Recombinant Plasmodium falciparum glyoxalase I (PfGlx I) was characterized as monomeric Zn2+-containing enzyme of 44 kDa. The K M value of the methylglyoxal–glutathione adduct is 77±15 μM, the k cat value being 4000 min−1 at 25°C and pH 7.0. PfGlx I consists of two halves, each of which is homologous to the small 2-domain glyoxalase I of man. Both parts of the pfglx I gene were overexpressed; the C-terminal half of PfGlx I was found to be a stable protein and formed an enzymatically active dimer. These results support the hypothesis of domain-swapping and subunit fusion as mechanisms in glyoxalase I evolution.
