尽管重组蛋白质具有治疗潜力，但其细胞渗透性和稳定性仍然是重大挑战。在这里，我们证明循环化的重组蛋白质可以用作可渗透和稳定传递到细胞和聚二乙炔基脂质体中的通用载体。利用分割内源酶介导的过程，生成了含有短四精氨酸（R4）和六组氨酸（H6）标签的循环化模型荧光蛋白质，而不损害其天然蛋白功能。令人惊讶的是，与线性的R4/H6标记蛋白质相比，循环化的对应物在癌细胞和合成脂质体中具有显著增加的渗透性，以及在癌细胞中更高的抗酶降解能力。这些性质可能是短功能肽存在时对蛋白质施加的结构约束的结果。此外，与非循环化对照相比，循环化的光蛋白负载脂质体在癌细胞中的光动力疗法显著改善。这些发现表明，我们的策略在蛋白质和治疗剂的细胞间传递中具有普适性。版权所有 © 2023. 由Elsevier B.V.出版。

Despite the therapeutic potential of recombinant proteins, their cell permeabilities and stabilities remain significant challenges. Here we demonstrate that cyclized recombinant proteins can be used as universal cargos for permeable and stable delivery into cells and polydiacetylene liposomes. Utilizing a split intein-mediated process, cyclized model fluorescent proteins containing short tetraarginine (R4) and hexahistidine (H6) tags were generated without compromising their native protein functions. Strikingly, as compared to linear R4/H6-tagged proteins, the cyclized counterparts have substantially increased permeabilities in both cancer cells and synthetic liposomes, as well as higher resistances to enzymatic degradation in cancer cells. These properties are likely a consequence of structural constraints imposed on the proteins in the presence of short functional peptides. Additionally, photodynamic therapy by cyclized photoprotein-loaded liposomes in cancer cells was significantly improved in comparison to that by their non-cyclized counterparts. These findings suggest that our strategy will be universally applicable to intercellular delivery of proteins and therapeutics.Copyright © 2023. Published by Elsevier B.V.