title: Soybean toxin (SBTX), a protein from soybeans that inhibits the life cycle of plant and human pathogenic fungi.
abstract: Soybean toxin (SBTX) is a 44 kDa glycoprotein that is lethal to mice (LD(50) = 5.6 mg/kg). This study reports the toxicity of SBTX on pathogenic fungi and yeasts and the mechanism of its action. SBTX inhibited spore germination of Aspergillus niger and Penicillium herguei and was toxic to Candida albicans, Candida parapsilosis, Kluyveromyces marxiannus , Pichia membranifaciens, and Saccharomyces cerevisiae. In addition, SBTX hampered the growth of C. albicans and K. marxiannus and inhibited the glucose-stimulated acidification of the incubation medium by S. cerevisiae, suggesting that SBTX interferes with intracellular proton transport to the external medium. Moreover, SBTX caused cell-wall disruption, condensation/shrinkage of cytosol, pseudohyphae formation, and P. membranifaciens and C. parapsilosis cell death. SBTX is toxic to fungi at concentrations far below the dose lethal to mice and has potential in the design of new antifungal drugs or in the development of transgenic crops resistant to pathogens.
authors.affiliation: Departamento de Bioquímica e Biologia Molecular, Universidade Federal do Ceará, Campus do Pici, CEP 60451-970 Fortaleza, Ceará, Brazil.
authors.forename: Janne Keila S
authors.initials: JK
authors.lastname: Morais
authors.forename: Valdirene M
authors.initials: VM
authors.lastname: Gomes
authors.forename: José Tadeu A
authors.initials: JT
authors.lastname: Oliveira
authors.forename: Izabela S
authors.initials: IS
authors.lastname: Santos
authors.forename: Maura
authors.initials: M
authors.lastname: Da Cunha
authors.forename: Hermogenes D
authors.initials: HD
authors.lastname: Oliveira
authors.forename: Henrique P
authors.initials: HP
authors.lastname: Oliveira
authors.forename: Daniele O B
authors.initials: DO
authors.lastname: Sousa
authors.forename: Ilka M
authors.initials: IM
authors.lastname: Vasconcelos
mesh_terms: D000818:Animals; D000935:Antifungal Agents / Q000494:pharmacology* / Q000633:toxicity; D001234:Aspergillus niger / Q000187:drug effects / Q000254:growth & development; D002175:Candida / Q000187:drug effects / Q000254:growth & development; D002176:Candida albicans / Q000187:drug effects / Q000254:growth & development; D005659:Fungicides, Industrial / Q000494:pharmacology* / Q000633:toxicity; D006023:Glycoproteins / Q000494:pharmacology* / Q000633:toxicity; D006801:Humans; D007716:Kluyveromyces / Q000187:drug effects / Q000254:growth & development; D007928:Lethal Dose 50; D051379:Mice; D010407:Penicillium / Q000187:drug effects; D010843:Pichia / Q000187:drug effects / Q000254:growth & development; D010935:Plant Diseases / Q000382:microbiology; D012441:Saccharomyces cerevisiae / Q000187:drug effects / Q000378:metabolism; D030262:Soybean Proteins / Q000494:pharmacology* / Q000633:toxicity; D013172:Spores, Fungal / Q000187:drug effects
chemical_list: D000935:Antifungal Agents; D005659:Fungicides, Industrial; D006023:Glycoproteins; C530414:SBTX protein, soybean; D030262:Soybean Proteins