A one-step purification of membrane proteins using a high efficiency immunomatrix.

A method is described by which an immunoaffinity matrix was constructed by binding antibody directly or indirectly to protein A-Sepharose 4B followed by cross-linking of the complex with dimethyl pimelimidate. This allows optimal spatial orientation of antibodies and, thus, maximum antigen binding efficiency. The affinity matrices were stable to high and low pH buffers without any significant antibody loss. The optimal conditions of antibody saturation, cross-linker concentration, and elution system were established and affinity columns made with the monoclonal antibodies J5, W6/32, and OKT9 for one-step isolation of the common acute lymphoblastic leukemia-associated antigen, HLA-AB antigens, and transferrin receptor, respectively, from cell lysates. The same methodology was also applied to immobilize transferrin with polyvalent anti-transferrin antibodies. This was then used to isolate the transferrin receptor from cell lysates.