https://scholar.dgist.ac.kr/handle/20.500.11750/888 2026-04-04T13:19:51Z https://scholar.dgist.ac.kr/handle/20.500.11750/59989 Title: Hydrogen Evolution via Oxygen Tolerant [NiFe]-Hydrogenase Immobilized on TiO2 Nanotubes Author(s): Kim, Hwapyong; Kim, Ki Nam; Lee, Sang-Hyeon; Nam, Chang-Hoon; Lee, Young-Sam; In, Su-Il Abstract: [FeFe]-hydrogenase has been of great interest due to its high enzymatic activity for hydrogen evolution reactions (HERs). However, the big challenge of [FeFe]-hydrogenase is a significant performance degradation in aerobic conditions. On the other hand, [NiFe]-hydrogenase of E. coli has an oxygen tolerant property. Therefore, using [NiFe]-hydrogenase is an effective solution to avoid performance degradation in aerobic conditions. Herein, we extracted [NiFe]-hydrogenases from E. coli and immobilized them on the TiO2 nanotube (TNT) electrode prepared by pyrrole-based electropolymerization for application in aerobic conditions. As a result, we can confirm that [NiFe]-hydrogenases coated TNT electrode demonstrates the increased HER activity underaerobic condition than control samples in in-vitro activity test using methylene viologen and linear sweep voltammetry. 2025-12-31T15:00:00Z https://scholar.dgist.ac.kr/handle/20.500.11750/57687 Title: The In vitro reconstituted the lens-specific intermediate filament with filensin and phakinin replicates the genotype-phenotype correlation for cataracts Author(s): Jeong, Jinju; Kwon, Mi Kyung; Nam, Yongho; Lee, Chang-Hun; Lee, Young-Sam Abstract: The intermediate filaments (IFs) family is one of the cyto-skeletons that regulate cell shape, size, stiffness, and movement. Unlike other cytoskeletons such as actin and tubulin, alpha-helical linear proteins of the IFs family constitute filament formation, which can be classified in six types depending on their assembly mechanisms. Filensin and phakinin, which are classified into the type-VI IFs, are only expressed in lens fiber cells and are composed of the lens-specific IFs. However, it is unclear how filensin and phakinin constitute filaments and have an impact on lens properties. Here, we studied the in vitro molecular assembly of human filensin and phakinin to identify the structural and functional relationships. We reconstituted the co-assembled filaments with human recombinant filensin and phakinin and determined its stoichiometry as the ratio of one-to-one. Filensin and phakinin filaments interacted with alpha-crystallin and assembled to make a beeded structure detected by the sedimentation assay and TEM. Moreover, the cataract disease mutant phakinin E233del caused short filaments and reduced resistance against heat and shear stress. We further showed that the alpha-helical rod domains in each protein are involved in the interaction between two proteins, and the intrinsically disordered head and tail domains regulates filament extension. Overall, we determined the molecular interaction in the lens-IFs, which confers the crystalline lens with stability against physical stress. These results suggest that the impaired integrity of the IF can lead to age-related diseases like cataracts and presbyopia. 2024-03-24T15:00:00Z https://scholar.dgist.ac.kr/handle/20.500.11750/57310 Title: Brief guide to senescence assays using cultured mammalian cells Author(s): Kang, Eunseok; Kang, Chanhee; Lee, Young-Sam; Lee, Seung-Jae V. Abstract: Cellular senescence is a crucial biological process associated with organismal aging and many chronic diseases. Here, we present a brief guide to mammalian senescence assays, including the measurement of cell cycle arrest, change in cellular morphology, senescence-associated β-galactosidase (SA-β-gal) staining, and the expression of senescence-associated secretory phenotype (SASP). This work will be useful for biologists with minimum expertise in cellular senescence assays. © 2024 The Author(s) 2024-08-31T15:00:00Z https://scholar.dgist.ac.kr/handle/20.500.11750/57090 Title: The ICL1 and MLS1 Genes, Integral to the Glyoxylate Cycle, are Essential and Specific for Caloric Restriction-Mediated Extension of Lifespan in Budding Yeast Author(s): Kwon, Young-Yon; Lee, Han-Jun; Lee, Myung-Jin; Lee, Young-Sam; Lee, Cheol-Koo Abstract: The regulation of complex energy metabolism is intricately linked to cellular energy demands. Caloric restriction (CR) plays a pivotal role in modulating the expression of genes associated with key metabolic pathways, including glycolysis, the tricarboxylic acid (TCA) cycle, and the glyoxylate cycle. In this study, the chronological lifespan (CLS) of 35 viable single-gene deletion mutants under both non-restricted and CR conditions, focusing on genes related to these metabolic pathways is evaluated. CR is found to increase CLS predominantly in mutants associated with the glycolysis and TCA cycle. However, this beneficial effect of CR is not observed in mutants of the glyoxylate cycle, particularly those lacking genes for critical enzymes like isocitrate lyase 1 (icl1Δ) and malate synthase 1 (mls1Δ). This analysis revealed an increase in isocitrate lyase activity, a key enzyme of the glyoxylate cycle, under CR, unlike the activity of isocitrate dehydrogenase, which remains unchanged and is specific to the TCA cycle. Interestingly, rapamycin, a compound known for extending lifespan, does not increase the activity of the glyoxylate cycle enzyme. This suggests that CR affects lifespan through a distinct metabolic mechanism. © 2024 The Authors. Advanced Biology published by Wiley-VCH GmbH. 2024-08-31T15:00:00Z