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中国农学通报 ›› 2010, Vol. 26 ›› Issue (1): 12-16.

所属专题: 生物技术 畜牧兽医

• 畜牧 动物医学 蚕 蜂 • 上一篇    下一篇

荷斯坦奶牛IFN-γ基因的克隆、序列分析及表达研究

李贞1,2,陈创夫1,2,乔军1,任艳1,张辉1,杨明峰1,刘佳旭1,倪伟1   

  • 收稿日期:2009-10-19 修回日期:2009-09-23 出版日期:2010-01-05 发布日期:2010-01-05

  • Received:2009-10-19 Revised:2009-09-23 Online:2010-01-05 Published:2010-01-05

摘要:

利用RT-PCR技术从黑白花奶牛外周血淋巴细胞总RNA中扩增IFN–γ(ccIFN-γ)基因,克隆至pMD18-T载体进行测序。测序结果表明,ccIFN-γ基因全长501bp, 编码166个氨基酸,其中前23个氨基酸残基构成信号肽序列,后面147氨基酸残基构成成熟肽,其中含有2个潜在的N-链糖基化位点。二级和三级结构预测发现,ccIFN-γ蛋白分子中存在7个的α-螺旋,中间由无规卷曲连接,折叠成由α-螺旋包绕的中空状结构。将ccIFN-γ成熟肽编码区序列进一步克隆至pET-28a,转化大肠杆菌BL21(DE3),用IPTG诱导表达。经SDS-PAGE分析,表达出与预期大小(20.6KDa)相符的重组蛋白,占菌体蛋白18.6%。Western blot检测证实表达的融合蛋白为牛IFN-γ,这为进一步开展重组ccIFN-γ生物学活性的研究奠定了基础。

关键词: 近红外光谱技术, 近红外光谱技术, 农作物, 应用

Abstract:

Chinese cow interferon-gamma (ccIFN-γ) gene was amplified by reverse transcription polymerase chain reaction (RT-PCR) from total RNA extracted from lymphocytes in the peripheral blood of bovine. The products of RT-PCR were cloned into pMD18-T vector and then sequenced. The sequencing result showed that the ORF of ccIFN-γ gene was 501bp, encoding 166 amion acids. The initiative 23 amino acids consist of signal peptide, the following 147 amino acids consisting of mature peptide. There are 2 N-glycosylation sites. The second and third molecule structure showed that ccIFN-γ has 7 α-helix that gathered and formed the structure of midheaven. Then mature peptide encoding sequence was inserted into the expressing plasmid pET-28a for expression in E.coli. SDS-PAGE results showed that the recombinant protein was successfully expressed after IPTG induction, with a molecular weight of 20.6 kDa as expected. Western blot analysis showed that the recombinant protein of ccIFN-γ is bovine IFN-γ. The experiment lays a foundation for the further study of bioactivity of recombinant bovine IFN-γ.

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