Cell Biological Studies on Protein Body-Vacuole Transformation in Germinating Castor Bean Seedlings.

在脂肪种子萌发过程中，蛋白质体相互融合，最终形成一个中央液泡。我们分析了蛋白体向液泡的转化过程，重点讨论了膜流系统中的膜融合。建立了蓖麻和南瓜籽中蛋白体膜和液泡膜的分离方法，并对膜蛋白的发育进行了研究。蓖麻籽蛋白体膜中检测到4种主要的膜蛋白（80kd、28kd、26kd、24kd），这些蛋白在蛋白体向液泡转化过程中含量减少。另一方面，在南瓜蛋白体膜中发现了5种主要蛋白（73 kD、51 kD、32 kD、27 kD、23 kD）。这些膜蛋白在转化过程中也减少了，而膜上出现了一些新的蛋白（94 kD, 58 kD, 16 kD）。免疫化学分析表明，蓖麻80 kD和26 kD与南瓜73 kD和32 kD发生了交叉反应，表明这两种蛋白具有相似的结构和功能。我们从南瓜籽中制备了针对这些膜蛋白的单特异性抗体。这些抗体对蛋白体膜融合的影响还在实验中。

Protein bodies are fused with each other and become finally a central vacuole during germination of fatty seed. We have analyzed the transfomation of protein bodies to vacuoles, especially focused on membrane fusion in membrane flow system.Methods for isolation of protein body membrane and vacuolar membrane from castor bean and pumpkin seed were established and the development of membrane proteins was studied. Four main membrane proteins (80 kD, 28 kD, 26 kD, 24 kd) were detected in protein body membrane from castor bean seed and amounts of these proteins were decreased during transformation of protein bodies to vacuoles. On the other hand, 5 main proteins (73 kD, 51 kD, 32 kD, 27 kD, 23 kD) were found in pumpkin protein body membrane. These membrane proteins were also decreased during the transformation whereas several new proteins (94 kD, 58 kD, 16 kD) appear in the membrane. Immunochemical analysis show that castor bean 80 kD and 26 kD were crossreacted with pumpkin 73 kD and 32 kD, suggesting that these proteins have similar structure and functions.We have prepared monospecific antibodies against these membrane proteins from pumpkin seed. The effect of these antibodies on fusion of protein body membrane are under experiments.