PathScan^® Phospho-Syk (panTyr) Sandwich ELISA Kit

The PathScan^® Phospho-Syk (panTyr) Sandwich ELISA Kit is a solid phase sandwich enzyme-linked immunosorbent assay (ELISA) that detects endogenous levels of Syk when phosphorylated at tyrosine residues. A Syk mouse mAb has been coated onto the microwells. After incubation with cell lysates, Syk (phospho and nonphospho) is captured by the coated antibody. Following extensive washing, a biotinylated phospho-tyrosine mouse detection antibody is added to detect tyrosine phosphorylation of the captured Syk protein. HRP-linked strepavidin is then used to recognize the bound detection antibody. HRP substrate, TMB, is added to develop color. The magnitude of the absorbance for this developed color is proportional to the quantity of Syk phosphorylated on tyrosine.

*Antibodies in this kit are custom formulations specific to kit.

CST's PathScan^® Phospho-Syk (panTyr) Sandwich ELISA Kit #7928 detects Syk when tyrosine phosphorylated. As shown in Figure 1, a significant induction of Syk tyrosine phosphorylation can be detected in Ramos cells following treatment with anti-human IgM using the Phospho-Syk (panTyr) Sandwich ELISA Kit #7928. The level of total Syk (phospho and nonphospho) remains unchanged as shown by western analysis. This kit detects proteins from the indicated species, as determined through in-house testing, but may also detect homologous proteins from other species.

Syk is a protein tyrosine kinase that plays an important role in intracellular signal transduction in hematopoietic cells (1-3). Syk interacts with immunoreceptor tyrosine-based activation motifs (ITAMs) located in the cytoplasmic domains of immune receptors (4). It couples the activated immunoreceptors to downstream signaling events that mediate diverse cellular responses, including proliferation, differentiation, and phagocytosis (4). There is also evidence of a role for Syk in nonimmune cells and investigators have indicated that Syk is a potential tumor suppressor in human breast carcinomas (5). Tyr323 is a negative regulatory phosphorylation site within the SH2-kinase linker region in Syk. Phosphorylation at Tyr323 provides a direct binding site for the TKB domain of Cbl (6,7). Tyr352 of Syk is involved in the association of PLCγ1 (8). Tyr525 and Tyr526 are located in the activation loop of the Syk kinase domain; phosphorylation at Tyr525/526 of human Syk (equivalent to Tyr519/520 of mouse Syk) is essential for Syk function (9).