%0 Journal Article %1 marassi_orientation_1999 %A Marassi, F M %A Opella, S J %A Juvvadi, P %A Merrifield, R B %D 1999 %J Biophys. J. %K Acid Agents,Antimicrobial Amino Cationic Data,Peptides,Protein Peptides,Biophysical Phenomena,Biophysics,In Proteins,Lipid Resonance Sequence Sequence,Animals,Anti-Infective Spectroscopy,Molecular Structure,Secondary Techniques,Insect Vitro bilayers,Magnetic %N 6 %P 3152--3155 %R 10.1016/S0006-3495(99)77145-6 %T Orientation of cecropin \A\ helices in phospholipid bilayers determined by solid-state \NMR\ spectroscopy %V 77 %X The orientation of the insect antibiotic peptide cecropin A (CecA) in the phospholipid bilayer membrane was determined using (15)N solid-state NMR spectroscopy. Two peptide samples, each specifically labeled with (15)N at Val(11) or Ala(27), were synthesized by solid phase techniques. The peptides were incorporated into phospholipid bilayers, prepared from a mixture of dimyristoylphosphatidylcholine and dimyristoylphosphatidylglycerol, and oriented on glass slides. The (15)N chemical shift solid-state NMR spectra from these uniaxially oriented samples display a single (15)N chemical shift frequency for each labeled residue. Both frequencies are near the upfield end of the (15)N chemical shift powder pattern, as expected for an alpha-helix with its long axis in the plane of the membrane and the NH bonds perpendicular to the direction of the magnetic field. These results support a mechanism of action in which CecA binds to and covers the membrane surface, thereby causing a general destabilization and leakiness of the lipid bilayer membrane. The data are discussed in relation to a proposed mechanism of membrane lysis and bacterial killing via an ion channel activity of CecA.

@article{marassi_orientation_1999, abstract = {The orientation of the insect antibiotic peptide cecropin A (CecA) in the phospholipid bilayer membrane was determined using (15)N solid-state NMR spectroscopy. Two peptide samples, each specifically labeled with (15)N at Val(11) or Ala(27), were synthesized by solid phase techniques. The peptides were incorporated into phospholipid bilayers, prepared from a mixture of dimyristoylphosphatidylcholine and dimyristoylphosphatidylglycerol, and oriented on glass slides. The (15)N chemical shift solid-state NMR spectra from these uniaxially oriented samples display a single (15)N chemical shift frequency for each labeled residue. Both frequencies are near the upfield end of the (15)N chemical shift powder pattern, as expected for an alpha-helix with its long axis in the plane of the membrane and the NH bonds perpendicular to the direction of the magnetic field. These results support a mechanism of action in which CecA binds to and covers the membrane surface, thereby causing a general destabilization and leakiness of the lipid bilayer membrane. The data are discussed in relation to a proposed mechanism of membrane lysis and bacterial killing via an ion channel activity of CecA.}, added-at = {2017-03-14T02:48:56.000+0100}, author = {Marassi, F M and Opella, S J and Juvvadi, P and Merrifield, R B}, biburl = {https://www.bibsonomy.org/bibtex/2af0519c995de0972c889a9610b71a661/nmrresource}, doi = {10.1016/S0006-3495(99)77145-6}, interhash = {074a37e7cb4967ca856c7a7fecdbc0ab}, intrahash = {af0519c995de0972c889a9610b71a661}, issn = {0006-3495}, journal = {Biophys. J.}, keywords = {Acid Agents,Antimicrobial Amino Cationic Data,Peptides,Protein Peptides,Biophysical Phenomena,Biophysics,In Proteins,Lipid Resonance Sequence Sequence,Animals,Anti-Infective Spectroscopy,Molecular Structure,Secondary Techniques,Insect Vitro bilayers,Magnetic}, month = dec, number = 6, pages = {3152--3155}, pmid = {10585936}, timestamp = {2017-03-14T02:49:21.000+0100}, title = {{Orientation of cecropin {\{}A{\}} helices in phospholipid bilayers determined by solid-state {\{}NMR{\}} spectroscopy}}, volume = 77, year = 1999 }