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Protein Expression and Purification

Yunlong Shen, Yuxi Wang, Xiaohua Jiang, Liang Lu, Chengdi Wang, Wenxin Luo, Yongxia Zhang, Pei Li, Zhengwei Du, Tengfei Dai, Congcong Wu, Aiping Fang, Yuqin Yao, Qian Peng, Jinliang Yang
Human epididymis protein-4 (HE4) may serve as a putative biomarker for the early diagnosis, therapy and especially prognosis of ovarian, lung and breast cancer. Detection and targeting of HE4 using the anti-HE4 antibody could be one of the effective strategies for the cancer diagnosis and treatment in clinical practice. In this study, a high-efficiency expression system was established to purify recombinant HE4. We obtained high purity HE4 in 400 mg quantity from 1 L culture supernatant of HEK293F cells. CCK-8 and cell cycle assays indicated that the purified recombinant HE4 protein could promote SKOV3 cell cycle and proliferation at the concentration of 0...
September 16, 2017: Protein Expression and Purification
Libo Jin, Yunpeng Wang, Nuo Xu, Dezhong Wang, Xiuming Liu, Renyi Peng, Chao Jiang, Xiaokun Li
β Gallinacin-3 (β Gal-3) is an antimicrobial peptide with strong antibacterial activity against Escherichia coli, Staphylococcus aureus and Salmonella typhimurium. In this study, the β Gal-3 gene was transferred into a plant genome by genetic engineering techniques. These transgenic plants can be used as feed additives to prevent poultry diseases and them might replace the antibiotics used in poultry industry. To ensure the β Gal-3 expresses effectively in Arabidopsis seeds, the expression was driven by promoter Ppha cloned from the β-phaseolin storage protein gene...
September 16, 2017: Protein Expression and Purification
Gol Mohammad Mojarrad Moghanloo, Maryam Khatami, Amin Javidanbardan, Seyed Nezamedin Hosseini
In biopharmaceutical science, ion-exchange chromatography (IEC) is a well-known purification technique to separate the impurities such as host cell proteins from recombinant proteins. However, IEC is one of the limiting steps in the purification process of recombinant hepatitis B surface antigen (rHBsAg), due to its low recovery rate (<50%). In the current study, we hypothesized that ionic strengths of IEC buffers are easy-to-control parameters which can play a major role in optimizing the process and increasing the recovery...
September 15, 2017: Protein Expression and Purification
Yosuke Iimura, Tomonori Sonoki, Hiroshi Habe
Laccase is used in various industrial fields, and it has been the subject of numerous studies. Trametes versicolor laccase has one of the highest redox potentials among the various forms of this enzyme. In this study, we optimized the expression of laccase in Saccharomyces cerevisiae. Optimizing the culture conditions resulted in an improvement in the expression level, and approximately 45 U/L of laccase was functionally secreted in the culture. The recombinant laccase was found to be a heavily hypermannosylated glycoprotein, and the molecular weight of the carbohydrate chain was approximately 60 kDa...
September 13, 2017: Protein Expression and Purification
Rebba C Boswell-Casteel, Jennifer M Johnson, Zygy Roe-Žurž, Kelli D Duggan, Hannah Schmitz, Franklin A Hays
Nucleosides play an essential role in the physiology of eukaryotes by acting as metabolic precursors in de novo nucleic acid synthesis and energy metabolism. Nucleosides also act as ligands for purinergic receptors. Equilibrative nucleoside transporters (ENTs) are polytopic integral membrane proteins that aid in regulating plasmalemmal flux of purine and pyrimidine nucleosides and nucleobases. ENTs exhibit broad substrate selectivity across different isoforms and utilize diverse mechanisms to drive substrate flux across membranes...
September 13, 2017: Protein Expression and Purification
Mooi Kwai Chan, Shern Kwok Lim, Noorizan Miswan, Ai Lan Chew, Rahmah Noordin, Boon Yin Khoo
This study described the isolation of the coding region of human topoisomerase I (TopoI) from MDA-MB-231 and the expression of multiple copy recombinant genes in four Pichia pastoris strains. First, polymerase chain reaction (PCR)-amplification of the enzyme coding region was performed. The PCR fragment was cloned into pPICZ-α-A vector and sequenced. It was then transformed into X33, GS115, SMD1168H and KM71H strains of Pichia. PCR-screening for positive clones was performed, and estimation of multiple copy integrants in each yeast strain was carried out using agar plates containing increasing concentrations of Zeocin(®)...
September 8, 2017: Protein Expression and Purification
Satoshi Inouye
A dihydrofolate reductase-deficient Chinese hamster ovary (CHO-K1/dhfr(-)) cell line stably expressing Gaussia luciferase with a histidine-tag sequence at the carboxyl terminus (GLase-His) was established. Recombinant GLase-His was purified from serum-containing culture medium by single-step Ni-chelate column chromatography in the presence of 2 M NaCl and 0.01% Tween 20. The protein yield of GLase-His with over 95% purity was 0.5 mg from 0.9 L of the cultured medium. The enzymatic properties of purified GLase-His were characterized...
September 6, 2017: Protein Expression and Purification
Yuanpeng Zhang, Xiaoming Yu, Liting Hou, Jin Chen, Pengcheng Li, Xuwen Qiao, Qisheng Zheng, Jibo Hou
The A1 subunit of cholera toxin (CTA1) retains the adjuvant function of CT, without its toxic side effects, making the molecule a promising mucosal adjuvant. However, the methods required to obtain a pure product are both complicated and expensive, constricting its potential commercial applicability. Here, we fused the peptidoglycan binding domain (PA) to the C-terminus of CTA1, which enabled the fusion protein to be expressed by Bacillus subtilis, and secreted into the culture medium. CTA1 was then purified and displayed on GEM particles using a one step process, which resulted in the formation of CTA1-GEM complexes...
September 1, 2017: Protein Expression and Purification
Tasha B Toro, Richard G Painter, Rashad A Haynes, Elena Y Glotser, Melyssa R Bratton, Jenae R Bryant, Kyara A Nichols, Asia N Matthew-Onabanjo, Ashley N Matthew, Derek R Bratcher, Chanel D Perry, Terry J Watt
Metal-dependent lysine deacetylases (KDACs) are involved in regulation of numerous biological and disease processes through control of post-translational acetylation. Characterization of KDAC activity and substrate identification is complicated by inconsistent activity of prepared enzyme and a range of multi-step purifications. We describe a simplified protocol based on two-step affinity chromatography. The purification method is appropriate for use regardless of expression host, and we demonstrate purification of several representative members of the KDAC family as well as a selection of mutated variants...
August 24, 2017: Protein Expression and Purification
David J Wright, Marc O'Reilly, Dominic Tisi
Historically chloroquine was used to treat the most deadly form of malaria, caused by the parasite Plasmodium falciparum. The selective pressure of chloroquine therapy led to the rapid emergence of chloroquine resistant parasites. Resistance has been attributed to the Plasmodium falciparum Chloroquine Resistance Transporter (PfCRT), an integral membrane protein of unknown structure. A PfCRT structure would provide new insights into how the protein confers chloroquine resistance and thereby also yield novel opportunities for developing anti-malarial therapies...
August 17, 2017: Protein Expression and Purification
Huanbo Tan, Wencheng Su, Pengju Wang, Wenyu Zhang, Michael Sattler, Peijian Zou
Telethonin anchors the N-terminal region of titin in the Z-disk of the sarcomere by binding to two immunoglobulin-like (Ig) domains (Z1 and Z2) of titin (Z1Z2). Thereby telethonin plays an important role in myofibril assembly and in muscle development and functional regulation. The expression and purification of recombinant telethonin is very challenging. In previous studies, recombinant telethonin expressed from E. coli was refolded in the presence of Z1Z2. Here, we report various strategies to establish a reliable and efficient protocol for the preparation of telethonin and titin Z1Z2 protein...
August 12, 2017: Protein Expression and Purification
Kalpana Tewari, Anil Dahuja, Archana Sachdev, Vaibhav Kumar, Kishwar Ali, Amresh Kumar, Sweta Kumari
γ-Tocopherol methyltransferase (γ-TMT) (EC is the last enzyme in the tocopherol biosynthetic pathway and it catalyzes the conversion of γ-tocopherol into α-tocopherol, the nutritionally significant and most bioactive form of vitamin E. Although the γ-TMT gene has been successfully overexpressed in many crops to enhance their α-tocopherol content but still only few attempts have been made to uncover its structural, functional and regulation aspects at protein level. In this study, we have cloned the complete 909bp coding sequence of Glycine max γ-TMT (Gm γ-TMT) gene that encodes the corresponding protein comprising of 302 amino acid residues...
August 12, 2017: Protein Expression and Purification
Ting Deng, Haoran Ge, Huahua He, Yao Liu, Chao Zhai, Liang Feng, Li Yi
Antimicrobial peptides (AMPs) consist of molecules acting on the defense systems of numerous organisms toward tumor and multiple pathogens, such as bacteria, fungi, viruses, and parasites. Compared to traditional antibiotics, AMPs are more stable and have lower propensity for developing resistance through functioning in the innate immune system, thus having important applications in the fields of medicine, food and so on. However, despite of their high economic values, the low yield and the cumbersome extraction process in AMPs production are problems that limit their industrial application and scientific research...
August 12, 2017: Protein Expression and Purification
Yuan-Zhong Zhao, Xuan Guo, Jin-Yi Zhong, Nan Guo, Lin-Cai Chen, Zhi-Yang Dong
Sulfur mustard (SM) can be hydrolyzed by haloalkane dehalogenases such as DhaA, LinB and DmbA. However, the low resistance to the elevated temperatures limited the practical application of haloalkane dehalogenases. Here we reported a new thermotolerant dehalogenase FM2382 from Fulvimarina manganoxydans sp. nov. 8047. The specific activity of FM2382 to SM is 0.6 U/mg. FM2382 possessed high heat stability (45 °C) in slight alkali environment (pH 7.5) and retained approximately 50% activity after incubation at 70 °C for 40 min...
August 11, 2017: Protein Expression and Purification
Narges Damavandi, Mozhgan Raigani, Atefeh Joudaki, Fatemeh Davami, Sirous Zeinali
The Chinese Hamster Ovary (CHO) cell lines, applicable to post-translational modifications, are preferred systems for biopharmaceutical protein production. In this study, by using the Jump-In™ TI™ technology which employs PhiC31 and R4 bacteriophage recombinases, a platform CHO-K1 cell line containing a R4-attP site was generated. Here, a combination of Quantitative Fluorescent-Polymerase Chain Reaction (QF-PCR) and semi-random, two-step PCR (ST-PCR), was performed to feature the platform cell clones. Our results show that QF-PCR and ST-PCR, can be utilized for efficient and accelerated cell line characterization...
August 9, 2017: Protein Expression and Purification
Ming Sang, Hui Wei, Jiaxin Zhang, Zhiheng Wei, Xiaolong Wu, Yan Chen, Qiang Zhuge
ABP-dHC-cecropin A is a linear cationic peptide that exhibits antimicrobial properties. To explore a new approach for expression of ABP-dHC-cecropin A using the methylotrophic yeast Pichia pastoris, we cloned the ABP-dHC-cecropin A gene into the vector pPICZαA. The SacI-linearized plasmid pPICZαA-ABP-dHC-cecropin A was then transformed into P. pastoris GS115 by electroporation. Expression was induced after a 96-h incubation with 0.5% methanol at 20 °C in a culture supplied with 2% casamino acids to avoid proteolysis...
August 4, 2017: Protein Expression and Purification
Jian-Hua Hao, Li-Ping Huang, Xiao-Tong Chen, Jing-Jing Sun, Jun-Zhong Liu, Wei Wang, Mi Sun
Cyclodextrin glycosyltransferase (CGTase) is an enzyme able to convert starch and other substrates into cyclodextrins (CDs). A marine strain Y112 producing α-CGTase was identified as Bacillus agaradhaerens Y112 by physiological and biochemical characterization, and 16S rDNA analysis. The gene coding for α-CGTase was cloned, sequenced and expressed in Escherichia coli BL21 (DE3) cells. Recombinant α-CGTase was purified in one-step chromatographic separation and its purity evaluated by SDS-PAGE, showing the presence of one band with a molecular mass of about 92 kDa...
July 27, 2017: Protein Expression and Purification
Jan Bláha, Barbora Kalousková, Ondřej Skořepa, Samuel Pažický, Petr Novák, Ondřej Vaněk
Human natural killer receptor protein 1 (NKR-P1, CD161, gene klrb1) is a C-type lectin-like receptor of natural killer (NK) cells responsible for recognition of its cognate protein ligand lectin-like transcript 1 (LLT1). NKR-P1 is the single human orthologue of the prototypical rodent NKR-P1 receptors. Naturally, human NKR-P1 is expressed on the surface of NK cells, where it serves as inhibitory receptor; and on T and NKT cells functioning as co-stimulatory receptor promoting secretion of IFNγ. Most notably, it is expressed on Th17 and Tc17 lymphocytes where presumably promotes targeting into LLT1 expressing immunologically privileged niches...
July 27, 2017: Protein Expression and Purification
Esmeralda Woestenenk, Peter Agback, Sofia Unnerståle, Ian Henderson, Tatiana Agback
A novel approach for separate expression of dengue virus NS3 protease and its NS2B cofactor domain is described in this paper. The two proteins are expressed in E.coli and purified separately and subsequently efficiently co-refolded to form a stable complex. This straightforward and robust method allows for separate isotope labeling of the two proteins, facilitating analysis by nuclear magnetic resonance (NMR) spectroscopy. Unlinked NS2B-NS3pro behaves better in NMR spectroscopy than linked NS2B-NS3pro, which has resulted in the backbone resonance assignment of the unlinked NS2B-NS3 complex bound to a peptidic boronic acid inhibitor...
July 24, 2017: Protein Expression and Purification
Ishita Sengupta, Jayant B Udgaonkar
The folding and aggregation of proteins has been studied extensively, using multiple probes. To facilitate such experiments, introduction of spectroscopically-active moieties in to the protein of interest is often necessary. This is commonly achieved by specifically labelling cysteine residues in the protein, which are either present naturally or introduced artificially by site-directed mutagenesis. In the case of the recombinant prion protein, which is normally expressed in inclusion bodies, the presence of the native disulfide bond complicates the correct refolding of single cysteine-containing mutant variants of the protein...
July 21, 2017: Protein Expression and Purification
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