Biosynthesis, processing, and extracellular release of alpha-L-fucosidase in lymphoid cell lines of different genetic origins.
Biosynthesis, processing, and extracellular release of alpha-L-fucosidase in lymphoid cell lines of different genetic origins.
复制标题
不同遗传起源的淋巴细胞系中α-L-岩藻糖苷酶的生物合成、加工和细胞外释放。
DOI：
10.1007/bf02401794
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发表时间：
1988
影响因子：
2.4
通讯作者：
Brown,KS
中科院分区：
文献类型：
--
作者：
DiCioccio,RA;Brown,KS
在人类中，血清中α-L-岩藻糖苷酶的数量由遗传决定。控制血清中酶水平的机制尚不清楚。建立了来源于血清中α-L-岩藻糖苷酶水平低、中等或高的个体的类藻细胞系。细胞内和细胞外α-L-岩藻糖苷酶的稳态水平以及酶的合成和分泌速率在细胞系之间重叠。因此，在该系统中不表达体内血清表型。在这些淋巴细胞系中，未观察到新生成的α-L-岩藻糖苷酶的定性处理存在明显差异。用35 S-甲硫氨酸从0.25至2小时脉冲标记的细胞具有aMr= 58，000的细胞内形式的酶。细胞脉冲1.5小时并用未标记的甲硫氨酸追踪21小时，细胞内形式的Mr = 60，000，细胞外形式的Mr = 62，000。所有三种酶形式都是糖蛋白，具有Mr = 52，000的共同多肽链，但具有不同的碳水化合物部分。没有证据表明α-l-岩藻糖苷酶的前体形式存在于组织和体液中。岩藻糖苷病是一种罕见的遗传性疾病，组织和体液中的α-l-岩藻糖苷酶活性较低或不存在。岩藻糖苷沉积症的突变和血清多态性图分别。与对照细胞相比，来自两个患有岩藻糖苷沉积症的同胞的类肉瘤细胞的胞内α-L-岩藻糖苷酶蛋白低8倍至341倍，比活性低11倍至56倍。残留的突变酶是一种糖蛋白，其多肽链的大小（Mr= 52，000）与对照酶几乎相同。然而，与对照酶相比，残留的突变酶是低糖基化和高分泌的。
In humans, the quantity of α-l-fucosidase in serum is determined by heredity. The mechanism controlling levels of the enzyme in serum is unknown. Lymphoid cell lines derived from individuals with either low, intermediate, or high α-l-fucosidase in serum were established. Steady-state levels of intracellular and extracellular α-l-fucosidase as well as rates of synthesis and secretion of enzyme overlapped among the cell lines. Thus,vivo} serum phenotypes were not expressed in this system. No appreciable differences in the qualitative processing of newly made α-l-fucosidase were observed among these lymphoid cell lines. Cells pulse-labeled with35S-methionine from 0.25 to 2 hr had an intracellular form of enzyme with aMr=58,000. Cells pulsed for 1.5 hr and chased for 21 hr with unlabeled methionine had an intracellular form ofMr=60,000 and an extracellular form ofMr=62,000. All three enzyme forms were glycoproteins with a common polypeptide chain ofMr=52,000 but with different carbohydrate moieties. No evidence for a high molecular mass precursor form of α-l-fucosidase was found. Fucosidosis is a rare, inherited disease in which α-l-fucosidase activity in tissues and body fluids is low or absent. The mutations for fucosidosis and the serum polymorphism map separately. Lymphoid cells from two siblings with fucosidosis had 8-fold to 341-fold less intracellular α-l-fucosidase protein with 11-fold to 56-fold lower specific activities than control cells. Residual mutant enzyme was a glycoprotein with a polypeptide chain virtually the same size (Mr=52,000) as control enzyme. However, residual mutant enzyme was hypoglycosylated and hypersecreted as compared to control enzyme.