Datura stramonium Lectin

Abstract

This chapter presents procedure for purification and characterization of a lectin from Datura stramonium. Datura stramonium lectin, which has an affinity for oligomers of N-acetyl-D-glucosamine, is purified by affinity chromatography on a column of p-aminobenzyl-N,N'-diacetyl-O-chitobioside-succinylaminohexyl- Sepharose. Datura stramonium lectin can be partially purified by a variety of affinity chromatographic methods. All procedures, however, result in a lectin contaminated with varying amounts of a 32,000 dalton protein. In the present procedure, most of this contaminating protein is preferentially removed prior to the affinity chromatographic step. This is accomplished in two ways. The first is storage of the PBS-extracted material at 4 ° before subjecting it to dialysis against acetic acid. As noted above, a brown precipitate, which consists largely of the contaminant, forms on standing. Second, the acetic acid precipitation step itself acts to remove further the contaminating protein. For rapid testing of Datura activity, one can use microcapillary test, utilizing the ability of the Datura lectin to precipitate carcinoembryonic antigen or a p-azophenyl-N,N'-diacetyl-β-chitobioside-bovine serum albumin conjugate. © 1982, Elsevier Inc. All rights reserved.