Abstract : The advanced clinical stage of breast cancer causes a lower survival rate even though the survival rate in the early stages is relatively high. Thus, the development of a rapid and easy-to-access diagnostic method is needed. In this study, a single chain Fv (scFv)-type antibody fragment that binds to HER2, a transmembrane protein overexpressed on breast cancer cells, was generated. The scFv was converted to a Quenchbody by site-specifically labeling the scFv using fluorescent dye through a maleimide-thiol reaction. The Quenchbody could detect a picomolar order of HER2 in a few minutes, and its signal-to-background ratio of fluorescence intensity was higher than a fluorescence scFv generated through a conventional fluorescent dye-conjugating method. The Quenchbody can be used as a probe for detecting and imaging of breast cancer cells for point-of-care diagnosis of breast cancer.
Abstract : Plastic is one of the fastest-growing consumer goods in modern society, and its usage continues to increase globally. Plastics with high hydrophobicity, such as polyethylene and polypropylene, or those with simple carbon-carbon (C-C) structures like polystyrene, are particularly difficult to degrade. Additionally, the biodegradation mechanisms of plastics such as polyvinyl chloride are not well understood. The widespread use of plastics poses significant environmental and waste management challenges. As an alternative, recent research has focused on the enzymatic degradation of plastics through microorganisms. This study suggests the potential for sustainability in the plastic industry and environmental protection.
Abstract : Microplastics(MPs), small plastic particles ubiquitous in the environment, pose emerging concerns for human health due to their ingestion, inhalation, and dermal exposure routes. This review summarizes current research on the effects of MPs on the human body. Ingested MPs, primarily from contaminated food and water sources, induce gastrointestinal inflammation, oxidative stress, and microbiota alterations, with potential systemic distribution and organ accumulation. Inhalation of airborne MPs may lead to respiratory inflammation and impaired lung function. Dermal contact with MPs raises concerns about skin absorption and dermatological effects. Understanding microplastic toxicity mechanisms, including their interactions with biological systems and role as carriers for harmful substances, is critical for risk assessment and policy development. Integrating knowledge from environmental science, toxicology, and public health is essential for addressing health risks associated with MPs exposure. Further research is needed to fill knowledge gaps and develop strategies for mitigating microplastic pollution, safeguarding human health, and promoting environmental sustainability.
Abstract : This study aimed to examine the effect of light wavelength on cell growth and carotenoid production in the freshwater green microalga Tetradesmus reginae during cultivation in bubble column photobioreactors (multi-cultivators) under different light colors (450 nm, blue; 660 nm, red; and CW5700K, white). The microalga cultured under white light showed the fastest specific cell growth rate (1.19 ± 0.00 /day) and highest fresh cell concentration (9.04 ± 0.01 g/L) on day 6. Next, the microalgal cells were cultivated under white light for 5 days to evaluate the effect of light wavelength on carotenoid production. Furthermore, the culture medium was replaced with an N- and P-depleted medium, and the microalgal cells were subjected to different light spectra to induce carotenoid production. Culture under blue light showed the highest carotenoid concentration (19.40 ± 0.19 mg/L) and the highest carotenoid productivity (2.08 ± 0.06 mg/L/day); however, cell concentration was the lowest (4.12 ± 0.00 mg/g dry cell weight) owing to the high carotenoid content. These results clearly show that effective growth and carotenoid production may be induced in Tetradesmus reginae at an appropriate light intensity and quality parameters. Thus, this study provides a basis for developing a light-supply strategy to increase microalgal biomass and carotenoid productivity.
Abstract : Development of antibodies neutralizing SARS-CoV-2 variants is very crucial due to their therapeutic potentials and structural study on their binding mode plays an important role in the design of therapeutic antibodies. m396 is an antibody which was originally developed for SARS-CoV-1. The antibody is known to bind to the receptor binding domain (RBD) of SARS-CoV-1 but not to show binding affinity against RBD of SARS-CoV-2. In this study, we demonstrated that m396 scFv exhibited binding affinity to the RBD of SARS-CoV-2 Beta variant. To understand the binding mode of m396 scFv and RBD of SARS-CoV-2 Beta variant, HADDOCK protein-protein docking condition was optimized and employed to model the complex structure of two proteins. Finally, the molecular interactions in the binding interface of the modeled complex were analyzed. This study suggests the possibility that m396 can be an efficient template antibody for SARS-CoV-2 variants. In addition, the optimized docking condition for the HADDOCK docking is expected to be utilized in the various computational studies on the binding of m396 and its variants against the RBDs of SARS-CoV variants.
Abstract : In this study, we investigated the effect of mutations in orthogonal aminoacyl-tRNA synthetase (aaRS) on the incorporation efficiency of para-azido-L-phenylalanine (AzF), and performed molecular modeling. We targeted three amino acid positions (178, 248, and 256) in the aaRS cloned in the previously reported pEVOL-pAzF-C1-K776 and generated aaRS mutants (M178T, F248L, K256E) using site-directed mutagenesis. Subsequently, we transformed Escherichia coli DH10B (pSEVA631pt-sfGFP204amb) with each of the pEVOL-pAzF-C1 plasmids containing the mutant aaRS and compared the specific fluorescence intensity upon AzF addition. With AzF addition, M178T and F248L mutants exhibited 1.36- and 1.19-fold increases, respectively, in specific fluorescence intensity compared to the control, while K256E mutant showed a 0.46-fold decrease. The selectivity for AzF was 1.987 for M178T, 1.931 for F248L, and 1.619 for K256E, all lower than the control. To interpret these experimental results, modeling and docking using Swiss-Model were performed. The results obtained in this study could be utilized for the development and interpretation of various aaRS for incorporating non-canonical amino acids into proteins.
Abstract : Production of recombinant acid α-glucosidase (GAA) with high-mannose glycan and least plant-specific residues in transgenic rice cell cultures is necessary for effective treatment of Pompe disease, a lysosomal storage disorder, using enzyme replacement therapy. Kifunensine was used as a regulator of N-glycosylation with plant expression system and it showed negative effect on the expression level of GAA. In order to increase protein expression with the presence of kifunensine, sorbitol was used as an alternative carbon source under sugar-depleted environment to enhance both cell viability and GAA production. Concentrations of kifunensine and sorbitol were optimized and the combined use of 2.5 mM kifunensine and 40 mM sorbitol was found to be the best for cell growth, viability and GAA expression. The content of high-mannose type glycan was 3.8% in control culture and 62% in 2.5 mM kifunensine alone. It could be improved up to 77.9% by the combined supplementation of 40 mM sorbitol. Therefore, it was clear that the combined use of kifunensine and sorbitol can improve GAA expression as well as the content of high-mannose type glycan.
Abstract : Currently, with the advent of protein and cell therapy, new drug drugs are largely divided into synthetic drugs and biopharmaceuticals, and biopharmaceuticals are composed of proteins, cells, or nucleic acids, and are sensitive to minute changes such as temperature, moisture, and vibration in the production and distribution process, so it is important to maintain safety and effectiveness. Biopharmaceuticals have a long period of preclinical, clinical, and approval from the patent application, so the period is short. When the patent expires, a 'biosimilar' manufactured with similar ingredients is released in the market with high competitiveness. This review examines new drugs with trastuzumab (Herceptin) IgG1 antibodies and their biosimilars that have been approved by the FDA, and reports a comparative analysis of the efficacy and safety of these drugs. Herceptin targets the HER2 receptor, which is overexpressed in breast cancer, by Genetech Pharmaceutical Company in the United States, and is an antibody drug used to treat breast and stomach cancer, and it was first approved by the FDA as an original product. Herceptin's five biosimilars are Kanjinti, Ogivri, Herzuma, Ontruzant, and Trazima, and each other pharmaceutical company has been recognized for having similar efficacy and safety to the existing Herceptin. Herceptin and biosimilars can differ in price, manufacturing process, development and approval process. Herceptin and its biosimilars show similar therapeutic effects and safety, which contributes to the commercialization and increased accessibility of biopharmaceuticals. It also increases accessibility at low prices, similar efficacy and safety, and in areas with low supply. For these reasons, it is widely sold worldwide. Although a separate immunoassay is not required in general, it may be necessary to evaluate the immune status according to the underlying disease, immunosuppression status, and previous drug use history of a particular patient. It is important to consult a doctor according to the patient's individual situation to determine the necessary test. Future research on biosimilars needs to focus on evaluating the long-term safety and efficacy of these products.
Abstract : This study evaluated the docking simulation platforms for the incorporation of amber-suppression tRNA synthetase and non-canonical amino acids (ncAAs). Recombinant Escherichia coli harboring mutant green fluorescence proteins and orthogonal amber-suppression tRNA synthetase/tRNA pair was cultivated with different ncAAs, and the fluorescence and growth were measured. For molecular docking simulation of synthetase and each ncAA, three different platforms were used and the binding affinity predictions were examined. By comparing simulation results with experimental fluorescence protein expression, the reliability of each platform was assessed. AzF exhibited the highest expression levels and strong binding affinity in simulations, while pFF and pAcF showed lower expression and weaker affinity, demonstrating consistent trends between experimental and simulation results. In contrast, BpF displayed high affinity in simulations but low expression levels, which was attributed to ligand positioning outside the active site, as revealed by structural analysis. Among the tested docking platforms, DiffDock-L and DynamicBind showed better predictive accuracy than Autodock Vina. The results obtained in this study will serve as a valuable resource for the effective design for the biosynthesis of recombinant proteins incorporated with non-canonical amino acids.
Abstract : Yeast artificial chromosomes (YACs) with expression clusters of three genes (AGAH71, AGAG1, and NABH558) responsible for agar degradation were constructed using chromosome manipulation technique. The three agar-degrading genes were stably introduced into chromosome II of the Saccharomyces cerevisiae strain, confirming efficient production and secretion of various agarases. For efficient chromosome manipulation, each splitting fragment (DNA module) was transformed, and yeast chromosome II (825 kb) was successfully split 270 kb-YAC, 38 kb-mini YAC and 524 kb-YAC through two-rounds chromosome splitting, resulting in the construction of the YKY180 strain, which has a total of 18 chromosomes. Splitting efficiency for chromosome manipulation was 27~100% and the expression level of foreign genes on 38 kb-mini YAC and enzyme activity were indistinguishable from those of the host strain. This means that the structural alteration of the chromosome did not affect gene expression level. The 38 kb-mini YAC demonstrated stable mitotic stability for up to 200 generations, and it was capable of producing various metabolites from agar degradation. This suggests that the artificially manipulated mini-YAC could have diverse industrial applications.
Hye-Jin Kim, Kyung June Yim, Hyun-Jin Jang, Seong-Joo Hong, Ji Young Jung, Seung Won Nam, Young-Jin Ryu , Choul-Gyun Lee, Su-Hwan Cheon, and Z-Hun Kim
Korean Society for Biotechnology and Bioengineering Journal 2023; 38(2): 127-134
https://doi.org/10.7841/ksbbj.2023.38.2.127
Jingyeong Kim and Chang-Soo Lee
Korean Society for Biotechnology and Bioengineering Journal 2023; 38(1): 59-69
https://doi.org/10.7841/ksbbj.2023.38.1.59
Seung-Hwa Yang, Yeo-Jin Lee, Hee-Sun Kang, Hyun-Jae Shin, and Moon-Hee Choi
Korean Society for Biotechnology and Bioengineering Journal 2024; 39(1): 25-33
https://doi.org/10.7841/ksbbj.2024.39.1.25
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