Yamada T, Shinnoh N, Kobayashi T
Department of Neurology, Faculty of Medicine, Kyushu University, Japan.
Neurochem Res. 1997 Mar;22(3):233-7. doi: 10.1023/a:1022477001703.
The adrenoleukodystrophy (ALD) gene product, ALD protein (ALDP), was not detected in fibroblasts from our or most other patients with ALD as determined by immunoblot or immunocytochemistry. We investigated the stability of mutant ALDP and found from pulse-chase experiments that the respective half-lives of the normal and mutant #140 (Gly512Ser) and #249 (Arg660Trp) were 72.6, 32.1 and 26.1 min, indicative that mutant ALDPs are less stable than normal ones. The mutant ALDPs were detectable in fibroblasts cultured with the protease inhibitor E-64 or leupeptin. Protease inhibitor treatment for 2 to 28 days did not affect the amount of very long chain fatty acid (VLCFA), C26:0, or VLCFA beta-oxidation activity in ALD fibroblasts. Protease inhibitors therefore suppress the degradation of ALDP but do not correct the impairment of VLCFA metabolism in ALD.
通过免疫印迹或免疫细胞化学检测发现，在我们的患者以及大多数其他肾上腺脑白质营养不良（ALD）患者的成纤维细胞中未检测到ALD基因产物ALD蛋白（ALDP）。我们研究了突变型ALDP的稳定性，通过脉冲追踪实验发现，正常型、突变型#140（Gly512Ser）和#249（Arg660Trp）的各自半衰期分别为72.6、32.1和26.1分钟，这表明突变型ALDP的稳定性低于正常型。在用蛋白酶抑制剂E-64或亮抑酶肽培养的成纤维细胞中可检测到突变型ALDP。蛋白酶抑制剂处理2至28天对ALD成纤维细胞中极长链脂肪酸（VLCFA）、C26:0的含量或VLCFAβ氧化活性没有影响。因此，蛋白酶抑制剂可抑制ALDP的降解，但不能纠正ALD中VLCFA代谢的损害。
