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Two lectins with different binding specificities have been isolated from extracts of seeds of Bandeiraea simplicifolia. The first, Bandeiraea lectin I  was specific for terminal non-reducing αDGalactosyl residues. It reacted with B substances from human ovarian cysts and with several galactomannans to form precipitin lines in agar gels. Polysaccharides with terminal αDGalactosyl residues, such as larch galactan, did not react. The lectin agglutinated B erythrocytes strongly but also reacted to a lower titre with A1 and very weakly with A2 erythrocytes [15, 28] indicating that terminal non-reducing αDGalNAc  can be accommodated in the-site to some extent. Recently, it was shown that B. simplicifolia lectin I (BS I) consists of five isolectins each of which is a tetrameric glycoprotein composed of A and B subunits; the A subunits are specific for αDGalNAc, the B subunits for αDGal .
The second lectin, Bandeiraea lectin II (BS II), isolated by affinity chromatography on chitin , is a glycoprotein (molecular weight 113,000) of four subunits of molecular weight 30,000. It does not agglutinate A, B or O erythrocytes. Quantitative precipitin assays showed it to react better with BSA conjugated to p-azophenyl αDGalNAc than with the β compound. In inhibition studies, the unusual observation was made that N,N’-diacetylchitobiose (DGlcNAcβ1 → 4DGlcNAc) and pNO2 phenyl αDGalNAc were highly active; methyl αDGalNAc was only one half as active but was eight times more active than methyl βDGlcNAc.