INTRACELLULAR FERULOYLATION OF PECTIC POLYSACCHARIDES
INTRACELLULAR FERULOYLATION OF PECTIC POLYSACCHARIDES
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DOI：
10.1007/bf00391095
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发表时间：
1987-06-01
期刊：
影响因子：
4.3
通讯作者：
FRY, SC
中科院分区：
文献类型：
--
作者：
FRY, SC
菠菜细胞壁的果胶多糖在阿拉伯糖和半乳糖残基上携带阿魏酰基。下面的实验旨在发现阿拉伯糖残基是否在细胞内或细胞外被阿魏酸化。培养的菠菜细胞在大约一段滞后期后开始以线性速率将外源[3H]阿拉伯糖掺入聚合物中。3-4分钟，尽管放射性多糖和伸展蛋白直到大约后才开始出现在质膜外。25-min滞后。在相同的细胞中，多糖结合阿魏酰-[3H]阿拉伯糖单位在大约一段滞后期后开始以线性速率积累放射性。4 - 5分钟。因此，多糖的阿拉伯糖残基在仍在细胞内时就开始阿魏酸化。25分钟后，多糖结合阿魏酰-[3H]阿拉伯糖单位的形成率没有明显增加，表明多糖的任何额外的细胞外阿魏酰化相对缓慢。这一结论得到了两种不同类型的脉冲追踪实验的支持，其中一种实验旨在检测合成后6天内阿魏烯酰化的多糖。
The pectic polysaccharides of spinach cell walls carry feruloyl groups on arabinose and galactose residues. The following experiments were designed to discover whether the arabinose residues are feruloylated intra- or extracellularly. Cultured spinach cells started to incorporate exogenouse [3H]arabinose into polymers at a linear rate after a lag period of approx. 3-4 min, although radioactive polysaccharides and extensin did not start to appear outside the plasmalemma until after an approx. 25-min lag. In the same cells, polysaccharide-bound feruloyl-[3H]arabinose units started to accumulate radioactivity at a linear rate after a lag period of approx. 4-5 min. Therefore, arabinose residues of polysaccharides began to be feruloylated while still intracellular. The rate of formation of polysaccharide-bound feruloyl-[3H]arabinose units did not appreciably increase after 25 min, showing that any additional extracellular feruloylation of the polysaccharide was relatively slow. This conclusion was supported by two different types of pulse-chase experiments, one of which was designed to detect feruloylation of polysaccharides up to 6 d after synthesis.