Department of Horticulture, University of Wisconsin, Madison, Wisconsin 53706.
Plant Physiol. 1976 May;57(5):730-3. doi: 10.1104/pp.57.5.730.
The soluble proteins of C(3) and C(4) mesophyll chloroplasts and C(4) bundle sheath extracts have been analyzed by gel electrophoresis for fraction I protein. Gel scans of soluble protein from C(4) bundle sheath extracts and C(3) mesophyll chloroplasts showed typical fraction I protein peaks that could be identified by ribulose diphosphate carboxylase activity. No such peak was observed for C(4) mesophyll chloroplasts, which also lacked both large and small subunits of ribulose diphosphate carboxylase on sodium dodecyl sulfate gels. The absence of fraction I protein in these chloroplasts was reflected in the soluble protein to chlorophyll ratios, which were roughly 3-fold lower than the ratio obtained for C(3) chloroplasts. The carboxylating enzyme in C(4) mesophyll cells, phosphoenolpyruvate carboxylase, was found to be a major protein in the cytoplasm of C(4) mesophyll protoplasts, and had higher mobility than fraction I protein.
已通过凝胶电泳对 C（3）和 C（4）叶肉叶绿体和 C（4）束鞘提取物的可溶性蛋白进行了分析，以研究分Ⅰ蛋白。C（4）束鞘提取物和 C（3）叶肉叶绿体可溶性蛋白的凝胶扫描显示出典型的分Ⅰ蛋白峰，可通过核酮糖二磷酸羧化酶活性进行鉴定。C（4）叶肉叶绿体中未观察到这种峰，在十二烷基硫酸钠凝胶上也缺乏核酮糖二磷酸羧化酶的大亚基和小亚基。这些叶绿体中缺乏分Ⅰ蛋白反映在可溶性蛋白与叶绿素的比例上，该比例比 C（3）叶绿体获得的比例低约 3 倍。C（4）叶肉细胞中的羧化酶，磷酸烯醇丙酮酸羧化酶，被发现是 C（4）叶肉原生质体细胞质中的主要蛋白质，其迁移率高于分Ⅰ蛋白。
