gp120 protein

The gp120 protein is a glycoprotein found on the outer surface of the HIV virion. It has a molecular weight of 120 and is crucial for the virus's ability to infect human cells.1

Before HIV can infect a cell, the gp120 protein must bind to a CD4 receptor on the surface of a helper T cell (also known as a CD4+ T cell). This binding event initiates a complex process that allows the virus's genetic material to enter the T cell. Helper T cells are vital components of the immune system, and their destruction by HIV leads to AIDS. The gp120 protein's interaction with CD4 and other cell-surface proteins, called chemokine receptors, facilitates HIV's entry into the host cell.12