Chemistry (Weinheim an der Bergstrasse, Germany), Jan 26, 2015
Peptide Structures Based on CD and NMR data, M. Á. Jiménez et al. demonstrate in their Full Paper... more Peptide Structures Based on CD and NMR data, M. Á. Jiménez et al. demonstrate in their Full Paper on page 8076 ff. that a peptide derived from a choline-binding repeat of the pneumococcal LytA protein (top) conserves its native β-hairpin fold (left) in aqueous solution, but forms a stable, amphipathic α-helix (right) in detergent micelles, as well as in lipid vesicles. These β-hairpin and α-helix structures differ greatly in the distribution of polar (blue & red)/hydrophobic (green) side chains.
Choline-binding modules (CBMs) have a bb-solenoid structure composed of choline-binding repeats( ... more Choline-binding modules (CBMs) have a bb-solenoid structure composed of choline-binding repeats( CBR), which consist of a b-hairpin followed by as hort linker.T o find minimal peptides that are able to maintain the CBR native structure and to evaluate their remaining cholinebinding ability,w eh ave analysed the third b-hairpin of the CBM from the pneumococcal LytA autolysin. Circular dichroism and NMR data reveal that this peptidef orms ah ighly stable native-like b-hairpin both in aqueous solution and in the presence of trifluoroethanol, but, strikingly,t he peptide structure is as table amphipathic a-helix in both zwitterionic (dodecylphosphocholine) and anionic (sodium dodecylsulfate) detergent micelles, as well as in smallu nilamellar vesicles. This b-hairpin to a-helix conversion is reversible. Given that the b-hairpin and a-helixd iffer greatlyi nt he distribution of hydrophobic and hydrophilic side chains, we propose that the amphipathicity is ar equirement for ap eptide structure to interact and to be stable in micelleso rl ipid vesicles. To our knowledge,t his "chameleonic" behaviour is the only described case of am icelle-induced structuralt ransition between two ordered peptide structures.
The results of conformational analysis of linear and cyclic peptides from the SALLEDPVG sequence ... more The results of conformational analysis of linear and cyclic peptides from the SALLEDPVG sequence of 276 284 glycoprotein D of Herpes simplex virus are presented. The epitope peptides were synthesized by SPPS and on resin cyclization was applied for preparation of cyclic compounds. Circular dichroism spectroscopy, Fourier-transform infrared spectroscopy and nuclear magnetic resonance (NMR) were used to determine of the solution structure of both linear and cyclic peptides. The results indicated that the cyclopeptides containing the core of the epitope (DPVG) as a part of the cycle have more stable b-turn structure than the linear peptides or the cyclic analogues, where the core motif is not a part of the cycle. NMR study of H-SALLc(EDPVGK)-NH confirm presence of a type I b-turn 2 structure which includes the DPVG epitope core. ᮊ
Chemistry (Weinheim an der Bergstrasse, Germany), Jan 26, 2015
Peptide Structures Based on CD and NMR data, M. Á. Jiménez et al. demonstrate in their Full Paper... more Peptide Structures Based on CD and NMR data, M. Á. Jiménez et al. demonstrate in their Full Paper on page 8076 ff. that a peptide derived from a choline-binding repeat of the pneumococcal LytA protein (top) conserves its native β-hairpin fold (left) in aqueous solution, but forms a stable, amphipathic α-helix (right) in detergent micelles, as well as in lipid vesicles. These β-hairpin and α-helix structures differ greatly in the distribution of polar (blue & red)/hydrophobic (green) side chains.
Choline-binding modules (CBMs) have a bb-solenoid structure composed of choline-binding repeats( ... more Choline-binding modules (CBMs) have a bb-solenoid structure composed of choline-binding repeats( CBR), which consist of a b-hairpin followed by as hort linker.T o find minimal peptides that are able to maintain the CBR native structure and to evaluate their remaining cholinebinding ability,w eh ave analysed the third b-hairpin of the CBM from the pneumococcal LytA autolysin. Circular dichroism and NMR data reveal that this peptidef orms ah ighly stable native-like b-hairpin both in aqueous solution and in the presence of trifluoroethanol, but, strikingly,t he peptide structure is as table amphipathic a-helix in both zwitterionic (dodecylphosphocholine) and anionic (sodium dodecylsulfate) detergent micelles, as well as in smallu nilamellar vesicles. This b-hairpin to a-helix conversion is reversible. Given that the b-hairpin and a-helixd iffer greatlyi nt he distribution of hydrophobic and hydrophilic side chains, we propose that the amphipathicity is ar equirement for ap eptide structure to interact and to be stable in micelleso rl ipid vesicles. To our knowledge,t his "chameleonic" behaviour is the only described case of am icelle-induced structuralt ransition between two ordered peptide structures.
The results of conformational analysis of linear and cyclic peptides from the SALLEDPVG sequence ... more The results of conformational analysis of linear and cyclic peptides from the SALLEDPVG sequence of 276 284 glycoprotein D of Herpes simplex virus are presented. The epitope peptides were synthesized by SPPS and on resin cyclization was applied for preparation of cyclic compounds. Circular dichroism spectroscopy, Fourier-transform infrared spectroscopy and nuclear magnetic resonance (NMR) were used to determine of the solution structure of both linear and cyclic peptides. The results indicated that the cyclopeptides containing the core of the epitope (DPVG) as a part of the cycle have more stable b-turn structure than the linear peptides or the cyclic analogues, where the core motif is not a part of the cycle. NMR study of H-SALLc(EDPVGK)-NH confirm presence of a type I b-turn 2 structure which includes the DPVG epitope core. ᮊ
Uploads
Papers by M. Jiménez