Name: hiv protease inhibitors and maturation
Uploaded: 2026-05-20T14:38:19.907Z
Duration: 1 min 19 s
Channel: JoVE

When viruses such as HIV enter host cells and replicate, they produce long precursor protein chains called polyproteins, including Gag and Gag-Pol.Gag makes up the structural parts of the virus, while Gag-Pol contains viral enzymes, including the viral protease.These polyproteins move to the host cell membrane, where they begin to assemble.When several Gag-Pol molecules come together, the protease regions form a dimer and become active.As the viral particle buds from the host cell, the active protease first cleaves itself from the Gag-Pol polyprotein, then cleaves the remaining polyproteins into smaller, functional proteins.This cleavage reorganizes the virion structure, helping the capsid to form properly and producing a mature HIV virion.Protease inhibitors are antiviral agents that enter infected host cells and bind to the viral proteases.This blocks protease activity and viral polyprotein cleavage, keeping HIV virions immature and noninfectious, which slows virus spread in the body.

inibitori della maturazione e dell'assemblaggio dei virioni

Inhibitors of Virion Maturation and Assembly

Come parte del loro ciclo di replicazione, alcuni virus sintetizzano lunghi precursori proteici chiamati poliproteine all&#x27;interno delle cellule ospiti infette. Nel virus dell&#x27;immunodeficienza umana, o HIV, vengono prodotte due principali poliproteine: Gag e Gag-Pol. La poliproteina Gag fornisce i componenti strutturali del virus, mentre Gag-Pol comprende enzimi virali essenziali come la trascrittasi inversa, l&#x27;integrasi e la proteasi. Dopo la sintesi, queste poliproteine si spostano verso la membrana della cellula ospite, dove si assemblano in una particella virale immatura che gemma dalla superficie cellulare.
Sebbene la gemmazione rilasci il virus dalla cellula ospite, il virione appena formato non &#xE8; ancora infettivo. La piena infettivit&#xE0; dipende dalla maturazione virale, che si basa sulla scissione ordinata delle poliproteine Gag e Gag-Pol. Questo passaggio &#xE8; catalizzato dalla proteasi virale, una proteasi aspartica codificata all&#x27;interno della poliproteina Gag-Pol. Il processamento proteolitico genera singole proteine strutturali, tra cui matrice, capside e nucleocapside, e consente agli enzimi virali di adottare le loro conformazioni attive. Questi eventi di scissione innescano un&#x27;importante riorganizzazione della struttura interna del virione, dando come risultato il nucleo condensato tipico delle particelle di HIV mature e infettive.
Gli inibitori della proteasi sono farmaci antiretrovirali diretti contro questa fase critica della maturazione. Legandosi al sito attivo della proteasi virale, questi agenti prevengono la scissione delle poliproteine virali. Di conseguenza, i virioni rilasciati dalle cellule infette rimangono strutturalmente immaturi, con proteine processate in modo improprio e un&#x27;architettura interna disordinata. Sebbene tali particelle possano ancora gemmare dalla cellula ospite, non sono infettive e non possono avviare un&#x27;infezione produttiva. Bloccando la maturazione virale, gli inibitori della proteasi riducono la replicazione virale e limitano la diffusione dell&#x27;HIV, rendendoli una componente essenziale della terapia antiretrovirale combinata.

Inibitori della maturazione e dell'assemblaggio dei virioni

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hiv protease inhibitors and maturation

HIV protease inhibitors block a key step in virus maturation. In human immunodeficiency virus (HIV), infected cells make two long precursor proteins called polyproteins. These are Gag and Gag-Pol. Gag provides the virus structure. Gag-Pol carries important viral enzymes, including reverse transcriptase, integrase, and protease.

After these polyproteins are made, they move to the host cell membrane. There, they help build an immature viral particle that buds from the cell surface. Budding releases the virus from the cell, but the new virion is still not infectious. It must first go through maturation.

Viral maturation depends on the cutting of Gag and Gag-Pol into smaller pieces. This process is called proteolytic processing. It is carried out by the viral protease, which is an aspartyl protease encoded within Gag-Pol. The cuts release structural proteins such as matrix, capsid, and nucleocapsid. They also let the viral enzymes adopt their active shapes. These changes reorganize the inside of the virion and form the condensed core found in mature HIV particles.

Protease inhibitors are antiretroviral drugs that stop this step. They bind to the active site of the viral protease and prevent the polyproteins from being cut. The virions can still bud from infected cells, but they stay structurally immature. Their proteins are not processed correctly, and their internal structure remains disordered. These particles are noninfectious and cannot start a productive infection. By blocking viral maturation, protease inhibitors reduce viral replication and help limit HIV spread. They are an important part of combination antiretroviral therapy.

HIV Protease Inhibitors and Maturation

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HIV protease inhibitors block a key step in virus maturation. In human immunodeficiency virus (HIV), infected cells make two long precursor proteins called polyproteins. These are Gag and Gag-Pol. Gag provides the virus structure. Gag-Pol carries important viral enzymes, including reverse transcriptase, integrase, and protease. After these polyproteins are made, they move to the host cell membrane. There, they help build an immature viral particle that buds from the cell surface. Budding...

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Learn how HIV protease inhibitors block polyprotein cleavage, prevent virion maturation, and leave new virus particles noninfectious in host cells.

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HIV Protease Inhibitors and Maturation

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