The 1H7 monoclonal antibody specifically binds to the α subunit of the human insulin-like growth factor-I (IGF-I) receptor that is also known as CD221. CD221 is a receptor tyrosine kinase that has high affinity for IGF-1 and low affinity for insulin and IGF-2. CD221 is synthesized as a 180 kDa precursor molecule that is processed into two subunits, a 135 kDa α subunit which is disulfide-linked to a 90 kDa β subunit. The mature IGF-IR complex is comprised of two extracellular α subunits and two transmembrane β subunits that each possesses a tyrosine kinase domain. When bound by ligand, the IGF-1 receptor autophosphorylates multiple tyrosine sites in its β chains and phosphorylates other signaling molecules that regulate cell growth, development, and neoplastic transformation. CD221 is structurally and functionally similar to the insulin receptor (aka, CD220) and is expressed on a variety of human hematopoietic and non-hematopoietic cells. The 1H7 antibody does not crossreact with the human insulin receptor and can block IGF-I- or IGF-II-stimulated cell growth.
This antibody is routinely tested by flow cytometric analysis. Other applications were tested at BD Biosciences Pharmingen during antibody development only or reported in the literature.