粉尘螨Der f4基因的克隆和蛋白分子特征分析
The Cloning and Bioinformatics Analysis of Der f4 Gene from the Dermatophagoide farinae

从深圳地区采集粉尘螨纯培养，提取总RNA，根据香港中文大学合成的尘螨基因序列并设计的引物，RT-PCR扩增出Der f4基因，克隆到pUC57载体后测序和进行生物信息学分析.将该目的基因克隆到pET-28a表达载体上得到重组质粒pET-28a-Der f4.用生物软件分析尘螨变应原Der f4序列. RT-PCR获得目的基因Der f4 cDNA全长为1593 bp.推测编码蛋白由526个氨基酸组成，生物信息学分析表明，Der f4具有多种磷酸化位点，含有信号肽，为疏水性蛋白，包含淀粉酶抑制剂功能结构域.获得Der f4基因全长，其编码的细胞外疏水性蛋白可能具有淀粉酶抑制剂活性.
RNA was extracted from Shenzhen area and the full-length of Der f4 gene was amplified by RT-PCR with the primers designed according to previous sequence published in Hong Kong chinese university. The target gene was cloned into pUC57 plasmid and sequenced Der f4 gene was recombinated into pET-28 a expression vector fol-lowing sequencing identification. And then Der f4 protein was characterized by bioinformatics software. The opening reading frame( ORF)of Der f4 was obtained by RT-PCR and was 1 593 bp in full length. The protein encoded by this sequence was deduced to be consisted with 526 amino acids. Bioinformatics analysis of Der f4 which proved to be hydrophobic proteins associated with amylase inhibitors function structure domain contained signal peptide and multiple phosphorylation site. The full-length cDNA for Der f4 obtained,which should en-code a hydrophobic extra-cellular protein associated with inhibition of amylase