title: Identification and characterization of an insect toxin protein, Bb70p, from the entomopathogenic fungus, Beauveria bassiana, using Galleria mellonella as a model system.
abstract: An insect-toxic protein, Bb70p, was purified from Beauveria bassiana 70 using ammonium sulfate precipitation, ion exchange chromatography, and gel filtration. Bb70p has a high affinity for anion exchangers and 2D electrophoresis results revealed a single spot with a molecular weight of 35.5 kDa and an iso-electric point of ∼4.5. Bb70p remains active from 4 to 60°C, within a pH range of 4-10, but is more active in slightly acidic pH. A pure protein, Bb70p does not have any carbohydrate side chains. The protein caused high mortality by intra-haemocelic injection into Galleria mellonella with LD50 of 334.4 μg/g body weight and activates the phenol oxidase cascade. With a partial amino acid sequence comparison using the NCBI database, we showed no homology to known toxin proteins of entomopathogenic fungi. Thus, Bb70p appears to be an insect toxin protein, demonstrating novelty. Identification of this insect-toxic protein presents potential to enhance the virulence of B. bassiana through genetic manipulation.
authors.affiliation: The World Agroforestry Centre, East and Central Asia, 132 Lanhei Rd, Heilongtan, Kunming 650201, Yunnan, China; Centre for Mountain Ecosystem Studies, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, Yunnan, China; Key Laboratory of Integrated Pest Management in Crops, Ministry of Agriculture, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, No. 12 Zhong-guancun South Street, Beijing 100081, People's Republic of China.
authors.forename: Sehroon
authors.initials: S
authors.lastname: Khan
authors.affiliation: Rice Research Institute, Yunnan Agriculture University, Heilongtan, Kunming 650201, Yunnan, China; Department of Chemistry, Faculty of Sciences, University of Science and Technology Bannu, Khyber Pakhtunkhwa, 28100 Bannu, Pakistan.
authors.forename: Sadia
authors.initials: S
authors.lastname: Nadir
authors.affiliation: Key Laboratory of Integrated Pest Management in Crops, Ministry of Agriculture, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, No. 12 Zhong-guancun South Street, Beijing 100081, People's Republic of China.
authors.forename: Guo
authors.initials: G
authors.lastname: Lihua
authors.affiliation: The World Agroforestry Centre, East and Central Asia, 132 Lanhei Rd, Heilongtan, Kunming 650201, Yunnan, China; Centre for Mountain Ecosystem Studies, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, Yunnan, China.
authors.forename: Jianchu
authors.initials: J
authors.lastname: Xu
authors.affiliation: CABI, Rue des Grillons 1, CH-2800 Delémont, Switzerland.
authors.forename: Keith A
authors.initials: KA
authors.lastname: Holmes
authors.affiliation: Key Laboratory of Integrated Pest Management in Crops, Ministry of Agriculture, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, No. 12 Zhong-guancun South Street, Beijing 100081, People's Republic of China. Electronic address: qiudewen@caas.net.cn.
authors.forename: Qiu
authors.initials: Q
authors.lastname: Dewen
mesh_terms: D000818:Animals; D052982:Beauveria / Q000235:genetics / Q000378:metabolism* / Q000472:pathogenicity; D001681:Biological Assay; D005656:Fungal Proteins / Q000302:isolation & purification / Q000494:pharmacology*; D009036:Moths / Q000187:drug effects*; D009183:Mycotoxins / Q000302:isolation & purification / Q000494:pharmacology*; D014774:Virulence / Q000235:genetics
chemical_list: D005656:Fungal Proteins; D009183:Mycotoxins
keywords: Bb70p; Beauveria bassiana; Entomopathogenic fungi; Filtrate; Galleria mellonella; Insect-toxic protein