关键词: LEA3蛋白, 戈壁异常球菌, 非生物胁迫, 酶活

Abstract: LEA3 (group 3 late embryogenesis abundant proteins) is a type of protein responsed to abiotic stresses and protects cells from damage. Deinococcus gobiensis I-0 was isolated from the Gobi Desert with drought, major temperature difference and strong solar radiation. It possessed highly strong resistance to ultraviolet (UV) radiation, ionizing radiation and desiccation. The protein encoded by Dgo_CA1631 gene in the genome was certain homologous with LEA3, so it was named as Dgl3, and its biological function was investigated in this article. Survival experiments revealed that Dgl3 could significantly enhance resistance of the expression strain BL21 to oxidative and freezing stresses and increase the resistance against to many damages. Likewise, the experiments in vitro demonstrated that the enzymatic activities of malate dehydrogenase and lactate dehydrogenase were effectively maintained due to Dg13 under oxidation and freeze-thaw cycles. Therefore, it was speculated that Dgl3 protein enhanced resistance of host to oxidation and freezing stresses by protecting cellular enzyme activities.

Key words: LEA3 protein, Deinococcus gobiensis I-0, abiotic stress, enzyme activity