Structural and functional characterization of sticholysin III: A newly discovered actinoporin within the venom of the sea anemone Stichodactyla helianthus
| Autor: | Esperanza Rivera-de-Torre, Álvaro Martínez-del-Pozo, Juan Palacios-Ortega, José G. Gavilanes, J. Peter Slotte, Jessica E. Garb |
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| Rok vydání: | 2020 |
| Předmět: |
0301 basic medicine
Bioquímica Models Molecular Pore Forming Cytotoxic Proteins Osmotic shock Biophysics Venom Sea anemone Biochemistry Hemolysis 03 medical and health sciences Cnidarian Venoms medicine Animals Amino Acid Sequence Organic Chemicals Helianthus Molecular Biology Pore-forming toxin Biología molecular Sheep 030102 biochemistry & molecular biology Stichodactyla helianthus biology Chemistry biology.organism_classification medicine.disease 030104 developmental biology Membrane Sea Anemones Sequence Alignment |
| Zdroj: | E-Prints Complutense. Archivo Institucional de la UCM Instituto de Salud Carlos III (ISCIII) |
| ISSN: | 1096-0384 |
| Popis: | Actinoporins are a family of pore-forming toxins produced by sea anemones as part of their venomous cocktail. These proteins remain soluble and stably folded in aqueous solution, but when interacting with sphingomyelin-containing lipid membranes, they become integral oligomeric membrane structures that form a pore permeable to cations, which leads to cell death by osmotic shock. Actinoporins appear as multigenic families within the genome of sea anemones: several genes encoding very similar actinoporins are detected within the same species. The Caribbean Sea anemone Stichodactyla helianthus produces three actinoporins (sticholysins I, II and III; StnI, StnII and StnIII) that differ in their toxic potency. For example, StnII is about four-fold more effective than StnI against sheep erythrocytes in causing hemolysis, and both show synergy. However, StnIII, recently discovered in the S. helianthus transcriptome, has not been characterized so far. Here we describe StnIII’s spectroscopic and functional properties and show its potential to interact with the other Stns. StnIII seems to maintain the well-preserved fold of all actinoporins, characterized by a high content of β-sheet, but it is significantly less thermostable. Its functional characterization shows that the critical concentration needed to form active pores is higher than for either StnI or StnII, suggesting differences in behavior when oligomerizing on membrane surfaces. Our results show that StnIII is an interesting and unexpected piece in the puzzle of how this Caribbean Sea anemone species modulates its venomous activity. |
| Databáze: | OpenAIRE |
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