Question

What part of the HIV lifecycle is disrupted by the drugs indinavir and amprenavir?

Short answer

Indinavir and amprenavir disrupt the assembly stage of the HIV lifecycle.

Step-by-step solution

- Understand the HIV Lifecycle

HIV, the virus that causes AIDS, goes through several stages to reproduce and spread throughout the body. These stages include binding and fusion, reverse transcription, integration, transcription, translation, assembly, and budding.

- Identify the Function of Indinavir and Amprenavir

Indinavir and amprenavir are both protease inhibitors. Protease inhibitors are a class of antiviral drugs that interfere with the protease enzyme that HIV uses to cleave newly synthesized polyproteins into the mature protein components of an infectious HIV virion.

- Determine the Disrupted Stage

Since protease inhibitors like indinavir and amprenavir prevent the action of the HIV protease enzyme, they disrupt the 'assembly' stage of the HIV lifecycle. During the assembly stage, the virus assembles its components into a mature virion. By inhibiting the protease enzyme, these drugs prevent the virus from maturing and becoming infectious.

Key concepts

HIV lifecycle stages

The HIV lifecycle consists of several important stages that allow the virus to multiply and infect more cells in the body. These stages are:

• Binding and fusion: HIV binds to a host cell surface and fuses with the cell membrane, entering the cell.
• Reverse transcription: Once inside, HIV uses reverse transcriptase to convert its RNA into DNA.
• Integration: The newly made viral DNA is then integrated into the host cell's DNA by the enzyme integrase.
• Transcription: The cell's machinery transcribes the integrated viral DNA into new viral RNA.
• Translation: This viral RNA is then translated into viral proteins.
• Assembly: New viral RNA and proteins move to the cell's surface, assembling into immature, non-infectious HIV particles.
• Budding: Finally, the immature HIV particles bud off from the host cell, taking part of its cell membrane, and eventually mature into infectious virus particles.

Each of these stages is crucial for HIV to replicate and spread throughout the body. Drugs targeting these stages can help manage and control the infection.

protease inhibitors

Protease inhibitors (PIs) are a class of antiviral drugs designed to block the action of protease, an enzyme produced by HIV. Protease plays a critical role during the assembly stage of the HIV lifecycle. When new viral particles are created, they are initially immature and non-infectious.

The protease enzyme cleaves these newly made polyproteins into mature proteins necessary for the formation of infectious HIV virions. Protease inhibitors, such as indinavir and amprenavir, prevent this cleavage process from occurring.

As a result, the viral particles remain immature and non-infectious, thus blocking the virus's ability to replicate and spread. By disrupting the action of protease, these inhibitors help slow down the progression of HIV infection and reduce viral load in patients.

antiviral drugs mechanism

Antiviral drugs fight against viruses using various mechanisms, each targeting different stages of the viral lifecycle.

Here are some common mechanisms of antiviral drugs:

• Entry inhibitors: These drugs prevent the virus from entering the host cell by blocking receptors on the cell surface or the viral envelope.
• Reverse transcriptase inhibitors: These drugs inhibit the reverse transcription process, preventing the virus from converting its RNA into DNA.
• Integrase inhibitors: These drugs block the integration of viral DNA into the host cell's genome, halting the replication process.
• Protease inhibitors: As mentioned earlier, these drugs inhibit the action of protease enzyme, preventing the maturation of viral particles.
• Maturation inhibitors: These drugs prevent the final steps in the maturation of viral particles, ensuring they remain non-infectious.

Each type of antiviral drug is designed to intervene at a specific point in the virus's lifecycle, making it harder for the virus to multiply and spread. The effective use of these drugs can suppress the viral load and improve the quality of life for those infected.