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Hervis YP, Valle A, Canet L, Rodríguez A, Lanio ME, Alvarez C, Steinhoff HJ, Pazos IF. Cys mutants as tools to study the oligomerization of the pore-forming toxin sticholysin I. Toxicon 2023; 222:106994. [PMID: 36529153 DOI: 10.1016/j.toxicon.2022.106994] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Revised: 12/08/2022] [Accepted: 12/09/2022] [Indexed: 12/23/2022]
Abstract
Sticholysin I (StI) is a water-soluble protein with the ability to bind membranes where it oligomerizes and forms pores leading to cell death. Understanding the assembly property of this protein may be valuable for designing potential biotechnological tools, such as stable or structurally defined nanopores. In order to get insights into the stabilization of StI oligomers by disulfide bonds, we designed and characterized single and double cysteine mutants at the oligomerization interface. The oligomer formation was induced in the presence of lipid membranes and visualized by SDS-PAGE. The contribution of the oligomeric structures to the membrane binding and pore-forming capacities of StI was assessed. Single and double cysteine introduction at the protein-protein oligomerization interface does not considerably affect the conformation and function of the monomeric protein. In the presence of membranes, a cysteine double mutation at positions 15 and 59 favored formation of different size oligomers stabilized by disulfide bonds. The results of this work highlight the relevance of these positions (15 and 59) to be considered for developing biosensors based on nanopores from StI.
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Affiliation(s)
- Yadira P Hervis
- Center for Protein Studies/Department of Biochemistry, Faculty of Biology, University of Havana, Havana, ZIP 10400, Cuba.
| | - Aisel Valle
- Center for Protein Studies/Department of Biochemistry, Faculty of Biology, University of Havana, Havana, ZIP 10400, Cuba.
| | - Liem Canet
- Center for Protein Studies/Department of Biochemistry, Faculty of Biology, University of Havana, Havana, ZIP 10400, Cuba.
| | | | - Maria E Lanio
- Center for Protein Studies/Department of Biochemistry, Faculty of Biology, University of Havana, Havana, ZIP 10400, Cuba.
| | - Carlos Alvarez
- Center for Protein Studies/Department of Biochemistry, Faculty of Biology, University of Havana, Havana, ZIP 10400, Cuba.
| | - Heinz J Steinhoff
- Department of Physics, University of Osnabrueck, Osnabrueck, 49069, Germany.
| | - Isabel F Pazos
- Center for Protein Studies/Department of Biochemistry, Faculty of Biology, University of Havana, Havana, ZIP 10400, Cuba.
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Sea Anemones, Actinoporins, and Cholesterol. Int J Mol Sci 2022; 23:ijms23158771. [PMID: 35955905 PMCID: PMC9369217 DOI: 10.3390/ijms23158771] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Revised: 08/01/2022] [Accepted: 08/05/2022] [Indexed: 11/17/2022] Open
Abstract
Spanish or Spanish-speaking scientists represent a remarkably populated group within the scientific community studying pore-forming proteins. Some of these scientists, ourselves included, focus on the study of actinoporins, a fascinating group of metamorphic pore-forming proteins produced within the venom of several sea anemones. These toxic proteins can spontaneously transit from a water-soluble fold to an integral membrane ensemble because they specifically recognize sphingomyelin in the membrane. Once they bind to the bilayer, they subsequently oligomerize into a pore that triggers cell-death by osmotic shock. In addition to sphingomyelin, some actinoporins are especially sensible to some other membrane components such as cholesterol. Our group from Universidad Complutense of Madrid has focused greatly on the role played by sterols in this water–membrane transition, a question which still remains only partially solved and constitutes the main core of the article below.
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