This page describes one published antibody panel. Other widely used anti-PrP antibodies exist, and supplier catalogues, current availability and validation in your own assay were not checked. Read the original paper and the supplier’s data sheet before ordering. About 100,000 of the paper’s 127,000 characters were read.
What is the POM panel?
Polymenidou and colleagues (PLoS One 2008) describe 19 monoclonal antibodies, POM1 to POM19, selected from 55 ELISA-positive hybridoma clones. They immunised PrP knockout (Prnp 0/0) mice with bacterially produced recombinant mouse PrP, residues 23 to 231, because wild-type mice are usually immunotolerant to PrP. Splenocytes were fused with Sp2/0-Ag14 myeloma cells.
What do the antibodies bind?
| Region | Antibodies | Notes from the paper |
|---|---|---|
| N-terminal octarepeat region | POM2, POM12, POM11 | POM2 and POM12 bind a repeated octapeptide. POM11 prefers a serine-containing variant. |
| Central unstructured region | POM3 | Binds HNQWNK, residues 95 to 100. |
| Globular C-terminal domain | POM4, POM10, POM19, POM5 | Discontinuous epitopes, mapped approximately. POM4, 10 and 19 depend on residues around 121 to 134 and 201 to 225. POM5 depends on residues near 170 to 174. |
Peptide competition worked for the N-terminal antibodies but not for those to the globular domain, which the authors attribute to conformational or discontinuous epitopes. Surface plasmon resonance grouped the C-terminal antibodies into complementarity groups. Reported affinities include 870 pM for POM19 and 580 pM for POM1.
What applications and species were tested?
The paper tested western blotting, ELISA, flow cytometry, immunohistochemistry, immunoprecipitation and surface plasmon resonance. It also reports single-chain variable fragments made from POM2, POM11, POM18 and POM19. Some antibodies immunoprecipitated protease-digested PrPSc.
Species reactivity differs by clone:
- POM1, 8, 9, 13, 15, 16 and 17 reacted with all wild-type and mutant proteins tested.
- POM4, 10 and 19 did not bind wild-type human or porcine PrP. Binding to human PrP was restored by the E219Q substitution.
- POM3, 4, 5, 10 and 19 did not recognise human PrP. All antibodies except POM3 and POM5 bound cervid PrP.
- POM6 and POM7 weakly recognised porcine PrP but not feline or canine PrP.
What caveats do the authors give?
None of the POM antibodies reacted with PrPSc in immunohistochemistry on prion-infected brain. The epitopes of the globular-domain antibodies were only approximately defined. POM2 and POM12 also detected an unidentified protein of about 37 kDa in knockout brain homogenate. The POM2 single-chain fragment was expressed almost entirely in inclusion bodies and needed denaturing purification and refolding, with heavy precipitation.
What is not known?
The text read does not state how to obtain the antibodies. It reports no competing interests, and antibody purification was contracted to GENOVAC GmbH. Commercial sources, clone-level validation by third parties, and antibodies from other laboratories are not covered here. For the D-Gen organisation entry in the Atlas, see D-Gen. Related pages are assays and protocols, strains and isolates and the resources hub.