Grzelczak Z F, Sattolo M H, Hanley-Bowdoin L K, Kennedy T D, Lane B G
Can J Biochem. 1982 Mar;60(3):389-97. doi: 10.1139/o82-046.
The most prominent methionine-labeled protein made when cell-free systems are programmed with bulk mRNA from dry wheat embryos has been identified with what may be the most abundant protein in dry wheat embryos. The protein has been brought to purity and has a distinctive amino acid composition, Gly and Glx accounting for almost 40% of the total amino acids. Designated E because of its conspicuous association with early inhibition of dry wheat embryos, the protein and its mRNA are abundant during the "early" phase (0--1 h) of postimbibition development, and easily detected during "lag" phase (1--5 h), but they are almost totally degraded soon after entry into the "growth" phase of development, by about 10 h postimbibition. The most prominent methionine-labeled protein peculiar to the cell-free translational capacity of bulk mRNA from "growth" phase embryos is not detected as a product of in vivo synthesis. Its electrophoretic properties and its time course of emergence, after 5 h postimbibition development, suggest that this major product of cell-free synthesis may be an in vitro counterpart to a prominent methionine-labeled protein made only in vivo, by "growth" phase embryos. Designated G because of its conspicuous association with "growth" phase development, the cell-free product does not comigrate with any prominent dye-stained band in electrophoretic distributions of wheat proteins. The suspected cellular counterpart to G, also, does not comigrate with a prominent dye-stained wheat protein during electrophoresis, and although found in particulate as well as soluble fractions of wheat embryo homogenates it is not concentrated in either nuclei or mitochondria, as isolated.
当用来自干燥小麦胚的大量mRNA对无细胞系统进行编程时，所产生的最显著的甲硫氨酸标记蛋白已被鉴定为可能是干燥小麦胚中最丰富的蛋白质。该蛋白质已达到纯化状态，具有独特的氨基酸组成，甘氨酸和谷氨酸占总氨基酸的近40%。由于其与干燥小麦胚早期抑制的明显关联而被命名为E，该蛋白质及其mRNA在吸胀后发育的“早期”阶段（0-1小时）含量丰富，在“滞后期”（1-5小时）易于检测到，但在进入发育的“生长”阶段后不久，即在吸胀后约10小时，它们几乎完全降解。在来自“生长”阶段胚的大量mRNA的无细胞翻译能力中特有的最显著的甲硫氨酸标记蛋白未被检测为体内合成产物。其电泳性质及其在吸胀后5小时发育后的出现时间进程表明，这种无细胞合成的主要产物可能是仅在体内由“生长”阶段胚产生的一种显著的甲硫氨酸标记蛋白的体外对应物。由于其与“生长”阶段发育的明显关联而被命名为G，无细胞产物在小麦蛋白的电泳分布中不与任何显著的染色带迁移到同一位置。推测的与G对应的细胞蛋白在电泳过程中也不与显著的染色小麦蛋白迁移到同一位置，并且尽管在小麦胚匀浆的颗粒和可溶部分中都能找到，但它在分离时并不集中在细胞核或线粒体中。
