Recombinant Immunoglobulin kappa variable 3-15 (IGKV3-15) Fragment (residues 21-115) is a highly purified protein fragment derived from the human immunoglobulin light chain variable domain. This 95-amino acid fragment is engineered for stability and solubility, making it an ideal tool for structural studies, antigen-binding assays, and immunological research.

Immunoglobulin kappa variable 3-15 represents the variable region of immunoglobulin light chains, which plays a critical role in antigen recognition during humoral immune responses. As part of antibodies produced by B lymphocytes, these variable domains form the antigen-binding site through pairing with heavy chain variable regions. The full-length protein functions as either a membrane-bound receptor on B cells or as a secreted antibody, triggering immune responses upon antigen binding. Through V-(D)-J rearrangement and somatic hypermutation, these domains enable remarkable antigen specificity and affinity maturation. The protein is naturally found in both secreted form and membrane-bound form in human cells. The provided fragment (residues 21-115) encompasses a stable, soluble portion of the variable domain suitable for experimental applications.