title: Pliable natural biocide: Jaburetox is an intrinsically disordered insecticidal and fungicidal polypeptide derived from jack bean urease.
abstract: Jaburetox is a polypeptide derived from jack bean (Canavalia ensiformis) urease and toxic to a broad spectrum of insects, phytopathogenic filamentous fungi and yeasts of medical importance. The elucidation of the structural basis for the mode of action of Jaburetox is the focus of this multifaceted study. Jaburetox in solution is a monomer of 11.0 kDa featuring a large hydrodynamic radius, suggestive of a disordered polypeptide. The intrinsically disordered nature of Jaburetox was theoretically predicted by a comprehensive bioinformatics analysis and experimentally confirmed by light scattering as well as by circular dichroism and NMR spectroscopy. NMR signal assignment provided backbone secondary chemical shifts that indicated that Jaburetox has a low propensity to assume a stable secondary structure. (15)N relaxation studies revealed significant backbone mobility, especially in the N-terminal portion of the polypeptide. The solution structure of Jaburetox shows the presence of an α-helical motif close to the N terminus, together with two turn-like structures situated in the central portion of the protein and close to the C terminus. Similar regions were predicted as potential protein-protein interaction sites using computational tools. The knowledge of the structural properties of Jaburetox in solution is a key step to correlate its structural and biological activities.
authors.affiliation: Graduate Program in Cellular and Molecular Biology - Center of Biotechnology, Federal University of Rio Grande do Sul, Porto Alegre, Brazil.
authors.forename: Fernanda C
authors.initials: FC
authors.lastname: Lopes
authors.forename: Olena
authors.initials: O
authors.lastname: Dobrovolska
authors.forename: Rafael
authors.initials: R
authors.lastname: Real-Guerra
authors.forename: Valquiria
authors.initials: V
authors.lastname: Broll
authors.forename: Barbara
authors.initials: B
authors.lastname: Zambelli
authors.forename: Francesco
authors.initials: F
authors.lastname: Musiani
authors.forename: Vladimir N
authors.initials: VN
authors.lastname: Uversky
authors.forename: Célia R
authors.initials: CR
authors.lastname: Carlini
authors.forename: Stefano
authors.initials: S
authors.lastname: Ciurli
mesh_terms: D020816:Amino Acid Motifs; D000818:Animals; D000935:Antifungal Agents / Q000737:chemistry*; D032449:Canavalia / Q000201:enzymology; D002942:Circular Dichroism; D004926:Escherichia coli / Q000378:metabolism; D005470:Fluorometry; D057446:Hydrodynamics; D007313:Insecta; D007306:Insecticides / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D010455:Peptides / Q000737:chemistry; D010940:Plant Proteins; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D013696:Temperature; D014510:Urease / Q000737:chemistry*
chemical_list: D000935:Antifungal Agents; D007306:Insecticides; D010455:Peptides; D010940:Plant Proteins; D014510:Urease; C525847:jaburetox-2Ec, Canavalia ensiformis
keywords: Canavalia ensiformis; Jaburetox; NMR spectroscopy; circular dichroism; light scattering; urease