Deck 36: Antiviral Chemotherapy

Question 1

How does the antiviral drug maraviroc,which was developed to inhibit entry of HIV,function?

A)It binds to the gp120 protein on the surface of the HIV virion.
B)It binds to the gp41 protein in the envelope of HIV.
C)It binds to the host protein CCR5.
D)It binds to the host protein CD4.
E)It binds to the lipids in the envelope of HIV and prevents membrane fusion.

Answer 1

C

Question 2

Which of the following viral enzymes encoded by cytomegalovirus is responsible for phosphorylating and activating the antiviral drug ganciclovir?

A)Guanine kinase
B)Cellular nucleotide kinase.
C)UL97,a serine-threonine protein kinase
D)Thymidine kinase
E)Thymidylate kinase

Answer 2

C

Question 3

The FDA approved the drug raltegravir in 2007 to treat infection with HIV.Which of the HIV enzymes does raltegravir inhibit?

A)DNA polymerase
B)gp120
C)Reverse transcriptase
D)Integrase
E)Protease

Answer 3

D

Question 4

How does the antiviral drug amantadine inhibit the replication of influenza?

A)It binds to the M2 ion channel and blocks the uncoating of the RNPs.
B)It binds to sialic acid on the host cell and prevents binding of the virion.
C)It binds to the HA protein on the virion and prevents binding to the host cell.
D)It binds to the polymerase protein and halts genome replication.
E)It binds to the nucleocapsid protein and prevents packaging of the viral RNA.

Question 5

Which of the following enzymes from herpes simplex virus is required to activate the antiviral drug acyclovir?

A)Ribonucleotide reductase.
B)Thymidine kinase.
C)DNA polymerase.
D)Nucleoside diphosphate kinase.
E)Guanine kinase.

Question 6

Which of the following describes how the nonnucleoside inhibitors of the HIV reverse transcriptase are different than the nucleoside inhibitors?

A)The nonnucleoside inhibitors prevent addition of the next nucleotide.
B)The nonnucleoside inhibitors do not bind to the active site of the enzyme.
C)The nonnucleoside inhibitors must be activated by the cellular thymidine kinase.
D)The nonnucleoside inhibitors prevent synthesis of the reverse transcriptase.
E)The nonnucleoside inhibitors lack a 3' OH group.

Question 7

How does the capsid-binding drug pleconaril inhibit entry of picornavirus particles?

A)It causes antibodies to bind to the capsid and blocks entry.
B)It causes the capsid to become degraded by proteases.
C)It binds to the same location on the capsid as the host cell receptor.
D)It displaces a lipid normally bound to a pocket on the capsid.
E)It binds to the envelope of the virus and prevents it from fusing with the plasma membrane.

Question 8

The neuraminidase inhibitors zanamivir and oseltamivir have been shown to have the highest effectiveness in reducing….

A)the number of deaths caused by the H5N1 bird influenza.
B)the number of missed school days by children with influenza.
C)the number of children who die from chicken pox.
D)the number of people who get the common cold each year.
E)the number of people who need to be vaccinated for influenza.

Question 9

The HIV1 protease is a good target for inhibiting virus replication because…..

A)it cleaves the gag-pol polyprotein during virus assembly.
B)it is required for the maturation of HIV1 virus particles.
C)it has an unusual cleavage sequence on its substrate.
D)the crystal structure for the enzyme is available.
E)All of the above answers are correct.

Question 10

Which of the following is a characteristic of a good target protein to be used in high throughput screening for potential antiviral compounds?

A)It is an essential protein for virus replication.
B)It is sufficiently different from cellular proteins.
C)It can be expressed and purified easily.
D)It's activity can be assayed for quickly and easily.
E)All of these are characteristics of a good viral target.

Question 11

The antiviral drug ganciclovir was approved to be used as a treatment for which of the following viruses?

A)HIV
B)Herpes simplex virus
C)Varicella-zoster virus
D)Cytomegalovirus
E)Vaccinia virus

Question 12

What was the first successful antiviral drug developed and which virus does it inhibit?

A)AZT; HIV.
B)3TC; hepatitis B virus.
C)Acyclovir; herpes simplex I.
D)Amantadine; influenza.
E)Nevirapine; HIV.

Question 13

In addition to treating virus infections in patients,some antiviral drugs have been useful tools in the research lab to dissect the function of viral proteins.

Question 14

Which of the following is NOT a reason why viral enzymes make good targets for the development of antiviral drugs?

A)Enzymes inhibitors bind more tightly to their targets than inhibitors of other proteins.
B)Drug companies have experience designing enzyme inhibitors.
C)Enzymes normally interact with small molecules.
D)Enzymes are usually well understood mechanistically.
E)Enzymes are present in low concentrations within the infected cell.

Question 15

The anti-influenza drug amantadine blocks entry of the virion by raising the pH of the endosome.

Question 16

What is the advantage of designing an antiviral drug that inhibits the very early or very late steps of viral replication?

A)The antiviral drug will be in higher concentrations in the body.
B)The antiviral drug does not need to enter the cell to work.
C)The antiviral drug will have a higher binding affinity for the viral protein.
D)The antiviral drug has a higher chance of inhibiting the virus infection.
E)The antiviral drug will be more easily eliminated from the body.

Question 17

The antiviral drug AZT inhibits which enzyme from which virus?

A)Protease from HIV
B)Reverse transcriptase from HIV
C)Integrase from HIV
D)Neuraminidase from influenza
E)DNA polymerase from herpes simplex virus

Question 18

What is the definition of a therapeutic index when discussing an antiviral drug?

A)The amount of the drug that inhibits the virus replication.
B)The amount of the drug that is toxic to the host cell.
C)The amount of the drug that is inhibits viral replication divided by the amount of the drug that is toxic.
D)The dose that exerts 50% toxic effect divided by the does that exerts a 50% antiviral effect.
E)The amount of the drug that kills 50% of the hosts.

Question 19

Many antiviral drugs,like AZT and acyclovir,belong to which of the following groups of compounds?

A)Nucleotide analogues
B)Nucleoside analogues
C)Nonnucleoside inhibitors
D)Neuraminidase inhibitors
E)Protease inhibitors

Question 20

Drugs that can treat viral infections were discovered about the same time as antibiotics,which are used to treat bacterial infections.

Question 21

Describe the two factors that determine how the antiviral drug acyclovir is specifically targeted to inhibit the replication of herpes simplex virus.

Question 22

Most of the currently available antiviral drugs target viral genome replication.

Question 23

Describe some of the factors that make drugs to inhibit virus infections harder to develop than the drugs used to fight bacterial infections.

Question 24

Explain the targeted-based high throughput screen approach to the discovery of new antiviral drugs.What makes a good viral target for this approach?

Question 25

The chemical structure of ritonavir,an inhibitor of the HIV protease,resembles both the original substrate and the transition state intermediate of the enzyme.

Question 26

Like other antiviral drugs that inhibit the HIV1 reverse transcriptase,nevirapine is a nucleoside analogue.