Customized N-glycosylation for the production of glucocerebrosidase in Arabidopsis

이균오,Ki Seong Ko,Jae Yong Yoo,Bích Ngọc Thị Vũ,Ji Ye Park 한국당과학회 2021 한국당과학회 학술대회 Vol.2021 No.01

Plants and plant cells are evolving with improved safety and production as attractive options for biopharmaceutical production. A significant barrier to the development of biopharmaceuticals in plants, however, lies in the fact that plant-derived N-glycans contain plant-specific sugar residues such as β1,2-xylose and α1,3-fucose bound to the pentasaccharide core (Man3GlcNAc2) as well as β1,3-galactose and α1,4-fucose involved in the formation of Lewis a (Lea) epitope that may cause allergic reactions in humans. Additionally, sugar residues such as α1,6-fucose, β1,4-galactose, and α2,6-sialic acid, which are believed to play important roles in biopharmaceutical action, storage, distribution, and half-life, are missing from the naturally occurring N-glycans in plants. To use plant cells as a means of producing biopharmaceuticals, it is essential to produce plants which contain N-glycan compatible with biopharmaceuticals. However, the structure of N-glycans appears to be related to hormone signalling and how the structure of N-glycans altered during glycoengineering influences plant production is still uncertain. Here, we suggest a strategy for producing customized N-glycans in plants and the related technological barriers.

Glycoengineering for production of biopharmaceuticals in plants

Ki Seong Ko,Jae Yong Yoo,Bích Ngọc Thị Vũ,Seok Han Yoon,Young Eun Lee,Kyun Oh Lee 한국당과학회 2021 한국당과학회 학술대회 Vol.2021 No.07

Cell cycle arrest mediated by WEE1 is involved in the unfolded protein response in plants

고기성,유재용,Nirmal Kumar Ramasamy,RIKNOHARMOKO,Bích Ngọc Thị Vũ,박지예,이균오 한국식물생명공학회 2018 Plant biotechnology reports Vol.12 No.5

Activation of the unfolded protein response (UPR) in mammalian cells leads to cell cycle arrest at the G1 phase (Thomas et al., J Biol Chem 288:7606–7617, 2013). However, how UPR signaling affects cell cycle arrest remains largely unknown in plants. Here, we examined UPR and endoreduplication in Col-0, wee1, and ER stress sensing-deficient ire1a&b plants during DNA replication and ER stress conditions. We found that WEE1, an essential negative regulator of the cell cycle, is involved in the maintenance of ER homeostasis during genotoxic stress and the ER stress hypersensitivity of ire1a&b is alleviated by loss-of-function mutation in WEE1. WEE1-mediated cell cycle arrest was required for IRE1–bZIP60 pathway activation during ER stress. In contrast, loss-of-function mutation in WEE1 caused increased expression of UPR-related genes during DNA replication stress. WEE1 and IRE1 were required for endoreduplication during DNA replication stress and ER stress, respectively. Taken together, these findings suggest that cell cycle regulation is associated with UPR activation in different manners during ER stress and DNA replication stress in Arabidopsis.

Glycoengineering for production of biopharmaceuticals in plants

Ki Seong Ko,Jae Yong Yoo,Bích Ngọc Thị Vũ,Seok Han Yoon,Young Eun Lee,Kyun Oh Lee 한국당과학회 2021 한국당과학회 학술대회 Vol.2021 No.07

Translatome analysis of CHO cells to identify key growth genes

Courtes, F.C.,Lin, J.,Lim, H.L.,Ng, S.W.,Wong, N.S.C.,Koh, G.,Vardy, L.,Yap, M.G.S.,Loo, B.,Lee, D.Y. Elsevier Science Publishers 2013 Journal of biotechnology Vol.167 No.3

We report the first investigation of translational efficiency on a global scale, also known as translatome, of a Chinese hamster ovary (CHO) DG44 cell line producing monoclonal antibodies (mAb). The translatome data was generated via combined use of high resolution and streamlined polysome profiling technology and proprietary Nimblegen microarrays probing for more than 13K annotated CHO-specific genes. The distribution of ribosome loading during the exponential growth phase revealed the translational activity corresponding to the maximal growth rate, thus allowing us to identify stably and highly translated genes encoding heterogeneous nuclear ribonucleoproteins (Hnrnpc and Hnrnpa2b1), protein regulator of cytokinesis 1 (Prc1), glucose-6-phosphate dehydrogenase (G6pdh), UTP6 small subunit processome (Utp6) and RuvB-like protein 1 (Ruvbl1) as potential key players for cellular growth. Moreover, correlation analysis between transcriptome and translatome data sets showed that transcript level and translation efficiency were uncoupled for 95% of investigated genes, suggesting the implication of translational control mechanisms such as the mTOR pathway. Thus, the current translatome analysis platform offers new insights into gene expression in CHO cell cultures by bridging the gap between transcriptome and proteome data, which will enable researchers of the bioprocessing field to prioritize in high-potential candidate genes and to devise optimal strategies for cell engineering toward improving culture performance.

Mammalian Systems Biotechnology Reveals Global Cellular Adaptations in a Recombinant CHO Cell Line

Yusufi, F.N.K.,Lakshmanan, M.,Ho, Y.S.,Loo, B.L.W.,Ariyaratne, P.,Yang, Y.,Ng, S.K.,Tan, T.R.M.,Yeo, H.C.,Lim, H.L.,Ng, S.W.,Hiu, A.P.,Chow, C.P.,Wan, C.,Chen, S.,Teo, G.,Song, G.,Chin, J.X.,Ruan, X. Cell Press 2017 Cell systems Vol.4 No.5

Effective development of host cells for therapeutic protein production is hampered by the poor characterization of cellular transfection. Here, we employed a multi-omics-based systems biotechnology approach to elucidate the genotypic and phenotypic differences between a wild-type and recombinant antibody-producing Chinese hamster ovary (CHO) cell line. At the genomic level, we observed extensive rearrangements in specific targeted loci linked to transgene integration sites. Transcriptional re-wiring of DNA damage repair and cellular metabolism in the antibody producer, via changes in gene copy numbers, was also detected. Subsequent integration of transcriptomic data with a genome-scale metabolic model showed a substantial increase in energy metabolism in the antibody producer. Metabolomics, lipidomics, and glycomics analyses revealed an elevation in long-chain lipid species, potentially associated with protein transport and secretion requirements, and a surprising stability of N-glycosylation profiles between both cell lines. Overall, the proposed knowledge-based systems biotechnology framework can further accelerate mammalian cell-line engineering in a targeted manner.

Performance Evaluation of the RTK-GNSS Navigating under Different Landscape

K.M. Ng,J. Johari,S.A.C. Abdullah,A. Ahmad,B. N. Laja 제어로봇시스템학회 2018 제어로봇시스템학회 국제학술대회 논문집 Vol.2018 No.10

The navigation of autonomous vehicles depends on various sensors. One of the technologies that assist in the vehicles position localization and navigation is the Global Positioning System (GPS). Enhancement of the GPS technology reveals the application of Real Time Kinematics (RTK)-GPS to achieve higher accuracy based on corrections sent from a base station to the receiver. However, there is limited evaluation of the performance of the RTK-GPS when the vehicle is travelling in land area that is obstructed by buildings and also in uneven landscape. Hence, the purpose of this work is to conduct an experimental and comparative study to evaluate the performance of the RTK-GPS in flat-unobstructed, uneven-unobstructed and uneven-obstructed situations respectively. Three locations that possess the respective landscape characteristics in the state of Selangor, Malaysia were chosen to conduct the experiments. Results of logged RTK coordinates were compared with coordinates of the actual path travelled by the vehicle using statistical methods. In addition, the quality indicators of the coordinates logged were also evaluated. The results show that navigation on flat-unobstructed and uneven-unobstructed landscape has similar performances with floating coordinates range of errors.

Indium tin oxide nanorods by dc sputtering

M.K. Fung,Y.C. Sun,A.M.C. Ng,A.B. Djurišić,W.K. Chan 한국물리학회 2011 Current Applied Physics Vol.11 No.3

Growth of indium tin oxide (ITO) nanorods by sputtering without any use of templates or oblique angle deposition has been achieved. The morphology, optical and electrical properties of ITO nanorods obtained under different deposition conditions have been characterized. The deposition conditions resulting in high transmission and low sheet resistance have been determined. Dense ITO nanorod array has potential for application as a contact in light-emitting diodes

Enhancement of Excretory Production of an Exoglucanase from Escherichia coli with Phage Shock Protein A (PspA) Overexpression

( Y. Y. Wang ),( Z. B. Fu ),( K. L. Ng ),( C. C. Lam ),( A. K. N. Chan ),( K. F. Sze ),( W. K. R. Wong ) 한국미생물 · 생명공학회 2011 Journal of microbiology and biotechnology Vol.21 No.6

Production of recombinant proteins by excretory expression has many advantages over intracellular expression in Escherichia coli. Hyperexpression of a secretory exoglucanase, Exg, of Cellulomonas fimi was previously shown to saturate the SecYEG pathway and result in dramatic cell death of E. coli. In this study, we demonstrated that overexpression of the PspA in the JM101(pM1VegGcexL-pspA) strain enhanced excretion of Exg to 1.65 U/ml using shake-flask cultivation, which was 80% higher than the highest yield previously obtained from the optimized JM101(pM1VegGcexL) strain. A much higher excreted Exg activity of 4.5 U/ml was further achieved with high cell density cultivation using rich media. Furthermore, we showed that the PspA overexpression strain enjoyed an elevated critical value (CV), which was defined as the largest quotient between the intracellular unprocessed precursor and its secreted mature counterpart that was still tolerable by the host cells prior to the onset of cell death, improving from the previously determined CV of 20/80 to the currently achieved CV of 45/55 for Exg. The results suggested that the PspA overexpression strain might tolerate a higher level of precursor Exg making use of the SecYEG pathway for secretion. The reduced lethal effect might be attributable to the overexpressed PspA, which was postulated to be able to reduce membrane depolarization and damage. Our findings introduce a novel strategy of the combined application of metabolic engineering and construct optimization to the attainment of the best possible E. coli producers for secretory/excretory production of recombinant proteins, using Exg as the model protein.

Adsorption Sciences and Technologies for Cooling and Desalination: A Review

Chakarborty A,Saha B. B,Koyama S Ng K. C,Kyaw T 한국에너지기후변화학회 2007 에너지기후변화학회지 Vol.2 No.2

The state-of-art of the adsorption sciences and technologies for the development of refrigeration and desalination is reviewed in the paper. The physical adsorption of adsorbent-adsorbate systems, the development history and recent progress in adsorption refrigeration and desalination technologies are reported, The paper shows that adsorption technologies are not only thermo-economically viable in terms of serving the needs for air-conditioning, refrigeration, ice making and fresh drinking water production purposes, but also the advanced sorption cycles meet the stringent demands for energy conservation and environment protection. Recently, a plethora of research investigation focuses on the large-scale integration of the AD cycles in both cooling and desalination applications as well as reducing the impact of environmental and thermal pollution.