Purification and Properties of S-Formylglutathione Hydrolase from Human Liver

摘要: Abstract S-Formylglutathione hydrolase, a new glutathione thiol esterase from human liver, has been purified into homogeneity according to disc electrophoretic and ultracentrifugal criteria. The final preparation catalyzes the hydrolysis of 4100 µmoles S-formylglutathione per min mg protein at 25° represents 2,350-fold purification over 23,000 x g supernatant liver homogenate. In addition S-formylglutathione, enzyme can catalyze S-acetylglutathione 200-fold slower velocity but no activity with S-lactylglutathione. elution volume in gel filtration column gives an apparent molecular weight 52,500 diffusion coefficient 6.57 10-7 cm2 s-1. sedimentation 4.24 S as judged analytical ultracentrifuge. From equilibrium experiment, is 55,500. Dodecyl sulfate electrophoresis indicates subunit 30,000. Thus, probably consists 2 subunits. isoelectric point obtained electrofocusing experiments 5.41. apparently contains reactive —SH group possible only presence thiols. Activity rapidly lost when thiols are removed, dithiothreitol regenerate part activity. Several types reagents inhibitory. Dithiothreitol reverse completely effect mercaptide-forming oxidizing agents. Amino also inactivate enzyme. addition, ascorbate folate Chelating agents organophosphates do not inhibit