Ni2+高效结合肽的筛选与作用研究

利用噬菌体随机十二肽库和金属亲和层析对重金属Ni2 进行结合肽筛选。经4轮生物淘洗、噬菌体扩增和DNA测序,获得一组多肽序列。GenBank Blast分析未发现同源序列,Clustal W多重序列比对也未找到Ni2 金属结合肽结合基序,但可能含有多聚组氨酸(His)2-5。噬菌体单克隆金属离子螯合树脂的亲和力测定和反筛、抑菌解毒试验表明:展示有金属结合肽的噬菌体不仅对Ni2 具有高亲和力,而且对其它金属离子也有作用,Cu2 、Ni2 、Co2 、Zn2 等金属离子对金属结合肽的亲和力显著高于Cd2 和Cr2 ,展示金属结合肽的噬菌体对重金属Ni2 具有一定的耐受和解毒作用。显微形态学观察也显示金属结合肽与金属螯合树脂的作用。对于了解重金属与多肽的相互作用机理以及环境重金属修复等均具有重要意义和价值。

Selection and interaction of Ni2+ metal-binding peptides

Ni~(2 ) binding peptides were selected from phage random dodecapeptide library by metal affinity chromatography.After four rounds of biopanning,phage amplification and DNA sequencing,a group of peptide sequences were obtained.GenBank blast found no homogenous sequences,Clustal W analysis showed no motifs but they were really riched in histidines and contained di-or more histidines(his)~(2-5).Affinity assays of selected metal-binding phages for various metal-charged NTA resins and the experiments of E.coli suppression and detoxification gave positive results for Ni~(2 ) binding peptides: strong affinities for Ni~(2 ) were found for Ni~(2 ) binding peptide displayed phages,as well as for other metals(Cu~(2 ),Co~(2 ),Zn~(2 ),Cr~(2 ),Cd~(2 ));affinities of the binding peptides for Cu~(2 ),Ni~(2 ),Co~(2 ) and Zn~(2 ) were much higher than that of Cd~(2 ) and Cr~(2 );in addition,Ni~(2 ) binding peptides displayed phages had effects on E.coli as to enhance the tolerance and detoxification of E.coli for heavy metals when exposed to Ni~(2 )and Cd~(2 ).The interactions of meal binding peptides for heavy metals were also disclosed by microscopic observation.The research offered great values for the study of the interaction between metals and peptides,as well as in other areas such as heavy metal bioremediation.