Zap 70, active, Recombinant, Human (TCR Zeta Associated Protein kinase 70kD)

ZAP-70 is a non-receptor protein tyrosine kinase (part of the Syk/ZAP-70 family) that is involved in signaling by the T-cell antigen receptor (TCR). Ligation of the TCR/CD3 receptor in Jurkat T-cells induces phosphoprotein complexes which contain ZAP-70 (1). TCR zeta chains are initially phosphorylated by p56Lck that lead to recruitment of ZAP-70 via its SH2 domain. ZAP-70 in turn phosphorylates other proteins in the TCR-phosphoprotein complex. ZAP-70 is tyrosine phosphorylated in Jurkat T cells and in purified peripheral T cells after MHC-I ligation. Phosphorylation of ZAP-70 after MHC-I ligation is dependent on TCR/CD3 surface expression. Substrates for ZAP-70 include the zeta-chain dimer of the TCR/CD3 complex and LAT (linker for activation of T cells) (2). Direct tyrosine phosphorylation of LAT with activated ZAP-70 is necessary and sufficient for the association and activation of signaling proteins. ZAP-70 efficiently phosphorylates LAT on tyrosine residues at positions 226, 191, 171, 132 and 127. These tyrosine residues in LAT have been shown to be required for the direct interaction and \nactivation of Vav, p85/p110alpha and phospholipase C g 1 (PLCg1) (3). \n\nSpecific Activity: 500nmol/min/mg\n \nActivity Assay: \nKinase activity is measured as the molar amount of phosphate incorporated into Poly Glu-Tyr substrate per minute per mg protein at 30 degrees C using a final concentration of 50uM [32P] ATP.\n\nStorage and Stability:\nMay be stored at 4 degrees C for short-term only. For long-term storage, aliquot to avoid repeated freezing and thawing and freeze at -70 degrees C. For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap. Aliquots are stable for at least 12 months.

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SPECIFICATIONS

Catalog Number

Z0300-10G

Size

5ug

Form

Supplied in 50mM Tris-HCl, pH 7.5, 150mM sodium chloride, 0.25mM DTT, 0.1mM EGTA, 0.1mM EDTA, 0.1mM PMSF, 25% glycerol.

Purity

(same/more than) 90% as determined by SDS-PAGE analysis.

References

1. Nel, A.E., Gupta, S., Lee, L., Ledbetter, J.A., Kanner, S.B. (1995) J Biol Chem. 27031:18428-36. \n2. Skov, S., Bregenholt, S., Claesson, M.H. (1997) J Immunol. 158(7):3189-96. \n3. Paz, P.E., Wang, S., Clarke, H., Lu, X., Stokoe, D., Abo, A. (2001) Biochem J. 356(Pt 2:461-71.