野花生豆凝集素的纯化和性质

用猪胃粘蛋白-Sepharose 4B作亲和吸附剂,可从野花生豆(Crotalarta mucronata)的种子中分离纯化出对人类A型血专一凝集的凝集素。该凝集素可用pH30.,Gly-HCl-1mol/L NaCl溶液解吸附。纯化的凝集素在PAGE或SDS-PAGE中均显示单一蛋白带,表明凝集素分子内只有一种亚基。用SDS-PAGE测得其亚基分子量为49,000。氨基酸组成分析表明,该凝集素富含甘氨酸和谷氨酸,不合甲硫氮酸。纯化的野花生豆凝集素(简称CML)含有4.11％的中性糖。它对人A型血细胞有强烈凝集作用,对AB型血有弱凝集作用,但对B型和O型血均不凝集。其对A型血细胞的凝集作用可被N-乙酰半乳糖胺抑制,但对AB型血则无抑制作用。CML是一个促有絲分裂原,对人外周血中淋巴细胞有促有絲分裂作用。

PURIFICATION AND CHARACTERIZATION OF A LECTIN WITH BIOOD GROUP A SPECIFICITY FROMCROTALARIA MUCRONATA

A blood group A specific lectin from Crotalaria mucronata seeds was purified by affinity chromatography on hog gastric mucin-sepharose 4B column and subsequent elution with pH 3.0 ,Gly-HCl-1mol/L NaCl.The purified lectin gave one band on acrylamide gel electrophoresis and on SDS acrylamide gel electrophoresis. The result showed that the leetin has only one kind of subunit. The molecular weight of subunit was 49,000 when SDS-PAGE was used. Amino acid analysis of the purified lectin showed that the lectin contains a large amount of Glycine and Glutamic acid, and has no Methionine.The purified Crotalaria mucronata lectin contains about 4.11% neutral sugar, sugar. This purified lectin agglutinates type A human red blood cells very strongly, and type AB very slightly,but does not agglutinate B or 0 cells. The most powerful inhibitor of the agglutination of type A red blood cells by the C. mucronata lectin is N-acetyl-D-Galaotosamine. This lectin is also a mitogen, it has mitogenic effect on human peripheral blood lymphocytes.