The glutathione redox couple modulates zinc transfer from metallothionein to zinc-depleted sorbitol dehydrogenase

Lijuan Jiang1, Wolfgang Maret1, Bert L. Vallée1
1Center for Biochemical and Biophysical Sciences and Medicine, Harvard Medical School, Seeley G. Mudd Building, 250 Longwood Avenue, Boston, MA 02115

Tóm tắt

The release and transfer of zinc from metallothionein (MT) to zinc-depleted sorbitol dehydrogenase (EC 1.1.1.14 ) in vitro has been used to explore the role of MT in cellular zinc distribution. A 1:1 molar ratio of MT to sorbitol dehydrogenase is required for full reactivation, indicating that only one of the seven zinc atoms of MT is transferred in this process. Reduced glutathione (GSH) and glutathione disulfide (GSSG) are critical modulators of both the rate of zinc transfer and the ultimate number of zinc atoms transferred. GSSG increases the rate of zinc transfer 3-fold, and its concentration is the major determinant for efficient zinc transfer. GSH has a dual function. In the absence of GSSG, it inhibits zinc transfer from MT, indicating that MT is in a latent state under the relatively high cellular concentrations of GSH. In addition, it primes MT for the reaction with GSSG by enhancing the rate of zinc transfer 10-fold and by increasing the number of zinc atoms transferred to four. 65 Zn-labeling experiments confirm the release of one zinc from MT in the absence of glutathione and the more effective release of zinc in the presence of GSH and GSSG. In vivo , MT may keep the cellular concentrations of free zinc very low and, acting as a temporary cellular reservoir, release zinc in a process that is dynamically controlled by its interactions with both GSH and GSSG. These results suggest that a change of the redox state of the cell could serve as a driving force and signal for zinc distribution from MT.

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Tài liệu tham khảo

10.1007/978-3-0348-6493-0_1

10.1007/978-3-0348-6784-9_1

B L Vallee, W Maret Metallothionein III, eds K T Suzuki, N Imura, M Kimura (Birkhäuser, Basel), pp. 1–27 (1993).

J H R Kägi Metallothionein III, eds K T Suzuki, N Imura, M Kimura (Birkhäuser, Basel), pp. 29–55 (1993).

10.1073/pnas.94.6.2233

10.1016/0076-6879(91)05077-9

10.1073/pnas.91.1.237

10.1016/0076-6879(91)05082-7

R K Scopes Protein Purification (Springer, New York), pp. 266 (1982).

10.1021/bi00452a011

10.1002/j.1460-2075.1984.tb01811.x

10.1016/B978-0-12-395630-9.50138-9

10.1016/0003-2697(85)90409-9

10.1021/ic00328a012

10.1111/j.1432-1033.1981.tb05693.x

10.1021/bi00405a035

10.1073/pnas.77.11.6334

10.1016/0003-9861(82)90010-8

10.1016/S0021-9258(18)60295-9

10.1042/bj2940219

10.1016/0076-6879(91)05122-C

A H Robbins, D E McRee, M Williamson, S A Collett, N H Xuong, W F Furey, B C Wang, C D Stout J Mol Biol 221, 1269–1293 (1991).

10.1021/bi00345a003

10.1042/bj2530611

10.1111/j.1432-1033.1992.tb17325.x

G K Andrews Prog Food Nutr Sci 14, 193–258 (1990).

10.1042/bj1870329

10.1016/S0021-9258(18)62444-5

10.1007/BF01993964

10.1074/jbc.270.6.2473

10.1073/pnas.93.17.8836

10.1126/science.1523409

10.1016/S0021-9258(19)77815-6

10.1093/jn/107.6.965

10.1016/0891-5849(96)00051-2

10.1096/fasebj.10.7.8635688

10.1016/0891-5849(96)00109-8

10.1016/0197-0186(94)00173-R

10.1007/s002800050708

10.1073/pnas.92.2.579

10.1016/0014-5793(74)80057-8

10.1093/jn/122.1.56