Isolation of the Canavalia ensiformis seed alpha-mannosidase by chromatography on concanavalin A, the lectin from the same plant, without involving its sugar binding site.

A method is described for the purification of the alpha-mannosidase from Canavalia ensiformis. By three consecutive steps, a more than 500-fold purification is achieved and the pure enzyme obtained in 75% yield. One of these steps utilizes the specific interaction of the alpha-mannosidase with concanavalin A, the lectin from the same plant. This interaction is dependent on pH and ionic strength but does not involve the sugar binding site of the lectin. The interaction between both proteins may be important also in vivo.