2MCX

Solid-state NMR structure of piscidin 3 in aligned 1:1 phosphatidylethanolamine/phosphoglycerol lipid bilayers

SOLID-STATE NMR

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NMR Experiment
Experiment	Type	Sample Contents	Solvent	Ionic Strength	pH	Pressure	Temperature (K)	Spectrometer
1	15N_1H solid-state de-HETCOR	15-20 mM [15N]-A12G17 PISCIDIN 3, 300-400 mM 1:1 (MOLAR) 1-PALMITOYL-2-OLEOYL-SN-GLYCERO-PHOSPHATIDYLETHANOLAMINE/1-PALMITOYL-2-OLEOYL-SN-GLYCERO-PHOSPHOGLYCEROL, 40 mM PHOSPHATE BUFFER WITH 100% H2O	100% H2O		6.0	ambient	305

NMR Spectrometer Information
Spectrometer	Manufacturer	Model	Field Strength
1	Bruker	AVANCE	900
2	Bruker	AVANCE	600

NMR Refinement
Method	Details	Software
simulated annealing	Structures were calculated using a simulated annealing protocol within Xplor-NIH with torsion angle molecular dynamics in the presence of experimentally determined restraints. Solid-state NMR experiments on static oriented lipid bilayer samples allowed for the measurements of anisotropic backbone 15N chemical shifts and 15N-1H dipolar couplings, which were used as the experimental restraints. The initial structure was an alpha helix with ideal phi/psi angles (-61/-45). The calculations also included the Xplor-NIH potential for knowledge-based torsion angles and the routine terms ANGL, BOND and IMPR. A total of 100 structures were generated and the 10 lowest energy structures were accepted for analysis and representation. By convention, the bilayer normal for all of the oriented samples is aligned along the z-axis of the calculated structures.	X-PLOR NIH

NMR Ensemble Information
Conformer Selection Criteria	structures with the lowest energy
Conformers Calculated Total Number	100
Conformers Submitted Total Number	10
Representative Model	1 (lowest energy)

Computation: NMR Software
#	Classification	Version	Software Name	Author
1	refinement	X-PLOR NIH		Brunger A. T. et.al.
2	structure calculation	X-PLOR NIH		Brunger A. T. et.al.