title: Crystallization and preliminary X-ray diffraction of the surfactant protein Lv-ranaspumin from the frog Leptodactylus vastus.
abstract: Lv-ranaspumin is a natural surfactant protein with a molecular mass of 23.5 kDa which was isolated from the foam nest of the frog Leptodactylus vastus. Only a partial amino-acid sequence is available for this protein and it shows it to be distinct from any protein sequence reported to date. The protein was purified from the natural source by ion-exchange and size-exclusion chromatography and was crystallized by sitting-drop vapour diffusion using the PEG/Ion screen at 293 K. A complete data set was collected to 3.5 Å resolution. The crystal belonged to the orthorhombic space group P2(1)2(1)2(1), with unit-cell parameters a = 51.96, b = 89.99, c = 106.00 Å. Assuming the presence of two molecules in the asymmetric unit, the solvent content was estimated to be 54%.
authors.affiliation: Laboratório de Ecologia Microbiana e Biotecnologia (LEMBiotech), Departamento de Biologia, Universidade Federal do Ceará, Avenida Humberto Monte 2977, Campus do Pici, Bloco 909, 60455-000 Fortaleza-CE, Brazil.
authors.forename: Denise Cavalcante
authors.initials: DC
authors.lastname: Hissa
authors.forename: Gustavo Arruda
authors.initials: GA
authors.lastname: Bezerra
authors.forename: Britta
authors.initials: B
authors.lastname: Obrist
authors.forename: Ruth
authors.initials: R
authors.lastname: Birner-Grünberger
authors.forename: Vânia Maria Maciel
authors.initials: VM
authors.lastname: Melo
authors.forename: Karl
authors.initials: K
authors.lastname: Gruber
mesh_terms: D000818:Animals; D001001:Anura; D003460:Crystallization; D018360:Crystallography, X-Ray; D008565:Membrane Proteins / Q000737:chemistry* / Q000302:isolation & purification
chemical_list: D008565:Membrane Proteins