2MCU
Solid-state NMR structure of piscidin 1 in aligned 3:1 phosphatidylcholine/phosphoglycerol lipid bilayers
SOLID-STATE NMR
NMR Experiment | ||||||||
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Experiment | Type | Sample Contents | Solvent | Ionic Strength | pH | Pressure | Temperature (K) | Spectrometer |
1 | 15N_1H solid-state de-HETCOR | 15-20 MM PISCIDIN 1, 300-400 MM 3:1 (molar) 1,2-dimyristoyl-sn-glycero-3-phosphatidylcholine/1,2-dimyristoyl-sn-glycero-3-phosphatidylglycerol, 40 MM PHOSPHATE BUFFER WITH 100% H2O | 100% H2O | 6.0 | ambient | 313 |
NMR Spectrometer Information | |||
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Spectrometer | Manufacturer | Model | Field Strength |
1 | Bruker | Avance | 900 |
2 | Bruker | Avance | 600 |
NMR Refinement | ||
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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. | Xplor-NIH |
NMR Ensemble Information | |
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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 | ||||
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# | Classification | Version | Software Name | Author |
1 | structure solution | Xplor-NIH | Brunger A. T. et.al. | |
2 | refinement | Xplor-NIH | Brunger A. T. et.al. |