Gp120
Glycoprotein Gp120, named for its molecular weight, is found on the surface of HIV envelope. Gp120 is associated with Gp41. It is involved in the binding of HIV to CD4 receptors thus attaching the virus to the host cell. In HIV the third variable loop (V3) residues 296-331 of Gp120 allows the virus to infect human immune cells. For more details see Molecular Mechanism of HIV-1 gp120 Mutations That Reduce CD4 Binding Affinity [1]Despite abundant efforts in HIV research the HI-virus remains one of the most serious infectious health threats for human worldwide. Infection involves the entry of the virus into CD4 carrying cells and is mediated by the recognition of the (colored in yellow) by (colored in green). The CD4-binding site of gp120 contains , termed the ‘CD4-binding loop’ (in blue) and the ‘outer domain exit (ODE) loop’ (colored in salmon), respectively. Importantly, is a key target site for gp120-ligands to interfere with the gp120-CD4 interaction and thereby hampering infection. Carbons of the important residues are colored in white, nitrogens in blue, and oxygens in red. Therapeutic ligands include for instance soluble CD4 and its variants. For the development of more potent gp120-ligands targeting the CD4-binding site we investigated two gp120-proteins from two clinical HIV isolates that exhibit a decreased affinity for soluble CD4. Each variant exhibits a set of simultaneous mutations in the CD4-binding loop and the ODE-loop. The exhibits three mutations in the CD4-binding loop (P369A, I371L, T373M) and two mutations in the ODE-loop (G471E, D474N). The protein contains three simultaneous mutations: V372E, T373M in the CD4-binding loop, and D474N in the ODE-loop. Carbons of the mutated residues are colored in white, nitrogens in blue, oxygens in red, and sulfur in yellow. To understand the phenomenon of reduced CD4-binding on a structural level the two gp120 variants were modeled, each with its specific set of mutations, and simulated using molecular dynamics. The results show that the mutant glutamates of both variants play a key role for reduced CD4 binding by affecting the conformation of the CD4-binding and ODE-loop. This knowledge should be helpful to predict the resistance of novel gp120 mutants or to design gp120-ligands with improved binding properties.
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3D structures of Gp1203D structures of Gp120
Updated on 18-August-2014
Gp120 from HIVGp120 from HIV
3dnl, 3dnn, 3dno, 3tgq, 3tgr, 3tgt, 3tih - Gp120 core
1meq – GP120 C5 domain – NMR
1niz, 1nj0, 2esx, 2esz, 1u6u, 1u6v - GP120 V3 loop – NMR
4jpj - Gp120 outer domain
Gp120 binary complexGp120 binary complex
3idx, 3idy, 2ny7. 4jdt - Gp120 core (mutant) + antibody
3se8, 3se9, 3hi1, 3rjq, 4jkp, 4jm2, 4lss, 4lsv - Gp120 + antibody
3ngb - Gp120 + antibody VRC01
4i3r, 4i3s - Gp120 outer domain + antibody VRC-PG04
4jan, 4lst - Gp120 Clade C + antibody
4jb9, 4lsp, 4lsq, 4lsr, 4lsu - Gp120 Clade A/E + antibody
4jpj - Gp120 Clade A + antibody
4jpw - Gp120 Clade A (mutant) + antibody
3u2s - Gp120 V1V2 region + antibody PG9
3tgs, 4dko, 4dkp, 4dkq, 4dkr - Gp120 core + piperidine derivative
4dku, 4dkv - Gp120 core (mutant) + CD4 mimetic
4jzw, 4jzz, 4k0a, 4ka2 - Gp120 core + CD4 mimetic miniprotein
Gp120 ternary complexGp120 ternary complex
1gc1, 1g9m, 1g9n, 1rzj, 1rzk, 1yyl, 1yym – Gp120 core (mutant) + hCD4 N terminal (mutant) + antibody 17B
2b4c - Gp120 core (mutant) + hCD4 N terminal + antibody X5
2nxy, 2nxz, 2ny0, 2ny1, 2ny2, 2ny3, 2ny4, 2ny5, 2ny6 - Gp120 core (mutant) + hCD4 N terminal + antibody 17B
3jwd, 3jwo - Gp120 core + hCD4 N terminal + antibody 48D
2i5y, 2i60 - Gp120 core + hCD4 N terminal + antibody 17B
4laj - Gp120 core + CD4 mimetic miniprotein + antibody
Gp120 from SIVGp120 from SIV
ReferencesReferences
- ↑ Kassler K, Sticht H. Molecular mechanism of HIV-1 gp120 mutations that reduce CD4 binding affinity. J Biomol Struct Dyn. 2013 Jan 9. PMID:23297802 doi:10.1080/07391102.2012.746946