CD8 alpha Protein, Rat (HEK293, Fc)

CD8 alpha is an important immune glycoprotein that serves as a coreceptor for MHC class I:peptide complexes, linking T cells to antigens presented by APCs. It interacts with TCR and MHC class I, recruits LCK kinase, and initiates multiple signaling pathways. CD8 alpha Protein, Rat (HEK293, Fc) is the recombinant rat-derived CD8 alpha protein, expressed by HEK293 , with C-hFc labeled tag. The total length of CD8 alpha Protein, Rat (HEK293, Fc) is 189 a.a., with molecular weight of 50-56 kDa.

The CD8 alpha protein, an integral membrane glycoprotein, plays a pivotal role in the immune response, serving multiple functions in responses against both external and internal threats. In T-cells, it functions primarily as a coreceptor for the MHC class I molecule:peptide complex, interacting simultaneously with the T-cell receptor (TCR) and the MHC class I proteins presented by antigen-presenting cells (APCs). This interaction facilitates the recruitment of the Src kinase LCK to the vicinity of the TCR-CD3 complex. LCK, in turn, initiates various intracellular signaling pathways by phosphorylating diverse substrates, ultimately leading to lymphokine production, motility, adhesion, and the activation of cytotoxic T-lymphocytes (CTLs). This mechanism enables CTLs to recognize and eliminate infected cells and tumor cells. In NK-cells, the presence of CD8A homodimers at the cell surface provides a survival mechanism, allowing the conjugation and lysis of multiple target cells. CD8A homodimer molecules also contribute to the survival and differentiation of activated lymphocytes into memory CD8 T-cells. CD8 alpha forms disulfide-linked heterodimers with CD8B at the cell surface and also homodimers in various cell types, including NK-cells and peripheral blood T-lymphocytes. Additionally, it interacts with the MHC class I HLA-A/B2M dimer and associates with LCK in a zinc-dependent manner.

Measured by its ability of the immobilized protein to support the adhesion of Jurkat human acute T cell leukemia cells. The ED₅₀ for this effect is 2.584 μg/mL, corresponding to a specific activity is 387.0 units/mg.

Rat

HEK293

C-hFc

P07725 (Q27-Y189)

24930  [NCBI]

QLQLSPKKVDAEIGQEVKLTCEVLRDTSQGCSWLFRNSSSELLQPTFIIYVSSSRSKLNDILDPNLFSARKENNKYILTLSKFSTKNQGYYFCSITSNSVMYFSPLVPVFQKVNSIITKPVTRAPTPVPPPTGTPRPLRPEACRPGASGSVEGMGLGFACDIY

Approximately 50-56 kDa due to the glycosylation.

Greater than 95% as determined by reducing SDS-PAGE.

Lyophilized powder.

Lyophilized from a 0.2 μm filtered solution of PBS, pH 7.4.

<1 EU/μg, determined by LAL method.

It is not recommended to reconstitute to a concentration less than 100 μg/mL in ddH₂O. For long term storage it is recommended to add a carrier protein (0.1% BSA, 5% HSA, 10% FBS or 5% Trehalose).

Stored at -20°C for 2 years. After reconstitution, it is stable at 4°C for 1 week or -20°C for longer (with carrier protein). It is recommended to freeze aliquots at -20°C or -80°C for extended storage.

Room temperature in continental US; may vary elsewhere.