1d7n: Difference between revisions

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[[Image:1d7n.jpg|left|200px]]<br /><applet load="1d7n" size="~~450~~" color="white" frame="true" align="right" spinBox="true"

[[Image:1d7n.jpg|left|200px]]<br /><applet load="1d7n" size="350" color="white" frame="true" align="right" spinBox="true"

caption="1d7n" />

'''SOLUTION STRUCTURE ANALYSIS OF THE MASTOPARAN WITH DETERGENTS'''<br />

==Overview==

Several complementary NMR approaches were used to study the interaction of, mastoparan, a 14-residue peptide toxin from wasp venom, with lipid, membranes. First, the 3D structure of mastoparan was determined using, 1H-NMR spectroscopy in perdeuterated (SDS-d25) micelles. NOESY experiments, and distance geometry calculations yielded a straight amphiphilic, alpha-helix with high-order parameters, and the chemical shifts of the, amide protons showed a characteristic periodicity of 3-4 residues., Secondly, solid-state 2H-NMR spectoscopy was used to describe the binding, of mastoparan to lipid bilayers, composed of headgroup-deuterated, dimyristoylglycerophosphocholine (DMPC-d4) and, dimyristoylphosphatidylglycerol (DMPG). By correlating the deuterium, quadrupole splittings of the alpha-segments and beta-segments, it was, possible to differentiate the electrostatically induced structural, response of the choline headgroup from dynamic effects induced by the, peptide. A partial phase separation was observed, leading to a DMPG-rich, phase and a DMPG-depleted phase, each containing some mastoparan. Finally, the insertion and orientation of a specifically 15N-labeled mastoparan (at, position Ala10) in the bilayer environment was investigated by solid-state, 15N-NMR spectroscopy, using macroscopically oriented samples. Two distinct, orientational states were observed for the mastoparan helix, namely an, in-plane and a trans-membrane alignment. The two populations of 90%, in-plane and 10% trans-membrane helices are characterized by a mosaic, spread of +/- 30 degrees and +/- 10 degrees, respectively. The biological, activity of mastoparan is discussed in terms of a pore-forming model, as, the peptide is known to be able to induce nonlamellar phases and, facilitate a flip-flop between the monolayers.

Several complementary NMR approaches were used to study the interaction of mastoparan, a 14-residue peptide toxin from wasp venom, with lipid membranes. First, the 3D structure of mastoparan was determined using 1H-NMR spectroscopy in perdeuterated (SDS-d25) micelles. NOESY experiments and distance geometry calculations yielded a straight amphiphilic alpha-helix with high-order parameters, and the chemical shifts of the amide protons showed a characteristic periodicity of 3-4 residues. Secondly, solid-state 2H-NMR spectoscopy was used to describe the binding of mastoparan to lipid bilayers, composed of headgroup-deuterated dimyristoylglycerophosphocholine (DMPC-d4) and dimyristoylphosphatidylglycerol (DMPG). By correlating the deuterium quadrupole splittings of the alpha-segments and beta-segments, it was possible to differentiate the electrostatically induced structural response of the choline headgroup from dynamic effects induced by the peptide. A partial phase separation was observed, leading to a DMPG-rich phase and a DMPG-depleted phase, each containing some mastoparan. Finally, the insertion and orientation of a specifically 15N-labeled mastoparan (at position Ala10) in the bilayer environment was investigated by solid-state 15N-NMR spectroscopy, using macroscopically oriented samples. Two distinct orientational states were observed for the mastoparan helix, namely an in-plane and a trans-membrane alignment. The two populations of 90% in-plane and 10% trans-membrane helices are characterized by a mosaic spread of +/- 30 degrees and +/- 10 degrees, respectively. The biological activity of mastoparan is discussed in terms of a pore-forming model, as the peptide is known to be able to induce nonlamellar phases and facilitate a flip-flop between the monolayers.

==About this Structure==

1D7N is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Vespula_lewisii Vespula lewisii] with NH2 as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http://~~ispc~~.weizmann.ac.il/oca-bin/ocashort?id=1D7N OCA].

1D7N is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Vespula_lewisii Vespula lewisii] with <scene name='pdbligand=NH2:'>NH2</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1D7N OCA].

==Reference==

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[[Category: sodium dodecyl sulfate bound conformation]]

''Page seeded by [http://~~ispc~~.weizmann.ac.il/oca OCA ] on ~~Tue Nov 20~~ 13:~~04:15 2007~~''

''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 12:13:49 2008''

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@@ Line 1: / Line 1: @@
-[[Image:1d7n.jpg|left|200px]]<br /><applet load="1d7n" size="450" color="white" frame="true" align="right" spinBox="true"
+[[Image:1d7n.jpg|left|200px]]<br /><applet load="1d7n" size="350" color="white" frame="true" align="right" spinBox="true"
 caption="1d7n" />
 '''SOLUTION STRUCTURE ANALYSIS OF THE MASTOPARAN WITH DETERGENTS'''<br />
 ==Overview==
-Several complementary NMR approaches were used to study the interaction of, mastoparan, a 14-residue peptide toxin from wasp venom, with lipid, membranes. First, the 3D structure of mastoparan was determined using, 1H-NMR spectroscopy in perdeuterated (SDS-d25) micelles. NOESY experiments, and distance geometry calculations yielded a straight amphiphilic, alpha-helix with high-order parameters, and the chemical shifts of the, amide protons showed a characteristic periodicity of 3-4 residues., Secondly, solid-state 2H-NMR spectoscopy was used to describe the binding, of mastoparan to lipid bilayers, composed of headgroup-deuterated, dimyristoylglycerophosphocholine (DMPC-d4) and, dimyristoylphosphatidylglycerol (DMPG). By correlating the deuterium, quadrupole splittings of the alpha-segments and beta-segments, it was, possible to differentiate the electrostatically induced structural, response of the choline headgroup from dynamic effects induced by the, peptide. A partial phase separation was observed, leading to a DMPG-rich, phase and a DMPG-depleted phase, each containing some mastoparan. Finally, the insertion and orientation of a specifically 15N-labeled mastoparan (at, position Ala10) in the bilayer environment was investigated by solid-state, 15N-NMR spectroscopy, using macroscopically oriented samples. Two distinct, orientational states were observed for the mastoparan helix, namely an, in-plane and a trans-membrane alignment. The two populations of 90%, in-plane and 10% trans-membrane helices are characterized by a mosaic, spread of +/- 30 degrees and +/- 10 degrees, respectively. The biological, activity of mastoparan is discussed in terms of a pore-forming model, as, the peptide is known to be able to induce nonlamellar phases and, facilitate a flip-flop between the monolayers.
+Several complementary NMR approaches were used to study the interaction of mastoparan, a 14-residue peptide toxin from wasp venom, with lipid membranes. First, the 3D structure of mastoparan was determined using 1H-NMR spectroscopy in perdeuterated (SDS-d25) micelles. NOESY experiments and distance geometry calculations yielded a straight amphiphilic alpha-helix with high-order parameters, and the chemical shifts of the amide protons showed a characteristic periodicity of 3-4 residues. Secondly, solid-state 2H-NMR spectoscopy was used to describe the binding of mastoparan to lipid bilayers, composed of headgroup-deuterated dimyristoylglycerophosphocholine (DMPC-d4) and dimyristoylphosphatidylglycerol (DMPG). By correlating the deuterium quadrupole splittings of the alpha-segments and beta-segments, it was possible to differentiate the electrostatically induced structural response of the choline headgroup from dynamic effects induced by the peptide. A partial phase separation was observed, leading to a DMPG-rich phase and a DMPG-depleted phase, each containing some mastoparan. Finally, the insertion and orientation of a specifically 15N-labeled mastoparan (at position Ala10) in the bilayer environment was investigated by solid-state 15N-NMR spectroscopy, using macroscopically oriented samples. Two distinct orientational states were observed for the mastoparan helix, namely an in-plane and a trans-membrane alignment. The two populations of 90% in-plane and 10% trans-membrane helices are characterized by a mosaic spread of +/- 30 degrees and +/- 10 degrees, respectively. The biological activity of mastoparan is discussed in terms of a pore-forming model, as the peptide is known to be able to induce nonlamellar phases and facilitate a flip-flop between the monolayers.
 ==About this Structure==
-D7N is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Vespula_lewisii Vespula lewisii] with NH2 as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=1D7N OCA].
+D7N is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Vespula_lewisii Vespula lewisii] with <scene name='pdbligand=NH2:'>NH2</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1D7N OCA].
 ==Reference==
@@ Line 23: / Line 23: @@
 [[Category: sodium dodecyl sulfate bound conformation]]
-''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Tue Nov 20 13:04:15 2007''
+''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 12:13:49 2008''