[Objective] The research aimed to study the secreted expression of S-edenosyl-L-methionine synthetase （SAMS） in Pichia pastoris. Method ] The gene coding SAMS, from the genomic DNA of Saccharomyces cerevisiae, was ...[Objective] The research aimed to study the secreted expression of S-edenosyl-L-methionine synthetase （SAMS） in Pichia pastoris. Method ] The gene coding SAMS, from the genomic DNA of Saccharomyces cerevisiae, was amplified by PCR and inserted into the secreted expression vector pPIC9K to get recombinant plasmid. The recombinant plasmid pPIC9K-sarr~ was integrated into Pichia pastoris GSl15 genome by electroporation and induced by methanol. The activity of the recombinant enzyme was measured using high-pedormance liquid chroma- tography （HPLC） by determining the production of S-adenosy-L-methionine （SAM） with the enzyme secreted. [ ResultJ The molecular weight of the expression protein identified by SDS-PAGE was about 50 kD, being larger than the theoretical molecular mass of SAMS, which might be due to the glycosytation in the process of secretion. Methanol-induction as well as preliminary purification could enhance the enzyme activity, espe- cially the latter, after which the specific activity of SAMS was improved to 61.48 U/rng. [Conclusion] SAMS with biological activity was secreted successfully in Pichia pastoris GSl15 for the first time. And it is the start for the genetic engineering strains to open up prospects for industrial production.展开更多
在重组人血清白蛋白(recombinant human serum albumin,rHSA)Pichia pastori表达系统中,研究了高密度培养时细胞生长、改变碳源和诱导表达时溶氧的变化和调控规律,溶氧与细胞生长和重组蛋白表达密切相关。发酵前期的细胞生长阶段,细胞...在重组人血清白蛋白(recombinant human serum albumin,rHSA)Pichia pastori表达系统中,研究了高密度培养时细胞生长、改变碳源和诱导表达时溶氧的变化和调控规律,溶氧与细胞生长和重组蛋白表达密切相关。发酵前期的细胞生长阶段,细胞需氧降低表明碳源甘油的消耗,根据溶氧水平适时流加碳源甘油;改变碳源前,应停止流加甘油碳源,并以溶氧指标判断甘油是否消耗完全;重组蛋白诱导时流加甲醇的速度应缓慢增大,并保持细胞一定的需氧水平。高密度培养时通过流加底物速度、搅拌转速、通气量和富氧培养来关联控制发酵液溶氧水平。展开更多
[Objective] This study aimed to investigate the secretory expression of P97R1 gene of Mycoplasma hyopneumoniae（Mhp） in Pichia pastoris expression system and the primary application; of the expression product. [Metho...[Objective] This study aimed to investigate the secretory expression of P97R1 gene of Mycoplasma hyopneumoniae（Mhp） in Pichia pastoris expression system and the primary application; of the expression product. [Method] A pair of specific primers was designed to conduct PCR according to the Mhp P97R1 gene sequence in Genbank, and the amplified P97R1 gene was cloned into the pPICZa-A yeast expression vector to construct the secretory recombinant expression vector pPICZa-A-P97R1. The plasmid pPICZa-A-p97R1 linearized by Sac I was transformed into P. pastoris GSl15 by electroporation. Positive transformant identified by PCR was incubated to express P97R1 protein after methanol induction. And the expression product was identified using SDS-PAGE and Western-blotting anal.wsis. [Result] P97R1 protein was successfully expressed in the P. pastoris system, with a secre- tory amount of 499μg/ml, and revealed good reactogenicity. Meanwhile, an indirect ELISA method was established with P97R1 protein after the optimization of each reaction factor, which showed good specificity and repeatability according to repeated tests. [Conclusion] This study provides bases for developing the ELISA Kit for anti- body detection and genetically engineered vaccine to Mhp.展开更多
文摘[Objective] The research aimed to study the secreted expression of S-edenosyl-L-methionine synthetase （SAMS） in Pichia pastoris. Method ] The gene coding SAMS, from the genomic DNA of Saccharomyces cerevisiae, was amplified by PCR and inserted into the secreted expression vector pPIC9K to get recombinant plasmid. The recombinant plasmid pPIC9K-sarr~ was integrated into Pichia pastoris GSl15 genome by electroporation and induced by methanol. The activity of the recombinant enzyme was measured using high-pedormance liquid chroma- tography （HPLC） by determining the production of S-adenosy-L-methionine （SAM） with the enzyme secreted. [ ResultJ The molecular weight of the expression protein identified by SDS-PAGE was about 50 kD, being larger than the theoretical molecular mass of SAMS, which might be due to the glycosytation in the process of secretion. Methanol-induction as well as preliminary purification could enhance the enzyme activity, espe- cially the latter, after which the specific activity of SAMS was improved to 61.48 U/rng. [Conclusion] SAMS with biological activity was secreted successfully in Pichia pastoris GSl15 for the first time. And it is the start for the genetic engineering strains to open up prospects for industrial production.
文摘在重组人血清白蛋白(recombinant human serum albumin,rHSA)Pichia pastori表达系统中,研究了高密度培养时细胞生长、改变碳源和诱导表达时溶氧的变化和调控规律,溶氧与细胞生长和重组蛋白表达密切相关。发酵前期的细胞生长阶段,细胞需氧降低表明碳源甘油的消耗,根据溶氧水平适时流加碳源甘油;改变碳源前,应停止流加甘油碳源,并以溶氧指标判断甘油是否消耗完全;重组蛋白诱导时流加甲醇的速度应缓慢增大,并保持细胞一定的需氧水平。高密度培养时通过流加底物速度、搅拌转速、通气量和富氧培养来关联控制发酵液溶氧水平。
基金Supported by the National Natural Science Foundation of China(31100136)the Special Fund for Independent Innovation of Agricultural Science and Technology in Jiangsu Province[CX(12)5051]~~
文摘[Objective] This study aimed to investigate the secretory expression of P97R1 gene of Mycoplasma hyopneumoniae（Mhp） in Pichia pastoris expression system and the primary application; of the expression product. [Method] A pair of specific primers was designed to conduct PCR according to the Mhp P97R1 gene sequence in Genbank, and the amplified P97R1 gene was cloned into the pPICZa-A yeast expression vector to construct the secretory recombinant expression vector pPICZa-A-P97R1. The plasmid pPICZa-A-p97R1 linearized by Sac I was transformed into P. pastoris GSl15 by electroporation. Positive transformant identified by PCR was incubated to express P97R1 protein after methanol induction. And the expression product was identified using SDS-PAGE and Western-blotting anal.wsis. [Result] P97R1 protein was successfully expressed in the P. pastoris system, with a secre- tory amount of 499μg/ml, and revealed good reactogenicity. Meanwhile, an indirect ELISA method was established with P97R1 protein after the optimization of each reaction factor, which showed good specificity and repeatability according to repeated tests. [Conclusion] This study provides bases for developing the ELISA Kit for anti- body detection and genetically engineered vaccine to Mhp.
