Watabe K, Iida S, Nakamura K, Ichikawa T, Kondo M
Microbiol Immunol. 1981;25(6):545-56. doi: 10.1111/j.1348-0421.1981.tb00056.x.
Developing forespores were isolated from Bacillus subtilis at different stages of sporulation and protein synthesis in the forespore compartment was examined. Pulse-labeling experiments indicated that [14C]phenylalanine was continuously incorporated into the sporangium throughout sporulation, and at t5 (early stage V of sporulation) 58% of the radioactivity was located in the forespore compartment. Significantly high incorporation of [14C]phenylalanine was observed when the isolated forespores at t5 were incubated with the corresponding mother-cell cytoplasmic fraction or an amino acid mixture. About 73% of the radioactivity incorporated into the isolated forespore at t5 was found in the cytoplasmic fraction and 26% in the membranous fraction. Analysis by sodium dodecyl sulfate-gel electrophoresis showed that the 14C-labeled cytoplasmic protein had a molecular weight of about 20,000, and that a protein having the same molecular weight was present in the t5 forespore as a slight protein band and also in the mature spore as a clear protein band. Gel electrophoresis also revealed that the 14C-labeled membranous-soluble protein (prepared by solubilization with detergents) had broad peaks with molecular weights of about 74,000, 33,000, 20,000, and 12,000.
在芽孢形成的不同阶段从枯草芽孢杆菌中分离出正在发育的前芽孢，并检测前芽孢隔室内的蛋白质合成。脉冲标记实验表明，在整个芽孢形成过程中，[14C]苯丙氨酸持续掺入营养细胞，在t5（芽孢形成的早期V阶段），58%的放射性位于前芽孢隔室内。当将t5时分离的前芽孢与相应的母细胞细胞质部分或氨基酸混合物一起孵育时，观察到[14C]苯丙氨酸的掺入量显著增加。在t5时掺入分离的前芽孢中的放射性，约73%存在于细胞质部分，26%存在于膜部分。十二烷基硫酸钠-凝胶电泳分析表明，14C标记的细胞质蛋白分子量约为20,000，并且分子量相同的一种蛋白在t5前芽孢中以微弱蛋白条带形式存在，在成熟芽孢中以清晰蛋白条带形式存在。凝胶电泳还显示，14C标记的膜可溶性蛋白（通过用去污剂溶解制备）具有分子量约为74,000、33,000、20,000和12,000的宽峰。
