Which viral protein does Fuzeon target in the HIV lifecycle?

Fuzeon, also known as enfuvirtide, specifically targets gp41, which is a crucial protein involved in the HIV lifecycle. gp41 is a transmembrane protein that facilitates the fusion of the HIV virus with the host cell membrane. By binding to gp41, Fuzeon prevents this fusion process, effectively inhibiting the virus from entering the host cells and thus halting the infection process.

In the context of HIV, gp120 is another protein found on the viral surface that plays a key role in receptor binding and is not the target of Fuzeon. P24 is a structural protein that forms part of the viral core, and env refers to the envelope protein that contains both gp120 and gp41, but Fuzeon's action is specifically on the gp41 component to disrupt the entry mechanism of the virus. Thus, targeting gp41 is essential for the therapeutic action of Fuzeon in preventing HIV fusion and subsequent infection.