Transduction of jellyfish superoxide dismutase mediated by TAT peptide ameliorates H₂O₂-induced oxidative stress in HaCaT cells

Superoxide dismutase (SOD) plays important roles in the balance of oxidation and antioxidation in body mostly by scavenging superoxide anion free radicals (O₂^.−). Previously, we reported a novel Cu/Zn SOD from jellyfish Cyanea capillata, named CcSOD1, which exhibited excellent SOD activity and high stability. TAT peptide is a common type of cell penetrating peptides (CPPs) that efficiently deliver extracellular biomacromolecules into cytoplasm. In this study, we constructed a recombinant expression vector that combined the coding sequences of TAT peptide and CcSOD1, and then obtained sufficient and high-purity TAT-CcSOD1 fusion protein. Compared with some reported SODs/CPP-SODs, TAT-CcSOD1 possessed stronger tolerance to heat and acid–base environment. TAT-CcSOD1 efficiently penetrated cell membrane and significantly enhanced the O₂^.− scavenging ability in cells, and attenuated H₂O₂-induced cytotoxicity and NO generation in HaCaT cells. This study serves as a critical step forward for the application of TAT-CcSOD1 as a potential protective/therapeutic agent against oxidative stress-related conditions in the future.