AXONAL TRANSPORTS OF BOC-GLY-ARG-ARG-MCA HYDROLYZING ENZYME IN RAT SCIATIC-NERVES

Study on neural axon transport is a very useful method to find a neuro n-specific protease. In the present study, the enzyme activity (releas e of 7-amino-4-methyl-coumarin from cyl-L-arginyl-L-arginine-4-methylc oumaryl-7-amide) was measured in the proximal, middle, and distal segm ents between 12 and 120 h after double ligations of rat sciatic nerves to find precursor processing enzyme specific for pair of basic amino acid residue. The enzyme activity was significantly increased not only in the proximal but also in the distal segments 12-120 h after the li gation, and the maximal enzyme activity was found in both segments at 72 h. The enzyme activity eluted by anion exchange chromatography of t he proximal segment showed at least three peaks, and was slightly high er than the activity of the distal one. The activity in the middle seg ment was very low in comparison with the activity in the proximal and distal segments. These data indicate that some of the enzymes specific for pair of basic amino acid residue are transported by both anterogr ade and retrograde axonal flow, and may undergo a neuron-specific proc essing. (C) 1998 Elsevier Science Ltd. All rights reserved.