type	Journal Article
authors	Park, J.; Osei, Y.D.; Churchich, J.E.
title	Isolation and characterization of recombinant mitochondrial 4-aminobutyrate aminotransferase
journal	J Biol Chem
Activity	2.6.1.19
sel	selected
ui	8385114
year	(1993)
volume	268
number	11
pages	7636-9
abstract	- 4-Aminobutyrate aminotransferase, which catalyzes the conversion of 4-aminobutyrate to succinic semialdehyde, is a key enzyme of the 4-aminobutyrate shunt. The amino acid sequence predicted from the cDNA sequence shows that the precursor protein consists of the mature enzyme of 473 amino acid residues and an amino-terminal segment of 27 amino acids (Kwon, O. S., Park, J., and Churchich, J. E. (1992) J. Biol. Chem. 267, 7215-7216). A recombinant 4-aminobutyrate aminotransferase has been expressed in Escherichia coli using pETIId as expression vector. The protein has been purified and characterized as a dimer (2 x 55 kDa). NH2-terminal sequence analysis has revealed the presence of an extra amino-terminal segment (signal peptide) predicted from the cDNA sequence. The isolated precursor of 4-aminobutyrate aminotransferase contains pyridoxal 5-phosphate and exhibits catalytic activity (18 units/mg) comparable to that of the mature enzyme (20 units/mg). The presequence peptide of the precursor of mitochondrial 4-aminobutyrate aminotransferase does not interfere with the folding and functional properties of the mature moiety of the aminotransferase.
last changed	2009/01/09 13:32