Shiobara Y, Suzuki K T
Faculty of Pharmaceutical Sciences, Chiba University, Inage, Japan.
J Chromatogr B Biomed Sci Appl. 1998 Jun 12;710(1-2):49-56. doi: 10.1016/s0378-4347(98)00142-x.
The role of albumin in the metabolism of inorganic selenium (Se) was studied in vivo and in vitro using a HPLC-ICP-MS method. Although Se injected in the form of selenite binds selectively to albumin after being reduced to selenide and then being effluxed into the plasma, Se was shown to be metabolized normally in the absence of albumin. The reduced form of Se, selenide, bound selectively to albumin but only to a percentage of it. The thiol group and the intermolecular disulfide group at the 34th cysteinyl residue of albumin were not responsible for the selective binding of Se to albumin. Selenide was suggested to be bound to a disulfide not a thiol group, i.e., to one of the 17 disulfide bonds in a conformationally different isoform of albumin.
采用高效液相色谱-电感耦合等离子体质谱法，在体内和体外研究了白蛋白在无机硒（Se）代谢中的作用。尽管以亚硒酸盐形式注入的硒在还原为硒化物然后流入血浆后会选择性地与白蛋白结合，但研究表明，在没有白蛋白的情况下，硒仍能正常代谢。还原形式的硒，即硒化物，会选择性地与白蛋白结合，但只是与其中一定比例的白蛋白结合。白蛋白第34位半胱氨酸残基处的巯基和分子间二硫键并非硒与白蛋白选择性结合的原因。有人提出，硒化物是与二硫键而非巯基结合，也就是说，是与白蛋白构象不同的异构体中的17个二硫键之一结合。
