采用RACE—PCR方法,从鲢(Hypophthalmichthys molitrix)头肾SMART cDNA中获得了679 bp IL-8 cDNA序列。结果显示:该序列包含169bp的5’非编码区,213bp3’端非编码区和297bp的开放阅读框;鲢IL-8的开放阅读框编码98个氨基酸残基,其中包含构成两对二硫键的4个保守半胱氨酸。RT-PCR结果显示鲢:IL-8mRNA主要在胰、肝脏和头肾中表达。将鲢IL-8不含信号肽的成熟多肽克隆到原核融合表达载体pQE30上,转入大肠杆菌M15内进行表达,经SDS-PAGE电泳后显示,重组融合蛋白在分子量约11kD处有一明显表达带,与预期计算的分子量大小相一致。
Interleukin-8 (IL-8) is a CXC chemokine, which can attract and activate specific types of leukocytes, such as lymphocytes and neut- rophils. The eDNA of silver carp IL-8 consists of 679 bp w/th 169 bp 5' untranslated region (UTR), 213 bp 3'UTR. An open reading frame of 297 bp encoded a 98-amino acid peptide, with four cysteines. Phylo- genetic analyses clearly demonstrated that silver carp IL-8 resembles the IL-8s of other fish. RT-PCR results revealed that stronger products in the pancreas, liver and head kidney were detected. Then the mature peptide of silver carp IL-8 was directionally connected the expression vector pQE30 to construct pQE30-IL8 recombinant. This recombinant was trans- formed into E. coli M15. An expected protein about llkD was found in M15 cell protein after inducting with IPTG by SDS- PAGE analysis.