HIV-1 gp41, Biotin

Human Immunodeficiency Virus type 1 (HIV-1) is a retrovirus that primarily targets the human immune system, leading to a progressive failure of the immune system and increased susceptibility to opportunistic infections. HIV-1 gp41 is a glycoprotein that plays a crucial role in the virus’s ability to infect host cells. It is part of the envelope protein complex, which also includes gp120. The gp41 protein facilitates the fusion of the viral membrane with the host cell membrane, a critical step in the viral entry process.

Recombinant HIV-1 gp41 refers to the laboratory-produced version of the gp41 protein. This recombinant protein is typically produced using bacterial expression systems, such as Escherichia coli (E. coli). The recombinant form is often used in research and diagnostic applications due to its high purity and consistency.

Biotin labeling involves attaching biotin molecules to the recombinant protein. Biotin is a small molecule that has a high affinity for streptavidin and avidin, proteins commonly used in various biochemical assays. The biotin-streptavidin interaction is one of the strongest known non-covalent interactions, making biotin-labeled proteins highly useful in a range of applications, including enzyme-linked immunosorbent assays (ELISA), Western blotting, and immunoprecipitation.

The biotin-labeled recombinant HIV-1 gp41 protein is produced in E. coli and is a non-glycosylated polypeptide chain. It contains the immunodominant regions of the HIV-1 gp41 protein, specifically amino acids 444-833 . The biotinylated version is often fused to beta-galactosidase at the N-terminus, resulting in a protein with a molecular weight of approximately 114 kDa .

The protein is typically formulated in a solution containing 8M urea, 20mM Tris-HCl (pH 8.0), and 10mM beta-mercaptoethanol . It is highly pure, with a purity greater than 95% as determined by high-performance liquid chromatography (HPLC) and SDS-PAGE analysis .

Biotin-labeled recombinant HIV-1 gp41 is widely used in research and diagnostic applications. It is particularly useful in ELISA and Western blot assays for the detection of HIV-1 antibodies. The high specificity and sensitivity of the biotin-labeled protein make it an excellent antigen for early detection of HIV seroconverters .

The biotin-labeled recombinant HIV-1 gp41 protein is stable at 4°C for up to one week but should be stored below -18°C for long-term storage . It is important to avoid repeated freeze-thaw cycles to maintain the protein’s integrity and functionality.