Linked Life Data

9369478

Source:http://linkedlifedata.com/resource/pubmed/id/9369478

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
46
pubmed:dateCreated
1997-12-19
pubmed:abstractText
There is lack of a correlation between biochemical studies and the observed clinical resistance of AIDS patients on long term AZT therapy. Mutant HIV-1 reverse transcriptase in the viral isolates from these patients shows a 100-fold decrease in sensitivity whereas little or no difference is observed in kinetic parameters in vitro using steady-state kinetic analysis. A detailed pre-steady-state kinetic analysis of wild type and the clinically important AZT resistant mutant (D67N, K70R, T215Y, K219Q) HIV-1 reverse transcriptase was conducted to understand the mechanistic basis of drug resistance. In contrast to steady-state techniques, a pre-steady-state kinetic analysis allows for the direct observation of catalytic events occurring at the active site of the enzyme, including subtle conformational changes enabling a greater degree of mechanistic detail. In this investigation the rate of incorporation of dTMP and AZTMP by wild type and mutant HIV-1 RT was determined using an RNA and the corresponding DNA template. The present study has shown a 1.5-fold decrease in the rate constant for polymerization (kpol) and a 2.5-fold decrease in the equilibrium dissociation constant (Kd) for AZTTP for the mutant reverse transcriptase as compared to the wild type, for RNA dependent DNA replication. These values translate into a 4-fold decrease in selectivity (kpol/Kd) for AZTMP incorporation by mutant reverse transcriptase as compared to wild type for RNA dependent DNA replication. No such decrease in selectivity was detected for DNA dependent replication. These results suggest that the basis of AZT resistance is related to RNA dependent replication rather than DNA dependent replication.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
18
pubmed:volume
36
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
14064-70
pubmed:dateRevised
2007-11-15
pubmed:meshHeading
pubmed:year
1997
pubmed:articleTitle
Pre-steady-state kinetic characterization of wild type and 3'-azido-3'-deoxythymidine (AZT) resistant human immunodeficiency virus type 1 reverse transcriptase: implication of RNA directed DNA polymerization in the mechanism of AZT resistance.
pubmed:affiliation
Department of Pharmacology, 333 Cedar Street, Yale University School of Medicine, New Haven, Connecticut 06520-8066, USA.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, U.S. Gov't, P.H.S.