桑寄生凝集素的纯化及部分性质研究

利用DEAE一纤维素柱盐离子浓度梯度洗脱,再经猪胃粘蛋白-Sepharose 4 B亲和柱可以从中药桑寄生中分离纯化出桑寄生凝集素。经pH8.9,Tris-EDTAN_2a-borate的PACE和SDS-PAGE测定均呈现单一蛋白带,测得其分子量为67 500,中性糖含量为14.6％,DNS法测得N-末端氨基酸为缬氨酸。氨基酸组成分析表明,该凝集素富含酸性氨基酸,而碱性氨基酸含量较少,不含精氨酸。当凝集素浓度为15.6μg/mL时,即可凝集兔红细胞,而对人的A、B、O型血细胞,凝集素浓度高达1000μg/mL,也不发生凝集反应。Gal、GalNAc、山梨糖、岩藻糖和松三糖对凝集兔红细胞的能力有抑制作用。桑寄生凝集素是一种促有丝分裂原,对猪血淋巴细胞的转化率达78％,细胞分裂比率为11.2％。

Purification and Characterization of Lectin From Loranthus Parasiticus (L.)Merr

The Loranthus parasiticus Lectin (LPL) was purified by DEAE-cellulose chromatography and a affinity chromatography on hog gastric mucin-Sepharose 4B.The purified LPL exhibits a single band both on pH8.9,Tris-EDTANa2-borate PAGE and SDS-PAGE, and the molecular weight of LPL is 67,500 d.By phenol-sulfuric acid method, LPL shows a sugar content of 14.6% The N-terminal amino acid is determined to be Val by DNS method.Analysis of amino acid composition of LPL shows that it has a high content of acidic amino acid,a few of basic amino acid but no Arg.LPL can agglutinate rabbit erythrocytes at the concentration of 15.6ug/mL, but no agglutination was observed with erythrocytes type A,B,O of human being,even the concentration of LPL was as high as 1000ug/mL.Galactose, N-acetylgaIactosa-mine, sorbose, fructose, fuctose and melicitose can inhibit the hemagglutination of rabbit erythrocytes by LPL.LPL is also a mitogen to hog peripheral lymphocytes,its transformation ratio is 78%, and its division ratio is 11.2%.