Saito Y, Tsubuki S, Ito H, Kawashima S
Department of Biochemistry, Tokyo Metropolitan Institute of Gerontology, Japan.
Neurosci Lett. 1990 Nov 27;120(1):1-4. doi: 10.1016/0304-3940(90)90153-z.
We have previously shown that, among many protease inhibitors examined, only a leupeptin analogue, Ac-Leu-Leu-Nle-al (ALLNal), induces neurite outgrowth in PC12h cells. Since this neurite outgrowth is different from that induced by nerve growth factor (NGF) in terms of morphology and persistence, the existence of a specific protease which regulates neurite formation in PC12h cells was expected. A set of 10 ALLNal analogue peptide protease inhibitors was synthesized and examined for their potency in inducing neurite outgrowth in PC12h cells. Substitution of the N-terminal acetyl residue in ALLNal by benzyloxycarbonyl (Z) increased the activity by about 4 times. For Z-Leu-Leu-X-al, neurite outgrowth was induced in the following order: Leu greater than Phe greater than Nva greater than Val = Ile = Nle greater than Ala greater than Gly at the X residue. The potency of Z-Leu-Leu-Leu-al (ZLLLal) was 50-fold stronger than that of ALLNal. ZLLLal provides a strong tool for characterizing this new type of protease.
我们之前已经表明，在众多被检测的蛋白酶抑制剂中，只有一种亮抑酶肽类似物，即乙酰 - 亮氨酸 - 亮氨酸 - 正亮氨酸 - 丙氨酸（ALLNal），能诱导PC12h细胞的神经突生长。由于这种神经突生长在形态和持续性方面与神经生长因子（NGF）诱导的不同，因此推测存在一种调节PC12h细胞神经突形成的特异性蛋白酶。合成了一组10种ALLNal类似物肽蛋白酶抑制剂，并检测它们在诱导PC12h细胞神经突生长方面的效力。用苄氧羰基（Z）取代ALLNal中的N端乙酰基残基，活性提高了约4倍。对于Z - 亮氨酸 - 亮氨酸 - X - 丙氨酸，在X残基处，神经突生长按以下顺序诱导：亮氨酸＞苯丙氨酸＞正缬氨酸＞缬氨酸 = 异亮氨酸 = 正亮氨酸＞丙氨酸＞甘氨酸。Z - 亮氨酸 - 亮氨酸 - 亮氨酸 - 丙氨酸（ZLLLal）的效力比ALLNal强50倍。ZLLLal为表征这种新型蛋白酶提供了一个有力工具。
