Distribution and characterization of peptidylglycine α-amidating monooxygenase activity in the ovine brain and hypothalamo-pituitary axis

Abstract

The production of α-amidated peptide hormones from their glycine-extended precursors is catalyzed by the specific enzyme peptidylglycine α-amidating monooxygenase (PAM). In the present study, the distribution and subcellular localization of PAM activity in the sheep brain was examined and compared with known sites of amidated peptide synthesis and release. Of the brain regions assayed, the preoptic anterior and medial basal areas of the hypothalamus contained the greatest concentration of amidating activity. Lower concentrations (>3-fold less) were found in the anterior and neurointermediate pituitary, median eminence, cerebral cortex, hippocampus, pons-medulla, and brainstem. Very low amoun..