Expression, purification, and characterization of fusion protein TAT-cytoglobin / 生物工程学报

he aim of this study was to obtain a cell-penetrating cytoglobin (Cygb), which combines the transmembrane function of cell-penetrating peptides TAT with the anti-aging and anti-fibrotic role of cytoglobin. The Cygb gene was complexed with TAT gene by overlapping PCR, inserted into the vector pET22b to construct the recombinant expression plasmid (pET22b-TAT-Cygb) and then transformed into Escherichia coli BL21 (DE3). The fusion protein TAT-Cygb, whose expression was induced by lactose, was purified by CM Sepharose Fast Flow Protocol and verified by Western blotting. The final TAT-Cygb had a molecular weight of 23 kDa with 95% purity, as shown by SDS-PAGE. As demonstrated by bioactivity experiments, TAT-Cygb exhibited a high specific peroxidase activity up to (422.30 ± 0.36) U/mg. Both TAT-Cygb and Cygb pretreatment group could protect Hacat cells against oxidation of H2O2, but only TAT-Cygb treatment group could remedy cells injuried by H2O2 (RGR = 98%), which was significantly different from Cygb treatment group (RGR = 79%). We successfully obtained the bioactive and cell-penetrating fusion protein TAT-Cygb that has the potential application in anti-aging, anti-fibrotic and anti-cancer.

Tumor-targeting carrier equipped with cell-penetrating peptides / 中国肿瘤生物治疗杂志

Equipping tumor-targeting carrier with cell-penetrating peptide with high transduction efficacy has become a trend. According to the fusion modes and tumor-targeting mechanisms, cell-penetrating peptides can be divided into five categories: first, self-targeting cell-penetrating peptides; second, fusion carriers made of targeting ligands and cell-penetrating peptides; third, cell-penetrating peptide-modified nano-carrier; fourth, tumor-microenvironment-targeting cell-penetrating peptides; fifth, other special cell-penetrating peptides. Fusion carriers, which can not be effectively released into the cytoplasm after transducted into target cells, can be further modified to increase their efficacy. In all, cell-penetrating peptide introduced into tumor-targeting carrier should provide a new era for anti-tumor pharmacy research and cancer therapy.