What is the Difference Between Nucleoside and Nucleotide Reverse Transcriptase Inhibitors?
🆚 Go to Comparative Table 🆚Nucleoside and nucleotide reverse transcriptase inhibitors are both types of antiviral drugs that target the reverse transcriptase enzyme, which is essential for the replication of viruses like HIV and hepatitis B. The main difference between them lies in their structure and mechanism of action:
- Nucleoside Reverse Transcriptase Inhibitors (NRTIs):
- These drugs mimic the structure of nucleosides, which are the building blocks of DNA and RNA.
- They need to be phosphorylated by cellular kinases before they can be recognized by the reverse transcriptase enzyme.
- Once inserted into the newly synthesized DNA chain, they act as competitive substrate inhibitors, stopping the elongation process due to the lack of a free hydroxyl group at the 3′ end.
- Examples of NRTIs include didanosine, zidovudine, stavudine, and abacavir.
- Nucleotide Reverse Transcriptase Inhibitors (NtRTIs):
- These drugs are similar to NRTIs but do not require initial phosphorylation by cellular kinases.
- Instead, host cells aid in phosphorylation, which is necessary for their antiviral activity.
- Once phosphorylated, they also act as competitive substrate inhibitors, stopping the elongation process of the DNA chain.
- Examples of NtRTIs include adefovir and tenofovir disoproxil fumarate.
Both NRTIs and NtRTIs are chain inhibitors, meaning they stop the replication of the viral DNA chain, effectively preventing the virus from replicating. However, the main difference is that NtRTIs do not require the initial phosphorylation step that NRTIs do, making them more direct inhibitors of the reverse transcriptase enzyme.
Comparative Table: Nucleoside vs Nucleotide Reverse Transcriptase Inhibitors
Nucleoside and nucleotide reverse transcriptase inhibitors are two types of antiretroviral drugs that inhibit the catalytic function of the viral reverse transcriptase enzyme. They are analogues of naturally occurring deoxyribonucleotides and lack a 3' hydroxyl group, which is essential for forming phosphodiester bonds with the next nucleotide. Here is a table comparing the differences between nucleoside and nucleotide reverse transcriptase inhibitors:
| Feature | Nucleoside Reverse Transcriptase Inhibitors | Nucleotide Reverse Transcriptase Inhibitors |
|---|---|---|
| Initial Phosphorylation | Require phosphorylation by the host cell to show antiviral activity | Do not require initial phosphorylation; host cells aid in phosphorylation |
| Examples | Didanosine, Zidovudine, Stavudine, Abacavir, etc. | Adefovir, Tenofovir disoproxil fumarate, etc. |
| Mechanism of Action | Competitive inhibition by blocking reverse transcriptase activity | Competitive inhibition; remove the need for initial phosphorylation |
Both types of inhibitors work as chain terminators, binding to the growing viral DNA strand and terminating its synthesis. They are used to treat retroviral infections like HIV and Hepatitis B. Side effects of these drugs may include vomiting, diarrhea, stomach problems, and headaches.
- Nucleotide vs Nucleoside
- NNRTI vs NRTI
- DNA vs RNA Nucleotide
- Antiviral vs Antiretroviral
- Transcription vs Reverse Transcription
- RNA Interference vs Antisense Oligonucleotide
- Nucleotide vs Nucleic Acid
- RNA Viruses vs Retroviruses
- Nicotinamide Riboside vs Nicotinamide Mononucleotide
- a Ribonucleotide vs a Deoxyribonucleotide
- Amino Acid vs Nucleotide
- Nicotinamide Adenine Dinucleotide vs Nicotinamide Riboside
- Provirus vs Retrovirus
- Nicotinamide vs Nicotinamide Riboside
- Bacterial Transposases vs Retroviral Integrases
- DNA Transposons vs Retrotransposons
- DNA vs RNA Synthesis
- Transposon vs Retrotransposon
- Retrovirus vs Virus