Expression of phenylalanine ammonia lyase as an intracellularly free and extracellularly cell surface-immobilized enzyme on a gut microbe as a live biotherapeutic for phenylketonuria  

作　　者：Yu Jiang Bingbing Sun Fenghui Qian Feng Dong Chongmao Xu Wuling Zhong Rui Huang Qiwei Zhai Yu Jiang Sheng Yang 

机构地区：[1]Shanghai Taoyusheng Biotechology Co.,Ltd.,Shanghai 201201,China [2]CAS Key Laboratory of Synthetic Biology,CAS Center for Excellence in Molecular Plant Sciences,Chinese Academy of Sciences,Shanghai 200032,China [3]Shanghai Research and Development Center of Industrial Biotechnology,Shanghai 201201,China [4]CAS Key Laboratory of Nutrition,Metabolism and Food Safety,Shanghai Institute of Nutrition and Health,Chinese Academy of Sciences,Shanghai 200031,China

出　　处：《Science China(Life Sciences)》2023年第1期127-136,共10页中国科学（生命科学英文版）

基　　金：supported by the National Natural Science Foundation of China(21825804,31921006);the National Science&Technology Major Project“Key New Drug Creation and Manufacturing Program”,China(2018ZX09711002-019);the Shanghai Municipal Science and Technology Major Project and the National Key Research and Development Program of China(2018YFA0800603)。

摘　　要：Phenylketonuria(PKU),a disease resulting in the disability to degrade phenylalanine(Phe)is an inborn error with a 1 in 10,000 morbidity rate on average around the world which leads to neurotoxicity.As an potential alternative to a protein-restricted diet,oral intake of engineered probiotics degrading Phe inside the body is a promising treatment,currently at clinical stage II(Isabella,et al.,2018).However,limited transmembrane transport of Phe is a bottleneck to further improvement of the probiotic’s activity.Here,we achieved simultaneous degradation of Phe both intracellularly and extracellularly by expressing genes encoding the Phe-metabolizing enzyme phenylalanine ammonia lyase(PAL)as an intracellularly free and a cell surface-immobilized enzyme in Escherichia coli Nissle 1917(EcN)which overcomes the transportation problem.The metabolic engineering strategy was also combined with strengthening of Phe transportation,transportation of PAL-catalyzed trans-cinnamic acid and fixation of released ammonia.Administration of our final synthetic strain TYS8500 with PAL both displayed on the cell surface and expressed inside the cell to the Pah^(F263S)PKU mouse model reduced blood Phe concentration by 44.4%compared to the control Ec N,independent of dietary protein intake.TYS8500 shows great potential in future applications for PKU therapy.

关 键 词：phenylalanine ammonia lyase cell surface display PHENYLKETONURIA TYS8500 oral administration 

分 类 号：R392[医药卫生—免疫学]