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61.
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Integration of cell line and process development to overcome the challenge of a difficult to express protein 下载免费PDF全文
Swati Dalvi Bryan St. Germain Wenqi Xie Scott Estes Rashmi Kshirsagar Thomas Ryll 《Biotechnology progress》2015,31(5):1201-1211
This case study addresses the difficulty in achieving high level expression and production of a small, very positively charged recombinant protein. The novel challenges with this protein include the protein's adherence to the cell surface and its inhibitory effects on Chinese hamster ovary (CHO) cell growth. To overcome these challenges, we utilized a multi‐prong approach. We identified dextran sulfate as a way to simultaneously extract the protein from the cell surface and boost cellular productivity. In addition, host cells were adapted to grow in the presence of this protein to improve growth and production characteristics. To achieve an increase in productivity, new cell lines from three different CHO host lines were created and evaluated in parallel with new process development workflows. Instead of a traditional screen of only four to six cell lines in bioreactors, over 130 cell lines were screened by utilization of 15 mL automated bioreactors (AMBR) in an optimal production process specifically developed for this protein. Using the automation, far less manual intervention is required than in traditional bench‐top bioreactors, and much more control is achieved than typical plate or shake flask based screens. By utilizing an integrated cell line and process development incorporating medium optimized for this protein, we were able to increase titer more than 10‐fold while obtaining desirable product quality. Finally, Monte Carlo simulations were performed to predict the optimal number of cell lines to screen in future cell line development work with the goal of systematically increasing titer through enhanced cell line screening. © 2015 American Institute of Chemical Engineers Biotechnol. Prog., 31:1201–1211, 2015 相似文献
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Arvind Gulati Natasha Sharma Pratibha Vyas Swati Sood Praveen Rahi Vijaylata Pathania Ramdeen Prasad 《Archives of microbiology》2010,192(11):975-983
An efficient phosphate-solubilizing plant growth–promoting Acinetobacter rhizosphaerae strain BIHB 723 exhibited significantly higher solubilization of tricalcium phosphate (TCP) than Udaipur rock phosphate (URP),
Mussoorie rock phosphate (MRP) and North Carolina rock phosphate (NCRP). Qualitative and quantitative differences were discerned
in the gluconic, oxalic, 2-keto gluconic, lactic, malic and formic acids during the solubilization of various inorganic phosphates
by the strain. Gluconic acid was the main organic acid produced during phosphate solubilization. Formic acid production was
restricted to TCP solubilization and oxalic acid production to the solubilization of MRP, URP and NCRP. A significant increase
in plant height, shoot fresh weight, shoot dry weight, root length, root dry weight, and root, shoot and soil phosphorus (P)
contents was recorded with the inoculated treatments over the uninoculated NP0K or NPTCPK treatments. Plant growth promotion as a function of phosphate solubilization suggested that the use of bacterial strain
would be a beneficial addition to the agriculture practices in TCP-rich soils in reducing the application of phosphatic fertilizers. 相似文献
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In this study, the kinetics of degradation of caffeine and related methylxanthines by induced cells of Pseudomonas sp. was performed. The kinetics data showed that degradation of caffeine, theobromine, and 7-methylxanthine followed Michealis–Menten
kinetics. The values of K
m
are low for caffeine and 7-methylxanthine and high for theobromine. Degradation of caffeine and theobromine was enhanced
in the presence of NADH and NADPH, whereas the degradation of 7-methylxanthine was unaffected. Among the various metal ions
tested, Fe2+ was found to enhance the rate of degradation for all three substrates, whereas Zn2+ and Cu2+ inhibited the degradation of caffeine and theobromine but not 7-methylxanthine. The differences in kinetic parameters and
cofactor requirement suggest the possibility of the involvement of more than one N-demethylases in the caffeine catabolic
pathway in Pseudomonas sp. The induced cells can serve as effective biocatalysts for the development of biodecaffeination techniques. 相似文献
66.
TNF-induced activation of the Nox1 NADPH oxidase and its role in the induction of necrotic cell death 总被引:2,自引:0,他引:2
Tumor necrosis factor (TNF) is an important cytokine in immunity and inflammation and induces many cellular responses, including apoptosis and necrosis. TNF signaling enables the generation of superoxide in phagocytic and vascular cells through the activation of the NADPH oxidase Nox2/gp91. Here we show that TNF also activates the Nox1 NADPH oxidase in mouse fibroblasts when cells undergo necrosis. TNF treatment induces the formation of a signaling complex containing TRADD, RIP1, Nox1, and the small GTPase Rac1. TNF-treated RIP1-deficient fibroblasts fail to form such a complex, indicating that RIP1 is essential for Nox1 recruitment. Moreover, the prevention of TNF-induced superoxide generation with dominant-negative mutants of TRADD or Rac1, as well as knockdown of Nox1 using siRNA, inhibits necrosis. Thus our study suggests that activation of Nox1 through forming a complex with TNF signaling components plays a key role in TNF-induced necrotic cell death. 相似文献
67.
Hubs in the protein-protein interaction network have been classified as "party" hubs, which are highly correlated in their mRNA expression with their partners while "date" hubs show lesser correlation. In this study, we explored the role of intrinsic disorder in date and party hub interactions. The data reveals that intrinsic disorder is significantly enriched in date hub proteins when compared with party hub proteins. Intrinsic disorder has been largely implicated in transient binding interactions. The disorder to order transition, which occurs during binding interactions in disordered regions, renders the interaction highly reversible while maintaining the high specificity. The enrichment of intrinsic disorder in date hubs may facilitate transient interactions, which might be required for date hubs to interact with different partners at different times. 相似文献
68.
Background
The alterations in skeletal muscle structure and function after prolonged periods of unloading are initiated by the chronic lack of mechanical stimulus of sufficient intensity, which is the result of a series of biochemical and metabolic interactions spanning from cellular to tissue/organ level. Reduced activation of skeletal muscle alters the gene expression of myosin heavy chain isoforms to meet the functional demands of reduced mechanical load, which results in muscle atrophy and reduced capacity to process fatty acids. In contrast, chronic loading results in the opposite pattern of adaptations. 相似文献69.
Vaish Swati Parveen Reshma Rajneesh Singh Nootan Gupta Divya Basantani Mahesh Kumar 《Journal of plant research》2022,135(6):823-852
Journal of Plant Research - Plant glutathione S-transferases are an ancient protein superfamily having antioxidant activity. These proteins are primarily involved in diverse plant functions such as... 相似文献
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