Biolegend, 846302, Purified anti-complement C3/C3b/iC3b/C3d Antibody, 100μg

Complement component 3 (C3) is a 185 kD glycoprotein composed of two chains linked by a disulfide bond. It is the fourth complement component to react in the classical pathway and is a key protein in the alternative and the lectin complement activation pathways. C3b is proteolytically generated from C3 by cleavage of the C3a-C3b peptide bond in the protein by C3 convertase. C3b can bind covalently, via its reactive thioester, to cell surface carbohydrates or immune aggregates. Macrophages and neutrophils recognize C3b by the complement receptor 1 (CR1, CD35). Opsonization of target surfaces with C3b is central to all three pathways of complement activation. The proteolytically inactive forms of C3b, iC3b, are generated by cleavage of the alpha chain at one or two positions by factor I in the presence of co-factors, such as factor H. A ~2 kD fragment of C3b, C3f, is generated when C3b is cleaved at two positions by factor I. Although iC3b is less active than C3b, iC3b’s interactions with lymphoid and phagocytic cells via CR2 (CD21) and CR3 (CD11b/CD18) can expand target-specific B and T cells. iC3b can be cleaved to form C3c and C3dg. Further proteolytic cleavage of C3dg generates C3d and C3g.
100μg
Verified Reactivity: Human
Antibody Type: Monoclonal
Host Species: Mouse
Immunogen: Human iC3b coupled to sepharose 4B
Formulation: Phosphate-buffered solution, pH 7.2, containing 0.09% sodium azide.
Preparation: The antibody was purified by affinity chromatography.
Concentration: 0.5 mg/ml
Storage & Handling: The antibody solution should be stored undiluted between 2°C and 8°C.
Application: WB - Quality testedDirect ELISA - VerifiedFC, ICC, ELISA Detection - Reported in the literature, not verified in house
Recommended Usage: Each lot of this antibody is quality control tested by Western blotting. For Western blotting, the suggested use of this reagent is 0.5 - 5.0 µg per ml. For Direct ELISA, the suggested use of this reagent is 0.01 - 2.0 µg per ml. It is recommended that the reagent be titrated for optimal performance for each application.
Application Notes: Additional reported applications (for the relevant formats) include: flow cytometry3, immunofluorescent staining2, and ELISA Detection1.This antibody recognizes human C3, C3b, iC3b, and C3d.
Application References(PubMed link indicates BioLegend citation): Tosic L, et al. 1989. J. Immunol. Methods 120:241. (ELISA) Kennedy AD, et al. 2003. Blood 101:1071. (IF) Lindorfer MA, et al. 2010. Blood 115:2283. (FC)
Product Citations: Leng K, et al. 2022. Nat Neurosci. 25:1528. PubMed Alberts A, et al. 2020. Sci Rep. 10:6391. PubMed Kim H, et al. 2022. Nat Commun. 13:6581. PubMed
RRID: AB_2572128 (BioLegend Cat. No. 846302)
Structure: C3 is a 185 kD glycoprotein that is cleaved to generate a 176 kD protein fragment, C3b. iC3b is proteolytically derived from C3b and exists as a mixture of 176 and 174 kD proteins. C3d is a 33.8 kD single chain proteolytic fragment of iC3b.
Distribution: Extracellular, plasma membrane, and serum.
Function: C3b is involved in all three complement pathways and is essential for effective complement activation and presentation of antigens to cells of the adaptive immune system. iC3b and C3d are less active than C3b, but the target-bound protein can expand target-specific B-cell and T-cell populations by interacting with lymphoid and phagocytic cells.
Interaction: Immune cells interact with C3b, iC3b and C3d using CR1, CR2/CR3 and CR2, respectively.
Ligand/Receptor: C3b can bind to Factor B, Factor P, Factor H, Factor I, C5, DAF (CD55), MCP (CD46), and CR1 (CD35). iC3b interacts with CR2 (CD21) and CR3 (CD11b/CD18). C3d binds to CR2.
Biology Area: Cell Biology, Complement, Immunology, Innate Immunity, Neuroinflammation, Neuroscience
Antigen References: 1. Lambris JD, et al. 1988. Immunol. Today 9:387-93. 2. Dempsey PW, et al. 1996. Science 271:348-50.
Gene ID: 718
UniProt: View information about C3/C3b/iC3b/C3d on UniProt.org
Clone: 1H8/C3b
Regulatory Status: RUO
Other Names: Complement Component 3, C3, C3b, iC3b, C3bi, C3d
Isotype: Mouse IgG2a, κ