Gp120 (HIV)
| Surface protein gp120 (HIV 1, isolate HXB2, group M, subtype B) | ||
|---|---|---|
| Mass / length primary structure | 479 amino acids | |
| Secondary to quaternary structure | Trimer of gp120 + gp41 | |
| Cofactor | gp41 | |
| Precursor | gp160 (824 aa) | |
| Isoforms | lots | |
| Identifier | ||
| External IDs | ||
gp120 is a glycoprotein that is found on the surface of HIV virus particles. The number 120 in its name means that its molecular mass is 120 kDa .
The protein consists of an outer and an inner area and a connecting bridge. It is made up of 500 amino acids . It forms a kind of cap over the end of gp41 and thus represents a gp120 / gp41 subunit. Without this cap, human antibodies could recognize the virus by attaching themselves to the end of gp41. When the virus now attaches itself to a human cell, gp120 changes its configuration suddenly and exposes gp41. This then attaches to the cell.
The HI virus often mutates and is therefore not recognized by the immune system. But there is one area that must always remain the same so that the virus can attach itself to human cells and infect them. The glycoprotein gp120, like gp41, is bound to the cell membrane by non-covalent bonds. Both are descendants of the cleaved protein gp160 . This infects every cell with a CD4 receptor, especially the T helper cell , by attaching itself to it. This compound is mainly ionic, although Van der Waals forces and hydrogen bonds also play a role.
Web links
- Morrow / Bukrinsky / reactome: Binding and entry of HIV virion