• Product name

    Anti-C3a / C3a des Arg antibody [2991]
    See all C3a / C3a des Arg primary antibodies
  • Description

    Mouse monoclonal [2991] to C3a / C3a des Arg
  • Host species

  • Specificity

    ab11873 reacts with a neo-epitope (des-Arg) on C3a that is formed when C3 is cleaved into C3a and C3b. ab11873 recognizes C3a and C3a des arg only. It has the most affinity with C3a des arg and least affinity with C3a. The des arg variant has an about 5x higher affinity than C3a. The antibody does not recognize C3b or full C3, as it recognizes a neo-epitope that is not available on C3.
  • Tested applications

    Suitable for: WBmore details
  • Species reactivity

    Reacts with: Human
  • Immunogen

    Human C3a des-Arg

  • Positive control

    • Activated human serum or purified human C3adesArg protein



Our Abpromise guarantee covers the use of ab11873 in the following tested applications.

The application notes include recommended starting dilutions; optimal dilutions/concentrations should be determined by the end user.

Application Abreviews Notes
WB Use at an assay dependent dilution. Predicted molecular weight: 9 kDa.


  • Function

    C3 plays a central role in the activation of the complement system. Its processing by C3 convertase is the central reaction in both classical and alternative complement pathways. After activation C3b can bind covalently, via its reactive thioester, to cell surface carbohydrates or immune aggregates.
    Derived from proteolytic degradation of complement C3, C3a anaphylatoxin is a mediator of local inflammatory process. It induces the contraction of smooth muscle, increases vascular permeability and causes histamine release from mast cells and basophilic leukocytes.
  • Tissue specificity

  • Involvement in disease

    Defects in C3 are the cause of complement component 3 deficiency (C3D) [MIM:613779]. A rare defect of the complement classical pathway. Patients develop recurrent, severe, pyogenic infections because of ineffective opsonization of pathogens. Some patients may also develop autoimmune disorders, such as arthralgia and vasculitic rashes, lupus-like syndrome and membranoproliferative glomerulonephritis.
    Genetic variation in C3 is associated with susceptibility to age-related macular degeneration type 9 (ARMD9) [MIM:611378]. ARMD is a multifactorial eye disease and the most common cause of irreversible vision loss in the developed world. In most patients, the disease is manifest as ophthalmoscopically visible yellowish accumulations of protein and lipid that lie beneath the retinal pigment epithelium and within an elastin-containing structure known as Bruch membrane.
    Defects in C3 are a cause of susceptibility to hemolytic uremic syndrome atypical type 5 (AHUS5) [MIM:612925]. An atypical form of hemolytic uremic syndrome. It is a complex genetic disease characterized by microangiopathic hemolytic anemia, thrombocytopenia, renal failure and absence of episodes of enterocolitis and diarrhea. In contrast to typical hemolytic uremic syndrome, atypical forms have a poorer prognosis, with higher death rates and frequent progression to end-stage renal disease. Note=Susceptibility to the development of atypical hemolytic uremic syndrome can be conferred by mutations in various components of or regulatory factors in the complement cascade system. Other genes may play a role in modifying the phenotype.
  • Sequence similarities

    Contains 1 anaphylatoxin-like domain.
    Contains 1 NTR domain.
  • Post-translational

    C3b is rapidly split in two positions by factor I and a cofactor to form iC3b (inactivated C3b) and C3f which is released. Then iC3b is slowly cleaved (possibly by factor I) to form C3c (beta chain + alpha' chain fragment 1 + alpha' chain fragment 2), C3dg and C3f. Other proteases produce other fragments such as C3d or C3g.
    Phosphorylation sites are present in the extracelllular medium.
  • Cellular localization

  • Information by UniProt
  • Database links

  • Alternative names

    • Acylation stimulating protein antibody
    • Acylation stimulating protein cleavage product antibody
    • ASP antibody
    • C3 and PZP-like alpha-2-macroglobulin domain-containing protein 1 antibody
    • C3 antibody
    • CO3_HUMAN antibody
    • Complement C3c alpha'' chain fragment 2 antibody
    • Complement component 3 antibody
    • Complement factor 3 antibody
    • Plp antibody
    see all


This product has been referenced in:

  • Jiménez-Reinoso A  et al. Human plasma C3 is essential for the development of memory B, but not T, lymphocytes. J Allergy Clin Immunol 141:1151-1154.e14 (2018). Read more (PubMed: 29113906) »
  • Kemper C & Kolev M Enzymatic Reactions and Detection of C3 Cleavage Fragments. Bio Protoc 4:N/A (2014). Read more (PubMed: 29094056) »
See all 2 Publications for this product

Customer reviews and Q&As

1-2 of 2 Abreviews or Q&A


Activation products of the complement cascade contain neo-epitopes that are not present in the individual native components.

I would therefore recommend Anti-C3a / C3a des Arg antibody [2991] (ab11873) as this antibody reacts with a neo-epitope (des-Arg) on C3a that is formed when C3 is cleaved into C3a and C3b.

ab11873 recognizes both C3a and C3a-desArg, with at least a 5x higher preference for C3a-desArg.

Read More
Human Serum (native serum or EDTA plasma)
native serum or EDTA plasma
Sandwich (Capture)

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Submitted Nov 01 2007

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