| Full text | |
| Author(s): |
Vicente, Eduardo F.
[1]
;
Basso, Luis Guilherme M.
[2]
;
Cespedes, Graziely F.
[1]
;
Lorenzon, Esteban N.
[1]
;
Castro, Mariana S.
[3]
;
Mendes-Giannini, Maria Jose S.
[4]
;
Jose Costa-Filho, Antonio
[5]
;
Cilli, Eduardo M.
[1]
Total Authors: 8
|
| Affiliation: | [1] UNESP Univ Estadual Paulista, Inst Quim, Dept Bioquim & Tecnol Quim, Araraquara, SP - Brazil
[2] Univ Sao Paulo, Grp Biofis Mol Sergio Mascarenhas, Inst Fis Sao Carlos, Sao Carlos, SP - Brazil
[3] Univ Brasilia, Brazilian Ctr Prot Res, Dept Cell Biol, Brasilia, DF - Brazil
[4] UNESP Univ Estadual Paulista, Fac Ciencias Farmaceut, Dept Anal Clin, Araraquara, SP - Brazil
[5] Univ Sao Paulo, Dept Fis, Fac Filosofia Ciencias & Letras Ribeirao Preto, BR-14049 Ribeirao Preto, SP - Brazil
Total Affiliations: 5
|
| Document type: | Journal article |
| Source: | PLoS One; v. 8, n. 4 APR 9 2013. |
| Web of Science Citations: | 13 |
| Abstract | |
Antimicrobial peptides (AMPs) isolated from several organisms have been receiving much attention due to some specific features that allow them to interact with, bind to, and disrupt cell membranes. The aim of this paper was to study the interactions between a membrane mimetic and the cationic AMP Ctx(Ile(21))-Ha as well as analogues containing the paramagnetic amino acid 2,2,6,6-tetramethylpiperidine-1-oxyl-4-amino-4-carboxylic acid (TOAC) incorporated at residue positions n = 0, 2, and 13. Circular dichroism studies showed that the peptides, except for {[}TOAC(13)] Ctx(Ile(21))-Ha, are unstructured in aqueous solution but acquire different amounts of alpha-helical secondary structure in the presence of trifluorethanol and lysophosphocholine micelles. Fluorescence experiments indicated that all peptides were able to interact with LPC micelles. In addition, Ctx(Ile(21))-Ha and {[}TOAC(13)] Ctx(Ile(21))-Ha peptides presented similar water accessibility for the Trp residue located near the N-terminal sequence. Electron spin resonance experiments showed two spectral components for {[}TOAC(0)] Ctx(Ile(21))-Ha, which are most likely due to two membrane-bound peptide conformations. In contrast, TOAC(2) and TOAC(13) derivatives presented a single spectral component corresponding to a strong immobilization of the probe. Thus, our findings allowed the description of the peptide topology in the membrane mimetic, where the N-terminal region is in dynamic equilibrium between an ordered, membrane-bound conformation and a disordered, mobile conformation; position 2 is most likely situated in the lipid polar head group region, and residue 13 is fully inserted into the hydrophobic core of the membrane. (AU) | |
| FAPESP's process: | 09/10997-7 - Interactions between model membranes and fusion peptides derived from SARS CoV glycoprotein s |
| Grantee: | Luís Guilherme Mansor Basso |
| Support Opportunities: | Scholarships in Brazil - Doctorate |
| FAPESP's process: | 10/17662-8 - Electron magnetic resonance in studies of structure, function and interactions of biologically-relevant molecules |
| Grantee: | Antonio José da Costa Filho |
| Support Opportunities: | Regular Research Grants |
| FAPESP's process: | 10/06526-6 - Synthetic Peptides in DHODH and fusion peptide Dengue virus studies. |
| Grantee: | Eduardo Maffud Cilli |
| Support Opportunities: | Regular Research Grants |