Vallette G, Benassayag C, Belanger L, Nunez E A, Jayle M F
Steroids. 1976 Sep;28(3):423-35. doi: 10.1016/0039-128x(76)90051-9.
The combination of polyacrylamide gel electrophoresis and Concanavalin-A-Sepharose affinity chromatography has permitted the isolation on a preparative scale, of four molecular forms of rat alpha1-fetoprotein: a "slow" and a "fast" fraction, each separable into Concanavalin-A-adorbed ("high carbohydrate", i.e. rich in accessible alphaD-Mannosyl and alphaD-Glucosyl residues) and a Concanavalin-A-non adsorbed ("low carbohydrate") fractions. These four iso-alpha-fetoproteins (iso-AFP) bind estradiol-17beta. However, they disclose differences in both their association constants and number of binding sites for this hormone. Very high affinity sites (10(9)) are mainly located on the "slow-low carbohydrate" form. Low affinity, high capacity sites are preferentially located on the "high carbohydrate" form. These results confirm the molecular and functional heterogeneity of rat AFP and suggest that the carbohydrate moiety of the protein may have a role in estrogen-AFP interactions.
聚丙烯酰胺凝胶电泳与伴刀豆球蛋白A - 琼脂糖亲和层析相结合，已能够在制备规模上分离出大鼠α1 - 甲胎蛋白的四种分子形式：一个“慢”组分和一个“快”组分，每个组分又可分为伴刀豆球蛋白A吸附型（“高碳水化合物”，即富含可及的α - D - 甘露糖基和α - D - 葡萄糖基残基）和伴刀豆球蛋白A非吸附型（“低碳水化合物”）组分。这四种甲胎蛋白同工型（同工AFP）都能结合雌二醇 - 17β。然而，它们在与该激素的结合常数和结合位点数量上都存在差异。极高亲和力位点（10⁹）主要位于“慢 - 低碳水化合物”形式上。低亲和力、高容量位点则优先位于“高碳水化合物”形式上。这些结果证实了大鼠AFP的分子和功能异质性，并表明该蛋白的碳水化合物部分可能在雌激素与AFP的相互作用中发挥作用。
