A facile approach has been developed to synthesize Fe3O4@PAM（polyacrylamide） nanoparticles（NPs） with carboxyl groups on the surfaces by copolymerization with acrylamide and acrylic acid in Fe3O4 NPs aqueous suspen...A facile approach has been developed to synthesize Fe3O4@PAM（polyacrylamide） nanoparticles（NPs） with carboxyl groups on the surfaces by copolymerization with acrylamide and acrylic acid in Fe3O4 NPs aqueous suspension. Nitrilotriacetic acid（NTA） was conjugated to the magnetic NPs via well-known carboniimide chemistry using EDC and NHS. The Ni^（2＋） ions loaded on the surface of NPs provide abundant docking sites for immobilization of His-tagged green fluorescent proteins（His-tagged GFP）. The high magnetic property of Fe3O4@PAM@NTA-Ni^（2＋） allows an easy separation of the NPs from solution under an external magnetic field, with high His-tagged protein binding capacity（42 μg protein/mg of NPs）. The NPs can be recycled for at least four times without significant loss of binding capacity to proteins. These materials show great potential to separate His-tagged protein with low-cost purification at industrial scale.展开更多
Kai-Xin-San consists of Ginseng Radix, Polygalae Radix, Acori Tatarinowii Rhizoma, and Poria at a ratio of 3:3:2:2. Kai-Xin-San has been widely used for the treatment of emotional disorders in China. However, no studi...Kai-Xin-San consists of Ginseng Radix, Polygalae Radix, Acori Tatarinowii Rhizoma, and Poria at a ratio of 3:3:2:2. Kai-Xin-San has been widely used for the treatment of emotional disorders in China. However, no studies have identified the key proteins implicated in response to Kai-Xin-San treatment. In this study, rat models of chronic mild stress were established using different stress methods over 28 days. After 14 days of stress stimulation, rats received daily intragastric administrations of 600 mg/kg Kai-Xin-San. The sucrose preference test was used to determine depression-like behavior in rats, while isobaric tags were used for relative and absolute quantitation-based proteomics to identify altered proteins following Kai-Xin-San treatment. Kai-Xin-San treatment for 2 weeks noticeably improved depression-like behaviors in rats with chronic mild stress. We identified 33 differentially expressed proteins: 7 were upregulated and 26 were downregulated. Functional analysis showed that these differentially expressed proteins participate in synaptic plasticity, neurodevelopment, and neurogenesis. Our results indicate that Kai-Xin-San has an important role in regulating the key node proteins in the synaptic signaling network, and are helpful to better understand the mechanism of the antidepressive effects of Kai-Xin-San and to provide objective theoretical support for its clinical application. The study was approved by the Ethics Committee for Animal Research from the Chinese PLA General Hospital(approval No. X5-2016-07) on March 5, 2016.展开更多
Total RNA was isolated from the hybridoma cell line (LC-1), which secretes anti-lung adenocarcinoma monoclonalantibody, and was transferred into cDNA. Based on the FR1 (framework region 1) and FR4 conserved regions of...Total RNA was isolated from the hybridoma cell line (LC-1), which secretes anti-lung adenocarcinoma monoclonalantibody, and was transferred into cDNA. Based on the FR1 (framework region 1) and FR4 conserved regions of LC-1 gene, thevariable regions of heavy chain (Vh) and light chain (Vl) were amplified, and the Vh and modified Vl were connected to singlechain Fv (ScFv) by SOE-PCR (splice overlap extension PCR). The modified ScFv was fused with green fluorescent protein (GFP)and introduced into E. coli JM109. The fusion protein induced by IPTG (Isopropylthiogalactoside) was about 57000 on a 10%SDS-PAGE gel (10% Sds Polyacrylamide Gel Electrophoresis), and primarily manifested as inclusion bodies. The renaturedprotein purified by Ni-NTA Superflow resins showed ability to bind to antigen on SPC-A-1 lung adenocarcinoma. In addition, theinduced host cells fluoresced bright green under 395 nm wavelength, which indicated that the expected protein with dual activitywas expressed in the prokaryotic system. The ScFv with GFP tag used in this research can be applied as a new reagent to detectimmunological dye, and provide a feasible way to detect adenocarcinoma in a clinical setting.展开更多
Human epididymal protease inhibitor （eppin） may be effective as a male contraceptive vaccine. In a number of studies, eppin with an engineered His6-tag has been produced using prokaryotic expression systems. For pro...Human epididymal protease inhibitor （eppin） may be effective as a male contraceptive vaccine. In a number of studies, eppin with an engineered His6-tag has been produced using prokaryotic expression systems. For production of pharmaceutical-grade proteins for human use, however, the His6-tag must be removed. This study describes a method for producing recombinant human eppin without a His6-tag. We constructed plasmid pET28a （＋）-His6-tobacco etch virus （TEV）-eppin for expression in Escherichia coli. After purification and refolding, the fusion protein His6-TEV-eppin was digested with TEV protease to remove the His6-tag and was further purified by NTA-Ni2＋ affinity chromatography. Using this procedure, 2 mg of eppin without a His6-tag was isolated from 1 I of culture with a purity of 〉95%. The immunogenicity of the eppin was characterized using male Balb/c mice.展开更多
The main aim of this mini-review is to illustrate strategies and industrial applications based on inteins (INTErnal proteINS), which belong to a class of autocatalytic enzymes that are able to perform a catalytic reac...The main aim of this mini-review is to illustrate strategies and industrial applications based on inteins (INTErnal proteINS), which belong to a class of autocatalytic enzymes that are able to perform a catalytic reaction on a single substrate. However, since practical applications of inteins are strongly guided by a detailed understanding of their biological mechanisms and functions, the first part of this review will thus briefly discuss the physiological roles of inteins, describing what is currently known about their mechanisms of action. In the second part, specific biotechnological applications of inteins will be outlined (i.e. their use for (i) the purification of recombinant proteins, (ii) the cyclization of proteins and (iii) the production of seleno-proteins), paying attention to both potential strengths and weaknesses of this technology.展开更多
基金Funded by the National Natural Science Foundation of China(Nos.21401051 and 51303049)Hubei Province Natural Science Foundation of China(Nos.2014CFB595 and 2014CFA080)+1 种基金Chutian Scholars Fund Project from the Education Department of Hubei ProvinceHundred Talents Program from the Organization Department of Hubei Province
文摘A facile approach has been developed to synthesize Fe3O4@PAM（polyacrylamide） nanoparticles（NPs） with carboxyl groups on the surfaces by copolymerization with acrylamide and acrylic acid in Fe3O4 NPs aqueous suspension. Nitrilotriacetic acid（NTA） was conjugated to the magnetic NPs via well-known carboniimide chemistry using EDC and NHS. The Ni^（2＋） ions loaded on the surface of NPs provide abundant docking sites for immobilization of His-tagged green fluorescent proteins（His-tagged GFP）. The high magnetic property of Fe3O4@PAM@NTA-Ni^（2＋） allows an easy separation of the NPs from solution under an external magnetic field, with high His-tagged protein binding capacity（42 μg protein/mg of NPs）. The NPs can be recycled for at least four times without significant loss of binding capacity to proteins. These materials show great potential to separate His-tagged protein with low-cost purification at industrial scale.
基金supported by the National Natural Science Foundation of China,No.81573876(to YH)
文摘Kai-Xin-San consists of Ginseng Radix, Polygalae Radix, Acori Tatarinowii Rhizoma, and Poria at a ratio of 3:3:2:2. Kai-Xin-San has been widely used for the treatment of emotional disorders in China. However, no studies have identified the key proteins implicated in response to Kai-Xin-San treatment. In this study, rat models of chronic mild stress were established using different stress methods over 28 days. After 14 days of stress stimulation, rats received daily intragastric administrations of 600 mg/kg Kai-Xin-San. The sucrose preference test was used to determine depression-like behavior in rats, while isobaric tags were used for relative and absolute quantitation-based proteomics to identify altered proteins following Kai-Xin-San treatment. Kai-Xin-San treatment for 2 weeks noticeably improved depression-like behaviors in rats with chronic mild stress. We identified 33 differentially expressed proteins: 7 were upregulated and 26 were downregulated. Functional analysis showed that these differentially expressed proteins participate in synaptic plasticity, neurodevelopment, and neurogenesis. Our results indicate that Kai-Xin-San has an important role in regulating the key node proteins in the synaptic signaling network, and are helpful to better understand the mechanism of the antidepressive effects of Kai-Xin-San and to provide objective theoretical support for its clinical application. The study was approved by the Ethics Committee for Animal Research from the Chinese PLA General Hospital(approval No. X5-2016-07) on March 5, 2016.
基金Project (No. 396007) supported by the National Natural ScienceFoundation of China
文摘Total RNA was isolated from the hybridoma cell line (LC-1), which secretes anti-lung adenocarcinoma monoclonalantibody, and was transferred into cDNA. Based on the FR1 (framework region 1) and FR4 conserved regions of LC-1 gene, thevariable regions of heavy chain (Vh) and light chain (Vl) were amplified, and the Vh and modified Vl were connected to singlechain Fv (ScFv) by SOE-PCR (splice overlap extension PCR). The modified ScFv was fused with green fluorescent protein (GFP)and introduced into E. coli JM109. The fusion protein induced by IPTG (Isopropylthiogalactoside) was about 57000 on a 10%SDS-PAGE gel (10% Sds Polyacrylamide Gel Electrophoresis), and primarily manifested as inclusion bodies. The renaturedprotein purified by Ni-NTA Superflow resins showed ability to bind to antigen on SPC-A-1 lung adenocarcinoma. In addition, theinduced host cells fluoresced bright green under 395 nm wavelength, which indicated that the expected protein with dual activitywas expressed in the prokaryotic system. The ScFv with GFP tag used in this research can be applied as a new reagent to detectimmunological dye, and provide a feasible way to detect adenocarcinoma in a clinical setting.
基金ACKNOWLEDGEMENTS The authors are grateful to Dr Zi-Chun Hua （The State Key Laboratory of Pharmaceutical Biotechnology and Department of Biochemistry, College of Life Science, Nanjing University, China） for kindly providing plasmid pET28a （＋） and TEV endoprotease and to Dr Michael G. O＇Rand （Laboratories for Reproductive Biology and Department of Cell and Developmental Biology, University of North Carolina at Chapel Hill, USA） for English-language editing. This study was supported by grants from the Key Project of the National Natural Science Foundation of China （No. 30930079） and the Chinese National Nature Science Foundation （No. 81001257）.
文摘Human epididymal protease inhibitor （eppin） may be effective as a male contraceptive vaccine. In a number of studies, eppin with an engineered His6-tag has been produced using prokaryotic expression systems. For production of pharmaceutical-grade proteins for human use, however, the His6-tag must be removed. This study describes a method for producing recombinant human eppin without a His6-tag. We constructed plasmid pET28a （＋）-His6-tobacco etch virus （TEV）-eppin for expression in Escherichia coli. After purification and refolding, the fusion protein His6-TEV-eppin was digested with TEV protease to remove the His6-tag and was further purified by NTA-Ni2＋ affinity chromatography. Using this procedure, 2 mg of eppin without a His6-tag was isolated from 1 I of culture with a purity of 〉95%. The immunogenicity of the eppin was characterized using male Balb/c mice.
基金MM would like to thank the Science Foundation Ireland(SFI)for a postgraduate scholarship received via a President of Ireland Young Researcher Award(PIYRA)bestowed on NMGS acknowledges the award of a Future Fellowship from the Australian Research Council.
文摘The main aim of this mini-review is to illustrate strategies and industrial applications based on inteins (INTErnal proteINS), which belong to a class of autocatalytic enzymes that are able to perform a catalytic reaction on a single substrate. However, since practical applications of inteins are strongly guided by a detailed understanding of their biological mechanisms and functions, the first part of this review will thus briefly discuss the physiological roles of inteins, describing what is currently known about their mechanisms of action. In the second part, specific biotechnological applications of inteins will be outlined (i.e. their use for (i) the purification of recombinant proteins, (ii) the cyclization of proteins and (iii) the production of seleno-proteins), paying attention to both potential strengths and weaknesses of this technology.
