The P-3E10 monoclonal antibody specifically recognizes CD298, the β3 subunit of the Na+/K+ ATPase (Sodium/potassium-transporting ATPase subunit beta-3). CD298 is a ~45-55 kDa single-pass, type II membrane protein that is encoded by ATP1B3 (ATPase Na+/K+ transporting subunit beta 3) which belongs to the P-type ATPases superfamily. CD298 is widely expressed on lymphocytes, monocytes, granulocytes, platelets, and on other hematopoietic and nonhematopoietic cells and cell lines. The Na+/K+ ATPase is an integral membrane protein complex with enzymatic activity that mediates the active transport and exchange of sodium and potassium ions across the plasma membrane. This complex is composed of α and β subunits. The α subunit is a 10-membrane-spanning, catalytic protein that contains binding sites for Na +, K + and ATP. The α subunits are associated with the smaller, regulatory glycoprotein β subunits. Upon ATP hydrolysis, the Na+/K+ ATPase transports Na+ ions out of the cell in exchange for K+ ions that are transported in. This establishes a transmembrane electrochemical gradient that is essential for osmoregulation and for the transport of various nutrients and other molecules by cells. The P-3E10 antibody can reportedly inhibit the activation and proliferation of T cells and B cells.
The antibody was conjugated to BD Horizon™ BV650 which is part of the BD Horizon Brilliant™ Violet family of dyes. This dye is a tandem fluorochrome of BD Horizon BV421 with an Ex Max of 405-nm and an acceptor dye with an Em Max at 650-nm. BD Horizon BV650 can be excited by the violet laser and detected in a filter used to detect APC-like dyes (eg, 660/20-nm filter). Due to the excitation and emission characteristics of the acceptor dye, there will be spillover into the APC and Alexa Fluor® 700 detectors. However, the spillover can be corrected through compensation as with any other dye combination.