Antibodies to the Nonnative Forms of d-Glyceraldehyde-3-Phosphate Dehydrogenase: Identification, Purification, and Influence on the Renaturation of the Enzyme

Monoclonal antibodies of two clones reacting with the nonnative forms of d-glyceraldehyde-3-phosphate dehydrogenase, EC 1.2.1.12 (GAPDH), were obtained. Antibodies of clone 6C5 belonged to IgG1 subtype; antibodies of clone 6G7 belonged to IgM type. The interaction of antibodies of both clones with the immobilized and soluble enzyme was studied. The specificity of antibodies to the definite oligomeric forms was demonstrated on immobilized monomers, dimers, and tetramers of GAPDH. The affinity of antibodies to monomeric and dimeric forms of GAPDH, either active or not, was demonstrated. At the same time the antibodies did not react with the tetrameric enzyme. The binding of antibodies had no influence on the enzymatic activity. However, the addition of antibodies to the denatured enzyme blocked the spontaneous renaturation of GAPDH. The immobilized antibodies of both clones were successfully used for the purification of GAPDH solution from the denatured admixtures.