Purification and Studies of Catechol‐O‐Methyltransferase of Rat Liver

Abstract
Rat liver catechol‐O‐methyltransferase was purified approximately 450‐fold by salt fractionation, get filtration, hydroxyapatite treatment, and ion‐exchange chromatography. The final enzyme preparation is homogeneous when subjected to disc electrophoresis and sedimentation analysis in the ultracentrifuge. The purified enzyme is very labile; reversible inactivation occurs upon storage. Reactivation is obtained by incubation with dithiothreitol. The molecular weight, determined by gel filtration, is 24000.