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Mutated Anti-Citrullinated Protein Antibody (E4NG-mutant)

Mutated Anti-Citrullinated Protein Antibody (E4NG-mutant)

Product number #10180 


 Suggested control antibody for E4NG (#10170)


Size and Prices

50 µg / 0.05 mL

100 µg / 0.1 mL


For bulk orders, please contact info@vacara.se to request a quote.

Price is excluding shipping cost. The shipping cost will be added on.

Product details

Description

This antibody is the mutated version of the E4NG antibody, with identical sequence, methods of production/purification and format to E4NG except two mutations in the paratope (W48M & S51A)1. This antibody has neglectable or no affinity to citrulline and does not have known cross-reactivity to other antigens1.

The E4NG-mutant antibody is recommended to be used as a control for E4NG antibody (#10170) in assays detecting citrulline-specificity of anti-citrullinated protein antibodies (ACPA) and is packed with product #10170 only and not sold separately.

Isotype 

Mouse IgG2b, κ

Specificity

May have minimal non-specific binding to CCP2, the cyclic citrullinated peptide(s) of the second generation of the anti-CCP test. The antibody does not react with known citrullinated proteins or peptides. Suitable to be paired with E4NG antibody (#10170) as a negative control for detecting citrullinated antigens.

Concentration

100 µg/ml

Size

50 µg/ 0.5 ml

100 µg/ 1.0 ml

Supplied in

PBS

Storage

Centrifuge briefly prior to opening vial. Store at +4°C short term (1-2 weeks). Aliquot and store at ‑20°C long term. Avoid repeated freeze/thaw cycles.

Recommended dilution

It is recommended the user determines the optimal dilution with E4NG for their application.



For Research Use Only. Not for use in diagnostic procedures.
Not for resale without express authorization.

References

He, Y., Ge, C., Moreno-Giró, À. et al. A subset of antibodies targeting citrullinated proteins confers protection from rheumatoid arthritis. Nat Commun 14, 691 (2023). https://doi.org/10.1038/s41467-023-36257-x

  Click here to download pdf

FAQs

Q1: What epitopes does E4 bind?

  • E4 is a chimeric monoclonal anti-citrullinated protein antibody (ACPA) derived from rheumatoid arthritis (RA) patient. It is a typical promiscuous ACPA that is highly specific to the citrulline side chain, which enables the binding to various epitopes containing citrulline. So far, E4 has been confirmed to bind to multiple citrullinated epitopes on collagen type 2 (COL2), alpha-enolase (ENO1), peptidylarginine deiminase 4 (PAD4) and more. 

https://www.nature.com/articles/s41584-019-0244-4

https://www.nature.com/articles/s41467-023-36257-x

https://www.sciencedirect.com/science/article/pii/S0003496725009021

Q2: What is the function of E4 in vivo?

  • E4 has been extensively characterized in animal models, one typical utilization is for collagen antibody induced arthritis (CAIA). In fact, E4 is the first human ACPA found to be protective in experimental arthritis, e.g. CAIA, by forming immune complex with citrullianted antigens and interacting with macrophages. More details can be found in the study below:

https://www.nature.com/articles/s41467-023-36257-x

Q3: Which assays can E4 be used for?

Taking the advantage of the well characterized epitope specificity and function, the antibody is highly flexible for adaptation in different purposes. The most common assay is ELISA, where the antibody could be used for capturing certain citrullinated or native COL2 epitopes. In immunofluorescence analysis, E4 binds strongly arthritic mouse joint cartilage. It also binds to naive or arthritic skin and esophagus tissue, ressembling the nature of typical ACPA.

https://www.nature.com/articles/s41467-023-36257-x

Q4: Which isotypes for E4 are available?

  • We have mouse IgG2b and human IgG1 versions for E4 antibody. We recommend the users to choose the secondary antibody for their assay accordingly.

Q5: What are the differences between E4 and E4m?

  • The E4m is the mutated version of E4 antibody, which has point-mutations on the CDR region of E4, prohibiting the interaction of its paratope with citrulline, thus abolishing its citrulline-binding and subsequently the protective effect in CAIA. It is the most ideal control antibody for E4. More details ca be found in the study below:

https://www.nature.com/articles/s41467-023-36257-x