Linked Life Data

21317031

Source:http://linkedlifedata.com/resource/pubmed/id/21317031

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
2011-4-19
pubmed:abstractText
Gluconobacter oxydans has a large number of membrane-bound dehydrogenases linked to the respiratory chain that catalyze incomplete oxidation of a wide range of organic compounds by oxidative fermentation. Because the respiratory chain is a primary site of reactive oxygen species (ROS) production, the bacterium is expected to have a high capacity to detoxify nascent ROS. In the present study, a gene that encodes a catalase of G. oxydans, which might act as a potential scavenger of H(2)O(2), was cloned, and the expression product (termed rGoxCat) was characterized biochemically. rGoxCat is a heme b-containing tetrameric protein (molecular mass, 320 kDa) consisting of identical subunits. The recombinant enzyme displayed a strong catalase activity with a k(cat) of 6.28×10(4) s(-1) and a K(m) for H(2)O(2) of 61 mM; however, rGoxCat exhibited no peroxidase activity. These results, along with the phylogenetic position of the enzyme, provide conclusive evidence that rGoxCat is a monofunctional, large-subunit catalase. The enzyme was most stable in the pH range of 4-9, and greater than 60% of the original activity was retained after treatment at pH 3.0 and 40°C for 1h. Moreover, the enzyme exhibited excellent thermostability for a catalase from a mesophilic organism, retaining full activity after incubation for 30 min at 70°C. The observed catalytic properties of rGoxCat, as well as its stability in a slightly acidic environment, are consistent with its role in the elimination of nascent H(2)O(2) in a bacterium that produces a large amount of organic acid via oxidative fermentation.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
1347-4421
pubmed:author
pubmed:copyrightInfo
Copyright © 2010. Published by Elsevier B.V.
pubmed:issnType
Electronic
pubmed:volume
111
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
522-7
pubmed:meshHeading
pubmed:year
2011
pubmed:articleTitle
Gene cloning and biochemical characterization of a catalase from Gluconobacter oxydans.
pubmed:affiliation
Department of Biomolecular Engineering, Graduate School of Engineering, Tohoku University, Aoba-ku, Sendai, Miyagi, Japan.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't