生理 pH 条件下金属硫蛋白之间的砷传递。

Arsenic transfer between metallothionein proteins at physiological pH.

机构信息

Department of Chemistry, The University of Western Ontario, London, Ontario N6A5B7, Canada.

出版信息

Biochem Biophys Res Commun. 2010 Oct 8;401(1):69-74. doi: 10.1016/j.bbrc.2010.09.010. Epub 2010 Sep 15.

DOI:10.1016/j.bbrc.2010.09.010

PMID:20833145

Abstract

As³+ bound to the two-domain, recombinant human metallothionein (isoform 1a) is stable at pH 7 and translocates via protein-protein interactions to other metallothionein proteins. The data show As³+ transfer from the two-domain β-α-hMT to binding sites in the isolated apo-β-hMT and apo-α-hMT. Under conditions of equilibrium, apo- and partially-metallated species coexist indicating that noncooperative demetallation of the As(6)-βα-hMT occurrs. As³+ transfer under conditions (pH 7) where the free As³+ ion is not stable, provides evidence that Cd²+ and Zn²+ transfer may also take place through protein-protein interactions and that partially metallated Cd-MT and Zn-MT would be stable.

摘要

三价砷与两域重组人金属硫蛋白（亚型 1a）结合，在 pH 7 时稳定，并通过蛋白-蛋白相互作用转移到其他金属硫蛋白蛋白上。研究数据表明，三价砷从两域β-α-hMT 转移到分离的 apo-β-hMT 和 apo-α-hMT 的结合位点。在平衡条件下，共存的是 apo-和部分金属化的物种，这表明非协同脱金属的 As(6)-βα-hMT 发生了。在 pH 7 条件下（游离三价砷离子不稳定）进行的三价砷转移，提供了证据表明 Cd²+和 Zn²+也可能通过蛋白-蛋白相互作用转移，并且部分金属化的 Cd-MT 和 Zn-MT 将是稳定的。