Variability in secondary structure of the antimicrobial peptide Cateslytin in powder, solution, DPC micelles and at the air-water interface.
Cateslytin (bCGA (344)RSMRLSFRARGYGFR(358)), a five positively charged 15 amino-acid residues arginine-rich antimicrobial peptide, was synthesized using a very efficient procedure leading to high yields and to a 99% purity as determined by HPLC and mass spectrometry. Circular dichroism, polarized attenuated total reflectance fourier transformed infrared, polarization modulation infrared reflection Absorption spectroscopies and proton two-dimensional NMR revealed the flexibility of such a peptide. Whereas being mostly disordered as a dry powder or in water solution, the peptide acquires a alpha-helical character in the "membrane mimicking" solvent trifuoroethanol. In zwitterionic micelles of dodecylphophatidylcholine the helical character is retained but to a lesser extent, the peptide returning mainly to its disordered state. A beta-sheet contribution of almost 100% is detected at the air-water interface. Such conformational plasticity is discussed regarding the antimicrobial action of Cateslytin.
Jean-François
Frantz
F
UMR 5248 CBMN, CNRS-Université Bordeaux 1-ENITAB, IECB, 2 rue Robert Escarpit, 33607, Pessac, France.
Khemtémourian
Lucie
L
Odaert
Benoît
B
Castano
Sabine
S
Grélard
Axelle
A
Manigand
Claude
C
Bathany
Katell
K
Metz-Boutigue
Marie-Hélène
MH
Dufourc
Erick J
EJ
D000388:Air; D000595:Amino Acid Sequence; D000900:Anti-Bacterial Agents / Q000138:chemical synthesis / Q000737:chemistry*; D053379:Chromogranin A / Q000138:chemical synthesis / Q000737:chemistry*; D002942:Circular Dichroism; D009682:Magnetic Resonance Spectroscopy; D008823:Micelles; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000138:chemical synthesis / Q000737:chemistry*; D019999:Pharmaceutical Solutions; D011208:Powders; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013054:Spectrophotometry, Atomic; D017550:Spectroscopy, Fourier Transform Infrared; D014270:Trifluoroethanol / Q000737:chemistry; D014867:Water
D000900:Anti-Bacterial Agents; D053379:Chromogranin A; D008823:Micelles; D010446:Peptide Fragments; D019999:Pharmaceutical Solutions; D011208:Powders; C527456:chromogranin A (344-358); D014867:Water; D014270:Trifluoroethanol