Self-assembly amphipathic peptides induce active enzyme aggregation that dramatically increases the

• 作 者: AnHuang;XiaofengYang;ShuangLi;
• 机 构: South China University of Technology Guangzhou,510006,China
• 出 处: 2015中国酶工程与糖生物工程学术研讨会
• 发表日期: 2015年期

　　An amphipathic self-assembly peptide 18A was fused to the C-terminus of oligomeric nitrilase.Expression in E.coli showed that the fusion enzyme assembled spontaneously into active aggregates with more than 90% native nitrilase activity.The enzyme aggregates were purified through cell lysis and centrifugation led to the facile preparation of immobilized particles (Nit-iSEA).The fusion of nitrilase resulted to the Nit-SEA and Nit-iSEA with about 6.7-and 10-fold enhanced the thermostability at 45 ℃.The nitrile tolerance was also dramatically improved, no apparent substrate inhibition was observed for Nit-iSEA over the range of 30 to 120 mM mandelonitrile.In addition, the Nit-iSEA could be recycled 20 times with about 5% loss in activity.To further investigate the impacts of short amphipathic peptides on the nirtilase, three other short peptides (R18A, ELK16, L6KD) were fused to the C-terminus of nitrilase.Results showed that R18A worked better in improving the operation stability of nitrilase than the other two peptides.