骆驼β-防御素caBD-1cDNA的克隆及序列分析

The cDNA Cloning and Sequencing of Camel β-defensin caBD-1

β-防御素是一类富含半胱氨酸的抗微生物多肽,主要表达在哺乳动物黏膜上皮内。我们发现了一种新的β-防御素—骆驼β-防御素-1(caBD-1)。从骆驼舌黏膜上皮组织中提取总RNA,采用RT-PCR技术扩增出caBD-1的cDNA,并重组到pBlueselectT载体,经限制性内切酶谱分析和DNA序列测定,证实所克隆的caBD-1的cDNA为β-防御素,因为该cDNA包含由192个碱基组成的开放读码框(ORF),该ORF编码64个氨基酸残基的前原防御素,该前原防御素含有β-防御素特征性结构即6个在特定位置上的保守半胱氨酸残基。骆驼β-防御素的发现对我们更好地理解骆驼黏膜防御机制有很大帮助。

Beta-defensins are a kind of cysteine-rich antimicrobiol peptides and they have been found in mammalian epithelial tissue. Here we report the identfication of a novel β-defensin from camel tissue,camel β-defensin-1(caBD-1). Total RNA was extracted from the tongue epithelia of camel and the cDNA encoding camel β-defensin (caBD-1) was amplified by the reverse transcription PCR(RT-PCR). The purified RT-PCR product was cloned into pBlueselect T vector. The results of restriction endonuclease pattern analysis of recombinant plasmid and DNA sequencing demonstrated that the caBD-1 is belong to the family of β-defensin because the cDNA contain a Open Reading Frame(ORF) of 192 bases which encoded a 64 amino acid prepro-peptide and the prepro-peptide contained the β-defensin consensus sequence of six invariantly spaced cysteine residues. This finding of the camel β-defensin facilitate a better understanding of mucosal defense mechanisms in camels.