Calcium-Activated neutral protease in the peripheral nerve, which requires μM order Ca2+, and its effect on the neurofilament triplet
✍ Scribed by Dr. K. Kamakura; S. Ishiura; K. Suzuki; H. Sugita; Y. Toyokura
- Publisher
- John Wiley and Sons
- Year
- 1985
- Tongue
- English
- Weight
- 1010 KB
- Volume
- 13
- Category
- Article
- ISSN
- 0360-4012
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✦ Synopsis
There are two types of calcium-activated neutral protease (CANP), m-CANP and p-CANP, following the nomenclature of Suzuki et a1 to show that each requires mM and pM Ca2+, respectively, for its activation. We found p-CANP activity in a crude CANP fraction extracted from the peripheral nerve, which degraded the neurofilament (N9 triplet (200 K, 160 K, 68 K), especially the 160 K component, at Ca2' concentrations of 50 pM and 0.1 mM. The triplet was degraded in the order of the 160 K, 68 K, and 200 K components, respectively. In addition, the effects of partially purified p-CANP of rabbit skeletal muscle, purified natural p- CANP of bovine liver, derived p-CANP prepared by autodigestion of chicken muscle m-CANP, m-CANP of chicken skeletal muscle, and cathepsin B of rat liver on the Nf were examined. Among the triplet components, the 160 K component was most rapidly degraded by all proteases so far tested. The difference in the effect of p-CANP and m-CANP or cathepsin B on susceptibility of the 200 K component to degradation might be due to the difference of the relative amounts of enzymes to Nf.