de Waard A, Hickman S, Kornfeld S
J Biol Chem. 1976 Dec 10;251(23):7581-7.
A soluble lectin which agglutinates trypsin-treated rabbit erythrocytes was purified from calf heart using affinity chromatography on asialofetuin-Sepharose. Its molecular weight was determined by gel filtration to be approximately 17,000. On polyacrylamide gel electrophoresis in sodium dodecyl sulfate, the predominant molecular species had a molecular weight of 9,000, suggesting that the lectin is a dimer. Binding studies performed with iodinated lectin revealed that neuraminidase-treated calf erythrocytes contained approximately 5 X 10(6) lectin binding sites per cell. Native calf and rabbit erythrocytes bound the lectin, but human and rat erythrocytes required neuraminidase and trypsin treatment, respectively, for lectin binding to occur. A number of saccharides, glycopeptides, and glycoproteins possess haptene inhibitory activity toward lectin binding to erythrocytes. The most potent of these have either galactose beta leads to galactose beta leads to, galactose beta N-acetylglucosamine beta leads to, or galactose beta leads to N-acetylglucosamine beta leads to sequences at their nonreducing termini. Lactose and galactose beta 1 leads to 3N-acetylgalactosamine are the next best haptenes. Finally, alpha-linked galactose residues and free galactose are very weak haptenes. The presences of a terminal sialic acid residue impairs haptene activity in all instances. Calf heart also contains a membrane-associated lectin which is very similar but not identical with the soluble lectin. A soluble beta-galactoside binding lectin was also isolated from calf lung. It has the same molecular size and subunit structure as the soluble heart lectin and is antigenically identical. In binding studies, the pattern of inhibition by various haptenes was the same for all three lectins.
一种能凝集经胰蛋白酶处理的兔红细胞的可溶性凝集素，通过在去唾液酸胎球蛋白 - 琼脂糖凝胶上进行亲和层析，从小牛心脏中纯化得到。通过凝胶过滤法测定其分子量约为17,000。在十二烷基硫酸钠聚丙烯酰胺凝胶电泳中，主要的分子种类分子量为9,000，这表明该凝集素是二聚体。用碘化凝集素进行的结合研究表明，经神经氨酸酶处理的小牛红细胞每个细胞含有约5×10⁶个凝集素结合位点。天然的小牛和兔红细胞能结合该凝集素，但人红细胞和大鼠红细胞分别需要经神经氨酸酶和胰蛋白酶处理后才能发生凝集素结合。许多糖类、糖肽和糖蛋白对凝集素与红细胞的结合具有半抗原抑制活性。其中最有效的在其非还原末端具有半乳糖β→半乳糖β→、半乳糖β-N-乙酰葡糖胺β→或半乳糖β→N-乙酰葡糖胺β→序列。乳糖和半乳糖β1→3N-乙酰半乳糖胺是次佳的半抗原。最后，α-连接的半乳糖残基和游离半乳糖是非常弱的半抗原。在所有情况下，末端唾液酸残基的存在都会损害半抗原活性。小牛心脏还含有一种与膜相关的凝集素，它与可溶性凝集素非常相似但并不相同。一种可溶性β-半乳糖苷结合凝集素也从小牛肺中分离出来。它与可溶性心脏凝集素具有相同的分子大小和亚基结构，并且抗原性相同。在结合研究中，所有三种凝集素对各种半抗原的抑制模式相同。
