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A phospholipase is an enzyme that hydrolyzes phospholipids into fatty acids and other lipophilic substances. There are four major classes, termed A, B, C and D, distinguished by the type of reaction which they catalyze: *Phospholipase A * *Phospholipase A1 - cleaves the SN-1 acyl chain. * *Phospholipase A2 - cleaves the SN-2 acyl chain, releasing arachidonic acid. *Phospholipase B - cleaves both SN-1 and SN-2 acyl chains; this enzyme is 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. Phospholipase A2 acts on the intact lecithin molecule and hydrolyses 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 bees and viper snakes.〔D. M. Vasudevan & S. Sreekumari, ''Textbook of Biochemistry'' (5th ed.)〕 ==See also== *Patatin-like phospholipase *Infantile neuroaxonal dystrophy 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「phospholipase」の詳細全文を読む スポンサード リンク
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