What are nucleotide and nucleoside analogs?

What are nucleotide and nucleoside analogs?

Nucleoside and nucleotide analogues are synthetic, chemically modified compounds that have been developed to mimic their physiological counterparts (Fig. 1) in order to exploit cellular metabolism and subsequently be incorporated into DNA and RNA to inhibit cellular division and viral replication.

What are structural analogs of nucleotides?

Structurally, nucleotide analogs are acyclic nucleoside phosphonates (nucleoside monophosphates) that are designed to circumvent the first phosphorylation step necessary for the activation of nucleoside analogs, such as zidovudine, stavudine, didanosine, lamivudine, and abacavir (1.

What is nucleoside used for?

Nucleosides are important biological molecules that function as signaling molecules and as precursors to nucleotides needed for DNA and RNA synthesis. Synthetic nucleoside analogues are used clinically to treat a range of cancers and viral infections.

What is a nucleoside analog quizlet?

synthetic compounds structurally similar to nucleosides such as guanosine and 2′-deoxythymidine, they act by interfering with the synthesis of virus nucleic acids. NUCLEOSIDE ANALOG- analog of guanosine, used for the treatment of infection with several RNA viruses, especially hepatitis C virus.

How do nucleotide analogs affect base pairing?

Base Analogues Since 5-bromouracil can pair with either adenine or guanine, it also affects base pairing during DNA replication, which leads to mutations. An analogue of adenine, 2-aminopurine, also causes mutations in a similar way since it can pair with either T or C.

How can nucleotide analogs affect DNA?

Once they are phosphorylated, they work as antimetabolites by being similar enough to nucleotides to be incorporated into growing DNA strands; but they act as chain terminators and stop viral DNA polymerase. They are not specific to viral DNA and also affect mitochondrial DNA.

Is AZT an example of nucleoside analogues?

Nucleoside analogue reverse transcriptase inhibitors including didanosine (ddI), lamivudine (3TC), stavudine (d4T), zalcitabine (ddC), and zidovudine (ZDV, formerly AZT) are used to treat human immunodeficiency virus (HIV) infection.

What are the examples of nucleoside?

Examples of nucleosides include cytidine, uridine, guanosine, inosine thymidine, and adenosine. A beta-glycosidic bond binds the 3′ position of the pentose sugar to the nitrogenous base. Nucleosides are used as anticancer and antiviral agents.

What are nucleoside analogs used for?

The nucleoside analogues are an important class of antiviral agents now commonly used in the therapy of human immunodeficiency virus (HIV) infection, hepatitis B virus (HBV), hepatitis C virus (HCV), cytomegalovirus (CMV), herpes simplex virus (HSV) and varicella-zoster (VZV) infection.

Is adefovir a nucleoside analog?

Nucleoside analogues that are phosphorylated at the 5’ site are often referred to as nucleotide analogues, but this distinction is artificial as these agents (tenofovir, adefovir) are also nucleoside analogues.

Why do antiviral nucleoside analogues fail?

Many of the antiviral nucleoside analogues are blocked at the 3’ hydroxyl group of the deoxyribonucleic acid, which results in failure of elongation of the nascent DNA molecule.

What is the mechanism of action of nucleoside analog inhibitors?

Nucleoside analog inhibitors are dNTPs or rNTPs that lack 3′-OH group. These inhibitors compete with nucleotide substrate to bind to the active site of polymerase. Once they are incorporated into the elongation chain of nucleic acid, chain termination results.