Chen E C, Tai S S, Peng C C, Tzen J T
Graduate Institute of Agricultural Biotechnology, National Chung-Hsing University, Taichung, Taiwan, ROC.
Plant Cell Physiol. 1998 Sep;39(9):935-41. doi: 10.1093/oxfordjournals.pcp.a029457.
Plant seeds store triacylglycerols in discrete organelles called oil bodies. An oil body preserves a matrix of triacylglycerols surrounded by a monolayer of phospholipids embedded with abundant structural proteins termed oleosins and probably some uninvestigated minor proteins of higher molecular mass. Three polypeptides of 27, 37, and 39 kDa (temporarily denominated as Sop1, Sop2, and Sop3) were regularly co-purified with seed oil bodies of sesame. Comparison of amino acid composition indicated that they were substantially less hydrophobic than the known oleosins, and thus should not be aggregated multimers of oleosins. The results of immuno-recognition to sesame proteins extracted from subcellular fractions of mature seeds, various tissues, and oil bodies purified from different stages of seed formation revealed that these three polypeptides were unique proteins gathered in oil bodies, accompanying oleosins and triacylglycerols, during the active assembly of the organelles in maturing seeds. Both in vivo and in intro, immunofluorescence labeling using secondary antibodies conjugated with FITC (fluorescein isothiocyanate) confirmed the localization of these three polypeptides in oil bodies.
植物种子在称为油体的离散细胞器中储存三酰甘油。油体保存着由单层磷脂包围的三酰甘油基质，磷脂中嵌入了丰富的结构蛋白，即油质蛋白，可能还有一些尚未研究的高分子量次要蛋白。27 kDa、37 kDa和39 kDa的三种多肽（暂时命名为Sop1、Sop2和Sop3）经常与芝麻种子油体共同纯化。氨基酸组成比较表明，它们的疏水性明显低于已知的油质蛋白，因此不应是油质蛋白的聚集多聚体。对从成熟种子的亚细胞组分、各种组织以及从种子形成不同阶段纯化的油体中提取的芝麻蛋白进行免疫识别的结果表明，这三种多肽是在成熟种子细胞器的活跃组装过程中，与油质蛋白和三酰甘油一起聚集在油体中的独特蛋白质。体内和体外实验中，使用与异硫氰酸荧光素（FITC）偶联的二抗进行免疫荧光标记，证实了这三种多肽在油体中的定位。
