IgG1 Protein, Human (HEK293, gD)

The constant region of immunoglobulin heavy chains, known as antibodies, represents membrane-bound or secreted glycoproteins produced by B lymphocytes. In the recognition phase of humoral immunity, these membrane-bound immunoglobulins act as receptors, initiating the clonal expansion and differentiation of B lymphocytes into immunoglobulin-secreting plasma cells upon binding specific antigens. Secreted immunoglobulins play a crucial role in the effector phase of humoral immunity, leading to the elimination of bound antigens. The antigen binding site is shaped by the variable domain of one heavy chain, along with that of its associated light chain, resulting in each immunoglobulin having two antigen binding sites with remarkable affinity for a particular antigen. Variable domains undergo V-(D)-J rearrangement and subsequent somatic hypermutations, enabling affinity maturation for a specific antigen following exposure and selection. IgG1 protein mediates effector functions on monocytes, triggering antibody-dependent cellular cytotoxicity (ADCC) of virus-infected cells. Immunoglobulins are composed of two identical heavy chains and two identical light chains, interconnected by disulfide linkages, and interact with FCGR1A, FCGR2A, and FCGR3A to mediate various effector functions.