Properties of S-adenosylmethionine decarboxylase from rabbit liver: effects of some hydrazone compounds on its activity.

Abstract 1. 1. S- Adenosylmethionine decarboxylase (EC 4.1.1.50) has been partially purified from rabbit liver by ammonium sulphate fractionation and gel filtration and anion exchange chromatographies. Sodium dodecylsulphate-polyacrylamide disc gel electrophoresis analysis showed an approximate dimeric subunit mol. wt of 34,000. 2. 2. The enzyme showed a pH optimum at 7.5 (in phosphate buffer) and did not require bivalent cations for catalysis. The enzyme showed sigmoid kinetics to S- adenosylmethionine with a Hill coefficient of 1.7, which became michaelian with K m 70 μM in the presence of 2.5 mM putrescine. 3. 3. Methylglyoxal bis(guanylhydrazone) was an effective inhibitor of the enzyme, but phenylated derivatives of this compound as phenylglyoxal bis(guanylhydrazone) and diphenylglyoxal bis(guanylhydrazone) inhibited less well.