The A2MR-α2 monoclonal antibody specifically reacts with a 600 kDa, type I membrane single protein, also known as the α2 Macroglobulin (α2M) receptor/low density lipoprotein receptor-related protein 1 (LRP-1). Reported to be an endocytic receptor involved with intracellular signalling, lipid homeostasis, clearance of apoptotic cells, and α2 Macroglobulin mediated clearance of secreted amyloid precursor protein found in Alzheimer patients. The single chain receptor undergoes cleavage, shortly after synthesis, into the 85 kDa transmembrane β chain that non-covalently binds to the extracellular 500-515 kDa a chain. It has a broad cellular distribution, but in the hematopoietic system it is expressed on monocyte lineage cells. α2M/LRP-1 mediates endocytosis of a variety of ligands including α2M-proteinase complexes, plasminogen activators in complex with plasminogen activator inhibitor, or Pseudomonas Exotoxin A. Ligand binding to α2M/LRP-1 is followed by rapid transport of the ligand to lysosomes for degradation.
The antibody was conjugated to BD Horizon™ BUV563 which is part of the BD Horizon Brilliant™ Ultraviolet family of dyes. This dye is a tandem fluorochrome of BD Horizon BUV395 which has an Ex Max of 348 nm and an acceptor dye. The tandem has an Em Max at 563 nm. BD Horizon BUV563 can be excited by the 355 nm ultraviolet laser. On instruments with a 561 nm Yellow-Green laser, the recommended bandpass filter is 585/15 nm with a 535 nm long pass to minimize laser light leakage. When BD Horizon BUV563 is used with an instrument that does not have a 561 nm laser, a 560/40 nm filter with a 535 nm long pass may be more optimal. Due to the excitation and emission characteristics of the acceptor dye, there may be spillover into the PE and PE-CF594 detectors. However, the spillover can be corrected through compensation as with any other dye combination.