Biomaterial Database

4'-Ethynyl-2-fluoro-2'-deoxyadenosine (EFdA) inhibits HIV-1 reverse transcriptase with multiple mechanisms. 2014

Eleftherios Michailidis, and Andrew D Huber, and Emily M Ryan, and Yee T Ong, and Maxwell D Leslie, and Kayla B Matzek, and Kamalendra Singh, and Bruno Marchand, and Ariel N Hagedorn, and Karen A Kirby, and Lisa C Rohan, and Eiichi N Kodama, and Hiroaki Mitsuya, and Michael A Parniak, and Stefan G Sarafianos

From the Christopher Bond Life Sciences Center and Department of Molecular Microbiology and Immunology, University of Missouri School of Medicine, Columbia, Missouri 65211.

4'-Ethynyl-2-fluoro-2'-deoxyadenosine (EFdA) is a nucleoside analog that, unlike approved anti-human immunodeficiency virus type 1 (HIV-1) nucleoside reverse transcriptase inhibitors, has a 3'-OH and exhibits remarkable potency against wild-type and drug-resistant HIVs. EFdA triphosphate (EFdA-TP) is unique among nucleoside reverse transcriptase inhibitors because it inhibits HIV-1 reverse transcriptase (RT) with multiple mechanisms. (a) EFdA-TP can block RT as a translocation-defective RT inhibitor that dramatically slows DNA synthesis, acting as a de facto immediate chain terminator. Although non-translocated EFdA-MP-terminated primers can be unblocked, they can be efficiently converted back to the EFdA-MP-terminated form. (b) EFdA-TP can function as a delayed chain terminator, allowing incorporation of an additional dNTP before blocking DNA synthesis. In such cases, EFdA-MP-terminated primers are protected from excision. (c) EFdA-MP can be efficiently misincorporated by RT, leading to mismatched primers that are extremely hard to extend and are also protected from excision. The context of template sequence defines the relative contribution of each mechanism and affects the affinity of EFdA-MP for potential incorporation sites, explaining in part the lack of antagonism between EFdA and tenofovir. Changes in the type of nucleotide before EFdA-MP incorporation can alter its mechanism of inhibition from delayed chain terminator to immediate chain terminator. The versatility of EFdA in inhibiting HIV replication by multiple mechanisms may explain why resistance to EFdA is more difficult to emerge.

UI	MeSH Term	Description	Entries
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D002460	Cell Line	Established cell cultures that have the potential to propagate indefinitely.	Cell Lines,Line, Cell,Lines, Cell
D003839	Deoxyadenosines	Adenosine molecules which can be substituted in any position, but are lacking one hydroxyl group in the ribose part of the molecule.	Adenine Deoxyribonucleosides,Adenylyldeoxyribonucleosides,Deoxyadenosine Derivatives,Deoxyribonucleosides, Adenine,Derivatives, Deoxyadenosine
D001483	Base Sequence	The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.	DNA Sequence,Nucleotide Sequence,RNA Sequence,DNA Sequences,Base Sequences,Nucleotide Sequences,RNA Sequences,Sequence, Base,Sequence, DNA,Sequence, Nucleotide,Sequence, RNA,Sequences, Base,Sequences, DNA,Sequences, Nucleotide,Sequences, RNA
D054303	HIV Reverse Transcriptase	A reverse transcriptase encoded by the POL GENE of HIV. It is a heterodimer of 66 kDa and 51 kDa subunits that are derived from a common precursor protein. The heterodimer also includes an RNAse H activity (RIBONUCLEASE H, HUMAN IMMUNODEFICIENCY VIRUS) that plays an essential role the viral replication process.	Reverse Transcriptase, HIV,Reverse Transcriptase, Human Immunodeficiency Virus,Transcriptase, HIV Reverse
D017931	DNA Primers	Short sequences (generally about 10 base pairs) of DNA that are complementary to sequences of messenger RNA and allow reverse transcriptases to start copying the adjacent sequences of mRNA. Primers are used extensively in genetic and molecular biology techniques.	DNA Primer,Oligodeoxyribonucleotide Primer,Oligodeoxyribonucleotide Primers,Oligonucleotide Primer,Oligonucleotide Primers,Primer, DNA,Primer, Oligodeoxyribonucleotide,Primer, Oligonucleotide,Primers, DNA,Primers, Oligodeoxyribonucleotide,Primers, Oligonucleotide
D018894	Reverse Transcriptase Inhibitors	Inhibitors of reverse transcriptase (RNA-DIRECTED DNA POLYMERASE), an enzyme that synthesizes DNA on an RNA template.	Reverse Transcriptase Inhibitor,Inhibitors, Reverse Transcriptase,Inhibitor, Reverse Transcriptase,Transcriptase Inhibitor, Reverse
D020134	Catalytic Domain	The region of an enzyme that interacts with its substrate to cause the enzymatic reaction.	Active Site,Catalytic Core,Catalytic Region,Catalytic Site,Catalytic Subunit,Reactive Site,Active Sites,Catalytic Cores,Catalytic Domains,Catalytic Regions,Catalytic Sites,Catalytic Subunits,Core, Catalytic,Cores, Catalytic,Domain, Catalytic,Domains, Catalytic,Reactive Sites,Region, Catalytic,Regions, Catalytic,Site, Active,Site, Catalytic,Site, Reactive,Sites, Active,Sites, Catalytic,Sites, Reactive,Subunit, Catalytic,Subunits, Catalytic
D020349	Surface Plasmon Resonance	A biosensing technique in which biomolecules capable of binding to specific analytes or ligands are first immobilized on one side of a metallic film. Light is then focused on the opposite side of the film to excite the surface plasmons, that is, the oscillations of free electrons propagating along the film's surface. The refractive index of light reflecting off this surface is measured. When the immobilized biomolecules are bound by their ligands, an alteration in surface plasmons on the opposite side of the film is created which is directly proportional to the change in bound, or adsorbed, mass. Binding is measured by changes in the refractive index. The technique is used to study biomolecular interactions, such as antigen-antibody binding.	Plasmon Resonance, Surface,Plasmon Resonances, Surface,Resonance, Surface Plasmon,Resonances, Surface Plasmon,Surface Plasmon Resonances