Inhibition of retroviral protease activity by an aspartyl proteinase inhibitor

Related Experiment Video

Updated: Oct 11, 2026

A High-throughput Cre-Lox Activated Viral Membrane Fusion Assay to Identify Inhibitors of HIV-1 Viral Membrane Fusion
07:22

A High-throughput Cre-Lox Activated Viral Membrane Fusion Assay to Identify Inhibitors of HIV-1 Viral Membrane Fusion

Published on: August 14, 2018

I Katoh1, T Yasunaga, Y Ikawa

  • 1Laboratory of Molecular Oncology, Tsukuba Life Science Center, Institute of Physical and Chemical Research, Ibaraki, Japan.

Nature
|October 15, 1987
PubMed

Insights

Retrovirus proteases are essential for viral maturation and infectivity. This study confirms retroviral proteases are aspartyl proteinases, inhibited by pepstatin A, suggesting therapeutic potential.

Area of Science:

  • Biochemistry
  • Virology
  • Molecular Biology

Background:

  • Retrovirus protease is crucial for cleaving viral polyproteins into functional proteins, enabling mature virus particle formation.
  • Protease activity is essential for retroviral infectivity; protease-defective viruses are immature and non-infectious.
  • Developing therapeutic drugs targeting retroviral proliferation requires understanding and potentially inhibiting virus maturation.

Purpose of the Study:

  • To confirm that retrovirus proteases belong to the aspartyl proteinase group.
  • To investigate the inhibitory effect of pepstatin A, an aspartyl proteinase-specific inhibitor, on retrovirus protease activity.
  • To explore the potential of targeting retrovirus proteases as a therapeutic strategy.

Main Methods:

  • Amino acid sequencing of purified retrovirus proteases and prediction from nucleotide sequences.
  • Enzyme activity assays on bovine leukaemia virus, Moloney murine leukaemia virus, and human T-cell leukaemia virus proteases.
  • Inhibition assays using pepstatin A, a known aspartyl proteinase inhibitor.

Main Results:

  • Amino acid sequencing revealed the characteristic Asp-Thr-Gly sequence in retrovirus proteases, indicative of aspartyl proteinases.
  • Pepstatin A significantly inhibited the enzymatic activity of bovine leukaemia, Moloney murine leukaemia, and human T-cell leukaemia virus proteases.
  • These findings confirm retroviral proteases as members of the aspartyl proteinase family.

Conclusions:

  • Retrovirus proteases are confirmed as aspartyl proteinases based on structural and functional evidence.
  • The susceptibility of retrovirus proteases to pepstatin A highlights their potential as therapeutic targets for antiviral drug development.
  • Interfering with retrovirus protease activity offers a viable strategy for combating diseases caused by retrovirus proliferation.

More Related Videos

Detection of Human Immunodeficiency Virus Type 1 (HIV-1) Antisense Protein (ASP) RNA Transcripts in Patients by Strand-Specific RT-PCR08:01

Detection of Human Immunodeficiency Virus Type 1 (HIV-1) Antisense Protein (ASP) RNA Transcripts in Patients by Strand-Specific RT-PCR

Published on: November 27, 2019

Quantitative Structure-Activity Relationship, Activity Prediction, and Molecular Dynamics of Non-nucleotide Reverse Transcriptase Inhibitors10:29

Quantitative Structure-Activity Relationship, Activity Prediction, and Molecular Dynamics of Non-nucleotide Reverse Transcriptase Inhibitors

Published on: May 9, 2025

Related Concept Videos

Retrovirus Life Cycles01:10

Retrovirus Life Cycles

Retroviruses have a single-stranded RNA genome that undergoes a special form of replication. Once the retrovirus has entered the host cell, an enzyme called reverse transcriptase synthesizes double-stranded DNA from the retroviral RNA genome. This DNA copy of the genome is then integrated into the host’s genome inside the nucleus via an enzyme called integrase. Consequently, the retroviral genome is transcribed into RNA whenever the host’s genome is transcribed, allowing the retrovirus to...
Retroviruses02:33

Retroviruses

Retroviruses and retrotransposons both insert copies of their genetic elements into the genome of the host cell. Thus, the viral genes are passed on when the host genome is replicated or translated. A typical retroviral DNA sequence contains 3-4 genes that encode the different proteins required for its structural assembly and function as a molecular parasite. This DNA is transcribed into a single mRNA, which is very similar in structure to conventional mRNAs, i.e., it is capped at the 5’...
Inhibitors of Viral Protein Synthesis01:30

Inhibitors of Viral Protein Synthesis

Protein synthesis is indispensable for viral replication, as viruses lack the cellular machinery required for this process and must hijack the host's translational apparatus. In response, host cells deploy a critical innate immune defense involving interferons, specialized cytokines that play a central role in inhibiting viral propagation.Upon viral detection, infected cells release interferons that bind to receptors on adjacent uninfected cells, activating the JAK-STAT signaling pathway and...
Inhibitors Of Virion Release01:25

Inhibitors Of Virion Release

Viral replication and dissemination rely on efficient mechanisms for host cell entry, genome replication, assembly, and release. Influenza viruses, such as types A and B, are negative-sense single-stranded RNA viruses with a segmented genome, that depend on two critical surface glycoproteins to carry out these processes: hemagglutinin (HA) and neuraminidase (NA). HA initiates infection by binding to sialic acid residues on the surface of host epithelial cells, facilitating receptor-mediated...
Antiviral Nucleoside Inhibitors01:22

Antiviral Nucleoside Inhibitors

Antiviral Nucleoside InhibitorsAntiviral nucleoside inhibitors are structural analogs of natural nucleosides that interfere with viral DNA or RNA synthesis. These compounds selectively target viral polymerases due to their resemblance to host nucleosides, thereby disrupting viral genome replication.Mechanism of Acyclovir ActionAcyclovir is a guanosine analog with a three-carbon acyclic side chain. It selectively targets herpes simplex virus type 1 (HSV-1), herpes simplex virus type 2 (HSV-2),...
Inhibitors of Virion Maturation and Assembly01:19

Inhibitors of Virion Maturation and Assembly

As part of their replication cycle, certain viruses synthesize long precursor proteins called polyproteins within infected host cells. In human immunodeficiency virus (HIV), two major polyproteins are produced: Gag and Gag-Pol. The Gag polyprotein supplies the structural components of the virus, while Gag-Pol includes essential viral enzymes such as reverse transcriptase, integrase, and protease. After synthesis, these polyproteins move to the host cell membrane, where they assemble into an...