What Makes the Bioactive Lipids Phosphatidic Acid and Lysophosphatidic Acid So Special?
| Autor: | Vladimir Chupin, Karen M. Carter, Ben de Kruijff, Edgar E. Kooijman, Koert N.J. Burger, Emma G. van Laar |
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| Rok vydání: | 2005 |
| Předmět: |
Models
Molecular Magnetic Resonance Spectroscopy Stereochemistry Lipid Bilayers Phosphatidic Acids Endoplasmic Reticulum Biochemistry chemistry.chemical_compound Deprotonation Phosphatidylcholine Lysophosphatidic acid Least-Squares Analysis Lipid bilayer Ions Phosphatidylethanolamine Molecular Structure Hydrogen bond Phosphatidylethanolamines Bilayer Cell Membrane Titrimetry Hydrogen Bonding Membranes Artificial Intracellular Membranes Phosphatidic acid Hydrogen-Ion Concentration chemistry Phosphatidylcholines lipids (amino acids peptides and proteins) Lysophospholipids Protons |
| Zdroj: | Biochemistry. 44:17007-17015 |
| ISSN: | 1520-4995 0006-2960 |
| DOI: | 10.1021/bi0518794 |
| Popis: | Phosphatidic acid and lysophosphatidic acid are minor but important anionic bioactive lipids involved in a number of key cellular processes, yet these molecules have a simple phosphate headgroup. To find out what is so special about these lipids, we determined the ionization behavior of phosphatidic acid (PA) and lysophosphatidic acid (LPA) in extended (flat) mixed lipid bilayers using magic angle spinning 31 P NMR. Our data show two surprising results. First, despite identical phosphomonoester headgroups, LPA carries more negative charge than PA when present in a phosphatidylcholine bilayer. Dehydroxy-LPA (1-oleoyl-3-(phosphoryl)propanediol) behaves in a manner identical to that of PA, indicating that the difference in negative charge between LPA and PA is caused by the hydroxyl on the glycerol backbone of LPA and its interaction with the phosphomonoester headgroup. Second, deprotonation of phosphatidic acid and lysophosphatidic acid was found to be strongly stimulated by the inclusion of phosphatidylethanolamine in the bilayer, indicating that lipid headgroup charge depends on local lipid composition and will vary between the different subcellular locations of (L)PA. Our findings can be understood in terms of a hydrogen bond formed within the phosphomonoester headgroup of (L)PA and its destabilization by competing intra- or intermolecular hydrogen bonds. We propose that this hydrogen bonding property of (L)PA is involved in the various cellular functions of these lipids. |
| Databáze: | OpenAIRE |
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