Recombinant Human CD4/LEU3 Protein (Fc Tag)

Specifications

Catalog number

PKSH033507-01

Size / count

10 µg

Dry ice

No

Hazardous

No

Discontinued

No

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. Viral protein U (VpU) of HIV-1 plays an important role in downregulation of the main HIV-1 receptor CD4 from the surface of infected cells. Physical binding of VpU to newly synthesized CD4 in the endoplasmic reticulum is an early step in a pathway leading to proteasomal degradation of CD4. Amino acids in both helices found in the cytoplasmic region of VpU in membrane-mimicking detergent micelles experience chemical shift perturbations upon binding to CD4, whereas amino acids between the two helices and at the C-terminus of VpU show no or only small changes, respectively. Paramagnetic spin labels were attached at three sequence positions of a CD4 peptide comprising the transmembrane and cytosolic domains of the receptor. VpU binds to a membrane-proximal region in the cytoplasmic domain of CD4.

Abbreviation

CD4; LEU3

Synonyms

CD4; CD4mut; Scd4; T-cell surface antigen T4/Leu-3; T-cell surface glycoprotein CD4

UniProt

P01730

Accession Number

P01730

Expression System

HEK293 Cells

Tag

C-Fc

Sequence

Lys26-Trp390

Field of Research

Immunology; Stem cells

Endotoxin

< 1.0 EU per μg of the protein as determined by the LAL method.

Purity

> 95 % as determined by reducing SDS-PAGE.

Bioactivity

Not validated for activity

Reconstitution

Please refer to the printed manual for detailed information.

Shipping Conditions

This product is provided as lyophilized powder which is shipped with ice packs.

Storage Conditions

Generally, lyophilized proteins are stable for up to 12 months when stored at -20 to -80°C. Reconstituted protein solution can be stored at 4-8°C for 2-7 days. Aliquots of reconstituted samples are stable at < -20°C for 3 months.

Calculated Molecular Weight

67.6 kDa

Observed Molecular Weight

70-85 kDa

Species

Human