Phospholipase

 ( Peripheral Membrane Proteins ) 

A phospholipase is an enzyme that hydrolyzes into and other lipophilic substances. There are four major classes, termed A, B, C, and D, which are distinguished by the type of reaction which they catalyze:

• Phospholipase A
• Phospholipase A₁ – cleaves the sn-1 Acyl group (where sn refers to stereospecific numbering).
• Phospholipase A₂ – cleaves the sn-2 Acyl group, releasing arachidonic acid.
• Phospholipase B – cleaves both sn-1 and sn-2 Acyl group; this enzyme is also known as a lysophospholipase.
• Phospholipase C – cleaves before the phosphate, releasing diglyceride and a phosphate-containing head group. Phospholipase C 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.

Endothelial lipase is primarily a phospholipase.

Phospholipase A₂ acts on the intact lecithin molecule and hydrolyzes the fatty acid esterified to the second carbon atom. The resulting products are lysolecithin and a fatty acid. Phospholipase A₂ is an enzyme present in the venom of , blennies and Viperidae.D. M. Vasudevan & S. Sreekumari, Textbook of Biochemistry (5th ed.)

• Patatin-like phospholipase
• Infantile neuroaxonal dystrophy

• Tappia, Paramjit S. & Dhalla, Naranjan S. (Editors): Phospholipases in Health and Disease. Springer, 2014. Print; eBook