as both PLA1 and PLA2.

Phospholipase C (PLC)[edit | edit source]

Phospholipase C enzymes cleave the phosphodiester bond at the glycerol side of the phospholipid, releasing diacylglycerol (DAG) and a phosphorylated head group, such as inositol trisphosphate (IP3). These products are important in signal transduction pathways.

Phospholipase D (PLD)[edit | edit source]

Phospholipase D enzymes hydrolyze the phosphodiester bond at the head group side of the phospholipid, producing phosphatidic acid and a free head group, such as choline.

Biological Functions[edit | edit source]

Phospholipases are involved in a variety of biological functions, including:

  • Membrane Dynamics: They participate in the remodeling of cell membranes by altering the composition of phospholipids.
  • Signal Transduction: Phospholipases generate second messengers that are crucial for transmitting signals within cells.
  • Lipid Mediator Production: They are involved in the production of lipid mediators like prostaglandins and leukotrienes, which are important in inflammation and immune responses.

Clinical Significance[edit | edit source]

Phospholipases have been implicated in several diseases and pathological conditions:

  • Inflammatory Diseases: Overactivity of PLA2 can lead to excessive production of inflammatory mediators.
  • Neurological Disorders: Abnormal phospholipase activity is associated with neurodegenerative diseases.
  • Cancer: Altered phospholipase expression and activity have been observed in various cancers, affecting cell proliferation and metastasis.

Related Pages[edit | edit source]

WikiMD
Navigation: Wellness - Encyclopedia - Health topics - Disease Index‏‎ - Drugs - World Directory - Gray's Anatomy - Keto diet - Recipes

Search WikiMD

Ad.Tired of being Overweight? Try W8MD's physician weight loss program.
Semaglutide (Ozempic / Wegovy and Tirzepatide (Mounjaro / Zepbound) available.
Advertise on WikiMD

WikiMD's Wellness Encyclopedia

Let Food Be Thy Medicine
Medicine Thy Food - Hippocrates

Medical Disclaimer: WikiMD is not a substitute for professional medical advice. The information on WikiMD is provided as an information resource only, may be incorrect, outdated or misleading, and is not to be used or relied on for any diagnostic or treatment purposes. Please consult your health care provider before making any healthcare decisions or for guidance about a specific medical condition. WikiMD expressly disclaims responsibility, and shall have no liability, for any damages, loss, injury, or liability whatsoever suffered as a result of your reliance on the information contained in this site. By visiting this site you agree to the foregoing terms and conditions, which may from time to time be changed or supplemented by WikiMD. If you do not agree to the foregoing terms and conditions, you should not enter or use this site. See full disclaimer.
Credits:Most images are courtesy of Wikimedia commons, and templates, categories Wikipedia, licensed under CC BY SA or similar.

Contributors: Prab R. Tumpati, MD