The E4.3 monoclonal antibody specifically binds to CD46. CD46 is also known as membrane cofactor protein (MCP). CD46 is a type I membrane glycoprotein composed of two non-disulfide linked α (66 kDa) and β (56 kDa) chains expressed on lymphocytes, monocytes and granulocytes. It is not expressed on erythrocytes or platelets. There are four isoforms of the dimer which function as complement regulatory factors. CD46 promotes the enzymatic degradation of activated C3b and/or C4b deposited on host cells. It also serves as the measles virus receptor.
The antibody was conjugated to BD Horizon Red 718, which has been developed exclusively for BD Biosciences as a better alternative to Alexa Fluor® 700. BD Horizon Red 718 can be excited by the red laser (628 – 640 nm) and, with an Em Max around 718 nm, it can be detected using a 730/45 nm filter. Due to similar excitation and emission properties, we do not recommend using R718 in combination with APC-R700 or Alexa Fluor® 700.