Purification and properties of a catechol methyltransferase of the yeast Candida tropicalis

In an effort to investigate catechol methyltransferase activity in sources other than mammalian tissues and cells, a high level of enzyme activity was found in the yeast fungus Candida tropicalis CBS 94. Partial purification of the enzyme (approx. 550 fold with a recovery of 7%) could be achieved by using ion-exchange and gel filtration techniques. The molecular weight was estimated at 32,000 +/- 2,000 by gel filtration on Sephadex G-100. In isoelectric focusing experiments on Sephadex G-75 the enzyme exhibited a pI-value of 5.0 +/- 0.1. In contrast to catechol methyltransferase from various mammalian tissues the enzyme activity was prepared from the pH 5-sediment. The substrate specifity is comparable to other catechol methyltransferases.