Transcobalamin II, also known as TCN2 and TC II, is a plasma protein that binds cobalamin (Cbl; vitamin B12) as it is absorbed in the terminal ileum and distributes to tissues. The circulating transcobalamin II-cobalamin complex binds to receptors on the plasma membrane of tissue cells and is then internalized by receptor-mediated endocytosis. Transcobalamin II is a non-glycolated secretory protein of molecular mass 43 kDa. Its plasma membrane receptor (TC II-R) is a heavily glycosylated protein with a monomeric molecular mass of 62 kDa. Human TCN2 gene is composed of nine exons and eight introns spanning approximately 20 kb with multiple potential transcription start sites. A number of genetic abnormalities are characterized either by a failure to express TCN2 or by synthesis of an abnormal protein. The TCN2 deficiency results in cellular cobalamin deficiency, an early onset of megaloblastic anaemia, and neurological abnormalities.
Measured by its binding ability in a functional ELISA. Immobilized human TCN2-His at 10µg/mL (100?L/well) can bind biotinylated mouse CD320-His.The EC50 of biotinylated mouse CD320-His is 18-42 ng/mL.
Endotoxin:
<1.0 EU per µg as determined by the LAL method.
Protein Construction:
A DNA sequence encoding the human TCN2 (NP_000346.2) (Met 1-Trp 427) with a C-terminal polyhistidine tag was expressed.
Purity:
> 90 % as determined by reducing SDS-PAGE.
Mol Mass:
46.7 kDa
AP Mol Mass:
43 kDa
Formulation:
Lyophilized from sterile PBS, pH 7.4
Shipping:
This product is provided as lyophilized powder which is shipped with ice packs.
Stability and Storage:
Lyophilized proteins are stable for up to 12 months when stored at -20 to -80°C. Reconstituted protein solution can be stored at 4-8°C for 2-7 days. Aliquots of reconstituted samples are stable at < -20°C for 3 months.
