Linked Life Data

2692712

Source:http://linkedlifedata.com/resource/pubmed/id/2692712

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
25
pubmed:dateCreated
1990-3-5
pubmed:abstractText
Resonance energy transfer was used to determine separation distances between fluorescent derivatives of substrates for Klenow fragment and a unique sulfhydryl, cysteine 907, on the enzyme. Fluorescent derivatives of duplex DNA, deoxynucleotide triphosphates (dNTP), and deoxynucleotide monophosphates (dNMP), modified with aminonaphthalenesulfonates (ANS), served as energy-transfer donors to the fluorophore used to modify cysteine 907, 4-[N-[(iodoacetoxy)ethyl]-N-methylamino]-7-nitrobenz-2-oxa-1,3-diazole (IANBD). The labeling of cysteine 907 with NBD caused no decrease in the enzyme's polymerase activity, suggesting that the probe did not significantly alter the conformation of the enzyme. The efficiency of singlet-singlet resonance energy transfer was determined from the quantum yield of the donor in the presence and absence of acceptor. By Förster's theory, the measured distances between cysteine 907 and binding sites for duplex DNA, dNTP, and dNMP were 25-39, 19-28, and 17-26 A, respectively. As the fluorophores, attached to the substrates via a tether arm, are separated from the substrates by approximately 12 A, the distances measured between binding sites are subject to this uncertainty. To measure the separation between binding sites for duplex DNA and dNMP, and to reduce the uncertainty introduced by the tether arm, two experiments were carried out. In the first, duplex DNA was labeled with the acceptor fluorophore NBD and used with the donor ANS-modified dNMP to yield a measured distance separating these two sites of 19-28 A.(ABSTRACT TRUNCATED AT 250 WORDS)
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
12
pubmed:volume
28
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
9586-93
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1989
pubmed:articleTitle
Resonance energy transfer measurements between substrate binding sites within the large (Klenow) fragment of Escherichia coli DNA polymerase I.
pubmed:affiliation
Department of Chemistry, Pennsylvania State University, University Park 16802.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.