Conformational properties, membrane interaction, and antibacterial activity of the peptaibiotic chalciporin A: Multitechnique spectroscopic and biophysical investigations on the natural compound and labeled analogs
| Autor: | Jens Z. Pedersen, Cristina Peggion, Simona Oancea, Fernando Formaggio, Chiara Pignaffo, Marco Bortolus, Annalisa Dalzini, Sergei A. Dzuba, Claudio Toniolo, Lorenzo Stella, Geta Hilma, Annalisa Bortolotti, Yuri D. Tsvetkov, Barbara Biondi, Marta De Zotti, Victoria N. Syryamina |
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| Rok vydání: | 2018 |
| Předmět: |
conformation
Stereochemistry Biophysics biological activity Peptide 010402 general chemistry 01 natural sciences Biochemistry Biomaterials chemistry.chemical_compound Amphiphile Side chain chalciporin membrane penetration peptaibiotics Settore BIO/10 Settore CHIM/02 - Chimica Fisica chemistry.chemical_classification 010405 organic chemistry Organic Chemistry Nitroxyl Biological activity 0104 chemical sciences Membrane chemistry Selectivity Antibacterial activity |
| Zdroj: | Peptide Science. 110:e23083 |
| ISSN: | 2475-8817 |
| DOI: | 10.1002/bip.23083 |
| Popis: | In this work, an extensive set of spectroscopic and biophysical techniques (including FT-IR absorption, CD, 2D-NMR, fluorescence, and CW/PELDOR EPR) was used to study the conformational preferences, membrane interaction, and bioactivity properties of the naturally occurring synthetic 14-mer peptaibiotic chalciporin A, characterized by a relatively low (≈20%), uncommon proportion of the strongly helicogenic Aib residue. In addition to the unlabeled peptide, we gained in-depth information from the study of two labeled analogs, characterized by one or two residues of the helicogenic, nitroxyl radical-containing TOAC. All three compounds were prepared using the SPPS methodology, which was carefully modified in the course of the syntheses of TOAC-labeled analogs in view of the poorly reactive α-amino function of this very bulky residue and the specific requirements of its free-radical side chain. Despite its potentially high flexibility, our results point to a predominant, partly amphiphilic, α-helical conformation for this peptaibiotic. Therefore, not surprisingly, we found an effective membrane affinity and a remarkable penetration propensity. However, chalciporin A exhibits a selectivity in its antibacterial activity not in agreement with that typical of the other members of this peptide class. |
| Databáze: | OpenAIRE |
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