Improved Procedures for Purification of the Bandeiraea simplicifolia I Isolectins and Bandeiraea simplicifolia II Lectin by Affinity Chromatography

Abstract

B. simplicifolia plant seeds contained a family of 5 .alpha.-D-galactopyranosyl-binding isolectins (BS I-A4, A3B, A2B2, AB3, B4) and N-acetyl-D-glucosamine-binding lectin (BS II). After Pi/NaCl extraction and (NH4)2 SO4 fractionation, BS II was specifically adsorbed onto p-aminobenzyl-1-thio-N-acetyl-.beta.-D-glucosaminide-succinylaminohexylaminyl-Sepharose-4B. The BS I isolectins passed through this column and BS II was selectively eluted by Pi/NaCl containing 2 mM N-acetyl-D-glucosamine or by 0.1 M sodium acetate buffer pH 3.6. The material not bound to the column was loaded onto p-aminophenyl-.beta.-D-galactopyranosyl-succinylaminohexylaminyl-Sepharose-4B. BS I-A4 was eluted in a sharp peak with Pi/NaCl containing 1 mM N-acetyl-D-galactosamine. BS I-A3B, A2B2, AB3 and B4 were selectively eluted, in a single peak for each isolectin, with Pi/NaCl containing 3, 8, 15 and 50 mM methyl .alpha.-D-galactopyranoside, respectively.