Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
2008-12-24
pubmed:databankReference
pubmed:abstractText
In the course of a microbial screening of soil samples for new oxidases, different enrichment strategies were carried out. With choline as the only carbon source, a microorganism was isolated and identified as Arthrobacter nicotianae. From this strain, a gene coding for a choline oxidase was isolated from chromosomal DNA. This gene named codA was cloned in Escherichia coli BL21-Gold and the protein (An_CodA) heterologously overexpressed as a soluble intracellular protein of 59.1 kDa. Basic biochemical characterization of purified protein revealed a pH optimum of 7.4 and activity over a broad temperature range (15-70 degrees C). Specific activities were determined toward choline chloride (4.70 +/- 0.12 U/mg) and the synthetic analogs bis(2-hydroxyethyl)-dimethylammonium chloride (0.05 +/- 0.45 x 10(-2) U/mg) and tris-(2-hydroxyethyl)-methylammonium methylsulfate (0.01 +/- 0.12 x 10(-2) U/mg). With increasing number of oxidizable groups, a significant decrease in activity was noted. Determination of kinetic parameters in atmorspheric oxygen resulted in K (M) = 1.51 +/- 0.09 mM and V (max) = 42.73 +/- 0.42 mU/min for choline chloride and K (M) = 4.77 +/- 0.76 mM and V (max) = 48.40 +/- 2.88 mU/min for the reaction intermediate betaine aldehyde respectively. Nuclear magnetic resonance spectroscopic analysis of the products formed during the enzyme reaction with choline chloride showed that in vitro the intermediate betaine aldehyde exists also free in solution.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
1432-0614
pubmed:author
pubmed:issnType
Electronic
pubmed:volume
81
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
875-86
pubmed:meshHeading
pubmed-meshheading:18787818-Alcohol Oxidoreductases, pubmed-meshheading:18787818-Arthrobacter, pubmed-meshheading:18787818-Betaine, pubmed-meshheading:18787818-Choline, pubmed-meshheading:18787818-Cloning, Molecular, pubmed-meshheading:18787818-DNA, Bacterial, pubmed-meshheading:18787818-Enzyme Stability, pubmed-meshheading:18787818-Escherichia coli, pubmed-meshheading:18787818-Gene Expression, pubmed-meshheading:18787818-Hydrogen-Ion Concentration, pubmed-meshheading:18787818-Kinetics, pubmed-meshheading:18787818-Magnetic Resonance Spectroscopy, pubmed-meshheading:18787818-Molecular Sequence Data, pubmed-meshheading:18787818-Molecular Weight, pubmed-meshheading:18787818-Sequence Analysis, DNA, pubmed-meshheading:18787818-Soil Microbiology, pubmed-meshheading:18787818-Substrate Specificity, pubmed-meshheading:18787818-Temperature
pubmed:year
2009
pubmed:articleTitle
Heterologous expression and characterization of choline oxidase from the soil bacterium Arthrobacter nicotianae.
pubmed:affiliation
Research Centre Applied Biocatalysis, Petersgasse 14, 8010 Graz, Austria.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't