Tzen J T, Chuang R L, Chen J C, Wu L S
Graduate Institute of Agricultural Biotechnology, National Chung-Hsing University, Taichung, Taiwan.
J Biochem. 1998 Feb;123(2):318-23. doi: 10.1093/oxfordjournals.jbchem.a021939.
The oil bodies of plant seeds contain a triacylglycerol matrix surrounded by a monolayer of phospholipids embedded with alkaline proteins termed oleosins. Two distinct oleosin isoforms with molecular masses of 18 and 16 kDa are present in rice oil bodies. Chicken antibodies raised against oleosin 18 kDa and rabbit antibodies raised against oleosin 16 kDa did not cross-recognize these two homologous isoforms. This peculiar non-cross recognition was used to locate the two oleosin isoforms on the surface of oil bodies via immunofluorescence detection using anti-chicken IgG conjugated with FITC (fluorescein isothiocyanate) and anti-rabbit IgG conjugated with Texas-Red. The results revealed that both oleosin isoforms resided on each oil body in vivo and in vitro. Artificial oil bodies were reconstituted via sonication using triacylglycerol, phospholipid, and oleosins. The results indicated that the two rice oleosin isoforms could stabilize artificial oil bodies individually whereas oleosin 16 kDa provided better stability to the organelles than oleosin 18 kDa.
植物种子的油体含有一个三酰甘油基质，其周围是一层嵌入称为油质蛋白的碱性蛋白质的磷脂单分子层。在水稻油体中存在两种不同的油质蛋白亚型，分子量分别为18 kDa和16 kDa。针对18 kDa油质蛋白产生的鸡抗体和针对16 kDa油质蛋白产生的兔抗体不能交叉识别这两种同源亚型。这种特殊的非交叉识别被用于通过免疫荧光检测在油体表面定位这两种油质蛋白亚型，使用与异硫氰酸荧光素（FITC）偶联的抗鸡IgG和与德克萨斯红偶联的抗兔IgG。结果表明，两种油质蛋白亚型在体内和体外均存在于每个油体上。通过使用三酰甘油、磷脂和油质蛋白超声处理重建人工油体。结果表明，两种水稻油质蛋白亚型可以分别稳定人工油体，而16 kDa油质蛋白比18 kDa油质蛋白为细胞器提供更好的稳定性。
