Structural and functional characterization of a recombinant sticholysin I (rSt I) from the sea anemone Stichodactyla helianthus
Autor: | Eduardo Lissi, C. Alvarez, A. Valle, Javier Campos, Rafael Fando, María E. Lanio, L. Calderón, Eduardo Horjales, Amaury Pupo, A. Ramírez, Fabiola Pazos, Diana Martinez, Vivian Morera, Shirley Schreier, Mayra Tejuca, Fabio Henrique Dyszy |
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Rok vydání: | 2006 |
Předmět: |
Models
Molecular Pore Forming Cytotoxic Proteins Erythrocytes Lipid Bilayers Molecular Sequence Data Sea anemone Toxicology medicine.disease_cause Permeability law.invention Sequence Analysis Protein law medicine Animals Surface Tension Amino Acid Sequence Organic Chemicals Pore-forming toxin Liposome Base Sequence Stichodactyla helianthus biology Toxin Circular Dichroism Wild type Protein primary structure Surface Plasmon Resonance biology.organism_classification Recombinant Proteins Protein Structure Tertiary Sea Anemones Biochemistry Liposomes Recombinant DNA Sequence Alignment |
Zdroj: | TOXICON Artículos CONICYT CONICYT Chile instacron:CONICYT |
ISSN: | 0041-0101 |
DOI: | 10.1016/j.toxicon.2006.09.004 |
Popis: | Sticholysins I and II (Sts I and II) are two potent cytolysins from the sea anemone Stichodactyla helianthus. These isoforms present 13 substitutions, with three non-conservative located at the N-terminus. St II is considerably more hemolytic than St I in human red blood cells, a result explained by the smaller number of negatively charged groups present at St II's N-terminus. In the present work, we have obtained a recombinant St I (rSt I), differing from the wild type in a single amino acid residue (E16Q). This pseudo-wild type is structurally similar to St I and shows a similar capacity to interact with and form pores in model membranes. This was assessed by the intrinsic fluorescence increase in the presence of liposomes, their adsorption to bilayers (measured by SPR), their concentration at the air-water interface, their interaction with lipid monolayers and their capacity to promote the release of carboxyfluorescein entrapped in liposomes. In spite of these similarities, rSt I presents a larger hemolytic activity in human red blood cells than St I, being intermediate in activity between Sts I and II. The results obtained in the present work emphasize that even the change of one single E by Q at the N-terminal segment may modify the toxin HA and show that this functional property is the most sensitive to subtle changes in the protein primary structure. |
Databáze: | OpenAIRE |
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