Syntheses and structural characterization of water-soluble selenium reagents for the redox control of protein disulfide bonds

A new class of water-soluble redox reagents (1–4) that contain selenium as the active site was developed for the purpose of the redox control of protein structures. The X-ray crystallographic analyses revealed that trans-3,4-dihydroxy-1-selenolane (DHSred) (1) and its Se-oxide (DHSox) (2) have two axial hydroxy groups on the selenolane five-membered ring, whereas trans-1,2-diselenane-4,5-diol (DSTox) (3), a selenium analog of oxidized dithiothreitol (DTTox), has two equatorial hydroxy groups on the diselenane six-membered ring. According to the vicinal 3JHH coupling constants observed for 1–3, it was suggested that they adopt similar structures in solution to those in the solid state. Diselenothreitol (DSTred) (4), a selenium analog of dithiothreitol (DTTred), was also synthesized, but it was too air sensitive to be isolated. The reactions of 1–4 with DTTox and DTTred indicated that the oxidizing power of DHSox (2) exceeds by far that of DTTox, while the reducing power of DSTred (4) exceeds that of DTTred. © 2001 John Wiley & Sons, Inc. Heteroatom Chem 12:293–299, 2001