Abstract:
:Adefovir dipivoxil [9-(2-(bispivaloyloxymethyl)phosphonylmethoxyethyl)adenine (bis-POM PMEA)], an oral prodrug of adefovir (PMEA), is currently in phase III clinical testing for the treatment of human immunodeficiency virus-1 (HIV-1) infection. Previous in vitro experiments have shown that HIV-1 recombinant viruses expressing either a K65R or a K70E mutation in reverse transcriptase (RT) have reduced sensitivity to PMEA and that the K70E mutant also has impaired replication capacity in vitro. Genotypic analyses of samples from patients enrolled in a phase I/II clinical trial of adefovir dipivoxil demonstrated that the K70E RT mutation developed in two of 29 patients during extended therapy. To further investigate the molecular mechanisms involved in the resistance to PMEA, we cloned, expressed, and purified HIV-1 RT enzymes carrying either the K65R or K70E and, for comparison, the M184V mutation. The Km values of dNTPs for these mutant enzymes were not significantly altered from wild-type RT. The Ki values for the K65R mutant were increased from wild-type by 2-5-fold against a variety of inhibitors, whereas the Ki values for the M184V mutant were increased 12-fold specifically for 2', 3'-dideoxy-3'-thiacytidine (3TC) triphosphate. The Ki values for the K70E mutant were increased for PMEA diphosphate and 3TC triphosphate by 2-3-fold. These results are in agreement with antiviral drug susceptibility assay results. The three recombinant enzymes were also evaluated for their specific activities and processivities. All mutants were reduced in specific activity with respect to wild-type RT. In single-cycle processivity studies, the M184V mutant was, as expected, notably impaired. The K70E mutant was also slightly impaired, whereas the K65R mutant was slightly more processive than wild-type. These results with recombinant K70E RT are consistent with the reduced in vitro replication capacity of the K70E RT mutant of HIV-1 and further demonstrate that the K70E mutation confers minor PMEA and 3TC resistance to HIV-1.
journal_name
Mol Pharmacoljournal_title
Molecular pharmacologyauthors
Miller MD,Lamy PD,Fuller MD,Mulato AS,Margot NA,Cihlar T,Cherrington JMdoi
10.1124/mol.54.2.291subject
Has Abstractpub_date
1998-08-01 00:00:00pages
291-7issue
2eissn
0026-895Xissn
1521-0111journal_volume
54pub_type
杂志文章abstract::Regulator of G protein signaling (RGS) proteins are negative modulators of G protein signaling that have emerged as promising drug targets to improve specificity and reduce side effects of G protein-coupled receptor-related therapies. Several small molecule RGS protein inhibitors have been identified; however, enhanci...
journal_title:Molecular pharmacology
pub_type: 杂志文章
doi:10.1124/molpharm.120.000061
更新日期:2020-12-01 00:00:00
abstract::The intermediate-conductance Ca2+-activated K+ channel (KCa3.1) constitutes an attractive pharmacological target for immunosuppression, fibroproliferative disorders, atherosclerosis, and stroke. However, there currently is no available crystal structure of this medically relevant channel that could be used for structu...
journal_title:Molecular pharmacology
pub_type: 杂志文章
doi:10.1124/mol.116.108068
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abstract::[3H]Dihydroalprenolol ([3H]DHA) has been used extensively in receptor binding studies to measure beta-adrenergic receptors in the central nervous system. Usually, nonspecific binding has been defined by high concentrations of the beta-adrenergic receptor agonist isoproterenol or antagonists such as alprenolol or propr...
journal_title:Molecular pharmacology
pub_type: 杂志文章
doi:
更新日期:1989-07-01 00:00:00
abstract::The interaction of [3H]acetylcholine ([3H]AcCh) with the muscarinic receptor was studied in seven distinct rat brain regions and in heart atrium by employing 10 microM atropine to define specific binding. The specific binding exhibited by the labeled neurotransmitter was found to be sensitive to muscarinic but not to ...
journal_title:Molecular pharmacology
pub_type: 杂志文章
doi:
更新日期:1985-09-01 00:00:00
abstract::Lysosomes degrade cellular proteins and organelles and regulate cell signaling by providing a surface for the formation of critical protein complexes, notably molecular target of rapamycin (mTOR) complex 1 (mTORC1). Striking differences in the lysosomes of cancer versus normal cells suggest that they could be targets ...
journal_title:Molecular pharmacology
pub_type: 杂志文章
doi:10.1124/mol.118.113118
更新日期:2019-01-01 00:00:00
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journal_title:Molecular pharmacology
pub_type: 杂志文章
doi:
更新日期:1989-10-01 00:00:00
abstract::A nonnaturally occurring L-configuration nucleoside analog, L-beta-5-bromovinyl-(2-hydroxymethyl)-1,3-(dioxolanyl)uracil (L-BVOddU) selectively inhibited varicella-zoster virus growth in human embryonic lung (HEL) 299 cell culture with an EC(50) of 0.055 microM, whereas no inhibition of CEM and HEL 299 cell growth or ...
journal_title:Molecular pharmacology
pub_type: 杂志文章
doi:10.1124/mol.58.5.1109
更新日期:2000-11-01 00:00:00
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journal_title:Molecular pharmacology
pub_type: 杂志文章
doi:
更新日期:1991-02-01 00:00:00
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journal_title:Molecular pharmacology
pub_type: 杂志文章
doi:
更新日期:1988-09-01 00:00:00
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journal_title:Molecular pharmacology
pub_type: 杂志文章
doi:
更新日期:1999-11-01 00:00:00
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journal_title:Molecular pharmacology
pub_type: 杂志文章
doi:
更新日期:1989-10-01 00:00:00
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journal_title:Molecular pharmacology
pub_type: 杂志文章
doi:
更新日期:1996-08-01 00:00:00
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journal_title:Molecular pharmacology
pub_type: 杂志文章
doi:
更新日期:1983-09-01 00:00:00
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journal_title:Molecular pharmacology
pub_type: 杂志文章
doi:10.1124/mol.110.065169
更新日期:2010-09-01 00:00:00
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journal_title:Molecular pharmacology
pub_type: 杂志文章
doi:10.1124/mol.55.2.288
更新日期:1999-02-01 00:00:00
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journal_title:Molecular pharmacology
pub_type: 杂志文章
doi:10.1124/mol.112.084293
更新日期:2013-05-01 00:00:00
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journal_title:Molecular pharmacology
pub_type: 杂志文章
doi:
更新日期:1995-11-01 00:00:00
abstract::Extracellular protons inhibit N-methyl-D-aspartate (NMDA) receptors with an IC50 value in the physiological pH range. To identify the molecular determinants of proton sensitivity, we used scanning mutagenesis of the NR1 subunit to search for residues that control proton inhibition of NMDA receptors. Homology modeling ...
journal_title:Molecular pharmacology
pub_type: 杂志文章
doi:10.1124/mol.63.6.1212
更新日期:2003-06-01 00:00:00
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journal_title:Molecular pharmacology
pub_type: 杂志文章
doi:
更新日期:1993-10-01 00:00:00
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journal_title:Molecular pharmacology
pub_type: 杂志文章
doi:10.1124/mol.112.078162
更新日期:2012-08-01 00:00:00
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journal_title:Molecular pharmacology
pub_type: 杂志文章
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pub_type: 杂志文章
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更新日期:2002-05-01 00:00:00
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journal_title:Molecular pharmacology
pub_type: 杂志文章
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更新日期:2008-08-01 00:00:00
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journal_title:Molecular pharmacology
pub_type: 杂志文章
doi:10.1124/mol.63.3.624
更新日期:2003-03-01 00:00:00
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journal_title:Molecular pharmacology
pub_type: 杂志文章
doi:
更新日期:1987-12-01 00:00:00
abstract::Chronic stimulation of beta-adrenoceptors leads to increased mRNA and protein levels of pertussis toxin (PTX)-sensitive guanine nucleotide-binding proteins (G proteins) in the heart. In the present study the time course is reported of the effect of isoprenaline infusions on myocardial mRNA levels of Gi alpha-2, Gi alp...
journal_title:Molecular pharmacology
pub_type: 杂志文章
doi:
更新日期:1992-11-01 00:00:00
abstract::Identification of nonadrenergic binding sites for clonidine and related imidazolines in brain and peripheral tissues and partial purification of an endogenous ligand for these sites have led to the postulation of a novel transmitter/receptor system. The receptors seem to be present in adrenal medulla and to regulate c...
journal_title:Molecular pharmacology
pub_type: 杂志文章
doi:
更新日期:1991-12-01 00:00:00
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pub_type: 杂志文章
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更新日期:2010-01-01 00:00:00
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journal_title:Molecular pharmacology
pub_type: 杂志文章
doi:
更新日期:1993-04-01 00:00:00
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journal_title:Molecular pharmacology
pub_type: 杂志文章
doi:
更新日期:1986-03-01 00:00:00