Kato T, Yajima R, Sato N, Takahashi K, Shimizu C, Chikuma T
Laboratory of Molecular Recognition, Graduate School of Integrated Science, Yokohama, Japan.
Neurochem Int. 1998 Feb;32(2):163-70. doi: 10.1016/s0197-0186(97)00067-3.
Study on neural axon transport is a very useful method to find a neuron-specific protease. In the present study, the enzyme activity (release of 7-amino-4-methyl-coumarin from t-butyloxycarbonyl-glycyl-L-arginyl-L-arginine-4-methylcoumaryl-7-amide) was measured in the proximal, middle, and distal segments 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 ligation, and the maximal enzyme activity was found in both segments at 72 h. The enzyme activity eluted by anion exchange chromatography of the proximal segment showed at least three peaks, and was slightly higher than the activity of the distal one. The activity in the middle segment 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 anterograde and retrograde axonal flow, and may undergo a neuron-specific processing.
神经轴突运输研究是寻找神经元特异性蛋白酶的一种非常有用的方法。在本研究中，在大鼠坐骨神经双重结扎后12至120小时内，测量近端、中间和远端节段的酶活性（从叔丁氧羰基 - 甘氨酰 - L - 精氨酰 - L - 精氨酸 - 4 - 甲基香豆素酰胺释放7 - 氨基 - 4 - 甲基香豆素），以寻找对碱性氨基酸残基对具有特异性的前体加工酶。结扎后12至120小时，不仅近端节段的酶活性显著增加，远端节段的酶活性也显著增加，并且在72小时时在两个节段中均发现最大酶活性。近端节段经阴离子交换色谱洗脱的酶活性显示至少三个峰，并且略高于远端节段的活性。与近端和远端节段的活性相比，中间节段的活性非常低。这些数据表明，一些对碱性氨基酸残基对具有特异性的酶通过顺行和逆行轴突流运输，并且可能经历神经元特异性加工。
