Linked Life Data

14518005

Source:http://linkedlifedata.com/resource/pubmed/id/14518005

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2003-9-30
pubmed:abstractText
Conventional methods to determine esterase activity from insects are composed of a three-step process where the enzyme is allowed to hydrolyze a 1-naphthyl acetate substrate, that reaction is quenched by a SDS detergent, and then a Fast Blue B dye complex is formed with 1-naphthol, the product of 1-naphthyl acetate hydrolysis. These methods measure dye-product complex rather than the product, 1-naphthol. A new assay is presented that continuously monitors the formation of 1-naphthol with the hydrolysis of an esterase substrate. The esterase activity was determined as the slope of the linear regression change in absorbance over time at 320 nm. The continuous assay provides a simple, rapid, and sensitive method for measuring esterases extracted from a single diamondback moth in 1-10 min. The detection limit of the assay is approximately 0.6 microM 1-naphthol. The 1-naphthol product from the esterase reaction was confirmed by HPLC analysis. According to the assay, the K(m) and V(max) values of the esterase were 28 +/- 2 microM and 6.0 +/- 0.1 microM/min, respectively, at 37 degrees C for 1-naphthyl acetate. The K(i) value was 9 +/- 2 microM using azadirachtin, an insecticide from neem tree, Azadirachta indica (A.Juss). Azadirachtin was a reversible competitive inhibitor of the esterase activity.
pubmed:commentsCorrections
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0739-4462
pubmed:author
pubmed:issnType
Print
pubmed:volume
54
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
68-76
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2003
pubmed:articleTitle
A continuous spectrophotometric assay for the determination of diamondback moth esterase activity.
pubmed:affiliation
Beneficial Insects Research Unit, KSARC, Agricultural Research Service, U. S. Department of Agriculture, Weslaco, Texas 78596, USA. donxhe@hotmail.com
pubmed:publicationType
Journal Article