Purification and characterization of ten new rice NaCl-soluble proteins: identification of four protein-synthesis inhibitors and two immunoglobulin-binding proteins
Purification and characterization of ten new rice NaCl-soluble proteins: identification of four protein-synthesis inhibitors and two immunoglobulin-binding proteins
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十种新型水稻氯化钠可溶性蛋白的纯化和表征：四种蛋白合成抑制剂和两种免疫球蛋白结合蛋白的鉴定
作者：
G. G. Limas;M. Salinas;I. Moneo;Stefan Fischer;B. Wittmann;E. Méndez
水稻（Oryza sativa L.）CV.巴伊亚），包括四个蛋白质合成抑制剂和两个免疫球蛋白E（IgE）结合蛋白已被分离和表征。这些蛋白质以及一个以前已知的组分，α-球蛋白，纯化从0.5 M NaCl提取的水稻胚乳的一个新的，显然非变性，分离程序开发的大米蛋白。该方法基于用稀释的挥发性盐溶液和乙醇水溶液提取这种复杂的蛋白质混合物。这一初步步骤改善了这些蛋白质的分离，从而有利于随后通过反相高效液相色谱法进行纯化。这些新的蛋白质具有相似的相对分子质量（Mrs）从11000到17000。通过微区双向凝胶电泳分析蛋白质的纯度。其中四种成分被发现是体外蛋白质合成抑制剂在一个无细胞系统从大鼠脑。这四种抑制剂的NH 2-末端氨基酸序列在从电泳凝胶中分离的蛋白质直接印迹后从12至26个循环中确定。这些蛋白质与夫人之间的16000和17000表现出高度的同源性，从57%至75%，但似乎是无关的第四抑制剂。此外，α-球蛋白和Mr 12500的一种新型低分子量蛋白质似乎具有致敏性，因为它们与超敏患者血清中的IgE抗体结合。这两种蛋白质都具有封闭的NH 2末端氨基酸。
Ten new proteins from rice (Oryza saliva L. cv. Bahia) including four protein-synthesis inhibitors and two immunoglobulin E (IgE)-binding proteins have been isolated and characterized. These proteins as well as one previously known component, α-globulin, were purified from a 0.5 M NaCl extract of rice endosperm by a new, apparently non-denaturing, isolation procedure developed for rice proteins. The method is based on extractions of this complex protein mixture with a diluted volatile salt solution and an aqueous solution of ethanol. This preliminary step results in an improvement in the separation of these proteins, thus facilitating their subsequent purification by reversed-phased high-performance liquid chromatography. These new proteins have similar relative molecular masses (Mrs) from 11000 to 17000. The purity of the proteins was analyzed by micro two-dimensional gel electrophoresis. Four of these components were found to be in-vitro protein-synthesis inhibitors in a cell-free system from rat brain. The NH2-terminal amino-acid sequences of these four inhibitors were determined from 12 to 26 cycles after direct blotting of the separated proteins from electrophoresis gels. Three of these proteins with Mrs between 16000 and 17000 showed a high degree of homology ranging from 57% to 75% but seem to be unrelated to the fourth inhibitor. In addition, the α-globulin and one of the new low-molecular-weight proteins of Mr 12500 seemed to show allergenic properties since they bound IgE antibodies from the sera of hypersensitive patients. Boths proteins have blocked NH2-terminal amino acids.