Purification and Partial Characterization of a Hydroxyproline-Rich Glycoprotein in a Graminaceous Monocot, Zea mays.
Purification and Partial Characterization of a Hydroxyproline-Rich Glycoprotein in a Graminaceous Monocot, Zea mays.
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禾本科单子叶植物玉米中富含羟脯氨酸的糖蛋白的纯化和部分表征。
DOI：
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发表时间：
1987
期刊：
影响因子：
7.4
通讯作者：
Derekt . A. Lamport
中科院分区：
文献类型：
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作者：
M. Kieliszewski;Derekt . A. Lamport
禾本科单子叶植物通常含有低水平的富含羟脯氨酸的糖蛋白（HRGP）。由于HRGP通常位于细胞表面，我们使用完整细胞洗脱技术（100毫摩尔AlCl（3））从玉米细胞悬浮培养物中分离可溶性表面蛋白。进一步分馏的三氯乙酸可溶性的三氯乙酸的阳离子交换剂磷酸纤维素和BioRex-70给出了几个延迟，因此推测为碱性馏分，其中还含有羟脯氨酸（Hyp）。这些级分之一在涉及Superose-6凝胶过滤的最终纯化步骤后产生纯HRGP。由于该HRGP异常富含苏氨酸（25摩尔%），我们将其指定为富含苏氨酸-羟脯氨酸的糖蛋白（THRGP）;它含有约27%的碳水化合物，仅以阿拉伯糖基化Hyp的形式存在，主要是单糖（15%）和三糖（25%），其中48%的Hyp为非糖基化的-一种典型的禾本科单子叶植物特征。氨基酸分析证实了基本特征，并给出了低丙氨酸含量。与Yariv人工抗原呈阴性反应。这些特征表明THRGP不是阿拉伯半乳聚糖蛋白。另一方面，针对番茄伸展蛋白P1的抗体与THRGP发生了显著的交叉反应;这种交叉反应性和上述分析数据为伸展蛋白在禾本科单子叶植物中的存在提供了迄今为止最好的证据。
Graminaceous monocots generally contain low levels of hydroxyproline-rich Glycoproteins (HRGPs). As HRGPs are often at the cell surface, we used the intact cell elution technique (100 millimolar AlCl(3)) to isolate soluble surface proteins from Zea mays cell suspension cultures. Further fractionation of the trichloroacetic acid-soluble eluate on the cation exchangers phospho-cellulose and BioRex-70 gave several retarded, hence presumably basic fractions, which also contained hydroxyproline (Hyp). One of these fractions yielded a pure HRGP after a final purification step involving Superose-6 gel filtration. As this HRGP was unusually rich in threonine, (25 mole%) we designated it as a threonine-hydroxyproline-rich glycoprotein (THRGP); it contained about 27% carbohydrate occurring exclusively as arabinosylated Hyp, predominantly as the monosaccharide (15%), and trisaccharide (25%) with 48% Hyp nonglycosylated-a characteristically graminaceous monocot profile. Amino acid analysis confirmed the basic character, and gave a low alanine content. Reaction with Yariv artificial antigen was negative. These characteristics show that the THRGP is not an arabinogalactan protein. On the other hand, antibodies raised against tomato extensin P1 cross-reacted significantly with the THRGP; this cross-reactivity and the above analytical data provide the best evidence to date for the presence of extensin in a graminaceous monocot.