Diversities in animal vitronectins. Differences in molecular weight, immunoreactivity and carbohydrate chains

Six animal plasma vitronectins, human, horse, porcine, bovine, rabbit and chicken vitronectins purified by a novel method using two successive heparin affinity columns, showed marked diversity in molecular weight, immunoreactivity and carbohydrate composition. Chicken vitronectin had a distinctly different amino acid composition from the mammalian vitronectins; and bovine vitronectin was the only one to contain N-glycolylneuraminic acid as well as N-acetylneuraminic acid. Binding studies with horseradish peroxidase-labelled lectins indicated that all the vitronectins contained complex-type, sialylated N-linked sugar chains and that only porcine vitronectin had a fucosylated sugar chain. D-Galactosamine determinations and binding studies with horseradish peroxidase-peanut lectin on native and asialovitronectins revealed that the mammalian vitronectins other than human vitronectin contained O-linked sugar chains with sialic acid, chicken vitronectin contained unsialylated chains, and human vitronectin contained neither. The results indicate that diversities in vitronectins are apparent in their molecular weights and glycosylations, especially in the number and structure of O-linked sugar chains.