Phospholipase Cleavage Sites. Note that an enzyme that displays both PLA1 and PLA2 activities is called a Phospholipase B

A phospholipase is an enzyme that hydrolyzes phospholipids^[1] into fatty acids and other lipophilic substances. There are four major classes, termed A, B, C and D distinguished by what type of reaction they catalyze:

• Phospholipase A
  • Phospholipase A1 - cleaves the SN-1 acyl chain
  • Phospholipase A2 - cleaves the SN-2 acyl chain
• Phospholipase B - cleaves both SN-1 and SN-2 acyl chains, also known as a lysophospholipase.
• Phospholipase C - cleaves before the phosphate, releasing diacylglycerol and a phosphate-containing head group. Phospholipase Cs play a central role in signal transduction, releasing the second messenger Inositol triphosphate.
• Phospholipase D - cleaves after the phosphate, releasing phosphatidic acid and an alcohol.

Types C and D are considered phosphodiesterases.

Phospolipase A2 acts on intact lecithin molecule and hydrolyses the fatty acid esterified to the second carbon atom.the product formed is lysolecithin and fatty acid. lysolecithin is an enzyme present in the venom of the viper snakes.^[2]

[edit] See also

• Patatin-like phospholipase
• Infantile neuroaxonal dystrophy

[edit] References

[edit] External links

• MeSH Phospholipases
• Phospholipase Signaling Pathway