• Purity

  >85%, by SDS-PAGE under reducing conditions and visualized by silver stain

• Endotoxin Level

  <0.10 EU per 1 μg of the protein by the LAL method.  

• Activity

  Measured by its binding ability in a functional ELISA.

  When Recombinant Mouse LRPAP (Catalog # 4480-LR) is coated at 1 μg/mL (100 μL/well), the concentration of Recombinant Mouse VLDL R that produces 50% of the optimal binding response is found to be approximately 0.01?0.05 μg/mL.

  Alternately, when Recombinant Mouse VLDL R is coated at 2.5 μg/mL (100 μL/well), the concentration of Recombinant Mouse Reelin (Catalog # 3820-MR) that produces 50% of the optimal binding response is found to be approximately 0.5-2.5 μg/mL.

• Source

  Mouse myeloma cell line, NS0-derived Thr25-Ala798, with a C-terminal 10-His tag

• Accession #

• N-terminal Sequence    
  Analysis

  Thr25

• Predicted Molecular Mass

  86.4 kDa

• SDS-PAGE

  130-175 kDa, reducing conditions

Background: VLDL R

VLDL R is a 130 kDa type I transmembrane protein in the LDL receptor family that plays a significant role in lipid metabolism and in nervous system development and function (1, 2). Mouse VLDL R has a 774 aa extracellular domain (ECD) (aa 25 ? 798) and a 54 aa cytoplasmic domain. The ECD contains eight LDLR class A repeats, three EGF?like domains, six LDLR class B repeats, and a juxtamembrane region that is rich in O?linked glycosylation (3, 4, 5). The cytoplasmic domain contains one NPXY internalization motif. Mouse VLDL R has at least one 105 kDa alternative splice form. This variant (termed type II VLDL R) shows an Arg substitution for aa 751 ? 779, and has been associated with endothelial cells (5, 6). The VLDL R expressed here corresponds to a polymorphic form that shows a Cys at position 297 of the precursor. This generates a disulfide bond in the 7^th LDL class A domain that is not present when position 297 is occupied by Ser (SwissProt # P98156). The 7^th domain is suggested to be a critical determinant of apoE binding to VLDL R (7). VLDL R is predominantly expressed in striated muscle, adipose tissue, brain, and endothelial cells lining capillaries and small arterioles (3, 4, 8, 9). VLDL R participates in the tissue uptake of fatty acids from plasma by mediating the internalization of ApoE?containing lipoparticles (i.e. VLDL, beta ?VLDL, and chylomicron remnants) (8, 10). VLDL R binds and internalizes lipoprotein lipase (LPL) and mediates its transport from the basolateral to the lumenal face of endothelial cells (9, 11). VLDL R knockout mice are characterized by reduced LPL activity, reduced serum triglyceride clearance, and a resistance to developing obesity (10, 12, 13). VLDL R influences breast cancer cell motility by mediating the uptake of uPAR?PAI1 complexes (9, 14). Lipoprotein accumulation via macrophage VLDL R is instrumental in promoting the formation of atherosclerotic plaques (15). In the nervous system, VLDL R and ApoE R2 interactions with reelin are critical for neuronal migration and positioning in the developing brain (16). VLDL R also functions in adult hippocampal synapse maturation, synaptic plasticity, and memory formation (17, 18). The ECD of mouse VLDL R shares 95% aa sequence identity with human and rat VLDL R. Within shared regions, mouse VLDL R shares 55% and 53% aa sequence identity with ApoE R2 and LDL R, respectively.

• References:

1. Qiu, S. et al. (2006) Neurobiol. Learn. Mem. 85:16.

2. May, P. et al. (2005) Cell. Mol. Life Sci. 62:2325.

3. Gafvels, M.E. et al. (1994) Endocrinology 135:387.

4. Oka, K. et al. (1994) Eur. J. Biochem. 224:975.

5. Martensen, P.M. et al. (1997) Eur. J. Biochem. 248:583.

6. GenBank Accession # NP_001154892.

7. Ruiz, J. et al. (2005) J. Lipid Res. 46:1721.

8. Wyne, K.L. et al. (1996) Arterioscler. Thromb. Vasc. Biol. 16:407.

9. Argraves, K.M. et al. (1995) J. Biol. Chem. 270:26550.

10. Goudriaan, J.R. et al. (2001) Arterioscler. Thromb. Vasc. Biol. 21:1488.

11. Obunike, J.C. et al. (2001) J. Biol. Chem. 276:8934.

12. Yagyu, H. et al. (2002) J. Biol. Chem. 277:10037.

13. Goudriaan, J.R. et al. (2004) J. Lipid Res. 45:1475.

14. Webb, D.J. et al. (1999) J. Biol. Chem. 274:7412.

15. van Eck, M. et al. (2005) Atherosclerosis 183:230.

16. Jossin, Y. et al. (2004) J. Neurosci. 24:514.

17. Niu, S. et al. (2004) Neuron 41:71.

18. Weeber, E.J. et al. (2002) J. Biol. Chem. 277:39944.

• Long Name:

  Very Low Density Lipoprotein Receptor

• Entrez Gene IDs:

  7436 (Human); 22359 (Mouse)

• Alternate Names:

  CARMQ1; CHRMQ1; FLJ35024; very low density lipoprotein receptor; very low-density lipoprotein receptor; VLDL R; VLDL receptor; VLDLR; VLDL-R; VLDLRCH