Hatton M W, Regoeczi E, Wong K L, Kraay G J
Biochem Genet. 1977 Aug;15(7-8):621-40. doi: 10.1007/BF00484094.
Samples of homozygous bovine serum transferrins have been prepared and their purity has been ascertained by immunological techniques and electrophoretic analysis in SDS. Measurements of carbohydrate composition show that no significant differences exist among the phenotype variants AA, D1D1, D2D2, and EE. Chromatography of transferrin AA on DEAE-cellulose separated four subfractions, each of which corresponded well with one band obtained by polyacrylamide gel electrophoresis. Carbohydrate analyses of the individual subfractions did not show significant differences in sialic acid, hexose, or hexosamine contents. After desialylation with neuraminidase, each subfraction was converted to a major band and a minor band on gel electrophoresis. From the relative band positions of the desialylated transferrins, it was concluded that possession of sialyl residued by bovine transferrin is not the primary cause of electrophoretic multiplicity. Rather, sialic acid masks an underlying heterogeneity which most likely resides within the polypeptide chain. Further characterization of this heterogeneity will best be undertaken with the isolated asialotransferrin subfractions.
已制备出纯合牛血清转铁蛋白样本，并通过免疫技术和SDS中的电泳分析确定了其纯度。碳水化合物组成的测量结果表明，AA、D1D1、D2D2和EE表型变体之间不存在显著差异。转铁蛋白AA在DEAE-纤维素上的色谱分离出四个亚组分，每个亚组分与通过聚丙烯酰胺凝胶电泳获得的一条带很好地对应。各个亚组分的碳水化合物分析在唾液酸、己糖或己糖胺含量上未显示出显著差异。用神经氨酸酶去唾液酸化后，每个亚组分在凝胶电泳上都转化为一条主带和一条次带。从去唾液酸化转铁蛋白的相对条带位置得出结论，牛转铁蛋白中唾液酸残基的存在不是电泳多态性的主要原因。相反，唾液酸掩盖了一种潜在的异质性，这种异质性很可能存在于多肽链中。对这种异质性的进一步表征最好用分离出的去唾液酸转铁蛋白亚组分来进行。
