Conformational study of a custom antibacterial peptide cecropin B1: implications of the lytic activity

Sampath, S.; Arunkumar, A.I.; Wang, W.; Yu, Chin; Chen, H.M.

doi:10.1016/s0167-4838(00)00008-x

Cited by 39 publications

(37 citation statements)

References 29 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This structural motif includes a basic amphiphilic N-terminal helix linked to a more hydrophobic C-terminal helix by a flexible hinge region formed by a Gly-Pro sequence. Such a helix-hingehelix fold was also reported for sarcotoxin IA, a natural cecropin from Sarcophaga peregrina 33 as well as in custom-made lytic peptides such as cecropin B1 and B3 and shiva-3 (derivatives from the natural Hyalophora cecropin B [34][35][36] ) and in some cecropin-likes from vertebrates, for example, gaegurin 4 from the amphibian Rana rugosa. 37 The occurrence of the hinge region is related to the presence of a Gly-Pro or Gly-Xaa-Gly sequence in the primary structure of these peptides and not to the length of the peptide, since it is found in custom-made cecropin hybrids that are shorter (20 residues) than natural cecropins.…”

Section: Discussionsupporting

confidence: 58%

Solution structures of stomoxyn and spinigerin, two insect antimicrobial peptides with an α‐helical conformation

Landon

Meudal

Boulanger³

et al. 2005

Biopolymers

View full text Add to dashboard Cite

Stomoxyn and spinigerin belong to the class of linear cysteine-free insect antimicrobial peptides that kill a range of microorganisms, parasites, and some viruses but without any lytic activity against mammalian erythrocytes. Stomoxyn is localized in the gut epithelium of the nonvector stable fly that is sympatric with the trypanosome vector tsetse fly. Spinigerin is stored and secreted by hemocytes from the fungus-growing termite. The structure of synthetic stomoxyn and spinigerin in aqueous solution and in TFE/water mixtures was analyzed by CD and NMR spectroscopy combined with molecular modeling calculations. Stomoxyn and spinigerin adopt a flexible random coil structure in water while both assume a stable helical structure in the presence of TFE. In 50% TFE, the structure of stomoxyn is typical of cecropins, including an amphipathic helix at the N-terminus and a hydrophobic C-terminus with helical features that probably fold in a helical conformation at higher TFE concentration. In contrast to stomoxyn, spinigerin acquires very rapidly a helical conformation. In 10% TFE the helix is highly bent and the structure is poorly defined. In 50% TFE, the helical structure is well defined all along its sequence, and the slightly bent alpha-helix displays an amphiphilic character, as observed for magainin 2. The structural similarities between stomoxyn and cecropin A from Hyalophora cecropia and between spinigerin and magainin 2 suggest a similar mode of action on the bacterial membranes of both pairs of peptides. Our results also confirm that TFE induces helix formation and propagation for amino acids showing helical propensity in water but also enhances the helix propagation propensity of nonpolar beta-branched residues.

show abstract

Section: Discussionsupporting

confidence: 58%

Solution structures of stomoxyn and spinigerin, two insect antimicrobial peptides with an α‐helical conformation

Landon

Meudal

Boulanger³

et al. 2005

Biopolymers

View full text Add to dashboard Cite

show abstract

“…This amphipathicity of papiliocin is important because the hydrophilic sector faces toward the negatively charged head , have close contact with the acyl chains of the hydrophobic lipid. Papiliocin has a helix-hinge-helix structure in DPC micelles, which is very similar to those of other cecropins (26,67,68). This typical structural characteristic is likely important for the high antimicrobial and anti-inflammatory activity of papiliocin.…”

Section: Discussionmentioning

confidence: 73%

“…In this study, the tertiary structure of papiliocin, which is in the cecropin A family, determined in 300 mM DPC micelles was confirmed to adopt a helix-hinge-helix motif. The bent angle between the two helices of papiliocin is about 45-80°, indicating a flexibility that might be important for the antimicrobial and anti-inflammatory activities of papiliocin as well as its interaction with the membrane surface (26,67,68).…”

Section: Discussionmentioning

confidence: 99%

Structure and Function of Papiliocin with Antimicrobial and Anti-inflammatory Activities Isolated from the Swallowtail Butterfly, Papilio xuthus

Kim

Lee

Shin

et al. 2011

Journal of Biological Chemistry

151

View full text Add to dashboard Cite

Papiliocin is a novel 37-residue cecropin-like peptide isolated recently from the swallowtail butterfly, Papilio xuthus. With the aim of identifying a potent antimicrobial peptide, we tested papiliocin in a variety of biological and biophysical assays, demonstrating that the peptide possesses very low cytotoxicity against mammalian cells and high bacterial cell selectivity, particularly against Gram-negative bacteria as well as high anti-inflammatory activity. Using LPS-stimulated macrophage RAW264.7 cells, we found that papiliocin exerted its anti-inflammatory activities by inhibiting nitric oxide (NO) production and secretion of tumor necrosis factor (TNF)-␣ and macrophage inflammatory protein (MIP)-2, producing effects comparable with those of the antimicrobial peptide LL-37. We also showed that the innate defense response mechanisms engaged by papiliocin involve Toll-like receptor pathways that culminate in the nuclear translocation of NF-B. Fluorescent dye leakage experiments showed that papiliocin targets the bacterial cell membrane. To understand structure-activity relationships, we determined the three-dimensional structure of papiliocin in 300 mM dodecylphosphocholine micelles by NMR spectroscopy, showing that papiliocin has an ␣-helical structure from Lys 3 to Lys 21 and from Ala 25 to Val 36 , linked by a hinge region. Interactions between the papiliocin and LPS studied using tryptophan blue-shift data, and saturation transfer difference-NMR experiments revealed that Trp 2 and Phe 5 at the N-terminal helix play an important role in attracting papiliocin to the cell membrane of Gram-negative bacteria. In conclusion, we have demonstrated that papiliocin is a potent peptide antibiotic with both anti-inflammatory and antibacterial activities, and we have laid the groundwork for future studies of its mechanism of action.

show abstract

“…Cecropins are induced in the hemolymph following injection of live non-pathgenic bacteria and display strong bacteriolytic activity against a variety of Gramnegative bacteria. We have already investigated cecropin B (CB) and its analogues cecropins B1 and B3 in order to explore the relationships between phospholipid bilayer disruption, cell death, and cecropin sequence/structure using bacterial, cancer cell, and various in vitro systems (Chan et al, 1998a,b;Chen et al, 1997Chen et al, , 2000Chen et al, , 2003Hui et al, 2002;Hung et al, 1999;Sailam et al, 2000Sailam et al, , 2001Wang et al, 1998, Sailam et al, 1999. In the present study, we present an in vitro analysis of the mechanisms involved in the death of Gram-negative bacteria after cecropin treatment using transmission electron microscopy (TEM).…”

Section: Introductionmentioning

confidence: 99%

Transmission electron microscopic observations of membrane effects of antibiotic cecropin B on Escherichia coli

Chen

Chan

Lee

et al. 2003

Microscopy Res & Technique

View full text Add to dashboard Cite

The pathway of cell membrane lysis by the peptide antibiotic cecropin B (CB), which contains both a hydrophobic and an amphipathic alpha-helix, was analysed by assessing the morphological changes of Escherichia coli following treatment with the peptide. Exposure of green fluorescent protein (GFP)-expressing E. coli to CB does not lead to an efflux of GFP. Moreover, transmission electron microscopic (TEM) examination of cecropin B-treated cells showed that severe swelling precedes cell death and that the outer membrane becomes distended away from the plasma membrane. Using immuno-gold staining and TEM of E. coli expressing the maltose-binding protein in the cytoplasm, it was apparent that the protein remains restricted to the cytoplasmic compartment. These observations suggest that CB causes gross disruption of the outer membrane of Gram-negative bacteria. Circular dichroism measurements of CB in the presence of cell membrane-mimicking liposomes showed that CB forms secondary structure dependent on the ratio of [lipid]/[peptide]. These observations from this study are important for the future design of custom antimicrobial peptides.

show abstract

Conformational study of a custom antibacterial peptide cecropin B1: implications of the lytic activity

Cited by 39 publications

References 29 publications

Solution structures of stomoxyn and spinigerin, two insect antimicrobial peptides with an α‐helical conformation

Solution structures of stomoxyn and spinigerin, two insect antimicrobial peptides with an α‐helical conformation

Structure and Function of Papiliocin with Antimicrobial and Anti-inflammatory Activities Isolated from the Swallowtail Butterfly, Papilio xuthus

Transmission electron microscopic observations of membrane effects of antibiotic cecropin B on Escherichia coli

Contact Info

Product

Resources

About