Yamaguchi Y, Isemura M, Kosakai M, Sato A, Suzuki M, Kan M, Yosizawa Z
Biochim Biophys Acta. 1984 Oct 9;790(1):53-60. doi: 10.1016/0167-4838(84)90331-5.
Fibronectin was purified from fetal human plasma and characterized in comparison with fibronectin from adult human plasma. Fetal plasma fibronectin had an amino-acid composition, immunological properties, and cell-attachment-promoting activity similar to those of adult plasma fibronectin. However, fetal plasma fibronectin was shown to have a distinct carbohydrate composition which is characterized by the presence of fucose. To ascertain the differences in the carbohydrate moiety, 14C-labeled glycopeptides were prepared and sequentially analyzed with columns of immobilized concanavalin A and lentil lectin. Glycopeptides from fetal plasma fibronectin contained a population of glycopeptides which bound to both lectin gels. Almost all of the glycopeptides in this population lost their ability to bind to lentil lectin upon fucosidase digestion, indicating that fetal plasma fibronectin possesses a substantial amount of fucosylated biantennary glycans. In contrast, glycopeptides from adult plasma fibronectin practically lacked such glycopeptides. Another difference observed was that fetal plasma fibronectin had a larger amount of concanavalin A-unbound glycopeptides than did adult plasma fibronectin. These results indicate the presence of age-related variation in glycosylation of human plasma fibronectin.
纤连蛋白从人胎儿血浆中纯化出来，并与成人血浆中的纤连蛋白进行比较以进行表征。胎儿血浆纤连蛋白的氨基酸组成、免疫特性和促进细胞附着的活性与成人血浆纤连蛋白相似。然而，胎儿血浆纤连蛋白显示出具有独特的碳水化合物组成，其特征在于含有岩藻糖。为了确定碳水化合物部分的差异，制备了14C标记的糖肽，并用固定化伴刀豆球蛋白A和扁豆凝集素柱进行顺序分析。来自胎儿血浆纤连蛋白的糖肽含有一群与两种凝集素凝胶都结合的糖肽。该群体中几乎所有的糖肽在经岩藻糖苷酶消化后失去了与扁豆凝集素结合的能力，这表明胎儿血浆纤连蛋白具有大量的岩藻糖基化双天线聚糖。相比之下，成人血浆纤连蛋白的糖肽实际上缺乏此类糖肽。观察到的另一个差异是，胎儿血浆纤连蛋白中未与伴刀豆球蛋白A结合的糖肽比成人血浆纤连蛋白中的要多。这些结果表明人血浆纤连蛋白的糖基化存在与年龄相关的差异。
