Phosphoinositide 3 kinase, p85 alpha/p110 beta, active, Recombinant, Human (PI3K)

The PI3Kb isoform can be activated by insulin via the insulin receptor to initiate a cascade of events that control cell growth and metabolism. The activation of PI3Kb is mediated by the p85 regulatory subunit binding to tyrosine phosphorylated insulin receptor substrate (IRS) proteins (e.g. IRS-1 and IRS-2). It was also shown that PI3Kb is involved in apoptosis in human colon carcinoma cells. Injection of neutralizing antibodies specific to p110b in WiDr, HCT116 and CO 115 adenocarcinoma cells inhibited de novo DNA synthesis. PI3Kb is the major PI3K isoform required for apoptotic cell and Fc-g receptor mediated phagocytosis shown for primary mouse macrophages and the Jurkat human leukemia T cell line. It was shown by several research groups that the catalytic subunit of PI3Kb can be activated by Gbg subunits of G-protein coupled receptors. Recombinant Human Phosphoinositide 3-kinase beta is a glycosilated protein having a molecular weight as follows: p85 chain 83.5kD, p110 chain 124.3kD. Complex of N-terminal His6- tagged recombinant full-length human p110b and untagged, recombinant, full length, human p85a. Coexpressed by baculovirus in Sf21 insect cells. Specific Activity:, ~40U/mg, where one unit of PI3 Kinase (p110b/p85a) activity is defined as 1nmol phosphatidylinositol 3,4,5-trisphosphate formed per minute at 22°C with a final ATP concentration of 10uM. Applications: Kinase Assay, MS Tryptic Fingerprint: Confirmed identity as PI3 Kinase (p110b/p85a) with 26% amino acid coverage of the translated native p110bbeta sequence and 32% amino acid coverage of the translated native p85a. 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.