Auger Anick, Park Minyoung, Nitschke Felix, Minassian Lori M, Beilhartz Greg L, Minassian Berge A, Melnyk Roman A
‡Department of Biochemistry, University of Toronto, Toronto, ON, Canada.
∥Department of Paediatrics, University of Toronto, Toronto, ON, Canada.
Mol Pharm. 2015 Aug 3;12(8):2962-71. doi: 10.1021/acs.molpharmaceut.5b00233. Epub 2015 Jul 2.
Platforms enabling targeted delivery of proteins into cells are needed to fully realize the potential of protein-based therapeutics with intracellular sites-of-action. Bacterial toxins are attractive systems to consider as templates for designing protein transduction systems as they naturally bind and enter specific cells with high efficiency. Here we investigated the capacity of diphtheria toxin to function as an intracellular protein delivery vector. We report that diphtheria toxin delivers an impressive array of passenger proteins spanning a range of sizes, structures, and stabilities into cells in a manner that indicates that they are "invisible" to the translocation machinery. Further, we show that α-amylase delivered into cells by a detoxified diphtheria toxin chimera digests intracellular glycogen in live cells, providing evidence that delivered cargo is folded, active, and abundant. The efficiency and versatility of diphtheria toxin over existing systems open numerous possibilities for intracellular delivery of bioactive proteins.
为了充分发挥具有细胞内作用位点的蛋白质疗法的潜力，需要能够将蛋白质靶向递送至细胞内的平台。细菌毒素是颇具吸引力的系统，可作为设计蛋白质转导系统的模板，因为它们能自然高效地结合并进入特定细胞。在此，我们研究了白喉毒素作为细胞内蛋白质递送载体的能力。我们报告称，白喉毒素能以一种表明其对转运机制“不可见”的方式，将一系列令人印象深刻的包含不同大小、结构和稳定性的乘客蛋白递送至细胞内。此外，我们还表明，通过解毒的白喉毒素嵌合体递送至细胞内的α淀粉酶可在活细胞中消化细胞内糖原，这证明递送的货物已折叠、具有活性且数量充足。白喉毒素相对于现有系统的效率和多功能性为生物活性蛋白的细胞内递送开辟了众多可能性。
