Flt-1 (human 1338aa, rat 1336aa and mouse 1330aa), a putative receptor protein tyrosine kinase, is a receptor for VEGF and PLGF. Flt-1 (fms-like tyrosine kinase-1) is a member of the flt family of receptor tyrosine kinases that also includes KDR/flk-1 and flt-4. The flt family encodes receptors for VEGF (vascular endothelial growth factor) that are characterized by seven Ig-like loops within their extracellular domain and a split kinase domain within the cytoplasmic domain. VEGF is an important angiogenic factor of many solid tumors and is also involved in the differentiation of endothelial cells. It has been reported that flt-1 receptor dimerization precedes phosphorylation after VEGF binding. Flt-1 has also been described as VEGFR1 and Flk-2. It is type 1 membrane protein and is expressed in normal lung, placenta, liver, kidney, heart, and brain but not in tumor cells. Human Flt1 (GenBank Accession No. AF063657), (a.a. 783-end) with N-terminal His tag, MW 67.5kD, expressed in an Baculovirus infected Sf9 cell expression system. Specific Activity: 170 U/mg. One unit is defined as the amount of enzyme that will incorporate 1 nmol phosphate to the tyrosine substrate per minute at pH 7.4 and 30C. Assay buffer: 50mM HEPES, pH 7.4, 3mM MgCl2, 3mM MnCl2, 1mM DTT, 3uM Na-orthovanadate, 0.1mM ATP, 30ug/ml Poly (Glu:Tyr)4:1 substrate, and 4ug /ml recombinant Flt1. Application: useful for the study of enzyme kinetics, screening inhibitors, and selectivity profiling. Stability: >6 months at -80C
