The binding of thiamine pyrophosphate (TPP) to several enzymes has been determined by measuring cofactordependent activity after passage of each enzyme through a column of Sephadex G-25 to remove non-protein-bound cofactors. TPP was found to be bound irreversibly to yeast and Zymomonas pyruvate decarboxylases, Aerobacter (Yacetolactate synthetase, and Escherichia glyoxylate carboligase. Cofacto...

Two early and potential rate-limiting steps in the biosynthesis of isoquinoline alkaloids, such as morphine and codeine, in opium poppy (Papaver somniferum) involve decarboxylation of L-tyrosine and L-dihydroxyphenylalanine (L-dopa) to yield tyramine and dopamine, respectively. A DNA fragment was amplified by polymerase chain reaction (PCR) using degenerate primers designed to two highly conser...

The anaerobic metabolism of phenol in the beta-proteobacterium Thauera aromatica proceeds via carboxylation to 4-hydroxybenzoate and is initiated by the ATP-dependent conversion of phenol to phenylphosphate. The subsequent para carboxylation of phenylphosphate to 4-hydroxybenzoate is catalyzed by phenylphosphate carboxylase, which was purified and studied. This enzyme consists of four proteins ...

The advantages of using enzymes in the synthesis of organic compounds relate to their versatility, high reaction rates, and regioand stereospecificity and the relatively mild reaction conditions involved. Stereospecificity is especially important in the synthesis of bioactive molecules, as only one of the enantiomeric forms usually manifests bioactivity, whereas the other is often toxic. Althou...