CD4 Human (203-317)

CD4, also known as cluster of differentiation 4, is a single-chain transmembrane glycoprotein that plays a crucial role in the immune system. It is predominantly found on the surface of T-helper cells, which are essential for the immune response. The CD4 molecule is involved in the recognition of antigens presented by antigen-presenting cells (APCs) in conjunction with major histocompatibility complex (MHC) class II molecules .

The CD4 protein consists of several domains, with the 203-317 amino acid (a.a.) region being of particular interest. This region is part of the extracellular domain of the protein, which is responsible for binding to MHC class II molecules. The interaction between CD4 and MHC class II is critical for the activation of T-helper cells and the subsequent immune response .

CD4 is also known to serve as a receptor for the human immunodeficiency virus (HIV). The virus binds to the CD4 molecule on the surface of T-helper cells, allowing it to enter and infect the cells. This interaction is a key factor in the pathogenesis of HIV/AIDS .

Recombinant CD-4 (203-317 a.a.) is a human-derived protein produced using recombinant DNA technology. This involves inserting the gene encoding the CD4 protein into a host organism, such as Escherichia coli, which then produces the protein. The recombinant protein is typically purified and used for various research applications .

The recombinant CD-4 (203-317 a.a.) protein is often tagged with a His-tag to facilitate purification and detection. It is supplied as a sterile lyophilized powder and can be reconstituted in sterile water for use in laboratory experiments .

Recombinant CD-4 (203-317 a.a.) has several important applications in biomedical research, including:

• Protein Assays: Used to study the interaction between CD4 and other molecules, such as MHC class II and HIV.
• Antibody Production: Employed as an antigen to generate antibodies against the CD4 protein.
• Western Blotting: Utilized as a positive control in Western blot experiments to detect CD4 protein expression .

The recombinant CD-4 (203-317 a.a.) protein should be stored at -20°C to -80°C to maintain its stability. It is important to avoid repeated freeze-thaw cycles, as this can degrade the protein. When stored properly, the protein remains stable for up to 12 months .