Interfacial membrane properties modulate protein kinase C activation: role of the position of acyl chain unsaturation.
We studied the effects of the addition of a series of 1, 2-dioctadecenoyl-sn-glycerol-3-phosphoethanolamines to vesicles composed of 1-palmitoyl-2-oleoylphosphatidylserine and 1-palmitoyl-2-oleoylphosphatidylcholine on the activity and membrane binding of protein kinase C (PKC). The three phosphatidylethanolamines (PEs) were dipetroselinoyl-PE, dioleoyl-PE, and divaccenoyl-PE, which have double bonds in positions 6, 9, and 11, respectively. These lipids represent a group of structurally homologous compounds whose physical properties have been compared. We also used a fluorescent probe, 4-[(n-dodecylthio)methyl]-7-(N, N-dimethylamino)coumarin to measure the relative interfacial polarities of LUVs containing each of the three PEs. We find dipetroselinoyl-PE allows the least access of the fluorescent probe to the membrane. This is also the lipid that shows the lowest activation of PKC. The activity of PKC was found to correlate best with the interfacial properties of the three PEs rather than with the curvature energy of the membrane. The results show the sensitivity of the activity of PKC to small changes in lipid structure.
Department of Biochemistry, McMaster University Health Sciences Centre, Hamilton, Ontario, Canada.
J R
JR
Giorgione
R
R
Kraayenhof
R M
RM
Epand
D000818:Animals; D001665:Binding Sites; D003374:Coumarins / Q000737:chemistry; D004789:Enzyme Activation / Q000187:drug effects; D005231:Fatty Acids, Unsaturated / Q000737:chemistry*; D005454:Fluorescence Polarization; D005456:Fluorescent Dyes; D008563:Membrane Lipids / Q000737:chemistry*; D008565:Membrane Proteins / Q000378:metabolism; D010713:Phosphatidylcholines / Q000737:chemistry; D010714:Phosphatidylethanolamines / Q000737:chemistry; D010718:Phosphatidylserines / Q000737:chemistry; D010743:Phospholipids / Q000737:chemistry; D011493:Protein Kinase C / Q000378:metabolism*; D051381:Rats; D013050:Spectrometry, Fluorescence; D013499:Surface Properties
C102150:4-(n-dodecylthiomethyl)-7-(N,N-dimethylamino)coumarin; D003374:Coumarins; D005231:Fatty Acids, Unsaturated; D005456:Fluorescent Dyes; D008563:Membrane Lipids; D008565:Membrane Proteins; D010713:Phosphatidylcholines; D010714:Phosphatidylethanolamines; D010718:Phosphatidylserines; D010743:Phospholipids; C113791:dipetroselinoyl-PE; C113794:divaccenoyl-PE; C094877:dioleoyl phosphatidylethanolamine; C050294:1-palmitoyl-2-oleoylglycero-3-phosphoserine; D011493:Protein Kinase C; C028694:1-palmitoyl-2-oleoylphosphatidylcholine