生物学杂志

生物学杂志 ›› 2020, Vol. 37 ›› Issue (3): 35-.doi: 10.3969/j.issn.2095-1736.2020.03.035

• 研究报告 • 上一篇    下一篇

太平洋牡蛎胞外超氧化物歧化酶同源基因与蛋白质分析

  

  1. 1. 宁波大学 海洋学院， 宁波 315010；2. 青岛海洋科学技术试点国家实验室 海洋渔业科学与食物产出过程功能实验室， 青岛 266071；3. 浙江万里学院 浙江省水产种质资源重点实验室， 宁波 315100
  • 出版日期:2020-06-18 发布日期:2020-06-10
  • 通讯作者: 薛清刚，教授，主要从事贝类免疫学研究，E-mail: qinggxue@126.com;林志华，研究员，主要从事贝类育种养殖，E-mail: zhihua9988@126.com
  • 作者简介:毛小伟，硕士研究生，主要从事贝类免疫学研究，E-mail: 1259238168@qq.com
  • 基金资助:
    国家自然科学基金项目(31672629)；青岛国家海洋科学技术实验室科技创新项目(2015ASKI02-03) 

Studies on genes and protein activities of extracellular superoxide dismutase homologs in Pacific oysters (Crassostrea gigas)
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  1. Studies on genes and protein activities of extracellular superoxide dismutase homologs in Pacific oysters (Crassostrea gigas)
  • Online:2020-06-18 Published:2020-06-10

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摘要： 超氧化物歧化酶（SOD）通过清除生物体内产生的超氧化物而发挥抗氧化作用，其中，胞外超氧化物歧化酶（Ec-SOD）是重要细胞外抗氧化蛋白，但存在于牡蛎血浆内的Ec-SOD同源蛋白已经证实没有SOD酶活性。在太平洋牡蛎基因组中鉴定到3个与美洲牡蛎dominin高度相似的序列片段，并通过RT-PCR克隆验证均为表达基因，将其中的Cg-dominin 2成熟多肽在大肠杆菌中重组表达获得重组蛋白。抗氧化活性测定显示，重组Cg-dominin2的总抗氧化活性相当于0.0525 mmol/g Trolox。将太平洋牡蛎以不同浓度的Cd2+， Zn2+进行胁迫刺激，定量PCR检测显示Cg-dominin2基因的相对表达量有显著上调，血浆蛋白的对应金属含量也有所增加。上述结果提示太平洋牡蛎胞外超氧化物歧化酶同源蛋白可能通过参与体内金属代谢过程从而在抵御重金属胁迫中发挥作用。

关键词: 太平洋牡蛎, 超氧化物歧化酶, 抗氧化, 金属蛋白, 环境胁迫

Abstract: Superoxide dismutase (SOD) plays a role as an antioxidant by scavenging superoxide produced in organisms. Extracellular superoxide dismutase (Ec-SOD) is an important antioxidant protein in extracellular environments. However, Ec-SOD homologs in oyster plasma have been characterized to lack the SOD activity. In this study, 3 sequences that shared high similarity with dominin of the eastern oyster (Crassostrea virginica) were identified in the genome of the Pacific oyster (Crassostrea gigas) and verified by RT-PCR as real genes. The predicted mature peptide of Cg-dominin2, one of the 3 genes, was recombinantly expressed in Escherichia coli. The total antioxidant activity of the recombinant Cg-dominin 2 protein was equivalent to 0.0525 mmol/g Trolox. After challenges by zinc and cadmium ions, the relative expression of Cg-dominin2 gene was measured using qRT-PCR to be up-regulated significantly and the correspondent metal content of the oyster plasma proteins was also increased. These results suggested that the Ec-SOD homologs might play a role in defending against heavy metal stress in oysters by participating in metal metabolism.

Key words: Pacific oyster, superoxide dismutase, antioxidant, metalloprotein, environmental stress

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