Zeigler M, Bach G
Arch Biochem Biophys. 1985 Sep;241(2):602-7. doi: 10.1016/0003-9861(85)90586-7.
The subcellular distribution of ganglioside sialidase in Mucolipidosis IV (ML IV) cells was characterized by a series of Percoll gradients. Similar to normal cells, the enzyme cosedimented with plasma membrane markers, although this activity was reduced and exhibited decreased solubility in ML IV cells. Only trace amounts of ganglioside sialidase (less than 5%) was found in the lysosomes of normal cells. This activity was apparently reduced in ML IV cells but its minute activity in controls excluded further characterization of these differences. Plasma membranes on 6.7 and 5.6% Percoll gradients were biomodally distributed. Ganglioside sialidase in normal cells was found to be in both the heavier and the lighter membrane fractions, whereas the enzyme in ML IV cells was associated mainly with the denser membrane fraction. These data indicate that the enzyme in ML IV cells is characteristically different from normal in that it exhibits reduced activity and solubility and a different plasma membrane distribution.
通过一系列Percoll梯度法对黏脂贮积症IV型（ML IV）细胞中神经节苷脂唾液酸酶的亚细胞分布进行了表征。与正常细胞相似，该酶与质膜标志物共同沉降，尽管在ML IV细胞中这种活性降低且溶解度下降。在正常细胞的溶酶体中仅发现痕量的神经节苷脂唾液酸酶（少于5%）。在ML IV细胞中这种活性明显降低，但对照中的微小活性排除了对这些差异进行进一步表征的可能性。在6.7%和5.6%的Percoll梯度上的质膜呈双峰分布。发现正常细胞中的神经节苷脂唾液酸酶存在于较重和较轻的膜组分中，而ML IV细胞中的该酶主要与密度较大的膜组分相关。这些数据表明，ML IV细胞中的该酶在特性上与正常情况不同，因为它表现出活性和溶解度降低以及质膜分布不同。
