CHARACTERIZATION AND PARTIAL-PURIFICATION OF A PLASMA-MEMBRANE RECEPTOR FOR BACILLUS-THURINGIENSIS VAR KURSTAKI LEPIDOPTERAN-SPECIFIC DELTA-ENDOTOXIN

  • 1 July 1986
    • journal article
    • research article
    • Vol. 83, 89-101
Abstract
The lepidopteran-specific P1 .delta.-endotoxin of Bacillus thuringiensis var. kurstaki HD-1 was activated in vitro using insect gut proteases and found to be highly specific for the lepidopteran cell line Choristoneura fumiferana CF1 among a wide range of lepidoteran and dipteran cell lines tested. The toxicity of P1 against CF1 cells is inhibited by N-acetylgalactosamine (GalNAc), and the lectins soybean agglutinin (SBA) and wheat-germ agglutinin. Protein blotting was used to identify a glycoprotein of 146 .times. 103 Mr in the plasma membrane of CF1 cells, capable of binding both the toxin and SBA, which is specific for GalNAc. This glycoprotein was labelled using galactose oxidase and sodium boro-[3H]hydride and solubilized in Triton X-100 before partial purification by affinity chromatography on SBA-agarose. We propose that this glycoprotein is a good candidate for the cellular receptor of the lepidopteran-specific P1 .delta.-endotoxin of B. thuringiensis var. kurstaki HD-1.