Staub J M, Garcia B, Graves J, Hajdukiewicz P T, Hunter P, Nehra N, Paradkar V, Schlittler M, Carroll J A, Spatola L, Ward D, Ye G, Russell D A
Monsanto Company, 700 Chesterfield Village Parkway North, St. Louis, MO 63198, USA.
Nat Biotechnol. 2000 Mar;18(3):333-8. doi: 10.1038/73796.
Transgenic plants have become attractive systems for production of human therapeutic proteins because of the reduced risk of mammalian viral contaminants, the ability to do large scale-up at low cost, and the low maintenance requirements. Here we report a feasibility study for production of a human therapeutic protein through transplastomic transformation technology, which has the additional advantage of increased biological containment by apparent elimination of the transmission of transgenes through pollen. We show that chloroplasts can express a secretory protein, human somatotropin, in a soluble, biologically active, disulfide-bonded form. High concentrations of recombinant protein accumulation are observed (>7% total soluble protein), more than 300-fold higher than a similar gene expressed using a nuclear transgenic approach. The plastid-expressed somatotropin is nearly devoid of complex post-translational modifications, effectively increasing the amount of usable recombinant protein. We also describe approaches to obtain a somatotropin with a non-methionine N terminus, similar to the native human protein. The results indicate that chloroplasts are a highly efficient vehicle for the potential production of pharmaceutical proteins in plants.
由于降低了哺乳动物病毒污染物的风险、具备低成本大规模扩大生产的能力以及低维护要求，转基因植物已成为生产人类治疗性蛋白质的有吸引力的系统。在此，我们报告一项通过转质体转化技术生产人类治疗性蛋白质的可行性研究，该技术还具有通过明显消除花粉传播转基因来增强生物安全性的额外优势。我们表明，叶绿体能够以可溶、具有生物活性、形成二硫键的形式表达一种分泌蛋白——人生长激素。观察到重组蛋白积累浓度很高（>7%总可溶性蛋白），比使用核转基因方法表达的类似基因高出300多倍。质体表达的生长激素几乎没有复杂的翻译后修饰，有效增加了可用重组蛋白的量。我们还描述了获得与天然人类蛋白质类似的、N端无甲硫氨酸的生长激素的方法。结果表明，叶绿体是在植物中潜在生产药用蛋白质的高效载体。
