Published Paper Source: http://www.scientificamerican.com/article.cfm?id=new-protein-blocks-hiv
A team of researchers (led by Peter S. Kim) of the Whitehead Institute for Biomedical Research has discovered a protein that can block HIV.
The protein is 5-Helix and it blocks HIV entry into the body when it binds to a region of the HIV protein coat known as gp41 and therefore act as an entry inhibitor. To understand what this means, you must first understand how HIV enters into a human cell. This is done in 5 steps:
- Binding of HIV surface protein gp120 to CD4 receptor.
- A conformational change in gp120 increases its affinity for a co-receptor and exposes gp41
- Binding of gp120 to co-receptor CCR5 or CXCR4
- Penetration of the cell membrane by gp41. This approximates the membrane of HIV and T cell and promotes their fusion.
- Entry of the viral core into the cell.
Protein 5-Helix therefore prevents step 4, and gp41 does not penetrate the cell membrane when they bind together. Step 5 is avoided by consequence and the viral core is prevented from entering into the human cell.
HIV is always mutating, it never becomes fixed and 5-Helix also seems to successfully prevent a wide range of HIV strains and hence would be useful in creating a new class of anti-HIV drugs. 5-Helix may even help in fighting other viruses like Ebola, human respiratory syncytial virus (HRSV) and influenza all of which show similar characteristics to HIV.
On the other hand, 5-Helix can be used as preventative treatment or a vaccine.
T-20 is another entry inhibitor that also may have had the same effect as 5-Helix but it was required in large amounts to give a positive result while 5-helix gave the positive result in little amounts.
5-helix inhibits HIV in cell culture.The research team is now determining if 5-helix works in animal models so that they can develop it for humans.
I found this article to be particularly interesting because of the recent developments in HIV which includes a baby and 14 people that were ‘functionally cured’ of HIV. This story can be found in the following article:
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