Sequence Analysis of the Oligosaccharides from Scarlet Runner Bean Lectin

Two oligosaccharide chains from scarlet runner bean (Phaseolus coccineus var. rubronanus) lectin (PCL) were obtained by hydrazinolysis, Bio-Gel P-2 column chromatography, NaBH(4) reduction and then separated on a Bio-Gel P-2 column. The oligosaccharides were methanolysed, acetylysed and then transformed into derivatives of trimethylsilane. Gas chromatographic studies of these two derivatives showed that their compositions were: Man(8)XylGlcNAc(2) (oligosaccharide I) and Man(6)XylGlcNAc(2)Fuc (oligosaccharide II). The size of these two oligosaccharides after digestion by alpha-mannosidase, beta-xylosidase and alpha-fucosidase separately, were determined on a standardized Bio-Gel P-4 column. Thus the sequences of these two oligosaccharides were celucidated as: (Manalpha)(7)ManBetaXylBeta(GlcNAc)(2) and (Manalpha)(5)ManbetaXylbeta(GlcNAc)(2)Fucalpha.