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Anti-Citrullinated Protein Antibody (E4NG)

Anti-Citrullinated Protein Antibody (E4NG)

Product number #10170 


Patent protected (US11866512B2)


Derived from patients with rheumatoid arthritis Suggested control antibody: E4NG-mutant (#10180)


Size and Prices

100 µg / 0.1 mL500€


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

E4NG binds to citrullinated collagen type II (COL2) epitopes. E4NG-mutant is the control antibody that does not bind to citrulline. Binding to unmodified COL2 peptides is low by both E4NG and E4NG-mutant antibodies. Binding was determined by a multiplex flow immunoassay. (Results published in He et al Nat Comm 2023)


Description

Affinity purified mouse monoclonal anti-citrullinated protein antibody (ACPA) clone E4NG in PBS, sterile filtered (0.2 µm). The antibody was originally derived from rheumatoid arthritis (RA) patient, selected by single B cell isolated from RA patient with high reactivity to cyclic citrullinated peptide 2 (CCP2). The antibody is recombinantly expressed in HEK cells as chimeric antibody (human variable domain + mouse constant domain). The antibody recognizes multiple citrullinated proteins/peptides including CCP2, citrullinated collagen type 2 (COL2) peptides, citrullinated human/mouse alpha-enolase (citENO1) etc1., and potentially other citrullinated proteins/peptides typically manifested in RA, as a citrulline-specific antibody. E4NG has mutation on glycosylation sites in the variable domain, prohibiting expression of the Fab-glycan (no N-glycosylation on variable domain). E4NG has been used in applications including ELISA, multiplex immunoassay, immunohisto­chemistry and immuno­precipitation etc., and is therefore an ideal antibody for detecting citrullinated antigens. Additionally, in vivo and in vitro functional analysis also demonstrated that E4NG ACPA could protect against collagen antibody induced arthritis (CAIA) in mice.

Targets with alternative names

Citrullinated epitopes of COL2, Collagen alpha-1(II) chain, COL2A1, type II collagen, CII1; UniProt: P28481, P02458.

Citrullinated epitopes of ENO1, MPB11; UniProt: P06733.

Species reactivity

Mouse, human

Isotype 

Mouse IgG2b, κ

Specificity

The antibody widely recognizes citrullinated epitopes of different proteins, tested with CCP, citrullinated COL2 peptides and citrullinated ENO1, but likely with more untested citrullinated antigens.

Concentration

1 mg/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 for their application. The typical starting working dilutions: ELISA 1:500-1:1000, IHC 1:100-1:500.



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

 

References

  1. 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