title: Solubilization of soybean membrane binding sites for fungal beta-glucans that elicit phytoalexin accumulation.
abstract: Soybean membranes contain high-affinity binding sites for fungal beta-glucans. These sites may play a role in the recognition by soybean tissues of fungal phytoalexin elicitors. We have solubilized beta-glucan-binding activity from microsomal membranes using two C12-alkyl zwitterionic detergents, Zwittergent 3-12 (ZW 3-12) and the lysolecithin analog 1-dodecanoyl propanediol-3-phosphorylcholine [corrected] (ES12H). The solubilized binding sites displayed identical affinity for beta-glucans as that found in membranes (KD = 11-34 nM). Detergent-protein micelles with glucan binding activity eluted with approximate Mr values of 300,000 in ZW 3-12 and 380,000 in ES12H in gel permeation chromatography. Maximal binding activity eluted from a chromatofocusing column in the pH range between 6.2 and 6.6 with both ES12H and ZW 3-12, suggesting an apparent pI close to neutral.
authors.affiliation: Biologisches Institut II, Universität Freiburg, FRG.
authors.forename: E G
authors.initials: EG
authors.lastname: Cosio
authors.forename: T
authors.initials: T
authors.lastname: Frey
authors.forename: J
authors.initials: J
authors.lastname: Ebel
mesh_terms: D001665:Binding Sites; D002462:Cell Membrane / Q000378:metabolism*; D002850:Chromatography, Gel; D008411:Chytridiomycota / Q000378:metabolism*; D005936:Glucans / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D010838:Phytophthora / Q000378:metabolism*; D010936:Plant Extracts / Q000378:metabolism*; D012717:Sesquiterpenes; D012995:Solubility; D013025:Glycine max / Q000378:metabolism*; D013729:Terpenes; D000094162:Phytoalexins
chemical_list: D005936:Glucans; D010936:Plant Extracts; D012717:Sesquiterpenes; D013729:Terpenes; D000094162:Phytoalexins