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 Price

100 µg / 0.1 mL      500 €

For bulk orders, please contact to request a quote.

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

Data in He et al Nat Comm 2023 FigS1B


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)


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, immunohisto-chemistry 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.

Target 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, human1


Mouse IgG2b, κ



Sizes available

100 µg

Supplied in



Centrifuge briefly prior to opening the 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 are: IHC 1:100-1:500, ELISA 1:500-1:1000.


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



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).