Bean lectins : Part 1: Relationships between agglutinating activity and electrophoretic variation in the lectin-containing G2/albumin seed proteins of french bean (Phaseolus vulgaris L.).

Single seeds of over 100 bean cultivars were analyzed by two-dimensional electrophoresis. The cultivars could be classified into eight groups by virtue of their G2/albumin electrophoretic patterns: TG2, SG2, VG2, PrG2, BG2, MG2, PG2, and PiG2, The polypeptide compositions of these types were largely inter-related having particular polypeptides in common. It was possible to correlate the G2/albumin patterns with agglutinating activity of cow and rabbit blood cells as measured by the agglutination ratio (minimum concentration of extract required to agglutinate cow blood cells: minimum concentration of extract required to agglutinate rabbit blood cells). The active lectin polypeptides were identified by extracting lectins from agglutinated erythrocytes and by comparing the qualitative similarities and differences of the G2/albumin patterns and their agglutination activities. A reference catalogue of over 100 bean cultivars giving their phaseolin and G2/albumin electrophoretic patterns, and agglutination ratios is presented.