Phospholipase
Overview
 
A phospholipase is an enzyme that hydrolyzes phospholipid
Phospholipid
Phospholipids are a class of lipids that are a major component of all cell membranes as they can form lipid bilayers. Most phospholipids contain a diglyceride, a phosphate group, and a simple organic molecule such as choline; one exception to this rule is sphingomyelin, which is derived from...

s into fatty acid
Fatty acid
In chemistry, especially biochemistry, a fatty acid is a carboxylic acid with a long unbranched aliphatic tail , which is either saturated or unsaturated. Most naturally occurring fatty acids have a chain of an even number of carbon atoms, from 4 to 28. Fatty acids are usually derived from...

s and other lipophilic
Lipophilic
Lipophilicity, , refers to the ability of a chemical compound to dissolve in fats, oils, lipids, and non-polar solvents such as hexane or toluene. These non-polar solvents are themselves lipophilic — the axiom that like dissolves like generally holds true...

 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
      Phospholipase A1
      Phospholipase A1 is a phospholipase enzyme which removes the 1-acyl. Phospholipase A1 is a component of snake venom, but it also serves in normal metabolism to produce fatty acids from phospholipids. In melanocytic cells the Phospholipase A1 gene may be regulated by MITF.-External links:*...

       - cleaves the SN-1 acyl chain
      Fatty acid
      In chemistry, especially biochemistry, a fatty acid is a carboxylic acid with a long unbranched aliphatic tail , which is either saturated or unsaturated. Most naturally occurring fatty acids have a chain of an even number of carbon atoms, from 4 to 28. Fatty acids are usually derived from...

      .
    • Phospholipase A2
      Phospholipase A2
      Phospholipases A2 are enzymes that release fatty acids from the second carbon group of glycerol. This particular phospholipase specifically recognizes the sn-2 acyl bond of phospholipids and catalytically hydrolyzes the bond releasing arachidonic acid and lysophospholipids...

       - cleaves the SN-2 acyl chain
      Fatty acid
      In chemistry, especially biochemistry, a fatty acid is a carboxylic acid with a long unbranched aliphatic tail , which is either saturated or unsaturated. Most naturally occurring fatty acids have a chain of an even number of carbon atoms, from 4 to 28. Fatty acids are usually derived from...

      , releasing arachidonic acid
      Arachidonic acid
      Arachidonic acid is a polyunsaturated omega-6 fatty acid 20:4.It is the counterpart to the saturated arachidic acid found in peanut oil, Arachidonic acid (AA, sometimes ARA) is a polyunsaturated omega-6 fatty acid 20:4(ω-6).It is the counterpart to the saturated arachidic acid found in peanut oil,...

      .
  • Phospholipase B
    Phospholipase B
    Phospholipase B is an enzyme with a combination of both PLA1 and PLA2 activities; that is, it can cleave acyl chains from both the sn-1 and sn-2 positions of a phospholipid. In general, it acts on lysolecithin ....

     - cleaves both SN-1 and SN-2 acyl chain
    Fatty acid
    In chemistry, especially biochemistry, a fatty acid is a carboxylic acid with a long unbranched aliphatic tail , which is either saturated or unsaturated. Most naturally occurring fatty acids have a chain of an even number of carbon atoms, from 4 to 28. Fatty acids are usually derived from...

    s; this enzyme is also known as a lysophospholipase.
  • Phospholipase C
    Phospholipase C
    Phosphoinositide phospholipase C is a family of eukaryotic intracellular enzymes that play an important role in signal transduction processes. In general, this enzyme is denoted as Phospholipase C, although three other families of phospholipase C enzymes have been identified in bacteria and in...

     - cleaves before the phosphate, releasing diacylglycerol
    Diglyceride
    A diglyceride, or a diacylglycerol , is a glyceride consisting of two fatty acid chains covalently bonded to a glycerol molecule through ester linkages....

     and a phosphate-containing head group.
 
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