Of osage-orange lectin

Fig. 26. Inactivation of antifreeze and antilectin activities of antifreeze glycoprotein by /3-elimination of carbohydrate. Antilectin activity was determined by inhibition of Osage-orange lectin. Antifreeze activities were determined by measurements of freezing temperatures. /3-Elimination was done with glycoprotein concentrations of 0.1 mg/ml in 0.1 N NaOH at 20°C. Extent of/3-elimination was determined according to data of Table VIII. From Ahmed et al. (1973), reproduced with permission.

The active AFGP 1-5 were first reported by Chuba and co-workers (1973) to inhibit hemagglutination by a lectin prepared from the seeds of the Osage orange (Maclura pomifera). Although the structural requirements for the antilectin activity closely parallel those for antifreeze activity, these two activities appear to be unrelated, with the probable exception that they both require considerable integrity of the carbohydrate side chain and polymeric size. 

Table XIII shows the potency with which AFGP inhibited hemagglutination by Osage orange (Maclura pomifera) lectin. At a final concentration in the reaction mixtures of less than 1 /xg/ml, the active AFGP completely inhibited hemagglutination of both human group-0 and sheep erythrocytes. By contrast, the inactive AFGP component was some 50-100 times less active as an inhibitor. Several other randomly tested preparations containing glycoproteins of diverse origin were either inactive or comparatively weak inhibitors.

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