|
A human brain cDNA clone encoding glutathione synthetase (EC 6.3.2.3) has been
sequenced and expressed in Escherichia coli. The protein is 474 amino acids in
length with a subunit molecular mass of 52,352 Da. The recombinant protein
exhibits glutathione synthetase activity and occurs as a homodimer. The
recombinant glutathione synthetase was purified to homogeneity and had a
specific activity of 1.73 mumol/min per mg of protein, an isoelectric point of
5.35 and a pH optimum between 7.0 and 7.5. Southern blots of human genomic DNA
hybridized with the glutathione synthetase cDNA revealed a relatively simple
pattern of strongly hybridizing fragments, indicating the absence of a large
gene family and suggesting that there may be only one glutathione synthetase
gene in the human genome.
|
