Solution structures of stomoxyn and spinigerin, two insect antimicrobial peptides with an alpha-helical conformation
type: Dataset
description: 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 -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 -branched residues.
issued: 2026-05-08T19:55:33.348882
language: en
modified: 2026-05-08T19:55:33.348887
contact point: Organization
  fn: CCSD
keyword: antimicrobial-peptides
keyword: cecropin
keyword: circular-dichroism
keyword: helical-peptide
keyword: infoeu-reposemanticsarticle
keyword: innate-immunity
keyword: insect
keyword: journal-articles
keyword: mesh-amino-acid-sequence
keyword: mesh-animals
keyword: mesh-antimicrobial-cationic-peptides
keyword: mesh-circular-dichroism
keyword: mesh-magnetic-resonance-spectroscopy
keyword: mesh-models-molecular
keyword: mesh-molecular-sequence-data
keyword: mesh-muscidae
keyword: mesh-peptides
keyword: mesh-protein-folding
keyword: mesh-protein-structure-secondary
keyword: mesh-solutions
keyword: mesh-trifluoroethanol
keyword: nmr-structure
keyword: sdvbbmlife-sciences-q-biobiochemistry-molecular-biology
keyword: sdvlife-sciences-q-bio
keyword: spinigerin
keyword: stomoxyn
keyword: tfe
landing page: 0006-3525

Solution structures of stomoxyn and spinigerin, two insect antimicrobial peptides with an alpha-helical conformation
type: Distribution
format: HTML
issued: 2026-05-08T19:55:33.352696
modified: 2026-05-08T19:55:33.305515
access URL: https://hal.science/hal-00088871

test_moissonnage_selune
type: Agent