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Cell-surface discoidin in aggregating cells of Dictyostelium discoideum.

ABSTRACT: Both discoidin I and discoidin II have been detected on the surface of aggregating (10 h developmental stage) cells of Dictyostelium discoideum NC4 by radioiodination of the cell-surface followed by immunoprecipitation and sodium dodecyl sulphate/polyacrylamide-gel-electrophoretic analysis. Approx. 92% of cell-surface discoidin I and 72% of cell-surface discoidin II can be eluted with 0.5 M-galactose, showing that most of each endogenous lectin is not present as integral membrane protein but rather is bound to cell-surface discoidin receptors. Two-dimensional polyacrylamide-gel-electrophoretic analysis of discoidin I suggests that the native tetramer may be a hetero-multimer composed of both Ia and Ib subunits. Cell-surface discoidin I also contains both types of subunit, but it is not clear whether both subunits have corresponding cell-surface receptors.

SUBMITTER: Madley IC

PROVIDER: S-EPMC1158421 | biostudies-other | 1982 Jun

REPOSITORIES: biostudies-other

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Discoidin I from Dictyostelium discoideum and Interactions with oligosaccharides: specificity, affinity, crystal structures, and comparison with discoidin II.

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