Purification and characterization of two types of atrial natriuretic factor receptors from bovine adrenal cortex: guanylate cyclase-linked and cyclase-free receptors

Abstract

Atrial natriuretic factor (ANF) receptors with and without guanylate cyclase activity were simultaneously purified to apparent homogeneity from bovine adrenal zona glomerulosa cell membrane fractions. The particulate guanylate cyclase which co-purified with the ANF receptor showed one of the highest specific activity reported. The receptors with or without the guanylate cyclase activity showed high affinities to ANF (99-126). The receptor without the cyclase showed a high affinity to truncated ANF analogs, ANF (103-123) and ANF (105-121), whereas the cyclase-linked receptor had a much lower affinity to these analogs. Both of the receptors migrated as a single band with a molecular weight of 135,000 daltons on SDS-gel electrophoresis under non-reducing conditions. The 135,000 daltons band of the receptor without the cyclase was shifted to a 62,000 daltons band under reducing conditions, but the band for the cyclase-linked receptor was not shifted. These results demonstrated the presence of two subtypes of ANF receptor in bovine adrenal cortex and indicate two different modes of intracellular action of ANF.