type	Journal Article
authors	Nakao H, Shinoda S, Yamamoto S.
title	Purification and properties of carboxynorspermidine decarboxylase, a novel enzyme involved in norspermidine biosynthesis, from Vibrio alginolyticus
journal	J Gen Microbiol
Activity	4.1.1.96
Family	4.1.1.96
sel	unselected
ui	nobmc
year	(1990)
volume	136
number	9
pages	1699-704
abstract	A novel enzyme which catalyses the decarboxylation of carboxynorspermidine [H2N(CH2)3NHCH2CH2-CH(NH2)COOH] to yield norspermidine [H2N(CH2)3NH2], one of the unusual polyamines, was purified to apparent homogeneity (3100-fold) from cells of Vibrio alginolyticus. The enzyme has an apparent Mr of 86000, with a pI of 4·25, and is a dimer composed of identical subunits with an apparent Mr of 43500. The Km for carboxynorspermidine was 175 µM and for pyridoxal 5'-phosphate, 4·8 µM. The purified preparation had a specific activity of 24·1 µmol norspermidine produced min–1 (mg protein)–1. Carboxyspermidine, a structural homologue, was able fully to replace carboxynorspermidine as a substrate, to produce spermidine, but neither 2,3-diaminopropionic acid, 2,4-diaminobutyric acid, ornithine nor lysine showed detectable substrate activity. The optimum pH was 8·25. Dithiothreitol greatly stimulated the enzyme activity, maximum stimulation being observed at more than 5 mM-dithiothreitol.
last changed	2014/02/20 12:14