Facile preparation of the alpha-Gal-recognizing Griffonia simplicifolia I-B4 isolectin

The B4 isolectin from Griffonia simplicifolia is of great utility as a reagent for the identification of alpha-D-galactopyranosyl end groups. Its separation from isolectins containing A subunits has been greatly improved by a simple, rapid procedure using a column of N-acetylgalactosamine coupled to vinyl sulfone-activated Sepharose 4B to selectively retain the A subunit-containing isolectins. The procedure has the advantages over previous affinity procedures of speed (the isolation of B4 isolectin can be achieved in one day), simplicity, and high degree of resolution of the B4 isolectin.