<unk>  is a protease inhibitor: it inhibits HIV-1 and HIV-2 proteases. HIV protease is an aspartate protease which splits viral protein molecules into smaller fragments, and it is vital to both the replication of the virus within the cell, and also to the release of mature viral particles from an infected cell.<unk>  is a competitive inhibitor (2 nM) which is designed to bind tightly and is not cleaved due to the presence of a hydroxyl group as opposed to a keto group in the middle amino acid residue mimic, which would be otherwise S-phenylcysteine. All protease inhibitors bind to the protease, the precise mode of binding determines how the molecule inhibits the protease. The way<unk>  binds the enzyme may be sufficiently unique to reduce cross-resistance between it and other PIs. Also, not all PIs inhibit both HIV-1 and HIV-2 proteases.
Nelfinavir
Ritonavir
Amprenavir
Saquinavir
Fosamprenavir
Indinavir
Lopinavir
Entecavir