Pancreatic antigenic complex p64 69: involvement in regulation of insulin secretion and relation to glutamic acid decarboxylase.

The role of pancreatic beta-cell antigenic structures in modulation of insulin secretion in vitro was recently demonstrated by others. Here we report generation of a monoclonal antibody (mAB) ICA-1 to non-species specific beta-cell antigen(s) 64, 67 and 69 kDa. The mAB inhibits glucose stimulated insulin secretion in islet cell cultures. The ability of mAB ICA-1 to immunoprecipitate active glutamic acid decarboxylase from high speed supernatants of pancreatic and brain crude extracts was demonstrated. The 64, 67 and 69 kDa antigenic material was affinity purified from pancreatic islet cell high speed supernatants, active glutamic acid decarboxylase was found in the material. Immunoaffinity purification with mAB ICA-1 of GAD-like pancreatic beta-cell antigenic material has provided evidence of possible involvement of glutamic acid decarboxylase in modulation of insulin secretion.