Saunders C W, Schmidt B J, Mallonee R L, Guyer M S
J Bacteriol. 1987 Jul;169(7):2917-25. doi: 10.1128/jb.169.7.2917-2925.1987.
We have fused the structural gene (hsa) for human serum albumin (HSA) to the expression elements and signal sequence coding region of each of two genes from Bacillus amyloliquefaciens P, an alpha-amylase gene (amyBamP) and a neutral protease gene (nprBamP). Bacillus subtilis strains harboring either of these gene fusions synthesized a protein with the antigenic characteristics and size (68 kilodaltons) of HSA. Results from pulse-labeling studies indicated that the bacterially produced HSA was secreted from cells which had been converted to protoplasts. Results from similar studies with intact cells suggested that the signal sequence was removed from the hybrid protein, providing further evidence that B. subtilis can translocate this foreign protein across the cell membrane. Signal sequence removal was efficient when the level of HSA synthesis was low. However, in strains which synthesized HSA at a high level, signal sequence removal was less efficient.
我们已将人血清白蛋白（HSA）的结构基因（hsa）与解淀粉芽孢杆菌P的两个基因（一个α-淀粉酶基因[amyBamP]和一个中性蛋白酶基因[nprBamP]）的表达元件及信号序列编码区融合。携带这两种基因融合体之一的枯草芽孢杆菌菌株合成了一种具有HSA抗原特性和大小（68千道尔顿）的蛋白质。脉冲标记研究结果表明，细菌产生的HSA是从已转化为原生质体的细胞中分泌出来的。对完整细胞进行的类似研究结果表明，杂合蛋白中的信号序列被去除，这进一步证明枯草芽孢杆菌能够将这种外源蛋白转运穿过细胞膜。当HSA合成水平较低时，信号序列的去除效率较高。然而，在高水平合成HSA的菌株中，信号序列的去除效率较低。
