Secretory production of spider silk proteins in metabolically engineered Corynebacterium glutamicum for spinning into tough fibers |
| |
| Affiliation: | 1. State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic & Developmental Sciences, and School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, People''s Republic of China;2. Metabolic and Biomolecular Engineering National Research Laboratory, Department of Chemical & Biomolecular Engineering (BK21 Four Program), BioProcess Engineering Research Center, Bioinformatics Research Center, and Institute for the BioCentury, KAIST, Yuseong-gu, Daejeon, Republic of Korea;1. Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, 214122, China;2. National Engineering Laboratory of Cereal Fermentation Technology, Jiangnan University, Wuxi, 214112, China;3. Jiangsu Provincial Research Center for Bioactive Product Processing Technology, Jiangnan University, Wuxi, 214122, China;1. Centre for Food Technology, Danish Technological Institute, Kongsvang alle 29, DK-8000 Aarhus C, Denmark;2. Department of Chemical Engineering, Biotechnology and Environmental Technology, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark;1. Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China;2. Key Laboratory of Systems Microbial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China;3. College of Biotechnology, Tianjin University of Science and Technology, Tianjin, 300457, China;4. College of Food Science and Engineering, Tianjin University of Science and Technology, Tianjin, 300457, China;5. University of Chinese Academy of Sciences, Beijing, 100049, China;6. College of Life Science, Hebei Normal University, Shijiazhuang, 050024, China |
| |
| Abstract: | Spider dragline silk is a remarkable fiber made of unique proteins—spidroins—secreted and stored as a concentrated aqueous dope in the major ampullate gland of spiders. This feat has inspired engineering of microbes to secrete spidroins for spinning into tough synthetic fibers, which remains a challenge due to the aggregation-prone feature of the spidroins and low secretory capacity of the expression hosts. Here we report metabolic engineering of Corynebacterium glutamicum to efficiently secrete recombinant spidroins. Using a model spidroin MaSpI16 composed of 16 consensus repeats of the major ampullate spidroin 1 of spider Trichonephila clavipes, we first identified the general Sec protein export pathway for its secretion via N-terminal fusion of a translocation signal peptide. Next we improved the spidroin secretion levels by selection of more suitable signal peptides, multiplexed engineering of the bacterial host, and by high cell density cultivation of the resultant recombinant strains. The high abundance (>65.8%) and titer (554.7 mg L–1) of MaSpI16 in the culture medium facilitated facile, chromatography-free recovery of the spidroin with a purity of 93.0%. The high solubility of the purified spidroin enabled preparation of highly concentrated aqueous dope (up to 66%) amenable for spinning into synthetic fibers with an appreciable toughness of 70.0 MJ m−3. The above metabolic and processing strategies were also found applicable for secretory production of the higher molecular weight spidroin MaSpI64 (64 consensus repeats) to yield similarly tough fibers. These results suggest the good potential of secretory production of protein polymers for sustainable supply of fibrous materials. |
| |
| Keywords: | Spider dragline silk Spidroin Secretion Metabolic engineering Fiber spinning |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
