title: Sticholysin II, a cytolysin from the sea anemone Stichodactyla helianthus, is a monomer-tetramer associating protein.
abstract: Sticholysin II (Stn-II) is a pore-forming cytolysin. Stn-II interacts with several supports for size exclusion chromatography, which results in an abnormal retardation precluding molecular mass calculations. Sedimentation equilibrium analysis has revealed that the protein is an associating system at neutral pH. The obtained data fit a monomer-tetramer equilibrium with an association constant K4c of 10(9) M(-3). The electrophoretic pattern of Stn-II treated with different cross-linking reagents, in a wide range of protein concentrations, corroborates the existence of tetrameric forms in solution. A planar configuration of the four monomers, C4 or D2 symmetry, is proposed from modelling of the cross-linking data.
authors.affiliation: Departamento de Bioquímica y Biología Molecular, Facultad de Química, Universidad Complutense, Madrid, Spain.
authors.forename: V
authors.initials: V
authors.lastname: de los Ríos
authors.forename: J M
authors.initials: JM
authors.lastname: Mancheño
authors.forename: A
authors.initials: A
authors.lastname: Martínez del Pozo
authors.forename: C
authors.initials: C
authors.lastname: Alfonso
authors.forename: G
authors.initials: G
authors.lastname: Rivas
authors.forename: M
authors.initials: M
authors.lastname: Oñaderra
authors.forename: J G
authors.initials: JG
authors.lastname: Gavilanes
mesh_terms: D000818:Animals; D001704:Biopolymers; D002850:Chromatography, Gel; D002942:Circular Dichroism; D003603:Cytotoxins / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology; D006863:Hydrogen-Ion Concentration; D008970:Molecular Weight; D012615:Sea Anemones / Q000737:chemistry*; D013056:Spectrophotometry, Ultraviolet
chemical_list: D001704:Biopolymers; D003603:Cytotoxins