The monoclonal antibody M177 recognizes CD46, also designated membrane cofactor protein (MCP). CD46 is a 45-70 kDa protein with genetic and tissue-specific heterogeneity.- It is expressed on every cell and tissue, with the exception of erythrocytes. CD46 serves to inhibit complement activation on host tissue. It performs this function by serving as a cofactor which binds to C3b and C4b. This binding is permitted by factor I, a serine protease of plasma, to degrade C3b and C4b and serves to protect the host cell against autologous attack. It also serves as a receptor for measles virus.
Four isoforms of CD46 predominate and arise by alternative splicing of a single CD46 gene. CD46 cDNA encodes a signal sequence followed by four complement control protein domains (also called short consensus repeats (SCR)). The monoclonal antibody M177 reacts with the SCR2 domain.
Flow cytometry, Frozen sections, Functional studies, Immuno assays, Immuno precipitation, Western blot
FC: Antibody M177 stains the extracellular domain of CD46.
IP: 107 cells were lysed and immunoprecipitated with 25 µg M177 antibody and 25 µg protein G-sepharose
W:A non-reduced sample treatment and SDS-page was used. The band size is 45-70 kDa (Ref 1 and 2).
Dilutions to be used depend on detection system applied. It is recommended that users test the reagent and determine their own optimal dilutions. The typical starting working dilution is 1:50. For functional studies, in vitro dilutions have to be optimized in user’s experimental setting.
CD46 is expressed on every cell and tissue