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EC 1.97.1.10 Details
show Brenda entryEC number
1.97.1.10
Accepted name
thyroxine 5′-deiodinase
Reaction
3,5,3′-triiodo-L-thyronine + iodide + A + H+ = L-thyroxine + AH2
Other name(s)
diiodothyronine 5′-deiodinase [ambiguous],
iodothyronine 5′-deiodinase,
iodothyronine outer ring monodeiodinase,
type I iodothyronine deiodinase,
type II iodothyronine deiodinase,
thyroxine 5-deiodinase [misleading],
L-thyroxine iodohydrolase (reducing)
Systematic name
acceptor:3,5,3′-triiodo-L-thyronine oxidoreductase (iodinating)
CAS registry number
70712-46-8
Comment
The enzyme activity has only been demonstrated in the direction of 5′-deiodination, which renders the thyroid hormone more active. The enzyme consists of type I and type II enzymes, both containing selenocysteine, but with different kinetics. For the type I enzyme the first reaction is a reductive deiodination converting the -Se-H group of the enzyme into an -Se-I group; the reductant then reconverts this into -Se-H, releasing iodide.
History
created 1984 as EC 3.8.1.4, transferred 2003 to EC 1.97.1.10, deleted 2015
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1 Oxidoreductases
1.1 Acting on the CH-OH group of donors
1.6.7.1 created 1972, deleted 1978 1.6.7.2 created 1972, deleted 1978 1.6.7.3 created 1978, deleted 1978 1.6.99.4 created 1965, deleted 1972 1.6.99.8 created 1972, deleted 2002 1.6.99.9 created 1972, deleted 2002 1.6.99.10 created 1978, deleted 1981 1.6.99.11 created 1989, deleted 2002 1.6.99.12 created 1989, deleted 2002 1.6.99.13 created 1992, deleted 2002 1.97.1.5 created 2000 deleted 2001 1.97.1.6 created 2000 deleted 2001 1.97.1.7 created 2000, deleted 2001
