Linked Life Data

10995279

Source:http://linkedlifedata.com/resource/pubmed/id/10995279

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
9
pubmed:dateCreated
2000-11-13
pubmed:abstractText
The polyphenol oxidase from field bean (Dolichos lablab) seeds has been purified to apparent homogeneity by a combination of ammonium sulfate precipitation, DEAE-Sephacel chromatography, phenyl agarose chromatography, and Sephadex G-200 gel filtration. The purified enzyme has a molecular weight of 120 +/- 3 kDa and is a tetramer of 30 +/- 1.5 kDa. Native polyacrylamide gel electrophoresis of the purified enzyme revealed the presence of a single isoform with an observed pH optimum of 4.0. 4-Methyl catechol is the best substrate, followed by catechol, and L-3,4-dihydroxyphenylalanine, all of which exhibited a phenomenon of inhibition by excess substrate. No activity was detected toward chlorogenic acid, catechin, caffeic acid, gallic acid, and monophenols. Tropolone, both a substrate analogue and metal chelator, proved to be the most effective competitive inhibitor with an apparent K(i) of 5.8 x 10(-)(7) M. Ascorbic acid, metabisulfite, and cysteine were also competitive inhibitors.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0021-8561
pubmed:author
pubmed:issnType
Print
pubmed:volume
48
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
3839-46
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2000
pubmed:articleTitle
Purification and characterization of a polyphenol oxidase from the seeds of field bean (Dolichos lablab).
pubmed:affiliation
Department of Protein Chemistry and Technology, Central Food Technological Research Institute, Mysore 570013, India.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't