Since peptidylglycine alpha-amidating monooxygenase (PAM) and carboxypeptidase H (CPH) are transported by a rapid anterograde axonal Bow in rat sciatic nerves, different properties of those enzymes were examined in the cell body (dorsal root ganglia) and axon (sciatic nerves) of rat. The relative enzyme activities of soluble to membrane-associated forms - the sciatic nerves were higher than those in the ganglia. On a gel permeation chromatogram, 3 peaks (100, 70 and 30 kDa) of PAM activity appeared in both tissues. There are main peaks at 70 kDa in the ganglia and at 30 kDa in the sciatic nerves. From these data, we suppose that PAM in rat sciatic nerves is proteolytically processed during the axonal transport of secretion granules. Copyright (C) 1996 Elsevier Science Ltd.