Agricultural Research Service, United States Department of Agriculture and Department of Agronomy, University of Wisconsin, Madison, Wisconsin 53706.
Plant Physiol. 1977 May;59(5):836-41. doi: 10.1104/pp.59.5.836.
The primary storage protein synthesized during oat (Avena sativa L.) groat development is a globulin. Polysomes were isolated from oat groats 12 days after anthesis. These polysomes directed the incorporation of radioactive amino acids into protein in a cell-free protein synthesis system containing wheat germ supernatant. The Mg(2+) optimum was 4 mm, the pH optimum was 6-8, and the amount of amino acid incorporation depended on polysome concentration. Incorporation of amino acids was linear for about 10 min and approached a maximum after 20 min. Using the initiation inhibitor, T-2 toxin, it was determined that about 36% of the amino acid incorporation was due to the initiation of new polypeptide chains. The in vitro product co-electrophoresed with authentic oat groat globulin on polyacrylamide-sodium dodecyl sulfate (SDS) gels. The cyanogen bromide peptides of the in vitro product partially corresponded with those from authentic globulin when electrophoresed on polyacrylamide-SDS gels. These data suggest that the in vitro product is primarily oat globulin. The polysome population was separated into membrane-bound and free polysomes. Membrane-bound polysomes synthesized about twice the amount of protein as did free polysomes. Products synthesized in vitro on both types of polysomes were essentially the same.
在燕麦（Avena sativa L.）麦粒发育过程中合成的主要贮藏蛋白是球蛋白。从小麦灌浆后第 12 天的燕麦麦粒中分离出多核糖体。这些多核糖体在含有麦胚上清液的无细胞蛋白合成系统中指导放射性氨基酸掺入蛋白。Mg（2+）的最适浓度为 4mM，pH 最适范围为 6-8，氨基酸掺入量取决于多核糖体的浓度。氨基酸掺入量在大约 10 分钟内呈线性，20 分钟后达到最大值。使用起始抑制剂 T-2 毒素，确定约 36%的氨基酸掺入归因于新多肽链的起始。体外产物与真实的燕麦麦粒球蛋白在聚丙烯酰胺-十二烷基硫酸钠（SDS）凝胶上共电泳。体外产物的氰化溴肽与真实球蛋白的电泳产物部分对应，当在聚丙烯酰胺-SDS 凝胶上电泳时。这些数据表明，体外产物主要是燕麦球蛋白。多核糖体群体被分离成膜结合和游离多核糖体。膜结合多核糖体合成的蛋白量是游离多核糖体的两倍。在两种多核糖体上体外合成的产物基本相同。
