We attempted to identify the total proteome in sesame lipid droplets. Results from two-dimensional electrophoresis showed 139 protein spots in lipid droplet samples. Each spot was isolated, digested with trypsin, and applied to liquid chromatography–tandem mass spectrometry (Q-Tof Premier). As a result, 103 spots were identified. Although oleosin, caleosin, and steroleosin are known major components of the lipid droplet, many other proteins were also found in the lipid droplet. In addition to the three major proteins, TAG factor protein, glyceraldehyde-3-phosphate dehydrogenase, F₁ ATPase, 70-kDa heat shock protein, seed maturation protein PM24, and 11S globulin precursor isoforms 3 and 4 were found in the lipid droplet. Three types of oleosins, 15-, 15.5-, and 17-kDa were present in the sesame lipid droplet, and the 15.5-kDa oleosin had high homology with oleosin from Coffea canephora. It has been shown by acid phosphatase treatment that oleosin proteins contain phosphate groups. Protein disulfide-isomerase 2 precursor, calreticulin-1, and BiP, which are known as marker proteins of the endoplasmic reticulum, were found as the components of the lipid droplet. Immunoconfocal microscopy was used to show that 11S globulin precursor isoform 3 and 4 were indeed localized in the lipid droplet. The presence of 11S globulin in the lipid droplets suggested a new mechanism for the lipid droplet formation.

中文翻译：

---

芝麻中脂滴的蛋白质组学分析。

我们试图鉴定芝麻脂质小滴中的总蛋白质组。二维电泳结果显示脂质滴样品中有139个蛋白斑点。分离每个斑点，用胰蛋白酶消化，然后用于液相色谱-串联质谱分析法（Q-Tof Premier）。结果，确定了103个斑点。尽管油质脂蛋白，钙油蛋白和固醇脂蛋白是脂质小滴的主要成分，但在脂质小滴中也发现了许多其他蛋白质。除了三种主要蛋白外，TAG因子蛋白，甘油醛-3-磷酸脱氢酶F ₁在脂滴中发现了ATPase，70 kDa热激蛋白，种子成熟蛋白PM24和11S球蛋白前体同工型3和4。芝麻脂滴中存在15-，15.5-和17-kDa三种类型的油质蛋白，而15.5-kDa的油质蛋白与来自加拿大咖啡的油质蛋白具有高度同源性。酸性磷酸酶处理已表明，油质蛋白含有磷酸基。发现蛋白质二硫键异构酶2前体Calreticulin-1和BiP被称为内质网的标记蛋白，它们是脂质小滴的成分。免疫球镜检查显示11S球蛋白前体同工型3和4确实位于脂质液滴中。脂质滴中11S球蛋白的存在提示了脂质滴形成的新机制。