Anti-Complement C4-B [NbB5]

Description:

Recombinant monoclonal antibody to Complement C4-B. Manufactured using AbAb’s Recombinant Platform with variable regions (i.e. specificity) from the llama peripheral blood lymphocytes NbB5.

Clone Name:

NbB5

Published Application(s):

ELISA

Published Species Reactivity:

Human

UniProt Accession Number of Target Protein: P0C0L5

Alternative Name(s) of Target: C4b; CO4; CPAMD3; C4B-2; Basic complement C4; C3 and PZP-like alpha-2-macroglobulin domain-containing protein 3
Immunogen: The original antibody was generated by immunizing Llama glama with purified human C4b.

Specificity: This antibody binds the human complement C4b. Cleavage of the mammalian plasma protein C4 into C4b initiates opsonization, lysis, and clearance of microbes and damaged host cells by the classical and lectin pathways of the complement system. Dysregulated activation of C4 and other initial components of the classical pathway may cause or aggravate pathologies, such as systemic lupus erythematosus, Alzheimer disease, and schizophrenia.

Application Notes: The binding characterization of this antibody for human complement C4b was done using ELISA. This antibody binds human complement C4b with a binding affinity of Kd=67 pM. This antibody shows preferential binding towards C4b as compared to C4. The ability of this antibody to modulate complement activity was assessed in a classical pathway hemolytic lysis assay. Reduced lysis indicating complement inhibition was observed for NbB5 at all serum concentration tested. This antibody also prevented the formation of the proconvertase and effectively prevented the C4b cleavage (PMID: 35428691).

Antibody first published in: De la O Becerra et al. Multifaceted Activities of Seven Nanobodies against Complement C4b. J Immunol. 2022 May 1; 208(9): 2207–2219. PMID:35428691
Note on publication: Describes the generation of 7 nanobodies against human complement C4b.