红桂木凝集素的纯化与性质研究

Purification and Characterization of Lectin from the Seeds of Artocarpus lingnanensis

红桂木（Ａｒｔｏｃａｒｐｕｓｌｉｎｇｎａｎｅｎｓｉｓ）、俗名胭脂，属桑科桂木属，为亚热带、热带植物．红桂木种子含丰富的红桂木凝集素（Ａｒｔｏｃａｒｐｕｓｌｉｎｇｎａｎｅｎｓｉｓｌｅｃｔｉｎ，ＡＬＬ），但迄今国内外均未见关于它的报道．我们采用Ｇａｌ－Ｓ...

Artocarpus lingnanensis lectin (ALL) was purified and studied on its physicochemical and binding immunoglobulin property.ALL had been extracted with pH 7 2,0 01 mol/L PBS,then isolated and purified from the seeds of Artocarpus lingnanensis by 30%～60% saturated ammonium sulfate fractionation and affinity chromatography on Gal Sepharose 6B eluted with 0 2 mol/L Gal.ALL is homogeneous basically on uncontinuous PAGE.The lectin,which was analysed by Sephadex G 100 chromatography and SDS PAGE,has an apparent M r of about 59 000 and is composed of two kinds of subunits which have M r 14 000 and 16 000 respectively.Isoelectric focusing on PAGE showed that lectin gave a spread of components,whose p I are 9 30,9 10,8 90,8 75,8 20 and 6 50 respectively.ALL is a glycoprotein with assay of schiff's stain.The two N terminals are arginine and glycine using DNS Cl method.It contains about 7.0% neutral sugar.ALL agglutinates erythrocytes of the animals and those of human's A,B,O and AB bloodgroups.The hemagglutination of ALL is strongly inhibited by Gal NAc and Gal in test of hemagglutinating inhibition.The lectin is sensitive to heat,but within the range of 4 5～9 5,stable to pH changes.By double immunodiffusion,it has been found that serum lectin binding protein could combine with goat anti human IgA and anti human IgG,colostrum lectin binding protein could combine with goat anti human IgA,These suggest that ALL can bind human serum IgA,IgG(mainly IgA)or colostrum IgA.The subspecies of Ig which ALL can bind will being studied.