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Membrane Allostery and Hydrophobic Binding Sites Control Substrate Specificity of Lipolytic Enzymes
Author(s) -
Mouchlis Varnavas D.,
McCammon J. Andrew,
Dennis Edward A.
Publication year - 2018
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.2018.32.1_supplement.528.6
Subject(s) - membrane , phospholipid , chemistry , allosteric regulation , biochemistry , enzyme , arachidonic acid , cytosol , biophysics , lipidomics , active site , biology
Connecting molecular structure with cellular function is fundamental to understanding the mechanism of action of water‐soluble enzymes acting on cell membranes ( PNAS 2015, 112 , E516–E525). Cytosolic (cPLA 2 ), calcium‐independent (iPLA 2 ) and lipoprotein‐associated (Lp‐PLA 2 ) provide an ideal system for studying protein‐lipid molecular recognition and membrane functioning. cPLA 2 is the main arachidonic acid provider for the eicosanoid pathway, iPLA 2 is involved in membrane phospholipid remodeling and Lp‐PLA 2 was found to associate with LDL and HDL in human plasma to hydrolyze phospholipids containing short‐chain and oxidized fatty acids. A lipidomics mass spectrometric assay allowed us to define unique specificity of PLA 2 s towards a wide variety of phospholipids that was not feasible with existing assays. Computational techniques such as molecular dynamics simulations and docking guided by hydrogen/deuterium (H/D) exchange experimental data showed that membrane phospholipids bind to allosteric sites located on the interfacial surface of PLA 2 s, shifting their conformation from the “closed” to the “open” state. This process enables PLA 2 s to extract and bind a phospholipid molecule in the active site where the hydrolysis occurs. This is a novel study addressing recognition between water‐soluble enzymes and membranes as well as substrate specificity, binding and interactions using computational techniques guided by experimental data. PLA 2 s are implicated in chronic inflammatory diseases and understanding their association with membranes as well as their interactions with substrates will allow us to identify potent and selective inhibitors that can be further developed as anti‐inflammatory agents ( J. Med. Chem. 2016, 59 , 4403–4414). Support or Funding Information NIH grant GM20501‐41 This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal .