title: SAXS study of the snake toxin alpha-crotamine.
abstract: alpha-crotamine is a small toxic protein (42 amino acid residues with three disulphide bridges) present in the venom of Crotallus durissus terrificus. Molecular parameters (Rg = 13.7 A, S = 3,000 A2, V = 9,200 A3 and Dmax = 40 A) were derived from SAXS curves obtained from a solution of this protein at pH = 4.5. An excellent agreement between the experimental distance distribution curve and that calculated from a model consisting of two lobes linked by the Cys(18)-Cys(30) disulphide bridge.
authors.affiliation: Instituto de Biociências, Letras e Ciências Exatas, UNESP, Departamento de Fisica, Sáo José do Rio Preto-SP, Brazil.
authors.forename: J R
authors.initials: JR
authors.lastname: Beltran
authors.forename: Y P
authors.initials: YP
authors.lastname: Mascarenhas
authors.forename: A F
authors.initials: AF
authors.lastname: Craievich
authors.forename: C J
authors.initials: CJ
authors.lastname: Laure
mesh_terms: D000595:Amino Acid Sequence; D002850:Chromatography, Gel; D003435:Crotalid Venoms / Q000302:isolation & purification; D004220:Disulfides; D008969:Molecular Sequence Data; D011487:Protein Conformation; D012984:Software; D014961:X-Ray Diffraction / Q000379:methods
chemical_list: D003435:Crotalid Venoms; D004220:Disulfides; C010563:crotamine