home
***
CD-ROM
|
disk
|
FTP
|
other
***
search
/
The Arsenal Files 6
/
The Arsenal Files 6 (Arsenal Computer).ISO
/
health
/
med9603.zip
/
M9630612.TXT
< prev
next >
Wrap
Text File
|
1996-02-27
|
3KB
|
46 lines
Document 0612
DOCN M9630612
TI Mechanism of inhibition of duck hepatitis B virus polymerase by
(-)-beta-L-2',3'-dideoxy-3'-thiacytidine.
DT 9603
AU Severini A; Liu XY; Wilson JS; Tyrrell DL; Glaxo Heritage Research
Institute, Department of Medical; Microbiology and Infectious Diseases,
University of Alberta,; Edmonton, Canada.
SO Antimicrob Agents Chemother. 1995 Jul;39(7):1430-5. Unique Identifier :
AIDSLINE MED/96104876
AB We have used the endogenous reverse transcriptase reaction of viral core
particles from duck liver to elucidate the mechanism of inhibition of
duck hepatitis B virus (DHBV) replication by the nucleoside analog
(-)-beta-L-2',3'-dideoxy-3'-thiacytidine (3TC). As is the case in human
immunodeficiency virus replication, 3TC-5'-triphosphate (3TC-TP) acts as
a chain terminator for the DNA polymerase activities. The results of
several different experiments support this conclusion, which explains
the potent activity of 3TC against the hepadnaviruses. In isolated DHBV
core particles, 3TC-TP inhibited the reverse transcriptase in a manner
that resembled competitive inhibition with respect to dCTP. However, the
kinetics of inhibition was not linear on a double-reciprocal plot for
the highest concentrations of 3TC-TP and the lowest concentration of
dCTP. This anomaly would be expected if binding to the nucleotide site
was followed by DNA chain termination. Calculations that used only the
linear part of the curve yielded a Ki of 0.78 +/- 0.10 microM 3TC-TP.
The inhibition of core particles incubated in vitro with 3TC-TP was not
reversed by removal of the free inhibitor. 3TC-TP inactivated the
reverse transcriptase activity in a concentration-dependent manner. The
Km of the chain termination reaction was calculated at 0.71 +/- 0.05
microM. Similar competitive kinetics and irreversible inhibition were
also obtained on the endogenous DNA polymerase from viral particles from
serum, suggesting that 3TC-TP also acts as a chain terminator of the
DNA-directed DNA polymerase of DHBV replication.(ABSTRACT TRUNCATED AT
250 WORDS)
DE Animal Antiviral Agents/*PHARMACOLOGY Base Sequence Ducks DNA
Polymerases/*ANTAGONISTS & INHIB Hepatitis B Virus, Duck/DRUG
EFFECTS/*ENZYMOLOGY/PHYSIOLOGY Kinetics Molecular Sequence Data
Nucleotides/METABOLISM RNA-Directed DNA Polymerase Support, Non-U.S.
Gov't Viral Core Proteins/*ANTAGONISTS & INHIB Virus Replication/DRUG
EFFECTS Zalcitabine/*ANALOGS & DERIVATIVES/PHARMACOLOGY JOURNAL
ARTICLE
SOURCE: National Library of Medicine. NOTICE: This material may be
protected by Copyright Law (Title 17, U.S.Code).