High‐affinity binding of fungal β‐glucan fragments to soybean (Glycine max L.) microsomal fractions and protoplasts

Eric G. COSIO, Heike PÖPPERL, Walter E. SCHMIDT, Jürgen EBEL

Producción científica: Contribución a una revistaArtículorevisión exhaustiva

104 Citas (Scopus)


We have recently reported the existence of binding sites in soybean membranes for a β‐glucan fraction derived from the fungal pathogen Phytophthora megasperma f. sp. glycinea, which may play a role in the elicitor‐mediated phytoalexin response of this plant [Schmidt, W. E. & Ebel, J. (1987) Proc. Natl Acad. Sci. USA 84, 4117–4121]. The specificity of β‐glucan binding to soybean membranes has now been investigated using a variety of competing polyglucans and oligoglucans of fungal origin. P. megaspermaβ‐glucan binding showed high apparent affinity for branched glucans with degrees of polymerization greater than 12. Binding affinity showed good correlation with elicitor activity as measured in a soybean cotyledon bioassay. Modification of the glucans at the reducing end with phenylalkylamine reagents had no effect on binding affinity. This characteristic was used to synthesize an oligoglucosyl tyramine derivative suitable for radioiodination. The 251I‐glucan (15–30 Ci/mmol) provided higher sensitivity and lower detection limits for the binding assays while behaving in a manner identical to the [3H]glucan used previously. More accurate determinations of the Kd value for glucan binding indicated a higher affinity than previously shown (37 nM versus 200 nM). The 251I‐glucan was used to provide the first reported evidence of specific binding of a fungal β‐glucan fraction in vivo to soybean protoplasts. The binding affinity to protoplasts proved identical to that found in microsomal fractions.

Idioma originalInglés
Páginas (desde-hasta)309-315
Número de páginas7
PublicaciónEuropean Journal of Biochemistry
EstadoPublicada - ago. 1988
Publicado de forma externa


Profundice en los temas de investigación de 'High‐affinity binding of fungal β‐glucan fragments to soybean (Glycine max L.) microsomal fractions and protoplasts'. En conjunto forman una huella única.

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