Structural and functional characterisation of a novel peptide from the Australian sea anemone Actinia tenebrosa

Khaled A Elnahriry; Dorothy C C Wai; Bankala Krishnarjuna; Noha N Badawy; Balasubramanyam Chittoor; Christopher A MacRaild; Billy J Williams-Noonan; Joachim M Surm; David K Chalmers; Alan H Zhang; Steve Peigneur; Mehdi Mobli; Jan Tytgat; Peter Prentis; Raymond S Norton

doi:10.1016/j.toxicon.2019.07.002

Structural and functional characterisation of a novel peptide from the Australian sea anemone Actinia tenebrosa

Toxicon. 2019 Oct:168:104-112. doi: 10.1016/j.toxicon.2019.07.002. Epub 2019 Jul 11.

Authors

Affiliations

¹ Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, VIC, 3052, Australia.
² School of Biomedical Sciences, Faculty of Health, Queensland University of Technology, Brisbane, Australia; Institute of Health and Biomedical Innovation, Queensland University of Technology, Kelvin Grove, Australia.
³ Centre for Advanced Imaging, The University of Queensland, St. Lucia, 4072, Brisbane, Australia.
⁴ Toxicology and Pharmacology, University of Leuven, O&N 2, 3000, Leuven, Belgium.
⁵ School of Earth, Environmental and Biological Sciences, Science and Engineering Faculty, Queensland University of Technology, Brisbane, Australia; Institute for Future Environments, Queensland University of Technology, Brisbane, Australia.
⁶ Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, VIC, 3052, Australia; ARC Centre for Fragment-Based Design, Monash University, Parkville, VIC, 3052, Australia. Electronic address: ray.norton@monash.edu.

PMID: 31302115
DOI: 10.1016/j.toxicon.2019.07.002

Abstract

Sea anemone venoms have long been recognised as a rich source of peptides with interesting pharmacological and structural properties. Our recent transcriptomic studies of the Australian sea anemone Actinia tenebrosa have identified a novel 13-residue peptide, U-AITx-Ate1. U-AITx-Ate1 contains a single disulfide bridge and bears no significant homology to previously reported amino acid sequences of peptides from sea anemones or other species. We have produced U-AITx-Ate1 using solid-phase peptide synthesis, followed by oxidative folding and purification of the folded peptide using reversed-phase high-performance liquid chromatography. The solution structure of U-AITx-Ate1 was determined based on two-dimensional nuclear magnetic resonance spectroscopic data. Diffusion-ordered NMR spectroscopy revealed that U-AITx-Ate1 was monomeric in solution. Perturbations in the 1D ¹H NMR spectrum of U-AITx-Ate1 in the presence of dodecylphosphocholine micelles together with molecular dynamics simulations indicated an interaction of U-AITx-Ate1 with lipid membranes, although no binding was detected to 100% POPC and 80% POPC: 20% POPG lipid nanodiscs by isothermal titration calorimetry. Functional assays were performed to explore the biological activity profile of U-AITx-Ate1. U-AITx-Ate1 showed no activity in voltage-clamp electrophysiology assays and no change in behaviour and mortality rates in crustacea. Moderate cytotoxic activity was observed against two breast cancer cell lines.

Keywords: Cysteine-containing peptide; Lipid interactions; NMR spectroscopy; Sea anemone; Structure.

MeSH terms

Amino Acid Sequence
Animals
Cell Line, Tumor
Decapoda
Humans
MCF-7 Cells
Molecular Dynamics Simulation
Oocytes
Peptides / chemical synthesis
Peptides / chemistry*
Peptides / toxicity
Sea Anemones / chemistry*
Transcriptome
Xenopus laevis

Substances

Peptides