特異性：BiP (Immunoglobulin heavy chain binding protein, Mr 78 kDa) The immunoglobulin heavy chain binding protein BiP (Binding Protein, [1]) is a member of the hsp70 family of heat shock proteins, and is identical to the glucose regulated protein grp78.2 While BiP was originally described for its function in B cells, it is now known to be distributed in a variety of tissues, if not ubiquitous. The highly conserved hsp 70 proteins have an essential physiological role in stress responses and as "molecular chaperones," which are responsible for a variety of functions such as protein transport, prevention of protein toxicity and direction of protein folding.1-5 With regard to its immunological role, BiP is a component of the endoplasmic reticulum and binds free intracellular heavy chains in nonsecreting pre-B cell lines (u+,L-) or incompletely assembled Ig precursors in H+L+ secreting hybridomas and myelomas. In the absence of light chain synthesis, heavy chains remain associated with BiP and are not secreted. BiP is an ATP binding protein and the dissociation of the BiP-heavy chain complex is probably driven by the ATPase activity attributed to BiP.7 Monoclonal antibody 76-E6 recognizes a conserved epitope localized within the region of amino acids 497 to 581 of BiP.8
