JAK2, active, Recombinant, Human (Janus Kinase 2)

The Janus (JAK) family of cytoplasmic tyrosine kinases has been implicated in signal transduction induced by cytokines and growth factors, physically associated with ligand-bound receptors. This association that results in tyrosine phosphorylation and activation. JAK1 is approximately 130kD and contains a C-terminal tyrosine kinase domain, an adjacent kinase or kinase-related domain, and five other domains that are highly conserved among JAK family members. Family members such as JAK1, JAK2, and TYK2 are ubiquitous, whereas JAK3 is predominantly expressed in T lymphocytes. Studies with mutant cells that do not express JAK1, JAK2, or TYK2 show that their activation is essential for cellular signaling. JAK family kinases may either phosphorylate each other or be phosphorylated by a yet undescribed tyrosine kinase. Different cytokines can activate via phosphorylation distinct JAK family members. In some cells, the membrane-associated gp130 protein has been implicated in the induction of JAK family phosphorylation, although gp130 itself has no known activity. C-terminal His6-tagged, recombinant, human JAK2, aa808-end, expressed by baculovirus in Sf21 cells. , Specific Activity: , ~4000U/mg, where one unit of JAK2 activity is defined as 1nmol phosphate incorporated into 100uM PDKtide (KTFCGTPEYLAPEVRREPRILSEEEQEMFRDFDYIADWC) per minute at 30°C with a final ATP concentration of 100uM. Applications: MS Tryptic Fingerprint: Confirmed identity as JAK2 with 40% amino acid coverage of the translated native sequence., JAK2 Kinase Assay: 3.1-12.4ng of this lot of enzyme phosphorylated 100uM PDKtide in the assay. Assay background was subtracted from the actual counts to yield the results. Storage and Stability: May be stored at 4°C for short-term only. For long-term storage, store at -20°C. Aliquots are stable for at least 6 months at -20°C. For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap. Further dilutions can be made in assay buffer.