HIV type 2 Envelope glycoprotein 36, recombinant protein from E. coli
Recombinant Human Immunodeficiency Virus Type 2 Envelope, Gp36, contains the HIV-2 immunodominant region of envelope gp36 (Not full-length gp36), but does not contain a fusion partner. Immunoreactive with HIV-2 positive sera. It was expressed in E. coli,
> 95% pure (10% PAGE coomassie staining). DEAE Sepharose chromatography
50mM Tris HCl, 8M Urea, pH 8.4
2-8°C short term, -20°C long term
HIV-1 and HIV-2 appear to package their RNA differently. HIV-1 binds to any appropriate RNA whereas HIV-2 preferentially binds to mRNA which creates the Gag protein itself. This means that HIV-1 is better able to mutate. HIV-2 is transmitted in the same ways as HIV-1: Through exposure to bodily fluids such as blood, semen, tears and vaginal fluids. Immunodeficiency develops more slowly with HIV-2.HIV-2 is less infectious in the early stages of the virus than with HIV-1.The infectiousness of HIV-2 increases as the virus progresses.Major differences include reduced pathogenicity of HIV-2 relative to HIV-1, enhanced immune control of HIV-2 infection and often some degree of CD4-independence. Despite considerable sequence and phenotypic differences between HIV-1 and 2 envelopes, structurally they are quite similar. Both membrane-anchored proteins eventually form the 6-helix bundles from the N-terminal and C-terminal regions of the ectodomain, which is common to many viral and cellular fusion proteins and which seems to drive fusion. HIV-1 gp41 helical regions can form more stable 6-helix bundles than HIV-2 gp41 helical regions however HIV-2 fusion occurs at a lower threshold temperature (25°C), does not require Ca2+ in the medium, is insensitive to treatment of target cells with cytochalasin B, and is not affected by target membrane glycosphingolipid composition.
The env gp36 ectodomain is highly conserved and elicits a type-specific antibody response. Hence, most licensed diagnostic assays incorporate gp36-derived antigens to detect HIV2 specific antibodies. It is becoming important to differentiate between single infection with either HIV1 or HIV2 and dual infection.
Gp36; HIV 2; Human immunodeficiency virus 2; Human Immunodeficiency Virus Type 2; HIV-2 Gp36; Human Immunodeficiency Virus Type 2 Gp36; Retroviridae; Lentivirus