融合蛋白CTP-SOD在毕赤酵母中的表达、纯化及抗氧化能力

Expression and purification of fusion protein CTP-SOD in Pichia pastoris and antioxidant capacity analysis

摘要:

超氧化物歧化酶(SOD)是一种在生物界广泛存在的抗氧化酶，在抗衰老、抗肿瘤、抗免疫疾病和电磁辐射上都起着重要的作用。本实验利用含有细胞质转导肽 (CTP，一种能够携带外源大分子穿过细胞膜，定位于细胞质的短肽) 基因序列的特异引物，以人总RNA反转录产物为模板，扩增出了CTP和人铜锌超氧化物歧化酶 (Cu/Zn SOD) 的融合基因。运用毕赤酵母表达系统成功表达了具有活性的CTP-SOD融合蛋白。CTP-SOD预处理HeLa细胞后，明显提高了邻苯三酚 (Progallol) 诱导氧化胁迫下HeLa细胞的存活率，和对照组野生型SOD相比具有显著性差异。结果表明，CTP-SOD融合蛋白比野生型SOD更容易进入细胞，具有更高效的抗氧化功能。

Abstract:

Cytoplasmic transduction peptide (CTP) is a newly designed transduction peptide, by which special molecules can be carried out and localized into cytoplasmic compartment. Superoxide dismutase (SOD) is a protein that is difficult to go into cytoplasm. In this study, CTP-SOD fusion gene was amplified from human cDNA by PCR, and the active recombinant protein was successfully expressed in Pichia pastoris. HeLa cells pretreated with CTP-SOD showed a significantly improved survival against the pyrogallol-induced oxidative stress, suggesting CTP-SOD could cross the cell membrane more efficiently and protect cells from oxidative stress.