|
type |
Journal Article |
authors |
Esaki, N.; Nakamura, T.; Tanaka, H.; Soda, K. |
title |
Selenocysteine lyase, a novel enzyme that specifically acts on selenocysteine. Mammalian distribution and purification and properties of pig liver enzyme |
journal |
J Biol Chem |
Activity |
4.4.1.16 |
ui |
82167522 |
year |
(1982) |
volume |
257 |
number |
8 |
pages |
4386-91. |
| |
keywords |
Animal |
abstract |
We have found a novel enzyme that exclusively decomposes L- selenocysteine into L-alanine and H2Se in various mammalian tissues, and have named it selenocysteine lyase. The enzyme from pig liver has been purified to homogeneity. It has a molecular weight of approximately 85,000, and contains pyridoxal 5'-phosphate as a coenzyme. Its maximum reactivity is at about pH 9.0. Balance studies showed that 1 mol of selenocysteine is converted to equimolar amounts of alanine and H2Se. The following amino acids are insert: L-cysteine, L-serine, L-cysteine sulfinate, selenocysteamine, Se-ethyl-DL- selenocysteine, and L-selenohomocysteine. L-Cysteine (Ki, 1.0 mM) competes with L-selenocysteine (Km, 0.83 mM) to inhibit the enzyme reaction. The enzyme is the first proven enzyme that specifically acts on selenium compounds. |
last changed |
2002/11/12 16:17 |
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