Linked Life Data

8142484

Source:http://linkedlifedata.com/resource/pubmed/id/8142484

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1994-5-4
pubmed:abstractText
A putative uridine-binding site of uridine phosphorylase (EC 2.4.2.3) from E. coli was modified with fluorescein 5'-isothiocyanate (FITC). Treatment with FITC irreversibly inactivates the enzyme (Ki = 1.0 mM, k2 = 0.15 min-1). Under the conditions of 90% inactivation the incorporation of the reagent reaches about 1 mol per mol of the enzyme subunit. Addition of uridine prevents the enzyme inactivation by FITC. In contrast to this, addition of a second substrate phosphate increases the rate of inactivation by 2.3-fold (k2 = 0.34 min-1), but has no effect on the affinity of the reagent to the enzyme. The modified protein retains the ability to bind phosphate but not uridine. According to differential absorption spectroscopy data, the binding of phosphate to the active site of the enzyme is accompanied by conformational changes which may accelerate the inactivation rate. The data presented suggest that in the UPase FITC occupies the putative uridine-binding site, while the phosphate-binding site still retains the ability to interact with the second substrate.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0006-3002
pubmed:author
pubmed:issnType
Print
pubmed:day
16
pubmed:volume
1205
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
54-8
pubmed:dateRevised
2000-12-18
pubmed:meshHeading
pubmed:year
1994
pubmed:articleTitle
Selective modification of putative uridine-binding site of uridine phosphorylase from E. coli with fluorescein 5'-isothiocyanate.
pubmed:affiliation
Institute for Genetics of Microorganisms, Moscow, Russia.
pubmed:publicationType
Journal Article