Degradation of catechin and purification and partial characterization of catechin oxygenase fromChaetomium cupreum

An enzyme capable of cleaving catechin was present in the mycelium ofCheatomium cupreum. Maximum synthesis of the enzyme occurred after 15 days growth. Sucrose and maltose increased enzyme synthesis among the carbon sources tested. Catechol, protocatechuic acid and phloroglucinol carboxylic acid were the intermediates of catechin degradation.Cheatomium cupreum containedmeta-cleaving enzymes for catechol and protocatechuic acid metabolism. Pyruvate was identified as an end-product. Catechin oxygenase from the mycelium ofC. cupreum was purified to homogeneity. It was optimum at pH 7.0 and 50°C and was highly specific for catechin, with a K_m of 4 m. Its molecular size was 40 kDa, as determined by gel filtration and gel electrophoresis, and it had a pI of 9.1.p-Chloromercuric benzoate, iodoacetate, N-ethylmaleimide, 2,2-dipyridyl and EDTA markedly inhibited the enzyme activity. It was a glycoprotein.T. Sambandam was and A. Mahedevan is with the Center for Advanced Studies in Botany, University of Madras, Guindy Campus, Madras-600025, India. T. Sambandam is now with the Department of Medicine, University of Alabama at Birmingham, Birmingham, AL 35294, USA.