Anti-Human CD38 (HB-7) - DyLight® 550 (C1003-GRP)

CD38 is a type II transmembrane glycoprotein that functions as an adhesion molecule with ectoenzymatic activities that contribute to intracellular calcium mobilization 1,2. Dysregulation is associated with a number of diseases, including HIV, autoimmune, type II diabetes mellitus, osteoporosis, and hematological malignancies such as multiple myeloma (MM) 1, a neoplasm characterized by clonal expansion of malignant plasma cells 2. Because CD38 is strongly and uniformly expressed on myeloma cells, but has limited expression on normal cells, anti-CD38 antibody HB-7 was used to develop an antibody drug conjugate (ADC) capable of killing human myeloma and lymphoma cell lines 3. This ADC is composed of HB-7 conjugated to a chemically modified ricin molecule and is able to block protein synthesis in multiple myeloma cells and in normal bone marrow mononuclear cells. HB-7 was developed by immunizing BALB/c mice with viable cells of the Human Burkitt lymphoma B cell line BJAB 4. The antibody binds to an epitope in the carboxyl terminus of CD38 between residues 273-285, which is also the site of enzyme activity 5. Binding is unaffected by the presence of NAD+ and does not influence CD38 catalytic activity 6.