藏羊IFN-γ基因的扩增、序列分析及蛋白结构预测

Amplification,Sequence Analysis and Protein Structure Prediction of IFN-γ Gene of Tibetan Sheep

为了研究藏羊IFN-γ基因的功能,提取藏羊脾脏总RNA,通过RT-PCR扩增藏羊IFN-γ基因并测序,应用DNA Star软件进行序列分析及编码蛋白结构预测。结果表明,藏羊IFN-γ基因长度为429bp,其中腺嘌呤和胸腺嘧啶含量较高,该基因编码143个氨基酸,其中疏水性氨基酸和亲水性氨基酸的含量较高。藏羊IFN-γ基因与参考绵羊、山羊、藏羚羊和牛IFN-γ基因的核苷酸序列同源性依次为100%、99.3%、99.1%和97.2%,氨基酸序列同源性依次为100%、99.3%、99.3%和95.8%。IFN-γ蛋白主要由α螺旋组成,亲水性较高,含有5种蛋白质功能位点,分别为1个酪蛋白激酶Ⅱ磷酸化位点、1个酰胺化位点、2个N-糖基化位点、2个cAMP和cGMP依赖的蛋白激酶磷酸化位点和3个蛋白激酶C磷酸化位点。

In order to study the function of IFN-γgene of Tibetan sheep,the total RNA was extracted from spleen of Tibetan sheep firstly,then the IFN-γgene of Tibetan sheep was amplified by RT-PCR and sequenced.Finally,the DNA Star software was used to analyze the gene sequence and predict the protein structure.The result showed that the length of IFN-γgene was 429 bp,with a higher content of adenine and thymine,and it encoded 143 amino acids,among which hydrophobic amino acids and polar amino acids were richer.The nucleotide sequence homology of IFN-γgene with that of Ovis aries,Capra hircus,Pantholops hodgsonii and Bos taurus were 100%,99.3%,99.1% and 97.2% respectively,and the amino acid sequence homology were 100%,99.3%,99.3%and 95.8%respectively.In addition,the IFN-γprotein was mainly composed ofα-helix,its hydrophilicity was high,and it contained five kinds of protein functional sites,including one casein kinase II phosphorylation site,one amidation site,two N-glycosylation sites,two cAMP-and cGMP-dependent protein kinase phosphorylation sites and three protein kinase C phosphorylation sites.These results provided some references for studying the immune function of IFN-γgene of Tibetan sheep in Qinghai province.