Please use this identifier to cite or link to this item: https://hdl.handle.net/10356/98894
Title: Structure, activity and interactions of the cysteine deleted analog of tachyplesin-1 with lipopolysaccharide micelle : mechanistic insights into outer-membrane permeabilization and endotoxin neutralization
Authors: Saravanan, Rathi
Mohanram, Harini
Joshi, Mangesh
Torres, Jaume
Ruedl, Christiane
Bhattacharjya, Surajit
Domadia, Prerna N.
Keywords: DRNTU::Science::Biological sciences
Issue Date: 2012
Source: Saravanan, R., Mohanram, H., Joshi, M., Domadia, P. N., Torres, J., Ruedl, C.,& Bhattacharjya, S. (2012). Structure, activity and interactions of the cysteine deleted analog of tachyplesin-1 with lipopolysaccharide micelle: Mechanistic insights into outer-membrane permeabilization and endotoxin neutralization. Biochimica et Biophysica Acta (BBA) - Biomembranes, 1818(7), 1613-1624.
Series/Report no.: Biochimica et Biophysica Acta (BBA) - biomembranes
Abstract: Tachyplesin-1, a disulfide stabilized β-hairpin antimicrobial peptide, can be found at the hemocytes of horse shoe crab Tachypleus tridentatus. A cysteine deleted linear analog of tachyplesin-1 or CDT (KWFRVYRGIYRRR-NH2) contains a broad spectrum of bactericidal activity with a reduced hemolytic property. The bactericidal activity of CDT stems from selective interactions with the negatively charged lipids including LPS. In this work, CDT–LPS interactions were investigated using NMR spectroscopy, optical spectroscopy and functional assays. We found that CDT neutralized LPS and disrupted permeability barrier of the outer membrane. Zeta potential and ITC studies demonstrated charge compensation and hydrophobic interactions of CDT with the LPS-outer membrane, respectively. Secondary structure of the peptide was probed by CD and FT-IR experiments indicating β-strands and/or β-turn conformations in the LPS micelle. An ensemble of structures, determined in LPS micelle by NMR, revealed a β-hairpin like topology of the CDT peptide that was typified by an extended cationic surface and a relatively shorter segment of hydrophobic region. Interestingly, at the non-polar face, residue R11 was found to be in a close proximity to the indole ring of W2, suggesting a cation–π type interactions. Further, saturation transfer difference (STD) NMR studies established intimate contacts among the aromatic and cationic residues of CDT with the LPS micelle. Fluorescence and dynamic light scattering experiments demonstrated that CDT imparted structural destabilization to the aggregated states of LPS. Collectively, atomic resolution structure and interactions of CDT with the outer membrane-LPS could be exploited for developing potent broad spectrum antimicrobial and anti-sepsis agents.
URI: https://hdl.handle.net/10356/98894
http://hdl.handle.net/10220/12689
ISSN: 0005-2736
DOI: http://dx.doi.org/10.1016/j.bbamem.2012.03.015
Fulltext Permission: none
Fulltext Availability: No Fulltext
Appears in Collections:SBS Journal Articles

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