Klotho beta, Recombinant, Mouse (Beta-klotho, BKL, BetaKlotho, Klotho beta-like Protein)

Klotho b, a divergent structural member of the glycosidase I superfamily, is expressed primarily in the liver and pancreas, with lower expression in adipose tissue.1 Like Klotho, Klotho b facilitates binding between FGF19 subfamily members and their receptors via formation of a ternary complex.2 The Klotho b mediated interaction of FGF15 (human FGF19) with FGF Receptor 4 in the liver negatively regulates bile acid synthesis by controlling the secretion of two key bile acid synthase genes, cholesterol 7-a hydroxylase (Cyp7a1) and sterol 12-a hydroxylase (Cyp8b1).2-4 Klotho b is also a cofactor for the interaction of FGF21 with FGF Receptor 1c in adipocytes, which allows FGF21 to stimulate GLUT1 expression, upregulating adipocyte insulin-dependent glucose uptake.2-3, 5 The 1043 amino acid (aa) type I transmembrane protein is composed of a 51 aa signal sequence, a 943 aa extracellular domain (ECD) containing two glycosidase-like regions, a 21 aa transmembrane domain, and 28 aa intracellular tail. Since Klotho-related proteins lack critical active site Glu residues present in b-glycosidases, it was initially unclear whether they were functional enzymes.1, 6 However, glucuronidase activity has since been demonstrated for Klotho, indicating that physiologically relevant enzymatic activity for Klotho b is also possible.7 The extracellular domain shares 79%, 79%, 80% and 67% identity with human, bovine, canine and rat Klotho b, respectively. The low identity with rat reflects aa discordance within rodent ECD.\n\nHybridoma: \nA DNA sequence encoding the extracellular domain of mouse Klotho Beta was fused to a polyhistdine tag at the C-terminus. The protein was expressed in a mouse myeloma cell line, NS0.\n\nMolecular Mass: 110.2kD. As a result of glycosylation, the recombinant mouse Klotho Beta migrates as an approximately 140kD protein in SDS-PAGE under reducing conditions. \n\nBiological Activity: Measured by its ability to stimulate proliferation of NIH 3T3 cells. The ED50 for this effect is typically 0.75-3ug/ml in the presence of 2ug/ml of rhFGF-21\n\nEndotoxin: (same/less than) 1EU/ug of the protein as determined by the LAL method.\n\nStorage and Stability:\nMay be stored at 4 degrees C for short-term only. For long-term storage, aliquot and store at -20 degrees C. Aliquots are stable for at least 6 months at -20 degrees 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.

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SPECIFICATIONS

Catalog Number

K1893-05

Size

50ug

Form

Supplied as a liquid in PBS, 0.1 mM EDTA, 50% glycerol, pH 6.8.

Purity

(same/more than) 90%, as determined by SDS-PAGE and visualized by silver stain.

References

1. Mian, I. S., 1998, Blood Cells Mol. Dis. 24:83 - 100\n2. Ito, S. et al., 2005, J. Clin. Invest. 115:2202 - 2208\n3. Kurosu, H. et al., 2007, J. Biol. Chem. 282:26687.\n4. Lin, B. C. et al., 2007, J. Biol. Chem. 282:27277.\n5. Ogawa, Y. et al., 2007, Proc. Natl. Acad. Sci USA 104:7432\n6. Chang, Q. et al., 2005, Science 310: 490 - 493\n7. Goetz, R. et al., 2007, Mol. Cell. Biol. 27:3417

Additional Info

Recognizes mouse Klotho beta. species sequence homology: Human 79%, bovine 79%, canine 80% and rat Klotho beta 67%.