NMR Structures and Interactions of Temporin-1Tl and Temporin-1Tb with Lipopolysaccharide Micelles

Bhunia, Anirban; Saravanan, Rathi; Mohanram, Harini; Mangoni, Maria Luisa; Bhattacharjya, Surajit

doi:10.1074/jbc.m110.189662

Cited by 87 publications

(77 citation statements)

References 75 publications

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“…It was shown, for instance, that in the presence of LPS the peptide 3D structure can be significantly different when compared to that obtained using plasma membrane models. [40][41][42] Nevertheless, the results presented in this work support the idea that the presence of negatively charged lipids in the bilayer is necessary for Esc(1-18) to bind, and fold into a highly ordered threedimensional structure. Our findings also provide an explanation for Esc(1-18) selectivity for the negatively charged plasma membranes of bacteria.…”

Section: Resultssupporting

confidence: 68%

Folded Structure and Insertion Depth of the Frog-Skin Antimicrobial Peptide Esculentin-1b(1–18) in the Presence of Differently Charged Membrane-Mimicking Micelles

Manzo¹,

Casu²,

Rinaldi³

et al. 2014

J. Nat. Prod.

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Antimicrobial peptides (AMPs) are effectors of the innate immunity of most organisms. Their role in the defense against pathogen attack and their high selectivity for bacterial cells make them attractive for the development of a new class of antimicrobial drugs. The N-terminal fragment of the frog-skin peptide esculentin-1b (Esc(1-18)) has shown broad spectrum antimicrobial activity.Similarly to most cationic AMPs, it is supposed to act by binding to and damaging the negatively charged plasma-membrane of bacteria. Differently from many other AMPs, Esc(1-18) activity is preserved in biological fluids such as serum. In this work, a structural investigation was performed through NMR spectroscopy. The 3D structure was obtained in the presence of either zwitterionic or negatively charged micelles as membrane models for eukaryotic and prokaryotic membranes, respectively. Esc(1-18) showed a higher affinity for and deeper insertion into the latter, and adopted an amphipathic helical structure characterized by a kink at the residue G8. These findings were confirmed by measuring penetration into lipid monolayers. The presence of negatively charged lipids in the bilayer appears to be necessary for Esc(1-18) to bind, fold in the right threedimensional structure and, ultimately, to exert its biological role as an AMP. 3The lack of a new class of antibiotics is an urgent problem, as many important pathogens are rapidly developing resistance to most of the clinically usable antibiotics. 1,2 Clinical impact of antibiotic resistance is immense, with increasing length of hospital stay, costs and mortality. 3,4 Antimicrobial peptides (AMPs) have attracted the interest of the scientific community as promising candidates for the development of a new class of antimicrobial drugs. They are part of the innate immune system of the majority of the multicellular organisms, and are typically characterized by a wide spectrum of antimicrobial activity, from Gram-negative to Gram-positive bacteria, fungi, protozoa and enveloped viruses. [5][6][7] Despite amino acid sequence homology is not high, AMPs share some common features. They are relatively short (< 60 residues), cationic, have a large content (≥ 50%) of hydrophobic residues and adopt an amphipathic three-dimensional folding when interacting with pathogens" membranes. 6 Generally, AMPs destroy or permeate the microbial plasma-membrane. The membrane is formed through evolutionarily well conserved biosynthetic processes and represents a non-selective target, making modifications by the microorganisms difficult and, thus, resistance onset is unlikely. 8 Several recent articles have reviewed in detail the different modes of action postulated for AMPs. [9][10][11] The amphipathic conformation adopted by the AMP, with the hydrophilic residues interacting with the polar head groups of the phospholipids and the water molecules, and the hydrophobic residues being protected from water contacts by inserting into the lipid bilayer core, is considered essential for it to exert the antimicro...

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Section: Resultssupporting

confidence: 68%

Folded Structure and Insertion Depth of the Frog-Skin Antimicrobial Peptide Esculentin-1b(1–18) in the Presence of Differently Charged Membrane-Mimicking Micelles

Manzo¹,

Casu²,

Rinaldi³

et al. 2014

J. Nat. Prod.

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“…A similar observation has been made in designed Lys/Leu-based AMP or KL12, whereby the peptide showed limited activity against Gramnegative bacteria (49). AMPs trapped in LPS in oligomeric states are unable to traverse or translocate through the outer membrane, possibly causing their inactivation (52,54,55). In the present study, we demonstrate that a short LPS binding peptide motif or ␤-boomerang motif, GWKRKRFG, designed in our laboratory (56,57), rescues these inactive AMPs, including TA, TB, and KL12 peptide from the LPS outer membrane.…”

mentioning

confidence: 90%

Resurrecting Inactive Antimicrobial Peptides from the Lipopolysaccharide Trap

Mohanram

Bhattacharjya

2014

Antimicrob Agents Chemother

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Host defense antimicrobial peptides (AMPs) are a promising source of antibiotics for the treatment of multiple-drug-resistant pathogens. Lipopolysaccharide (LPS), the major component of the outer leaflet of the outer membrane of Gram-negative bacteria, functions as a permeability barrier against a variety of molecules, including AMPs. Further, LPS or endotoxin is the causative agent of sepsis killing 100,000 people per year in the United States alone. LPS can restrict the activity of AMPs inducing aggregations at the outer membrane, as observed for frog AMPs, temporins, and also in model AMPs. Aggregated AMPs, "trapped" by the outer membrane, are unable to traverse the cell wall, causing their inactivation. In this work, we show that these inactive AMPs can overcome LPS-induced aggregations while conjugated with a short LPS binding ␤-boomerang peptide motif and become highly bactericidal. The generated hybrid peptides exhibit activity against Gram-negative and Gram-positive bacteria in high-salt conditions and detoxify endotoxin. Structural and biophysical studies establish the mechanism of action of these peptides in LPS outer membrane. Most importantly, this study provides a new concept for the development of a potent broad-spectrum antibiotic with efficient outer membrane disruption as the mode of action.

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“…31 The complete sequence specic proton resonance assignments were determined using both two-dimensional total correlation spectroscopy (TOCSY) and NOESY. The NOESY spectra for all the peptides showed only a weak intra-and sequential NOE between the backbone and side chain proton resonances (data not shown).…”

Section: Atomic Level Interaction Of Fk13 With Human Telomeric Gquadrmentioning

confidence: 99%

Restriction of telomerase capping by short non-toxic peptides via arresting telomeric G-quadruplex

et al. 2017

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The stabilization of a G-quadruplex structure in human telomeric DNA has become a promising strategy in the development of cancer therapeutics. Here, we report FK13 (a small fragment of human cathelicidin peptide LL37, residues 17-29) and its mutant peptides (KR12A, KR12B and KR12C) inhibiting telomerase activity by stabilizing the telomeric G-quadruplex structures. An array of biophysical studies like fluorescence anisotropy, circular dichroism spectroscopy, circular dichroism melting, isothermal titration calorimetry, and high resolution nuclear magnetic resonance spectroscopy, in conjunction with molecular dynamics simulations, are employed to examine the interaction of peptides with the Gquadruplex structure. Furthermore, the peptide-quadruplex interaction is monitored in ex vivo systems, the telomerase over-expressed MCF7 breast adeno-carcinoma cell line. MTT assay and flow cytometry studies indicate selective antiproliferative activities of the peptides towards cancer cells over normal kidney epithelial cell line. Confocal microscopy evidenced nuclear transport and localisation of the peptides. A telomerase repeat amplification protocol assay further evidences telomere uncapping and abrogation of telomerase catalysing activity upon administration of peptides. Hence, arresting Gquadruplex structures using short peptides brings in a new mechanistic insight for the development of future peptide based therapeutics against cancer.

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NMR Structures and Interactions of Temporin-1Tl and Temporin-1Tb with Lipopolysaccharide Micelles

Cited by 87 publications

References 75 publications

Folded Structure and Insertion Depth of the Frog-Skin Antimicrobial Peptide Esculentin-1b(1–18) in the Presence of Differently Charged Membrane-Mimicking Micelles

Folded Structure and Insertion Depth of the Frog-Skin Antimicrobial Peptide Esculentin-1b(1–18) in the Presence of Differently Charged Membrane-Mimicking Micelles

Resurrecting Inactive Antimicrobial Peptides from the Lipopolysaccharide Trap

Restriction of telomerase capping by short non-toxic peptides via arresting telomeric G-quadruplex

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