ACS Chem Biol. 2010 Aug 20;5(8):747-52. doi: 10.1021/cb1001153.
The inability of proteins to potently penetrate mammalian cells limits their usefulness as tools and therapeutics. When fused to superpositively charged GFP, proteins rapidly (within minutes) entered five different types of mammalian cells with potency up to approximately 100-fold greater than that of corresponding fusions with known protein transduction domains (PTDs) including Tat, oligoarginine, and penetratin. Ubiquitin-fused supercharged GFP when incubated with human cells was partially deubiquitinated, suggesting that proteins delivered with supercharged GFP can access the cytosol. Likewise, supercharged GFP delivered functional, nonendosomal recombinase enzyme with greater efficiencies than PTDs in vitro and also delivered functional recombinase enzyme to the retinae of mice when injected in vivo.
蛋白质无法有效地穿透哺乳动物细胞，限制了它们作为工具和治疗药物的用途。当与超正电荷 GFP 融合时，蛋白质会迅速（在几分钟内）进入五种不同类型的哺乳动物细胞，效力比具有已知蛋白转导结构域（PTD）的相应融合体高 100 倍左右，包括 Tat、寡精氨酸和 penetratin。与人类细胞孵育的融合了泛素的超正电荷 GFP 被部分去泛素化，这表明与超正电荷 GFP 一起递送的蛋白质可以进入细胞质。同样，超正电荷 GFP 递呈功能性、非内体重组酶，其在体外的效率高于 PTD，并且当体内注射到小鼠的视网膜时，也递呈了功能性重组酶。
