High-affinity binding of a protein-lipopolysaccharide phytotoxin from Verticillium dahliae to cotton membranes.
The presence of a specific binding site for a protein-lipopolysaccharide (PLP) phytotoxin isolated from culture filtrates of Verticillium dahliae has been demonstrated in plasma membranes from cotton seedlings. The 125I-labelled PLP was used as a ligand in binding assays with plasma membrane enriched fractions. Root tissue exhibited the highest amount of binding activity compared to hypocotyl and cotyledon tissue. Binding of the [125I]PLP was saturable, reversible, and with an affinity (Kd = 1.42 x 10(-8) M) comparable with the concentration required for biological activity. A single class of binding site was found, and the maximal number of binding sites were estimated as 5.4 x 10(-15) mol/micrograms protein.
Meyer
R
R
Plant Biotechnology Section, Agriculture Research Council, Pretoria, South Africa.
Dubery
I A
IA
D001665:Binding Sites; D002462:Cell Membrane / Q000378:metabolism; D005656:Fungal Proteins / Q000378:metabolism*; D003368:Gossypium / Q000378:metabolism* / Q000382:microbiology; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008070:Lipopolysaccharides / Q000378:metabolism*; D003904:Mitosporic Fungi / Q000378:metabolism* / Q000472:pathogenicity; D009183:Mycotoxins / Q000378:metabolism*; D011485:Protein Binding
D005656:Fungal Proteins; D008070:Lipopolysaccharides; D009183:Mycotoxins