Low-density particles (W-particles) containing catalase in Zellweger syndrome and normal fibroblasts.
Low-density particles (W-particles) containing catalase in Zellweger syndrome and normal fibroblasts.
复制标题
齐薇格综合征和正常成纤维细胞中含有过氧化氢酶的低密度颗粒（W 颗粒）。
DOI：
10.1073/pnas.88.22.10084
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发表时间：
1991
影响因子：
11.1
通讯作者：
Chen,GL
中科院分区：
文献类型：
--
作者：
Aikawa,J;Chen,WW;Kelley,RI;Tada,K;Moser,HW;Chen,GL
根据组织学和生化标准，Zellweger综合征患者的过氧化物酶体似乎缺失或严重不足。通过使用15-30%（wt/vol）Nycodenz/蔗糖梯度来研究过氧化物酶体外过氧化氢酶活性（成熟过氧化物酶体的常用标记物）的亚细胞定位，我们在1.13 g/cm 3的平衡密度下检测到齐薇格综合征成纤维细胞中的单峰活性，低于成熟过氧化物酶体的预期1.17 g/cm 3。在原始梯度或具有更高盐浓度的梯度中再离心后，基本上所有过氧化氢酶活性以原始密度的级分回收。过氧化氢酶峰的活性通过洋地黄皂苷滴定和过滤测定结合Triton X-100处理进一步分析。过氧化氢酶活性通过0.1微米和0.22微米，但保留在0.025微米膜过滤器上（平均孔径）。用Triton X-100处理后，几乎所有的过氧化氢酶活性都通过了过滤器。分级数据、毛地黄皂苷潜伏期测量和洗涤剂对过滤行为的影响的结果表明，过氧化氢酶不像通常认为的那样游离于齐薇格综合征成纤维细胞的胞质溶胶中，而是游离于颗粒（W颗粒）中。类似的低密度含过氧化氢酶的颗粒，不同于过氧化物酶体，也发现在正常的成纤维细胞。我们发现，L-α-羟酸氧化酶，另一种过氧化物酶体基质酶，也存在于W-颗粒来自正常和齐薇格综合征成纤维细胞。我们推测，低密度过氧化氢酶的W-颗粒可能代表一个不成熟或不完整的形式的过氧化物酶体不同于先前描述的“过氧化物酶体鬼”在齐薇格综合征成纤维细胞。
By both histological and biochemical criteria, peroxisomes in patients with Zellweger syndrome appear to be absent or severely deficient. By using 15-30% (wt/vol) Nycodenz/sucrose gradients to study the subcellular localization of extraperoxisomal catalase activity, a commonly used marker for mature peroxisomes, we detected a single peak of activity in Zellweger syndrome fibroblasts at an equilibrium density of 1.13 g/cm3, lower than the expected 1.17 g/cm3 of mature peroxisomes. Upon recentrifugation in either the original gradient or one with a higher salt concentration, essentially all catalase activity was recovered in fractions of the original densities. The activity of the catalase peak was further analyzed by a digitonin titration and filtration assay in combination with Triton X-100 treatment. The catalase activity passed through 0.1-microns and 0.22-microns but was retained on 0.025-microns membrane filters (mean pore size). After treatment with Triton X-100 nearly all catalase activity passed through the filters. The results from fractionations data, digitonin latency measurement, and the detergent effect on the filtration behavior suggest that catalase is not free in the cytosol of Zellweger syndrome fibroblasts as commonly thought but in particles (W-particles). Similar low-density catalase-containing particles, distinct from peroxisomes, are also found in normal fibroblasts. We found that L-alpha-hydroxyacid oxidase, another peroxisomal matrix enzyme, is also present in W-particles derived from normal and Zellweger syndrome fibroblasts. We speculate that the low-density catalase-containing W-particle may represent an immature or incomplete form of peroxisome distinct from previously described "peroxisomal ghosts" in Zellweger syndrome fibroblasts.