title: Cholesterol modulates the membrane effects and spatial organization of membrane-penetrating ligands for G-protein coupled receptors.
abstract: The ligands of certain G-protein coupled receptors (GPCRs) are membrane soluble and reach their target from the lipid bilayer. Lipid composition and dynamics will therefore modulate the activity of these receptors, but specific roles of lipid components, including the ubiquitous cholesterol (Chol), are not clear. We have probed the organization and dynamics of such a lipid-bilayer-penetrating ligand, the endogenous ligand for the κ-opioid receptor (KOR) dynorphin A (1-17) (DynA), using molecular dynamics (MD) simulations of DynA in cholesterol-depleted and cholesterol-enriched model membranes. DynA is found to penetrate deep inside fluid dimyristoylphosphatidylcholine (DMPC) bilayers, and resides with its N-terminal helix at ∼6 Å away from the bilayer midplane, in a tilted orientation, at an ∼50° angle with respect to the membrane normal. In contrast, DynA inside DMPC/Chol membranes with 20% cholesterol (DMPC/Chol) is situated with its helical segment ∼5 A higher, i.e., closer to the lipid/water interface and in a relatively vertical orientation. The DMPC membrane shows greater thinning around the insertion and permits a stronger influx of water inside the hydrocarbon core than the DMPC/Chol membranes. Relating these results to data about key GPCR residues that have been implicated in interactions with membrane-inserting GPCR ligands, we conclude that the position of DynA in DMPC/Chol, but not in pure DMPC, correlates with generally proposed GPCR ligand entry pathways. Our predictions provide a possible mechanistic explanation as to why DynA binding to KOR, and the subsequent activation of the receptor, is facilitated in cholesterol-enriched environments. A quantitative description of DynA-induced membrane deformations is obtained with a continuum theory of membrane deformations (CTMD) that is based on hydrophobic matching. Comparison with the MD data reveals the significance of the lipid tail packing energy contribution in the DMPC/Chol mixtures in predicting equilibrium membrane shape around DynA. On this basis, specific corrections are introduced to this energy term within the CTMD framework, thereby extending the applicability of the CTMD framework to lipid raft mixtures and their interactions with GPCR proteins and their ligands.
authors.affiliation: Department of Physiology and Biophysics, Weill Cornell Medical College of Cornell University, New York, New York, USA. gek2009@med.cornell.edu
authors.forename: George
authors.initials: G
authors.lastname: Khelashvili
authors.forename: Sayan
authors.initials: S
authors.lastname: Mondal
authors.forename: Olaf S
authors.initials: OS
authors.lastname: Andersen
authors.forename: Harel
authors.initials: H
authors.lastname: Weinstein
mesh_terms: D000595:Amino Acid Sequence; D002462:Cell Membrane / Q000737:chemistry / Q000378:metabolism*; D002784:Cholesterol / Q000737:chemistry / Q000378:metabolism*; D004134:Dimyristoylphosphatidylcholine / Q000737:chemistry / Q000378:metabolism; D004399:Dynorphins / Q000737:chemistry; D057927:Hydrophobic and Hydrophilic Interactions; D008024:Ligands; D008051:Lipid Bilayers / Q000737:chemistry / Q000378:metabolism; D021962:Membrane Microdomains / Q000737:chemistry / Q000378:metabolism; D008968:Molecular Conformation; D056004:Molecular Dynamics Simulation; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000737:chemistry / Q000378:metabolism; D043562:Receptors, G-Protein-Coupled / Q000378:metabolism*; D017473:Receptors, Opioid, kappa / Q000378:metabolism; D014867:Water / Q000378:metabolism
chemical_list: D008024:Ligands; D008051:Lipid Bilayers; D010446:Peptide Fragments; D043562:Receptors, G-Protein-Coupled; D017473:Receptors, Opioid, kappa; D014867:Water; D004399:Dynorphins; D002784:Cholesterol; D004134:Dimyristoylphosphatidylcholine
references.citation: Biophys J. 2003 Mar;84(3):2080-9
references.pmid: 12609909
references.citation: Biophys J. 2000 Nov;79(5):2583-604
references.pmid: 11053132
references.citation: Adv Protein Chem. 2003;63:243-90
references.pmid: 12629973
references.citation: Biochim Biophys Acta. 2006 Sep;1758(9):1292-302
references.pmid: 16542637
references.citation: Phys Rev Lett. 1990 Apr 23;64(17):2094-2097
references.pmid: 10041575
references.citation: Biochim Biophys Acta. 2007 Apr;1768(4):794-807
references.pmid: 17188232
references.citation: J Comput Aided Mol Des. 2006 Feb;20(2):97-107
references.pmid: 16783601
references.citation: J Phys Chem B. 2010 Jun 10;114(22):7524-34
references.pmid: 20518573
references.citation: Biophys J. 2010 Jul 7;99(1):175-83
references.pmid: 20655845
references.citation: Curr Opin Drug Discov Devel. 2005 Sep;8(5):577-84
references.pmid: 16159019
references.citation: Prog Lipid Res. 2006 Jul;45(4):295-333
references.pmid: 16616960
references.citation: Biophys J. 2001 Apr;80(4):1649-58
references.pmid: 11259280
references.citation: Biophys J. 2008 Nov 1;95(9):4324-36
references.pmid: 18658211
references.citation: Biochemistry. 1997 Feb 25;36(8):1971-81
references.pmid: 9047294
references.citation: J Am Chem Soc. 2002 Jan 16;124(2):318-26
references.pmid: 11782184
references.citation: Chem Phys Lipids. 2006 Sep;143(1-2):1-10
references.pmid: 16737691
references.citation: J Biol Chem. 2005 Apr 1;280(13):12212-20
references.pmid: 15657045
references.citation: Nature. 2008 Jul 10;454(7201):183-7
references.pmid: 18563085
references.citation: Proc Natl Acad Sci U S A. 2009 Mar 10;106(10):3654-8
references.pmid: 19225105
references.citation: Biophys J. 2010 Jan 20;98(2):248-57
references.pmid: 20338846
references.citation: Biophys J. 1999 Jan;76(1 Pt 1):351-9
references.pmid: 9876147
references.citation: Biopolymers. 1991 May;31(6):785-92
references.pmid: 1657234
references.citation: Annu Rev Biophys Biomol Struct. 2004;33:269-95
references.pmid: 15139814
references.citation: Proteins. 2009 Aug 1;76(2):403-17
references.pmid: 19173312
references.citation: Biophys J. 2001 Aug;81(2):643-58
references.pmid: 11463613
references.citation: Biophys J. 2007 Jun 1;92(11):3960-7
references.pmid: 17369407
references.citation: Biophys J. 2000 Mar;78(3):1376-89
references.pmid: 10692323
references.citation: Trends Biochem Sci. 2005 Aug;30(8):430-6
references.pmid: 15996869
references.citation: Cell Mol Life Sci. 2000 Oct;57(11):1577-92
references.pmid: 11092453
references.citation: Chem Biol. 2008 Nov 24;15(11):1207-19
references.pmid: 19022181
references.citation: Biochim Biophys Acta. 1995 Sep 13;1238(2):163-76
references.pmid: 7548131
references.citation: Biophys J. 1998 Apr;74(4):1966-83
references.pmid: 9545056
references.citation: J Lipid Res. 2003 Apr;44(4):655-67
references.pmid: 12562849
references.citation: Phys Rev Lett. 2008 May 16;100(19):198103
references.pmid: 18518492
references.citation: Biophys J. 1998 Sep;75(3):1372-83
references.pmid: 9726938
references.citation: Biophys J. 2000 Nov;79(5):2331-44
references.pmid: 11053113
references.citation: Biophys J. 1999 Jul;77(1):3-22
references.pmid: 10388736
references.citation: Biophys J. 1997 Jul;73(1):267-76
references.pmid: 9199791
references.citation: Biochim Biophys Acta. 2009 Jan;1788(1):97-121
references.pmid: 18823938
references.citation: Nat Rev Mol Cell Biol. 2006 Jan;7(1):9-19
references.pmid: 16365634
references.citation: J Comput Chem. 2005 Dec;26(16):1781-802
references.pmid: 16222654
references.citation: J Phys Chem B. 1998 Apr 30;102(18):3586-616
references.pmid: 24889800
references.citation: Annu Rev Biophys Biomol Struct. 2003;32:257-83
references.pmid: 12543707
references.citation: Nature. 1998 Aug 20;394(6695):798-801
references.pmid: 9723621
references.citation: Cell. 2003 Nov 14;115(4):377-88
references.pmid: 14622593
references.citation: Biochemistry. 2004 Dec 14;43(49):15318-28
references.pmid: 15581344
references.citation: J Phys Chem B. 2005 Mar 24;109(11):5300-11
references.pmid: 16863197
references.citation: Biochim Biophys Acta. 2008 Jun;1778(6):1460-6
references.pmid: 18358828
references.citation: Methods Enzymol. 2002;343:329-71
references.pmid: 11665578
references.citation: Biochim Biophys Acta. 2005 Dec 30;1746(3):172-85
references.pmid: 16043244
references.citation: Physiology (Bethesda). 2006 Dec;21:430-9
references.pmid: 17119156
references.citation: Biochim Biophys Acta. 1978 Oct 19;513(1):43-58
references.pmid: 718889
references.citation: Annu Rev Biophys Biomol Struct. 2007;36:107-30
references.pmid: 17263662
references.citation: Biophys J. 2009 Jul 8;97(1):50-8
references.pmid: 19580743
references.citation: J Biol Chem. 2010 Jun 4;285(23):17954-64
references.pmid: 20220143
references.citation: Nature. 1998 Aug 20;394(6695):802-5
references.pmid: 9723622
references.citation: J Lipid Res. 1998 May;39(5):947-56
references.pmid: 9610760
references.citation: Biophys J. 2008 May 15;94(10):3935-44
references.pmid: 18234811
references.citation: Biopolymers. 1995;37(1):5-16
references.pmid: 7880967
references.citation: Z Naturforsch C. 1973 Nov-Dec;28(11):693-703
references.pmid: 4273690
references.citation: J Phys Chem B. 2006 Dec 28;110(51):25562-4
references.pmid: 17181184
references.citation: Eur Biophys J. 2003 Feb;31(8):575-85
references.pmid: 12582817
references.citation: J Med Chem. 1997 Sep 26;40(20):3254-62
references.pmid: 9379445
references.citation: Biochemistry. 1990 Nov 27;29(47):10676-84
references.pmid: 2271675
references.citation: Biophys Chem. 2004 Feb 1;107(2):151-64
references.pmid: 14962596
references.citation: Pharmacol Ther. 2004 Jul;103(1):21-80
references.pmid: 15251227
references.citation: Colloids Surf B Biointerfaces. 2004 Oct 10;38(1-2):11-4
references.pmid: 15465298
references.citation: Biophys J. 2009 Sep 16;97(6):1626-35
references.pmid: 19751667
references.citation: Biopolymers. 1983 Dec;22(12):2577-637
references.pmid: 6667333
references.citation: PLoS One. 2009;4(2):e4382
references.pmid: 19194506
references.citation: J Pharmacol Exp Ther. 2006 Jun;317(3):1295-306
references.pmid: 16505160
references.citation: Biophys J. 2006 Apr 1;90(7):2368-82
references.pmid: 16399829
references.citation: J Biol Chem. 1989 May 15;264(14):8151-5
references.pmid: 2722776
references.citation: Biochim Biophys Acta. 1979 Oct 19;557(1):259-63
references.pmid: 549641
references.citation: Science. 2010 Jan 1;327(5961):46-50
references.pmid: 20044567
references.citation: J Chem Phys. 2004 May 22;120(20):9841-7
references.pmid: 15268001
references.citation: Biochim Biophys Acta. 2007 Oct;1768(10):2586-95
references.pmid: 17662236
references.citation: Trends Pharmacol Sci. 2007 Aug;28(8):397-406
references.pmid: 17629961
references.citation: Biochemistry. 1992 Jul 28;31(29):6739-47
references.pmid: 1637810
references.citation: J Mol Endocrinol. 2004 Apr;32(2):325-38
references.pmid: 15072542
references.citation: Biophys J. 2002 Aug;83(2):1004-13
references.pmid: 12124282
references.citation: Biochemistry. 1988 Jun 28;27(13):4668-73
references.pmid: 3167010
references.citation: Nature. 1997 Jun 5;387(6633):569-72
references.pmid: 9177342
references.citation: AAPS J. 2006 Jan 06;7(4):E871-84
references.pmid: 16594640