Anti-LCK Antibody

From Antibodies.com, this rabbit polyclonal IgG reagent targets LCK, the 56 kDa Src-family non-receptor tyrosine kinase (UniProt P06239) that initiates T-cell receptor signaling in T lymphocytes. The unconjugated antibody is supplied as 100 µl of liquid and has been validated for Western blot, immunohistochemistry, immunofluorescence, and flow cytometry on human and mouse samples.

LCK contains N-terminal myristoylation and palmitoylation motifs that anchor it to the inner plasma membrane, together with an N-terminal SH3 domain, a central SH2 domain, and a C-terminal catalytic tyrosine kinase domain. Its enzymatic activity is upregulated by trans-autophosphorylation at Tyr394 within the activation loop and downregulated by Csk-mediated phosphorylation at Tyr505 in the C-terminal tail, and loss-of-function variants in LCK cause the combined immunodeficiency disorder IMD22.

On T-cell receptor engagement, membrane-proximal LCK phosphorylates the ITAM motifs of the associated CD3 chains, generating docking sites that recruit ZAP-70, which LCK in turn activates by phosphorylation. The LCK SH2 domain also binds the cytoplasmic tails of the CD4 and CD8 co-receptors, coupling peptide-MHC recognition to the downstream tyrosine phosphorylation cascade. The reagent therefore supports work on thymic selection, mature T-cell activation, ITAM phosphorylation, and LCK-dependent leukemic signaling, and it can be applied in flow cytometry to resolve LCK-positive T-cell populations. To preserve activity, limit freeze-thaw cycles of the vial, protect from light, and refrigerate between uses.