Purification and characterization of a polyphenol oxidase from the Kew cultivar of Indian pineapple fruit.

Das, J. R. and Bhat, S. G. and Gowda, L. R. (1997) Purification and characterization of a polyphenol oxidase from the Kew cultivar of Indian pineapple fruit. Journal of Agricultural and Food Chemistry, 45 (6). 2031-2035, 35 ref..

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Abstract

Three isoforms of polyphenol oxidase (PPO, EC 1.10.3.1, catechol oxidase) were purified to apparent homogeneity from the Kew cv. of Indian pineapple fruit in a four-step procedure. The major isoenzyme, with a yield of 45%, was found to be a tetramer of identical subunits of molecular mass approx. 25 kDa. An ionic strength dependent association-dissociation equilibrium was observed with pineapple PPO. Amino acid analysis of the major isoenzyme indicated the presence of a high content of glutamic acid, glycine, and serine and a low content of the sulphur-containing amino acids. The enzyme was optimally active between pH 6 and 7. The PPO did not show any cresolase activity, and the preferred substrates were diphenols. Ascorbic acid, L-cysteine, and potassium metabisulphite were found to be potent inhibitors of PPO.

Item Type:	Article
Uncontrolled Keywords:	PHENOLASES-; PINEAPPLES-; CATECHOL-OXIDASES
Subjects:	600 Technology > 08 Food technology > 24 Fruits 500 Natural Sciences and Mathematics > 04 Chemistry and Allied Sciences > 16 Enzyme Chemistry
Divisions:	Dept. of Biochemistry
Depositing User:	Food Sci. & Technol. Information Services
Date Deposited:	08 Aug 2008 09:40
Last Modified:	18 Nov 2016 10:49
URI:	http://ir.cftri.res.in/id/eprint/7806

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