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