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Human CD4 / LEU3 Protein (aa 1-208, His Tag)

CD4mut

Catalog Number P10400-H08H1
Organism Species Human
Host Human Cells
Synonyms CD4mut
Molecular Weight The secreted recombinant human CD4 (aa 1-208) consists of 194 amino acids and has a predicted molecular mass of 21.7 kDa. In SDS-PAGE under reducing conditions, the apparent molecular mass of rhCD4 is approximately 26 kDa.
predicted N Lys 26
SDS-PAGE
Purity > 94 % as determined by SDS-PAGE
Protein Construction A DNA sequence encoding the human CD4 (NP_000607.1) N-terminal two domains (D1D2) (Met 1-Ser 208) was fused with a polyhistidine tag at the C-terminus.
Bio-activity 1. Measured by its ability to bind human CD28 in a functional ELISA .
2. Measured by the ability of the immobilized protein to support the adhesion of HeLa human cervical epithelial carcinoma cells . When 5 x 10E4 cells/well are added to CD4-coated plates (2.5 μg/ml and 100 μl/well), approximately 40 %-60 % will adhere specifically after 60 minutes at 37℃.
Research Area Immunology |Adaptive Immunity |T Cell |T Cell CD Antigen
Formulation Lyophilized from sterile PBS, pH 7.4
1. Normally 5 % - 8 % trehalose, mannitol and 0.01% Tween80 are added as protectants before lyophilization. Specific concentrations are included in the hardcopy of COA.
Background T-cell surface glycoprotein CD4,  is a single-pass type I membrane protein. CD4 contains three Ig-like C2-type (immunoglobulin-like) domains and one Ig-like V-type (immunoglobulin-like) domain. CD4 is a glycoprotein expressed on the surface of T helper cells, regulatory T cells, monocytes, macrophages, and dendritic cells. The CD4 surface determinant, previously associated as a phenotypic marker for helper/inducer subsets of T lymphocytes, has now been critically identified as the binding/entry protein for human immunodeficiency viruses (HIV). The human CD4 molecule is readily detectable on monocytes, T lymphocytes, and brain tissues. All human tissue sources of CD4 bind radiolabeled gp120 to the same relative degree; however, the murine homologous protein, L3T4, does not bind the HIV envelope protein. CD4 is a co-receptor that assists the T cell receptor (TCR) to activate its T cell following an interaction with an antigen presenting cell. Using its portion that resides inside the T cell, CD4 amplifies the signal generated by the TCR. CD4 interacts directly with MHC class II molecules on the surface of the antigen presenting cell via its extracellular domain. The CD4 molecule is currently the object of intense interest and investigation both because of its role in normal T-cell function, and because of its role in HIV infection. CD4 is a primary receptor used by HIV-1 to gain entry into host T cells. HIV infection leads to a progressive reduction of the number of T cells possessing CD4 receptors.
Reference
  • Farrar WL, et al. (1988) Characterization of CD4 glycoprotein determinant-HIV envelope protein interactions: perspectives for analog and vaccine development. Crit Rev Immunol. 8(4): 315-39.
  • Biddison WE, et al. (1989) CD4 expression and function in HLA class II-specific T cells. Immunol Rev. 109: 5-15.
  • Singh SK, et al. (2012) Mapping the interaction between the cytoplasmic domains of HIV-1 viral protein U and human CD4 with NMR spectroscopy. FEBS J. 279(19):3705-14.