title: Phage display of Bacillus thuringiensis CryIA(a) insecticidal toxin.
abstract: The display of proteins or peptides on the surface of filamentous phages or phagemids has been shown to be a very powerful technology for the rescue of specific binders from large combinatorial libraries, as well as to select derivatives of known proteins with altered binding properties. The Bacillus thuringiensis (Bt) crystal proteins are a large family of insecticidal toxins which bind to receptors found on the brush border of larval midgut cells, different crystal toxins having different larval specificities. Here we describe the display of different CryIA(a) toxin regions on the surface of phagemids using the display vector pHEN1, the purpose being the identification of toxin sequences suitable for mutagenesis and selection using phage display. We show that CryIA(a) domain II, in which the receptor binding activity is located, is efficiently displayed as well as being secreted as soluble protein into the periplasm of bacterial cell. This forms the basis of a simple means for the modification of toxin specificity and the selection of toxin proteins with novel or expanded host ranges.
authors.affiliation: Dipartimento di Biologia, Universita' degli Studi di Trieste, Italy. marzari@icgeb.trieste.it
authors.forename: R
authors.initials: R
authors.lastname: Marzari
authors.forename: P
authors.initials: P
authors.lastname: Edomi
authors.forename: R K
authors.initials: RK
authors.lastname: Bhatnagar
authors.forename: S
authors.initials: S
authors.lastname: Ahmad
authors.forename: A
authors.initials: A
authors.lastname: Selvapandiyan
authors.forename: A
authors.initials: A
authors.lastname: Bradbury
mesh_terms: D001413:Bacillus thuringiensis / Q000235:genetics*; D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins / Q000235:genetics*; D001427:Bacterial Toxins / Q000235:genetics*; D017104:Bacteriophage M13; D003001:Cloning, Molecular; D004731:Endotoxins / Q000235:genetics*; D015870:Gene Expression; D005822:Genetic Vectors; D006460:Hemolysin Proteins; D007306:Insecticides; D019151:Peptide Library; D011993:Recombinant Fusion Proteins / Q000235:genetics
chemical_list: D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins; D001427:Bacterial Toxins; D004731:Endotoxins; D006460:Hemolysin Proteins; D007306:Insecticides; D019151:Peptide Library; D011993:Recombinant Fusion Proteins; C030956:insecticidal crystal protein, Bacillus Thuringiensis