https://scholar.dgist.ac.kr/handle/20.500.11750/743 Mon, 03 Aug 2026 07:44:48 GMT 2026-08-03T07:44:48Z https://scholar.dgist.ac.kr/handle/20.500.11750/60516 Title: Expression and purification of the ectodomain of erythropoietin receptor fused to mCitrine or mTFP1 fluorescent protein in Escherichia coli Author(s): 강은호; Ashim Janbolat; Ji, Sangho; Han, Min Ae; Yu, Wookyung; Kim, Sung Jae; Hong, Eunmi; Moon, Cheil; Lee, Chang-Hun Abstract: The erythropoietin receptor (EPOR) is a single-pass transmembrane protein that homo-dimerizes upon binding with its renal ligand erythropoietin (EPO) to trigger downstream signaling. Its extracellular ectodomain mediates ligand binding. Therefore, a fusion protein of the EPOR ectodomain can be useful for various in vitro assays, such as a binding assay with an EPO-like peptide, if overexpressed in Escherichia coli (E.coli). In this study, we hypothesized that fusion proteins of the EPOR ectodomain with mCitrine or mTFP1, expressed in bacteria, could enable in vitro Fo & uml;rster resonance energy transfer experiments. Two fusion proteins, EPOR-mCitrine and EPORmTFP1, were overexpressed in E. coli but obtained as inclusion bodies. Urea solubilization and stepwise dialysis yielded soluble fusion proteins. Circular dichroism spectroscopy revealed that EPOR-mCitrine had greater secondary structure content than EPOR-mTFP1. When combined with recombinant human EPO, the hydrodynamic radius of EPOR-mCitrine changed, as measured using dynamic light scattering, confirming binding. This interaction was further validated using isothermal titration calorimetry. We propose that bacterially produced EPOR-mCitrine is a useful in vitro tool for measuring EPO binding. Tue, 30 Jun 2026 15:00:00 GMT https://scholar.dgist.ac.kr/handle/20.500.11750/60516 2026-06-30T15:00:00Z https://scholar.dgist.ac.kr/handle/20.500.11750/60475 Title: Broadband Circularly Polarized Light Detection via Spin-Selective Charge Transport in Quantum Dot Photodiodes Author(s): Kim, Minseo; Li, Shi; Lee, Kyunghoon; Ahn, Eonhyoung; Lee, Soyeon; Kim, Kiwook; Kim, Hang; Yu, Wookyung; Choi, Changsoon; Lim, Jung Ah; Hwang, Jeeseong; Kim, Dae-Hyeong; Yang, Jiwoong Abstract: Circularly polarized light (CPL) detection provides polarization-resolved information, enabling advanced applications in quantum technologies, bioimaging, secure communications, and multi-level optical data processing. However, conventional CPL photodetectors typically rely on intrinsically chiral absorbers, restricting operation to the UV-vis range and hindering extension into the near-infrared (NIR) and shortwave infrared (SWIR), which are critical for deep tissue imaging and low-visibility sensing. Here, we demonstrate broadband CPL detection with quantum dot (QD) photodiodes that exploit the chiral-induced spin selectivity effect in chiral-ZnO charge transport layers. Chiral ligand-functionalized ZnO electron transport layers selectively transmit spin-polarized charge carriers from QDs, enabling CPL-specific photocurrent generation even in spectral regions without intrinsic chiral absorption. Heavy-metal-free Cu-In-Se QD-photodiodes exhibit outstanding specific detectivity (D *) of 1.28 x 1012 Jones without external bias and broadband CPL detection (g Iph: similar to 0.17 at 260 nm and similar to 0.13 at 780 nm), while PbS QD-devices extend CPL detection across 250-1700 nm (UV-Vis-NIR-SWIR) with superior performance (D *: 1.45 x 1012 Jones). The chiral-transport-driven strategy offers fundamental insights into CPL photodetection and establishes a scalable and optically passive platform for broadband polarization-resolved optoelectronics. Sat, 28 Feb 2026 15:00:00 GMT https://scholar.dgist.ac.kr/handle/20.500.11750/60475 2026-02-28T15:00:00Z https://scholar.dgist.ac.kr/handle/20.500.11750/60291 Title: Accurate conformational ensembles of intrinsically disordered proteins using reweighting based on NMR chemical shifts Author(s): Jeon, Juhyeong; Yang, Wonjin; Park, Sangmin; Kim, Jin Hae; Lee, Young-Ho; Yu, Wookyung Abstract: Intrinsically disordered proteins and protein regions (IDRs) underpin a wide range of vital biological processes but exhibit dynamic and heterogeneous conformations. Currently, many computational efforts seek to elucidate the conformational ensembles of these disordered proteins, yet most methods still struggle to fully capture their structural diversity. Here, we integrate structural libraries of various IDRs—derived from coarse-grained molecular dynamics (MD) simulations and machine learning models—with experimental chemical shifts obtained from NMR spectroscopy. Through a maximum entropy reweighting approach, we obtain reliable ensembles that more accurately reflect observed chemical shifts and reveal transient states. Our results highlight the importance of comprehensive sampling strategies for capturing diverse conformational states. Furthermore, we show that these weighted ensembles faithfully track conformational rearrangements under various conditions such as temperature, mutational effects, and environment, which are not fully captured by experiments alone. This approach provides a dataset encompassing each IDR’s specific structures along with their weights, offering a foundation for systematically exploring IDR structural landscapes, refining our understanding of their functional roles, and shedding light on processes related to misfolding and aggregation. Copyright © 2026 the Author(s). Sat, 31 Jan 2026 15:00:00 GMT https://scholar.dgist.ac.kr/handle/20.500.11750/60291 2026-01-31T15:00:00Z https://scholar.dgist.ac.kr/handle/20.500.11750/59909 Title: Erythropoietin-derived Non-erythropoietic Peptides Conferring Oxidative Stress Resistance to Keratinocytes and Fibroblasts Author(s): Han, Min Ae; Ashim, Janbolat; Ji, Youngheum; Kang, Eunho; Jeong, Minchan; Kim, Sung Jae; Yu, Wookyung; Kim, Jin Hae; Moon, Cheil; Lee, Chang-Hun Abstract: Erythropoietin (EPO) exerts tissue-protective effects; however, its erythropoietic activity limits broader use. Three EPO-derived peptides (ML1-C1/C2/C3) were designed from the C-helix of EPO to remove erythropoietic activity while retaining cell-protective activity. Circular dichroism and nuclear magnetic resonance spectroscopies were used to assess the solution structures of ML1-C1/C2/C3 peptides. The peptide activities for cytoprotection and growth support were assessed using skin-relevant cells, HaCaT cells and 3T3-L1 cells, which proposes an effect on skin epithelial keratinocytes and pre-adipocytic fibroblasts, respectively. Also, an erythroid-precursor cell line, TF-1, was used to evaluate the erythropoietic function of the three peptides. Spectroscopic analyses of ML1-C1/C2/C3 peptides revealed similar secondary structures and different flexibilities between the peptides. While ML1-C1 and ML1-C3 had highly flexible loop-like structures, ML1-C2 had less flexible loop-like structures. Also, their cellular effects vary in a cell type-dependent manner. The EPO-derived peptides can attenuate H2O2-induced loss of viability in HaCaT cells and 3T3-L1 cells. Under low-serum conditions, the three peptides promoted HaCaT proliferation, whereas only ML1-C1 improved 3T3-L1 proliferation. In TF-1 cells, none of the peptides increased cell viability or hemoglobin staining, whereas recombinant human EPO did, indicating the lack of erythropoietic activity of the peptides under experimental conditions. These findings support the potential of EPO-derived peptides as skin-protective agents and motivate future work for skin therapeutics or cosmetic purposes. https://scholar.dgist.ac.kr/handle/20.500.11750/59909