• Species Reactivity

  Human

• Specificity

  Detects human VAP-B in direct ELISAs and Western blots. In direct ELISAs, approximately 25% cross-reactivity with recombinant human VAP-A is observed.

• Source

  Monoclonal Mouse IgG    ₁ Clone # 736904

• Purification

  Protein A or G purified from hybridoma culture supernatant

• Immunogen

  E. coli-derived recombinant human VAP-B    
  Ala2-Pro132    
  Accession # O95292

• Formulation

  Lyophilized from a 0.2 μm filtered solution in PBS with Trehalose. *Small pack size (SP) is supplied as a 0.2 µm filtered solution in PBS.

• Label

  Unconjugated

Applications

• Recommended    
  Concentration

  Sample

• Western Blot

  0.1 µg/mL

  See below

• 
  

• Immunohistochemistry

  8-25 µg/mL

  See below

• 
  

• CyTOF-ready

  Ready to be labeled using established conjugation methods. No BSA or other carrier proteins that could interfere with conjugation.

• 
  

• Intracellular Staining by Flow Cytometry

  2.5 µg/10    ⁶ cells

  See below

• 
  

Please Note: Optimal dilutions should be determined by each laboratory for each application.  are available in the Technical Information section on our website.

Data Examples

Preparation and Storage

• Reconstitution

  Sterile PBS to a final concentration of 0.5 mg/mL.

• Shipping

  The product is shipped at ambient temperature. Upon receipt, store it immediately at the temperature recommended below. *Small pack size (SP) is shipped with polar packs. Upon receipt, store it immediately at -20 to -70 °C

• Stability & Storage

  Use a manual defrost freezer and avoid repeated freeze-thaw cycles.    

• 12 months from date of receipt, -20 to -70 °C as supplied.

• 1 month, 2 to 8 °C under sterile conditions after reconstitution.

• 6 months, -20 to -70 °C under sterile conditions after reconstitution.

Background: VAP-B

Vesicle-associated membrane protein (VAMP)-associated protein B (VAP-B; also VAMP-B) is an ~30 kDa ubiquitously expressed type IV transmembrane protein belonging to the VAP family (1, 2). It is found in endoplasmic reticulum (ER), Golgi and other membranes as a homodimer or a heterodimer with VAP-A, probably associating through a GxxxG motif in the transmembrane regions (1, 2). Human VAP-B cDNA encodes 243 amino acids (aa) that include a 222 aa cytoplasmic domain and a 21 aa C-terminal membrane anchor. The cytoplasmic domain contains a mobile sperm protein (MSP) domain (aa 7‑124) and a coiled-coil region (aa 159‑196). Human VAP-B shares 90%, 89%, 96%, 96% and 94% aa identity with mouse, rat, canine, bovine and porcine VAP-B, respectively. VAP-A and VAP-B MSP domains recruit FFAT (two phenylalanines in an acidic tract)-motif-containing proteins to the cytosolic surface of ER membranes (2‑4). FFAT proteins mediate many of the effects of VAPs on regulation of membrane transport, phospholipid biosynthesis, microtubule organization, and the unfolded protein response (2, 3). VAPs also interact with some SNARE and viral proteins (2). A human polymorphism of VAP-B, P56S, is found in three familial motor neuron diseases, notably the amylotrophic lateral sclerosis variant ALS8 (2). It produces a non-functional protein that can dimerize with and inhibit function of normal VAP-B, leading formation of intracellular aggregates and increased ER-stress-induced death of motor neurons (5‑7). It can also promote cleavage and secretion of soluble VAP-B, which can then function as a ligand for EPH receptors (8). A naturally occurring 99 aa isoform of VAP-B that diverges at aa 71 within the MSP domain is termed VAP-C (1, 9). It also appears to be a negative regulator of VAP-A and VAP-B (9). While VAP-B is used by hepatitis C virus (HCV) for its propagation, VAP-C inhibits HCV propagation (9).

• References:

   

1. Nishimura, Y. et al. (1999) Biochem. Biophys. Res. Commun. 254:21.

2. Lev, S. et al. (2008) Trends Cell Biol. 18:282.

3. Peretti, D. et al., 2008, Mol. Biol. Cell 19:3871.

4. Kaiser, S.E. et al., 2005, Structure 13:1035.

5. Prosser, D.C. et al. (2008) J. Cell Sci. 121:3052.

6. Gkogkas, C. et al. (2008) Hum. Mol. Genet. 17:1517.

7. Suzuki, H. et al. (2009) J. Neurochem. 108:973.

8. Tsuda, H. et al. (2008) Cell 133:963.

9. Kukihara, H. et al. (2009) J. Virol. 83:7959.

• Long Name:

  VAMP [Vesicle-associated Membrane Protein]-associated Protein B and C

• Entrez Gene IDs:

  9217 (Human); 56491 (Mouse); 60431 (Rat)

• Alternate Names:

  ALS8; ALS8VAMP-B/VAMP-C; VAMP (vesicle-associated membrane protein)-associated protein B and C; VAMP-associated 33 kDa protein; VAMP-associated protein B/C; VAMP-B; VAMP-C; VAPB; VAP-B; VAP-B/VAP-C; VAPC; VAP-C; vesicle-associated membrane protein-associated protein B/C