A lectin from elder (Sambucus nigra L.) bark.

A lectin was isolated from elder (Sambucus nigra) bark by affinity chromatography on fetuin-agarose. It is a tetrameric molecule (Mr 140000) composed of two different subunits of Mr 34500 and 37500 respectively, held together by intramolecular disulphide bridges. The lectin is a glycoprotein and is especially rich in asparagine/aspartic acid, glutamine/glutamic acid, valine and leucine. It is also the first lectin isolated from a species belonging to the plant family Caprifoliaceae.