A lectin, monospecific for human blood group A red blood cells was extracted from seeds of
Crotalaria striata and purified by molecular sieving on Sephadex G-100 and ion-exchange on DEAEcellulose.
A molecular mass of 30 kDa was determined by SDS-polyacrylamide gel electrophoresis under
non-reducing and reducing conditions. Molecular sieving on a Superose 12 column indicated a molecular
mass of 110 kDa, suggesting the tetrameric nature of the native protein. Amino-acid composition showed
the presence of aminated carbohydrate residues on the lectin. N-terminal amino-acid sequencing showed a
striking similarity with the N-terminal sequence of the lectin from Crotalaria juncea, which is blood-group
non-specific.
