Spectroscopic investigation on gel‐forming β‐sheet assemblage of peptide derivatives

Ganesh, S.; Prakash, Sangeeta; Jayakumar, R.

doi:10.1002/bip.10493

Cited by 44 publications

(67 citation statements)

References 53 publications

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“…Although the band at 222 nm might suggest ␣-helical structure, the absence of a band at 208 nm and the cross over point at 211 nm support the ␤-sheet structure. A similar type of ECD spectrum was observed for peptide assemblage containing ␤-sheet structure [34]. The present result, thus, implies that the major conformational difference between the absence and presence of ethanol, at high concentration, is ␤-sheet.…”

Section: Resultssupporting

confidence: 73%

Ethanol and acetonitrile induces conformational changes in porcine pepsin at alkaline denatured state

Shanmugam

Selvi

Mandal

2012

International Journal of Biological Macromolecules

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Section: Resultssupporting

confidence: 73%

Ethanol and acetonitrile induces conformational changes in porcine pepsin at alkaline denatured state

Shanmugam

Selvi

Mandal

2012

International Journal of Biological Macromolecules

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“…β‐Sheet peptides usually give rise to CD spectra displaying a positive band between 195 and 200 nm, characteristic of the amide π→π* transition, and a negative band around 216 nm due to the amide n →π* transition 40. In addition, a crossover point between 204 and 207 nm is usually observed 41. On the other hand, the CD spectra of P11–30 present two negative bands, one more intense centered at 202 nm and another at 225 nm, showing that this fragment preferentially adopts a flexible conformation under these experimental conditions.…”

Section: Resultsmentioning

confidence: 88%

Model peptides mimic the structure and function of the N‐terminus of the pore‐forming toxin sticholysin II

Casallanovo¹,

Oliveira²,

Souza³

et al. 2005

Biopolymers

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To investigate the role of the N-terminal region in the lytic mechanism of the pore-forming toxin sticholysin II (St II), we studied the conformational and functional properties of peptides encompassing the first 30 residues of the protein. Peptides containing residues 1-30 (P1-30) and 11-30 (P11-30) were synthesized and their conformational properties were examined in aqueous solution as a function of peptide concentration, pH, ionic strength, and addition of the secondary structure-inducing solvent trifluoroethanol (TFE). CD spectra showed that increasing concentration, pH, and ionic strength led to aggregation of P1-30; as a consequence, the peptide acquired beta-sheet conformation. In contrast, P11-30 exhibited practically no conformational changes under the same conditions, remaining essentially structureless. Moreover, this peptide did not undergo aggregation. These differences clearly point to the modulating effect of the first 10 hydrophobic residues on the peptides aggregation and conformational properties. In TFE both the first ten hydrophobic peptides acquired alpha-helical conformation, albeit to a different extent, P11-30 displayed lower alpha-helical content. P1-30 presented a larger fraction of residues in alpha-helical conformation in TFE than that found in St II's crystal structure for that portion of the protein. Since TFE mimics the membrane environment, such increase in helical content could also occur upon toxin binding to membranes and represent a step in the mechanism of pore formation. The peptides conformational properties correlated well with their functional behavior. Thus, P1-30 exhibited much higher hemolytic activity than P11-30. In addition, P11-30 was able to block the toxin's hemolytic activity. The size of pores formed in red blood cells by P1-30 was estimated by measuring the permeability to PEGs of different molecular mass. The pore radius (0.95 +/- 0.01 nm) was very similar to that of the pore formed by the toxin. The results demonstrate that the synthetic peptide P1-30 is a good model of St II conformation and function and emphasize the contribution of the toxin's N-terminal region, and, in particular, the hydrophobic residues 1-10 to pore formation.

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“…PD36KF distinguished by simultaneous weak contents of b-turn and unordered structures that could result from turn mobility while presenting a compact strand structure. [30][31][32][33] This indicates the possible role of the simultaneous presence of threonine (highly b-sheet inducing residue) and phenylalanine (hydrophobic residue) ensuring strand cohesion. 41 Actually, in addition to the study of the first steps of (Table III) These findings also clearly highlighted the role of water molecules in peptide folding mechanisms.…”

Section: B-hairpin Spectral Fingerprintsmentioning

confidence: 94%

Structural malleability of plasticins: Preorganized conformations in solution and relevance for antimicrobial activity

et al. 2007

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Plasticins (23 long-residue glycine-leucine-rich dermaseptin-related peptides produced by the skin of South American hylids) have very similar amino acid sequences, hydrophobicities, and amphipathicities, but differ in their membrane-damaging properties and structurations (i.e. destabilized helix states, beta-hairpin, beta-sheet, and disordered states) at anionic and zwitterionic membrane interfaces. Structural malleability of plasticins in aqueous solutions together with parameters that may govern their ability to fold within beta-hairpin like structures were analyzed through circular dichroism and FTIR spectroscopic studies completed by molecular dynamics simulations in polar mimetic media. The goal of this study was to probe to which extent pre-existent peptide conformations, i.e. intrinsic "conformational landscape", may be responsible for variability in bioactive conformation and antimicrobial/hemolytic mechanisms of action of these peptides in relation with their various membrane disturbing properties. All plasticins present a turn region that does not always result in folding into a beta-hairpin shaped conformation. Residue at position 8 plays a major role in initiating the folding, while position 12 is not critical. Conformational stability has no major impact on antimicrobial efficacy. However, preformed beta-hairpin in solution may act as a conformational lock that prevents switch to alpha-helical structure. This lock lowers the antimicrobial efficiency and explains subtle differences in potencies of the most active antimicrobial plasticins.

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Spectroscopic investigation on gel‐forming β‐sheet assemblage of peptide derivatives

Abstract: Abstract:The conformational studies of peptide derivatives A and B in a gel state were studied by using circular dichroism (CD)

Cited by 44 publications

References 53 publications

Ethanol and acetonitrile induces conformational changes in porcine pepsin at alkaline denatured state

Ethanol and acetonitrile induces conformational changes in porcine pepsin at alkaline denatured state

Model peptides mimic the structure and function of the N‐terminus of the pore‐forming toxin sticholysin II

Structural malleability of plasticins: Preorganized conformations in solution and relevance for antimicrobial activity

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