Embellishment For Three Enzymes By Using Amphiphilic Compound Protein

The amphiphilic compound protein is composed of hydrophilic collagen-like polypeptide(CLP)and hydrophobic elastin-like polypeptide(ELP).The ELP is a kind of widely used structural protein,it is a peptideby the synthetic which structure similar to natural elastin peptide.It is ahydrophobic polypeptide formed by five repetitive sequence(VPGXG),and the CLP is ahydrophilic polypeptide formed by three repetitive sequence(GXY).The CLP has been modified by fusing it to an ELP through genetic engineering technology.The fusion polypeptide CLP-ELP combines the functions of self-assembly by the CLP segment and purification by the ELP segment.Superoxide dismutase(SOD)and D-amino acid oxidase(DAAO)have been separately fused to CLP-ELP through genetic engineering of the enzymes.The fused enzymes have been purified with a high purity through reversible phase transition.Induced by the CLP segment,SOD-CLP-ELP exhibited a proteinaceous microporous network(PMN),and DAAO-CLP-ELP exhibited a proteinaceous nanoporous network(PNN).The micro-size pores of PMN and nano-size pores of PMN behave as micro-size bioreactors and nano-size bioreactors,respectively.Circular dichroism(CD)sepetra demonstrated that the fused enzymes have significantly reduced the interfering effect of H2O2 on the secondary structures.Fluorescence spectra showed that the stability of the fused enzymes against denaturing by urea has been improved.As a result of the aforementioned advantages,the superoxide anion(.O2)scavenging ability of SOD-CLP-ELP is stronger than SOD,and the catalytic efficiency of DAAO-CLP-ELP is stronger than DAAO.The CAT-CLP-ELP can decompose H2O2 that Produced by the reaction.Therefore proved amphiphilic carrier decorated with excellent function,can not only make the structure more stable,also can make the enzyme catalytic activity promoted.