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Erkanli ME, El-Halabi K, Kang TK, Kim JR. Hotspot Wizard-informed engineering of a hyperthermophilic β-glucosidase for enhanced enzyme activity at low temperatures. Biotechnol Bioeng 2024. [PMID: 38682557 DOI: 10.1002/bit.28732] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2024] [Revised: 04/11/2024] [Accepted: 04/19/2024] [Indexed: 05/01/2024]
Abstract
Hyperthermophilic enzymes serve as an important source of industrial enzymes due to their high thermostability. Unfortunately, most hyperthermophilic enzymes suffer from reduced activity at low temperatures (e.g., ambient temperature), limiting their applicability. In addition, evolving hyperthermophilic enzymes to increase low temperature activity without compromising other desired properties is generally difficult. In the current study, a variant of β-glucosidase from Pyrococcus furiosus (PfBGL) was engineered to enhance enzyme activity at low temperatures through the construction of a saturation mutagenesis library guided by the HotSpot Wizard analysis, followed by its screening for activity and thermostability. From this library construction and screening, one PfBGL mutant, PfBGL-A4 containing Q214S/A264S/F344I mutations, showed an over twofold increase in β-glucosidase activity at 25 and 50°C compared to the wild type, without compromising high-temperature activity, thermostability and substrate specificity. Our experimental and computational characterizations suggest that the findings with PfBGL-A4 may be due to the elevation of local conformational flexibility around the active site, while slightly compacting the global protein structure. This study showcases the potential of HotSpot Wizard-informed engineering of hyperthermophilic enzymes and underscores the interplays among temperature, enzyme activity, and conformational flexibility in these enzymes.
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Affiliation(s)
- Mehmet Emre Erkanli
- Department of Chemical and Biomolecular Engineering, New York University, Brooklyn, New York, USA
| | - Khalid El-Halabi
- Department of Chemical and Biomolecular Engineering, New York University, Brooklyn, New York, USA
| | - Ted Keunsil Kang
- Department of Chemical and Biomolecular Engineering, New York University, Brooklyn, New York, USA
| | - Jin Ryoun Kim
- Department of Chemical and Biomolecular Engineering, New York University, Brooklyn, New York, USA
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Erkanli ME, El-Halabi K, Kim JR. Exploring the diversity of β-glucosidase: Classification, catalytic mechanism, molecular characteristics, kinetic models, and applications. Enzyme Microb Technol 2024; 173:110363. [PMID: 38041879 DOI: 10.1016/j.enzmictec.2023.110363] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2023] [Revised: 11/17/2023] [Accepted: 11/18/2023] [Indexed: 12/04/2023]
Abstract
High-value chemicals and energy-related products can be produced from biomass. Biorefinery technology offers a sustainable and cost-effective method for this high-value conversion. β-glucosidase is one of the key enzymes in biorefinery processes, catalyzing the production of glucose from aryl-glycosides and cello-oligosaccharides via the hydrolysis of β-glycosidic bonds. Although β-glucosidase plays a critical catalytic role in the utilization of cellulosic biomass, its efficacy is often limited by substrate or product inhibitions, low thermostability, and/or insufficient catalytic activity. To provide a detailed overview of β-glucosidases and their benefits in certain desired applications, we collected and summarized extensive information from literature and public databases, covering β-glucosidases in different glycosidase hydrolase families and biological kingdoms. These β-glucosidases show differences in amino acid sequence, which are translated into varying degrees of the molecular properties critical in enzymatic applications. This review describes studies on the diversity of β-glucosidases related to the classification, catalytic mechanisms, key molecular characteristics, kinetics models, and applications, and highlights several β-glucosidases displaying high stability, activity, and resistance to glucose inhibition suitable for desired biotechnological applications.
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Affiliation(s)
- Mehmet Emre Erkanli
- Department of Chemical and Biomolecular Engineering, New York University, 6 MetroTech Center, Brooklyn, NY 11201, United States
| | - Khalid El-Halabi
- Department of Chemical and Biomolecular Engineering, New York University, 6 MetroTech Center, Brooklyn, NY 11201, United States
| | - Jin Ryoun Kim
- Department of Chemical and Biomolecular Engineering, New York University, 6 MetroTech Center, Brooklyn, NY 11201, United States.
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Kim JR. Oligomerization by co-assembly of β-amyloid and α-synuclein. Front Mol Biosci 2023; 10:1153839. [PMID: 37021111 PMCID: PMC10067735 DOI: 10.3389/fmolb.2023.1153839] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Accepted: 03/07/2023] [Indexed: 04/07/2023] Open
Abstract
Aberrant self-assembly of an intrinsically disordered protein is a pathological hallmark of protein misfolding diseases, such as Alzheimer's and Parkinson's diseases (AD and PD, respectively). In AD, the 40-42 amino acid-long extracellular peptide, β-amyloid (Aβ), self-assembles into oligomers, which eventually aggregate into fibrils. A similar self-association of the 140 amino acid-long intracellular protein, α-synuclein (αS), is responsible for the onset of PD pathology. While Aβ and αS are primarily extracellular and intracellular polypeptides, respectively, there is evidence of their colocalization and pathological overlaps of AD and PD. This evidence has raised the likelihood of synergistic, toxic protein-protein interactions between Aβ and αS. This mini review summarizes the findings of studies on Aβ-αS interactions related to enhanced oligomerization via co-assembly, aiming to provide a better understanding of the complex biology behind AD and PD and common pathological mechanisms among the major neurodegenerative diseases.
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Chau E, Kim JR. α-synuclein-assisted oligomerization of β-amyloid (1-42). Arch Biochem Biophys 2022; 717:109120. [PMID: 35041853 PMCID: PMC8818042 DOI: 10.1016/j.abb.2022.109120] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Revised: 12/24/2021] [Accepted: 01/12/2022] [Indexed: 11/02/2022]
Abstract
Alzheimer's disease (AD) and Parkinson's disease (PD) are the two most common neurodegenerative disorders, characterized by aggregation of amyloid polypeptides, β-amyloid (Aβ) and α-synuclein (αS), respectively. Aβ and αS follow similar aggregation pathways, starting from monomers, to soluble toxic oligomeric assemblies, and to insoluble fibrils. Various studies have suggested overlaps in the pathologies of AD and PD, and have shown Aβ-αS interactions. Unfortunately, whether these protein-protein interactions lead to self- and co-assembly of Aβ and αS into oligomers - a potentially toxic synergistic mechanism - is poorly understood. Among the various Aβ isoforms, interactions of Aβ containing 42 amino acids (Aβ (1-42), referred to as Aβ42) with αS are of most direct relevance due to the high aggregation propensity and the strong toxic effect of this Aβ isoform. In this study, we carefully determined molecular consequences of interactions between Aβ42 and αS in their respective monomeric, oligomeric, and fibrillar forms using a comprehensive set of experimental tools. We show that the three αS conformers, namely, monomers, oligomers and fibrils interfered with fibrillization of Aβ42. Specifically, αS monomers and oligomers promoted oligomerization and stabilization of soluble Aβ42, possibly via direct binding or co-assembly, while αS fibrils hindered soluble Aβ42 species from converting into insoluble aggregates by the formation of large oligomers. We also provide evidence that the interactions with αS were mediated by various parts of Aβ42, depending on Aβ42 and αS conformers. Furthermore, we compared similarities and dissimilarities between Aβ42-αS and Aβ40-αS interactions. Overall, the present study provides a comprehensive depiction of the molecular interplay between Aβ42 and αS, providing insight into its synergistic toxic mechanism.
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Affiliation(s)
- Edward Chau
- Department of Chemical and Biomolecular Engineering, New York University, 6 MetroTech Center, Brooklyn, NY, 11201, USA
| | - Jin Ryoun Kim
- Department of Chemical and Biomolecular Engineering, New York University, 6 MetroTech Center, Brooklyn, NY, 11201, USA.
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Chau E, Kim JR. Engineering of a protein probe with multiple inputs and multiple outputs for evaluation of alpha synuclein aggregation states. Biochem Eng J 2022; 178:108292. [PMID: 35002469 PMCID: PMC8740893 DOI: 10.1016/j.bej.2021.108292] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The aggregation of α-synuclein (αS) into oligomers and fibrils is implicated in the pathology of Parkinson's Disease (PD). While a molecular probe for rapid and comprehensive evaluation of αS aggregation states is critical for a better understanding of PD pathology, identification of therapeutic candidates, and the development of early diagnostic strategies, no such probe has yet to be developed. A structurally flexible αS variant, PG65, was previously developed as a target binding-driven, conformation-switching molecular probe for rapid αS oligomer detection. Though informative, detection using PG65 provides no comprehensive assessment of the αS aggregation states. In the present study, we report engineering of a molecular probe, PG65-MIMO (a PG65 variant with Multiple-Inputs and Multiple-Outputs), that rapidly (within 2 hr) produces comprehensive information on αS aggregation states. PG65-MIMO generates distinct fluorescence responses to the three major αS conformers (monomers, oligomers, and fibrils). PG65-MIMO also displays unique fluorescent signals for αS oligomers, depending on the tris(2-carboxyethyl)phosphine (TCEP) concentration. Our results suggest that the TCEP dependent signaling of PG65-MIMO may be associated with its conformational states. Overall, our study illustrates engineering of an αS variant to create a molecular probe for handling multiple inputs and multiple outputs, addressing the technological gap in αS detection.
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Affiliation(s)
| | - Jin Ryoun Kim
- Corresponding author: Prof. Jin Ryoun Kim, Department of Chemical and Biomolecular Engineering, New York University, 6 MetroTech Center, Brooklyn, NY 11201, USA. Tel: 1-646-997-3719.
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Chau E, Kim H, Shin J, Martinez A, Kim JR. Inhibition of alpha-synuclein aggregation by AM17, a synthetic resveratrol derivative. Biochem Biophys Res Commun 2021; 574:85-90. [PMID: 34454326 DOI: 10.1016/j.bbrc.2021.08.049] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Revised: 07/29/2021] [Accepted: 08/18/2021] [Indexed: 10/20/2022]
Abstract
Parkinson's disease (PD) is linked to the aberrant self-assembly of the amyloid protein, α-synuclein (αS), where αS monomers aggregate to form oligomers and fibrils. Out of the three conformers, αS oligomers are the major toxic agents in PD, while αS fibrils may work as a reservoir for toxic oligomeric conformers. Thus, compounds that inhibit aggregation of αS monomers and disaggregate αS oligomers and fibrils may serve as therapeutic agents against PD. In this regard, resveratrol and its synthetic derivatives (e.g., AM17, which contains a copper ion-selective ionophoric motif) have previously been examined for their inhibitory effects on aggregation of amyloid proteins, such as the β-amyloid peptide implicated in Alzheimer's disease. In the current study, we employed an array of experimental tools, such as Thioflavin T fluorescence, transmission electron microscopy, immuno-dot blot assays, SDS- and native-PAGE, and circular dichroism, to determine the impact of AM17 and resveratrol on αS aggregation. To the best of our knowledge, we show for the first time that AM17 not only inhibits aggregation of αS monomers but also disaggregates αS oligomers and fibrils, independent of the copper ions. Similar αS aggregation inhibitory effects were observed with resveratrol only in the presence of the copper ion. The present study supports the high promise of applicability of AM17 as an effective amyloid aggregation inhibitor for various conformers and protein sequences.
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Affiliation(s)
- Edward Chau
- Department of Chemical and Biomolecular Engineering, New York University, 6 MetroTech Center, Brooklyn, NY, 11201, USA
| | - Hyunjoo Kim
- Department of Chemical and Biomolecular Engineering, New York University, 6 MetroTech Center, Brooklyn, NY, 11201, USA
| | - Jineun Shin
- Department of Biomedical Engineering, New York University, 6 MetroTech Center, Brooklyn, NY, 11201, USA
| | - Alberto Martinez
- Department of Chemistry, New York City College of Technology, 300 Jay St, Brooklyn, NY, 11201, USA
| | - Jin Ryoun Kim
- Department of Chemical and Biomolecular Engineering, New York University, 6 MetroTech Center, Brooklyn, NY, 11201, USA.
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Hemed-Shaked M, Cowman MK, Kim JR, Huang X, Chau E, Ovadia H, Amar KO, Eshkar-Sebban L, Melamed M, Lev LB, Kedar E, Armengol J, Alemany J, Beyth S, Okon E, Kanduc D, Elgavish S, Wallach-Dayan SB, Cohen SJ, Naor D. MTADV 5-MER peptide suppresses chronic inflammations as well as autoimmune pathologies and unveils a new potential target-Serum Amyloid A. J Autoimmun 2021; 124:102713. [PMID: 34390919 DOI: 10.1016/j.jaut.2021.102713] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2021] [Revised: 07/21/2021] [Accepted: 07/24/2021] [Indexed: 11/17/2022]
Abstract
Despite the existence of potent anti-inflammatory biological drugs e.g., anti-TNF and anti IL-6 receptor antibodies, for treating chronic inflammatory and autoimmune diseases, these are costly and not specific. Cheaper oral available drugs remain an unmet need. Expression of the acute phase protein Serum Amyloid A (SAA) is dependent on release of pro-inflammatory cytokines IL-1, IL-6 and TNF-α during inflammation. Conversely, SAA induces pro-inflammatory cytokine secretion, including Th17, leading to a pathogenic vicious cycle and chronic inflammation. 5- MER peptide (5-MP) MTADV (methionine-threonine-alanine-aspartic acid-valine), also called Amilo-5MER, was originally derived from a sequence of a pro-inflammatory CD44 variant isolated from synovial fluid of a Rheumatoid Arthritis (RA) patient. This human peptide displays an efficient anti-inflammatory effects to ameliorate pathology and clinical symptoms in mouse models of RA, Inflammatory Bowel Disease (IBD) and Multiple Sclerosis (MS). Bioinformatics and qRT-PCR revealed that 5-MP, administrated to encephalomyelytic mice, up-regulates genes contributing to chronic inflammation resistance. Mass spectrometry of proteins that were pulled down from an RA synovial cell extract with biotinylated 5-MP, showed that it binds SAA. 5-MP disrupted SAA assembly, which is correlated with its pro-inflammatory activity. The peptide MTADV (but not scrambled TMVAD) significantly inhibited the release of pro-inflammatory cytokines IL-6 and IL-1β from SAA-activated human fibroblasts, THP-1 monocytes and peripheral blood mononuclear cells. 5-MP suppresses the pro-inflammatory IL-6 release from SAA-activated cells, but not from non-activated cells. 5-MP could not display therapeutic activity in rats, which are SAA deficient, but does inhibit inflammations in animal models of IBD and MS, both are SAA-dependent, as shown by others in SAA knockout mice. In conclusion, 5-MP suppresses chronic inflammation in animal models of RA, IBD and MS, which are SAA-dependent, but not in animal models, which are SAA-independent.
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Affiliation(s)
- Maayan Hemed-Shaked
- The Lautenberg Center of Immunology and Cancer Research, Faculty of Medicine, Hebrew University of Jerusalem, Israel
| | - Mary K Cowman
- Department of Biomedical Engineering, Tandon School of Engineering, New York University, New York, NY, USA
| | - Jin Ryoun Kim
- Othmer-Jacobs Department of Chemical and Biomolecular Engineering, Tandon School of Engineering, Brooklyn, USA
| | - Xiayun Huang
- Othmer-Jacobs Department of Chemical and Biomolecular Engineering, Tandon School of Engineering, Brooklyn, USA
| | - Edward Chau
- Othmer-Jacobs Department of Chemical and Biomolecular Engineering, Tandon School of Engineering, Brooklyn, USA
| | - Haim Ovadia
- Department of Neurology, Agnes Ginges Center for Human Neurogenetics, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - Keren-Or Amar
- The Lautenberg Center of Immunology and Cancer Research, Faculty of Medicine, Hebrew University of Jerusalem, Israel
| | - Lora Eshkar-Sebban
- The Lautenberg Center of Immunology and Cancer Research, Faculty of Medicine, Hebrew University of Jerusalem, Israel
| | - Michal Melamed
- The Lautenberg Center of Immunology and Cancer Research, Faculty of Medicine, Hebrew University of Jerusalem, Israel
| | - Libat Bar Lev
- The Lautenberg Center of Immunology and Cancer Research, Faculty of Medicine, Hebrew University of Jerusalem, Israel
| | - Eli Kedar
- The Lautenberg Center of Immunology and Cancer Research, Faculty of Medicine, Hebrew University of Jerusalem, Israel
| | | | | | - Shaul Beyth
- Orthopedic Surgery Department, Hadassah University Hospital, Jerusalem, Israel
| | - Eli Okon
- Department of Pathology, Hadassah University Hospital, Jerusalem, Israel
| | - Darja Kanduc
- Biotechnologies and Biopharmaceutics, University of Bari, Bari, 70126, Italy
| | - Sharona Elgavish
- Bioinformatics Unit of the Hebrew University of Jerusalem and Hadassah Medical Center, Israel
| | - Shulamit B Wallach-Dayan
- Lung Cellular and Molecular Biology Laboratory, Institute of Pulmonary Medicine, Hadassah-Hebrew University Medical Center, Israel
| | - Shmuel Jaffe Cohen
- The Lautenberg Center of Immunology and Cancer Research, Faculty of Medicine, Hebrew University of Jerusalem, Israel
| | - David Naor
- The Lautenberg Center of Immunology and Cancer Research, Faculty of Medicine, Hebrew University of Jerusalem, Israel.
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Hwang HS, Park IY, Hong JI, Kim JR, Kim HA. Comparison of joint degeneration and pain in male and female mice in DMM model of osteoarthritis. Osteoarthritis Cartilage 2021; 29:728-738. [PMID: 33609695 DOI: 10.1016/j.joca.2021.02.007] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Revised: 01/13/2021] [Accepted: 02/08/2021] [Indexed: 02/02/2023]
Abstract
OBJECTIVE While the prevalence of radiographic and symptomatic osteoarthritis (OA) is higher in women, male mice are more frequently used in animal experiments to explore its pathogenesis or drug efficacy. In this study, we examined whether sexual dimorphism affects pain and joint degeneration in destabilization of the medial meniscus (DMM) mouse model. METHODS DMM or sham surgery was performed on the knee of male and female C57BL/6 mice. Joint damage was assessed by safranin O staining and scored using the Osteoarthritis Research Society International (OARSI) scoring system. Von Frey hair, incapacitance, and rotarod tests were conducted to measure joint pain. The analgesic effect of capsazepine (CPZ), a TRPV1 antagonist, was compared between male and female mice. RESULTS Histology and OARSI scoring analysis showed that cartilage degeneration developed, and progressed in both male and female DMM groups, however, damage was less severe in females at the late stage of OA. Pain behavior, as measured by mechanical allodynia, was displayed for longer in male DMM mice compared to females. Incapacitance data showed that CPZ significantly reduced DMM-induced pain in male mice but not in female mice. Immunofluorescence microscopy analysis demonstrated that DMM surgery increased the expression of TRPV1 in both female and male dorsal root ganglion (DRG). Injection of CPZ significantly suppressed TRPV1 expression in the DRG of male mice only. CONCLUSION Joint damage develops comparably in both female and male mice after DMM although it progresses less in females. There was a subtle sex difference in pain behaviors and analgesic efficacy of a TRPV1 antagonist, which was accompanied by a differential regulation of TPRV1.
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Affiliation(s)
- H S Hwang
- Division of Rheumatology, Department of Internal Medicine, Hallym University Sacred Heart Hospital, Kyunggi, 14068, South Korea; Institute for Skeletal Aging, Hallym University, Chunchon, 24251, South Korea
| | - I Y Park
- Division of Rheumatology, Department of Internal Medicine, Hallym University Sacred Heart Hospital, Kyunggi, 14068, South Korea; Institute for Skeletal Aging, Hallym University, Chunchon, 24251, South Korea
| | - J I Hong
- Division of Rheumatology, Department of Internal Medicine, Hallym University Sacred Heart Hospital, Kyunggi, 14068, South Korea; Institute for Skeletal Aging, Hallym University, Chunchon, 24251, South Korea
| | - J R Kim
- Division of Rheumatology, Department of Internal Medicine, Hallym University Sacred Heart Hospital, Kyunggi, 14068, South Korea; Institute for Skeletal Aging, Hallym University, Chunchon, 24251, South Korea
| | - H A Kim
- Division of Rheumatology, Department of Internal Medicine, Hallym University Sacred Heart Hospital, Kyunggi, 14068, South Korea; Institute for Skeletal Aging, Hallym University, Chunchon, 24251, South Korea.
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Candreva J, Chau E, Rice ME, Kim JR. Interactions between Soluble Species of β-Amyloid and α-Synuclein Promote Oligomerization while Inhibiting Fibrillization. Biochemistry 2019; 59:425-435. [PMID: 31854188 DOI: 10.1021/acs.biochem.9b00655] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Aggregations of β-amyloid (Aβ) and α-synuclein (αS) into oligomeric and fibrillar assemblies are the pathological hallmarks of Alzheimer's and Parkinson's diseases, respectively. Although Aβ and αS affect different regions of the brain and are separated at the cellular level, there is evidence of their eventual interaction in the pathology of both disorders. Characterization of interactions of Aβ and αS at various stages of their aggregation pathways could reveal mechanisms and therapeutic targets for the prevention and cure of these neurodegenerative diseases. In this study, we comprehensively examined the interactions and their molecular manifestations using an array of characterization tools. We show for the first time that αS monomers and oligomers, but not αS fibrils, inhibit Aβ fibrillization while promoting oligomerization of Aβ monomers and stabilizing preformed Aβ oligomers via coassembly, as judged by Thioflavin T fluorescence, transmission electron microscopy, and SDS- and native-PAGE with fluorescently labeled peptides/proteins. In contrast, soluble Aβ species, such as monomers and oligomers, aggregate into fibrils, when incubated alone under the otherwise same condition. Our study provides evidence that the interactions with αS soluble species, responsible for the effects, are mediated primarily by the C-terminus of Aβ, when judged by competitive immunoassays using antibodies recognizing various fragments of Aβ. We also show that the C-terminus of Aβ is a primary site for its interaction with αS fibrils. Collectively, these data demonstrate aggregation state-specific interactions between αS and Aβ and offer insight into a molecular basis of synergistic biological effects between the two polypeptides.
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Affiliation(s)
- Jason Candreva
- Department of Chemical and Biomolecular Engineering , New York University , 6 MetroTech Center , Brooklyn , New York 11201 , United States
| | - Edward Chau
- Department of Chemical and Biomolecular Engineering , New York University , 6 MetroTech Center , Brooklyn , New York 11201 , United States
| | - Margaret E Rice
- Departments of Neurosurgery, and Neuroscience and Physiology , New York University School of Medicine , New York , New York 10016 , United States
| | - Jin Ryoun Kim
- Department of Chemical and Biomolecular Engineering , New York University , 6 MetroTech Center , Brooklyn , New York 11201 , United States
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Charlton T, Shah V, Lynch T, Candreva J, Chau E, Yang Y, Kim H, Wood A, Kim JR. Amyloid Aggregation of Bacillus circulans Xylanase under Native Conditions and its Modulation by β-Amyloid-Derived Peptide Fragments. Chembiochem 2018; 19:2566-2574. [PMID: 30332530 DOI: 10.1002/cbic.201800472] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2018] [Revised: 10/13/2018] [Indexed: 12/31/2022]
Abstract
The aggregation of intrinsically disordered proteins into fibrils is implicated in many neurodegenerative diseases. Amyloid aggregation is a generic property of proteins as evidenced by globular proteins that often form amyloid aggregates under partially denaturing conditions. Recently, multiple lines of evidence have suggested that the amyloid aggregation of globular proteins can also occur under native conditions. Unfortunately, amyloid aggregation under native conditions has been demonstrated in only a handful of cases. Engineering a globular protein's amyloid aggregation might benefit from its fusion to an amyloid-derived fragment with reduced aggregation propensity. Unfortunately, the impacts of such fragments on the amyloid aggregation under native conditions have yet to be examined. In this study, we show that a globular protein, Bacillus circulans xylanase (BCX), can aggregate to form amyloid fibrils under native conditions. When BCX was mixed with or fused to the non-self-aggregating fragments, KLVFWAK and ELVFWAE-which were derived from β-amyloid (Aβ)-they modulated the BCX amyloid aggregation to differing extents. This study also provides insight into a correlation between the kinetic stability and amyloid aggregation of BCX, and supports a view that Aβ-derived fragments can be useful for the modulating amyloid aggregation of some, though not all, proteins.
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Affiliation(s)
- Timothy Charlton
- Department of Chemical and Biomolecular Engineering, New York University, 6 MetroTech Center, Brooklyn, NY, 11201, USA
| | - Vandan Shah
- Department of Chemical and Biomolecular Engineering, New York University, 6 MetroTech Center, Brooklyn, NY, 11201, USA
| | - Tonianna Lynch
- Department of Chemical and Biomolecular Engineering, New York University, 6 MetroTech Center, Brooklyn, NY, 11201, USA
| | - Jason Candreva
- Department of Chemical and Biomolecular Engineering, New York University, 6 MetroTech Center, Brooklyn, NY, 11201, USA
| | - Edward Chau
- Department of Chemical and Biomolecular Engineering, New York University, 6 MetroTech Center, Brooklyn, NY, 11201, USA
| | - YanXi Yang
- Department of Chemical and Biomolecular Engineering, New York University, 6 MetroTech Center, Brooklyn, NY, 11201, USA
| | - Hyunjoo Kim
- Department of Chemical and Biomolecular Engineering, New York University, 6 MetroTech Center, Brooklyn, NY, 11201, USA
| | - Amy Wood
- Department of Chemical and Biomolecular Engineering, New York University, 6 MetroTech Center, Brooklyn, NY, 11201, USA
| | - Jin Ryoun Kim
- Department of Chemical and Biomolecular Engineering, New York University, 6 MetroTech Center, Brooklyn, NY, 11201, USA
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Finch AJ, Kim JR. Thermophilic Proteins as Versatile Scaffolds for Protein Engineering. Microorganisms 2018; 6:microorganisms6040097. [PMID: 30257429 PMCID: PMC6313779 DOI: 10.3390/microorganisms6040097] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2018] [Revised: 09/23/2018] [Accepted: 09/23/2018] [Indexed: 01/18/2023] Open
Abstract
Literature from the past two decades has outlined the existence of a trade-off between protein stability and function. This trade-off creates a unique challenge for protein engineers who seek to introduce new functionality to proteins. These engineers must carefully balance the mutation-mediated creation and/or optimization of function with the destabilizing effect of those mutations. Subsequent research has shown that protein stability is positively correlated with "evolvability" or the ability to support mutations which bestow new functionality on the protein. Since the ultimate goal of protein engineering is to create and/or optimize a protein's function, highly stable proteins are preferred as potential scaffolds for protein engineering. This review focuses on the application potential for thermophilic proteins as scaffolds for protein engineering. The relatively high inherent thermostability of these proteins grants them a great deal of mutational robustness, making them promising scaffolds for various protein engineering applications. Comparative studies on the evolvability of thermophilic and mesophilic proteins have strongly supported the argument that thermophilic proteins are more evolvable than mesophilic proteins. These findings indicate that thermophilic proteins may represent the scaffold of choice for protein engineering in the future.
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Affiliation(s)
- Anthony J Finch
- Department of Chemical and Biomolecular Engineering, New York University, 6 MetroTech Center, Brooklyn, NY 11201, USA.
| | - Jin Ryoun Kim
- Department of Chemical and Biomolecular Engineering, New York University, 6 MetroTech Center, Brooklyn, NY 11201, USA.
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Abstract
Creation of a dual peptide system where beta-amyloid variants hetero-assemble but do not homo-assemble, sharing similarities with typical amyloid self-assemblies.
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Affiliation(s)
- Jason Candreva
- Chemical and Biomolecular Engineering
- New York University
- Brooklyn
- USA
| | - Edward Chau
- Chemical and Biomolecular Engineering
- New York University
- Brooklyn
- USA
| | - Edwin Aoraha
- Chemical and Biomolecular Engineering
- New York University
- Brooklyn
- USA
| | - Vikas Nanda
- Biochemistry and Molecular Biology
- Robert Wood Johnson Medical School
- Rutgers University
- USA
| | - Jin Ryoun Kim
- Chemical and Biomolecular Engineering
- New York University
- Brooklyn
- USA
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Shah V, Pierre B, Kirtadze T, Shin S, Kim JR. Stabilization of Bacillus circulans xylanase by combinatorial insertional fusion to a thermophilic host protein. Protein Eng Des Sel 2017; 30:281-290. [PMID: 28100651 DOI: 10.1093/protein/gzw081] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2016] [Accepted: 12/21/2016] [Indexed: 11/15/2022] Open
Abstract
High thermostability of an enzyme is critical for its industrial application. While many engineering approaches such as mutagenesis have enhanced enzyme thermostability, they often suffer from reduced enzymatic activity. A thermally stabilized enzyme with unchanged amino acids is preferable for subsequent functional evolution necessary to address other important industrial needs. In the research presented here, we applied insertional fusion to a thermophilic maltodextrin-binding protein from Pyrococcus furiosus (PfMBP) in order to improve the thermal stability of Bacillus circulans xylanase (BCX). Specifically, we used an engineered transposon to construct a combinatorial library of randomly inserted BCX into PfMBP. The library was then subjected to functional screening to identify successful PfMBP-BCX insertion complexes, PfMBP-BCX161 and PfMBP-BCX165, displaying substantially improved kinetic stability at elevated temperatures compared to unfused BCX and other controls. Results from subsequent characterizations were consistent with the view that lowered aggregation of BCX and reduced conformational flexibility at the termini was responsible for increased thermal stability. Our stabilizing approach neither sacrificed xylanase activity nor required changes in the BCX amino acid sequence. Overall, the current study demonstrated the benefit of combinatorial insertional fusion to PfMBP as a systematic tool for the creation of enzymatically active and thermostable BCX variants.
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Affiliation(s)
- Vandan Shah
- Othmer-Jacobs Department of Chemical and Biomolecular Engineering, New York University, 6 MetroTech Center, Brooklyn, NY 11201, USA
| | - Brennal Pierre
- Othmer-Jacobs Department of Chemical and Biomolecular Engineering, New York University, 6 MetroTech Center, Brooklyn, NY 11201, USA
| | - Tamari Kirtadze
- Othmer-Jacobs Department of Chemical and Biomolecular Engineering, New York University, 6 MetroTech Center, Brooklyn, NY 11201, USA
| | - Seung Shin
- Othmer-Jacobs Department of Chemical and Biomolecular Engineering, New York University, 6 MetroTech Center, Brooklyn, NY 11201, USA
| | - Jin Ryoun Kim
- Othmer-Jacobs Department of Chemical and Biomolecular Engineering, New York University, 6 MetroTech Center, Brooklyn, NY 11201, USA
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Grillakis AA, Pichard L, Kim JR, Yarnell AM. 1066 DIFFERENCES PERSIST IN SLEEP QUANTITY BETWEEN HEALTHY CONTROLS AND CONCUSSED INDIVIDUALS 3–12 MONTHS POST-INJURY. Sleep 2017. [DOI: 10.1093/sleepj/zsx050.1065] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Abstract
Protein insertional fusion and circular permutation are 2 promising protein engineering techniques for creating integrated functionalities and sequence diversity of a protein, respectively. Finding insertion locations for protein insertional fusion and new termini for circular permutation through a rational approach is not always straightforward, especially, for proteins without detailed structural knowledge. On the contrary, a combinatorial approach facilitates a comprehensive search to evaluate all potential insertion sites and new termini locations. Conventional methods used to create random insertional fusion libraries generate sub-optimal inter-domain linker length and composition between fused proteins. There are also methods available for construction of random circular permutation libraries. However, these methods too, impose many drawbacks, such as significant sequence modification at the new termini of circular permutants and additionally, require re-design of transposons for tailored expression of circular permutants. Furthermore, these conventional methods employ relatively inefficient blunt-end ligation during library construction. In this commentary, we present a concise overview and key findings of engineered Mu transposons, which have recently been developed in our group as a facile and efficient tool to alleviate limitations realized from conventional methods and to construct high quality libraries for random insertional fusion and random circular permutation.
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Affiliation(s)
- Vandan Shah
- Othmer-Jacobs Department of Chemical and Biomolecular Engineering, New York University , Brooklyn, NY, USA
| | - Jin Ryoun Kim
- Othmer-Jacobs Department of Chemical and Biomolecular Engineering, New York University , Brooklyn, NY, USA
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Shirke AN, Su A, Jones JA, Butterfoss GL, Koffas MA, Kim JR, Gross RA. Comparative thermal inactivation analysis ofAspergillus oryzaeandThiellavia terrestriscutinase: Role of glycosylation. Biotechnol Bioeng 2016; 114:63-73. [DOI: 10.1002/bit.26052] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2016] [Revised: 07/01/2016] [Accepted: 07/11/2016] [Indexed: 12/11/2022]
Affiliation(s)
- Abhijit N. Shirke
- Department of Chemistry and Chemical Biology; Rensselaer Polytechnic Institute; Troy New York
- Center for Biotechnology and Interdisciplinary Studies; Rensselaer Polytechnic Institute; Troy New York
| | - An Su
- Department of Chemistry and Chemical Biology; Rensselaer Polytechnic Institute; Troy New York
- Center for Biotechnology and Interdisciplinary Studies; Rensselaer Polytechnic Institute; Troy New York
| | - J. Andrew Jones
- Center for Biotechnology and Interdisciplinary Studies; Rensselaer Polytechnic Institute; Troy New York
- Department of Chemical and Biological Engineering; Rensselaer Polytechnic Institute; Troy New York
| | - Glenn L. Butterfoss
- Center for Genomics and Systems Biology; New York University Abu Dhabi; Abu Dhabi UAE
| | - Mattheos A.G. Koffas
- Center for Biotechnology and Interdisciplinary Studies; Rensselaer Polytechnic Institute; Troy New York
- Department of Chemical and Biological Engineering; Rensselaer Polytechnic Institute; Troy New York
| | - Jin Ryoun Kim
- Department of Chemical and Biomolecular Engineering; New York University Tandon School of Engineering; Brooklyn New York
| | - Richard A. Gross
- Department of Chemistry and Chemical Biology; Rensselaer Polytechnic Institute; Troy New York
- Center for Biotechnology and Interdisciplinary Studies; Rensselaer Polytechnic Institute; Troy New York
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17
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Pierre B, Labonte JW, Xiong T, Aoraha E, Williams A, Shah V, Chau E, Helal KY, Gray JJ, Kim JR. Molecular Determinants for Protein Stabilization by Insertional Fusion to a Thermophilic Host Protein. Chembiochem 2015; 16:2392-402. [DOI: 10.1002/cbic.201500310] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2015] [Indexed: 12/26/2022]
Affiliation(s)
- Brennal Pierre
- Othmer-Jacobs Department of Chemical and Biomolecular Engineering; New York University; 6 MetroTech Center Brooklyn NY 11201 USA
| | - Jason W. Labonte
- Department of Chemical and Biomolecular Engineering; Johns Hopkins University; 3400 North Charles Street Baltimore MD 21218 USA
| | - Tina Xiong
- Othmer-Jacobs Department of Chemical and Biomolecular Engineering; New York University; 6 MetroTech Center Brooklyn NY 11201 USA
- Department of Chemical and Biomolecular Engineering; Johns Hopkins University; 3400 North Charles Street Baltimore MD 21218 USA
| | - Edwin Aoraha
- Othmer-Jacobs Department of Chemical and Biomolecular Engineering; New York University; 6 MetroTech Center Brooklyn NY 11201 USA
| | - Asher Williams
- Othmer-Jacobs Department of Chemical and Biomolecular Engineering; New York University; 6 MetroTech Center Brooklyn NY 11201 USA
| | - Vandan Shah
- Othmer-Jacobs Department of Chemical and Biomolecular Engineering; New York University; 6 MetroTech Center Brooklyn NY 11201 USA
| | - Edward Chau
- Othmer-Jacobs Department of Chemical and Biomolecular Engineering; New York University; 6 MetroTech Center Brooklyn NY 11201 USA
| | - Kazi Yasin Helal
- Othmer-Jacobs Department of Chemical and Biomolecular Engineering; New York University; 6 MetroTech Center Brooklyn NY 11201 USA
| | - Jeffrey J. Gray
- Department of Chemical and Biomolecular Engineering; Johns Hopkins University; 3400 North Charles Street Baltimore MD 21218 USA
| | - Jin Ryoun Kim
- Othmer-Jacobs Department of Chemical and Biomolecular Engineering; New York University; 6 MetroTech Center Brooklyn NY 11201 USA
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18
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Pierre B, Shah V, Xiao J, Kim JR. Construction of a random circular permutation library using an engineered transposon. Anal Biochem 2015; 474:16-24. [DOI: 10.1016/j.ab.2014.12.011] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2014] [Revised: 12/12/2014] [Accepted: 12/16/2014] [Indexed: 02/01/2023]
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Abstract
A non-self-aggregating peptide ligand for β-amyloid aggregates created by simple point mutation of an β-amyloid-derived segment.
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Affiliation(s)
- Edwin Aoraha
- Othmer-Jacobs Department of Chemical and Biomolecular Engineering
- New York University
- Brooklyn
- USA
| | - Jason Candreva
- Othmer-Jacobs Department of Chemical and Biomolecular Engineering
- New York University
- Brooklyn
- USA
| | - Jin Ryoun Kim
- Othmer-Jacobs Department of Chemical and Biomolecular Engineering
- New York University
- Brooklyn
- USA
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20
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Abstract
Changes in diffusive movements, surface potential, and interfacial impedance of DNA monolayers are combined to analyze binding of unlabeled transcription factors.
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Affiliation(s)
- Keeshan Williams
- Department of Chemical & Biomolecular Engineering
- Polytechnic Institute of New York University
- Brooklyn, USA
| | - Chung-Sei Kim
- Department of Chemical & Biomolecular Engineering
- Polytechnic Institute of New York University
- Brooklyn, USA
| | - Jin Ryoun Kim
- Department of Chemical & Biomolecular Engineering
- Polytechnic Institute of New York University
- Brooklyn, USA
| | - Rastislav Levicky
- Department of Chemical & Biomolecular Engineering
- Polytechnic Institute of New York University
- Brooklyn, USA
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21
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Sun JM, Kim JR, Do IG, Lee SY, Lee J, Choi YL, Ahn JS, Ahn MJ, Park K. A phase-1b study of everolimus plus paclitaxel in patients with small-cell lung cancer. Br J Cancer 2013; 109:1482-7. [PMID: 23963141 PMCID: PMC3776982 DOI: 10.1038/bjc.2013.467] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2013] [Revised: 07/12/2013] [Accepted: 07/21/2013] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND The mammalian target of rapamycin (mTOR) pathway is dysregulated in small-cell lung cancer (SCLC) and everolimus is an oral mTOR inhibitor. METHODS This phase-1b study assessed everolimus safety at the levels of 2.5, 5, or 10 mg once daily in combination with paclitaxel (175 mg m(-2)) once every 3 weeks in previously treated SCLC patients. The primary end point was to determine the maximum tolerated dose of everolimus. RESULTS Among 21 enrolled patients, common drug-related adverse events were anaemia, neutropenia, thrombocytopenia, pain, hyperglycemia, and stomatitis. Out of 11 evaluable patients treated with everolimus at the level of 5 mg, 1 patient experienced dose-limiting toxicity (DLT) of grade 4 febrile neutropenia and grade 3 thrombocytopenia. The other two DLTs (grade 4 thrombocytopenia and grade 3 hyperglycemia) occurred in two out of three patients receiving everolimus 10 mg. The overall objective response rate was 28%. CONCLUSION Everolimus showed an acceptable safety profile and preliminary antitumour activity at the dose of 5 mg once daily when combined with 3-weekly paclitaxel 175 mg m(-2) in patients with SCLC.
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Affiliation(s)
- J M Sun
- Division of Hematology-Oncology, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Irwon-dong, Gangnam-gu, Seoul 135-710, Korea
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22
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Yuan H, Tank M, Alsofyani A, Shah N, Talati N, LoBello JC, Kim JR, Oonuki Y, de la Motte CA, Cowman MK. Molecular mass dependence of hyaluronan detection by sandwich ELISA-like assay and membrane blotting using biotinylated hyaluronan binding protein. Glycobiology 2013; 23:1270-80. [PMID: 23964097 DOI: 10.1093/glycob/cwt064] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Hyaluronan (HA) is widely detected in biological samples and its concentration is most commonly determined by the use of a labeled specific HA binding protein (aggrecan G1-IGD-G2, HABP), employing membrane blotting and sandwich enzyme-linked immunosorbent assay (ELISA)-like methods. However, the detected signal intensity or the quantified value obtained by using these surface-based methods is related to the molecular mass (M) of HA, especially for HA in the low M range below ~150 kDa. At the same mass or mass concentration, higher M HA gives a higher signal than lower M HA. We have experimentally determined the quantitative relationship between the M of HA (in the range 20-150 kDa) and the relative signal intensity in comparison with a standard HA, in a sandwich ELISA-like assay. An M-dependent signal correction factor (SCF) was calculated and used to correct the signal intensity, so that the corrected concentration value would more accurately reflect the true HA concentration in solution. The SCF for polydisperse low M HA was also calculated and compared with experimental results. When the molecular mass distribution of an HA sample is determined by a method such as gel electrophoresis, then its appropriately averaged SCF can be calculated and used to correct the signal in sandwich ELISA to obtain a more accurate concentration estimation. The correction method works for HA with M between ~150 and 20 kDa, but lower M HA is too poorly detected for useful analysis. The physical basis of the M-dependent detection is proposed to be the increase in detector-accessible fraction of each surface-bound molecule as M increases.
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Affiliation(s)
- Han Yuan
- Department of Chemical and Biomolecular Engineering, Polytechnic Institute of New York University, 6 Metrotech Center, Brooklyn, NY 11201, USA
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23
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Cho JE, Kim JR. Recent approaches targeting beta-amyloid for therapeutic intervention of Alzheimer's disease. ACTA ACUST UNITED AC 2013; 6:222-33. [PMID: 21834780 DOI: 10.2174/157488911796958002] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2011] [Accepted: 05/17/2011] [Indexed: 11/22/2022]
Abstract
Alzheimer's disease (AD) is a neurodegenerative disorder characterized by neuropathological features comprising amyloid deposits and neuronal losses in brain. In AD, aggregation of a β amyloid peptide (Aβ), produced from proteolytic cleavage of amyloid precursor protein, is believed to be implicated in the pathophysiological cascade leading to neuronal death. Most AD drugs currently available can only alleviate symptoms rather than modify the underlying molecular cause of AD. In this review, we describe and discuss the recent patents issued within the past two years focusing on therapeutic interventions targeting at various Aβ-associated pathological mechanisms of AD. The described therapeutic strategies include 1) reduction of synthesis of Aβ, 2) inhibition of Aβ aggregation, 3) immunotherapeutic/enzymatic clearance of Aβ, 4) targeting other amyloidogenic proteins interacting with Aβ and 5) amelioration of Aβ downstream toxic effects. Important issues to be considered for further improvement of therapeutic efficacy of these approaches are also discussed.
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Affiliation(s)
- Jung-Eun Cho
- Othmer-Jacobs Department of Chemical and Biological Engineering, Polytechnic Institute of New York University, 6 MetroTech Center, Brooklyn, NY 11201, USA
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24
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Hernandez M, Hu Y, Kim JR. A conformation-switching fluorescent protein probe for detection of alpha synuclein oligomers. Chem Commun (Camb) 2013; 49:10712-4. [DOI: 10.1039/c3cc44804e] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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25
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Michie IS, Kim JR, Dinsdale RM, Guwy AJ, Premier GC. Factors affecting microbial fuel cell acclimation and operation in temperate climates. Water Sci Technol 2013; 67:2568-2575. [PMID: 23752390 DOI: 10.2166/wst.2013.159] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
For the successful scale-up of microbial fuel cell (MFC) systems, enrichment strategies are required that not only maximise reactor performance but also allow anodic biofilms to be robust to environmental change. Cluster analysis of Denaturing Gradient Gel Electrophoresis community fingerprints showed that anodic biofilms were enriched according to substrate type and temperature. Acetate produced the highest power density of 7.2 W m(-3) and butyrate the lowest at 0.29 W m(-3), but it was also found that the trophic conditions used to acclimate the electrogenic biofilms also determined the MFC response to different substrate types, with both acetate and butyrate substrates recording power densities of 1.07 and 1.0 W m(-3) respectively in a sucrose enriched reactor. When temperature perturbations were introduced to investigate the stability of the different substrate acclimated electrogenic biofilms, the 20 °C acclimated acetate reactor was unaffected by 10 °C operation but all reactors acclimated at 35 °C were adversely affected. When the operating temperature was raised back to 35 °C both the acetate and butyrate reactors recovered electrogenic activity but the sucrose reactor did not. It is thought that this was due to the more complex syntropic interactions that are required to occur when metabolising more complex substrate types.
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Affiliation(s)
- I S Michie
- Faculty of Health, Sport and Science, Sustainable Environment Research Centre SERC, University of Glamorgan, Pontypridd, Mid-Glamorgan, CF37 1DL, UK.
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Shah V, Pierre B, Kim JR. Facile construction of a random protein domain insertion library using an engineered transposon. Anal Biochem 2012; 432:97-102. [PMID: 23026779 DOI: 10.1016/j.ab.2012.09.030] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2012] [Revised: 09/14/2012] [Accepted: 09/21/2012] [Indexed: 01/20/2023]
Abstract
Insertional fusion between multiple protein domains represents a novel means of creating integrated functionalities. Currently, there is no robust guideline for selection of insertion sites ensuring the desired functional outcome of insertional fusion. Therefore, construction and testing of random domain insertion libraries, in which a host protein domain is randomly inserted into a guest protein domain, significantly benefit extensive exploration of sequence spaces for insertion sites. Short peptide residues are usually introduced between protein domains to alleviate structural conflicts, and the interdomain linker residues may affect the functional outcome of protein insertion complexes. Unfortunately, optimal control of interdomain linker residues is not always available in conventional methods used to construct random domain insertion libraries. Moreover, most conventional methods employ blunt-end rather than sticky-end ligation between host and guest DNA fragments, thus lowering library construction efficiency. Here, we report the facile construction of random domain insertion libraries using an engineered transposon. We show that random domain insertion with optimal control of interdomain linker residues was possible with our engineered transposon-based method. In addition, our method employs sticky-end rather than blunt-end ligation between host and guest DNA fragments, thus allowing for facile construction of relatively large sized libraries.
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Affiliation(s)
- Vandan Shah
- Othmer-Jacobs Department of Chemical and Biomolecular Engineering, Polytechnic Institute of New York University, Brooklyn, NY 11201, USA
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27
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Hu Y, Zheng H, Su B, Hernandez M, Kim JR. Modulation of beta-amyloid aggregation by engineering the sequence connecting beta-strand forming domains. Biochim Biophys Acta 2012; 1824:1069-79. [PMID: 22709576 DOI: 10.1016/j.bbapap.2012.06.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2012] [Revised: 06/04/2012] [Accepted: 06/08/2012] [Indexed: 11/15/2022]
Abstract
Aggregation of beta-amyloid (Aβ) into oligomers and fibrils is associated with the pathology of Alzheimer's disease. The major structural characteristics of Aβ fibrils include the presence of β sheet-loop-β sheet conformations. Several lines of study suggested a potentially important role of the Aβ loop forming sequence (referred to as the Aβ linker region) in Aβ aggregation. Effects of mutations in several charged residues within the Aβ linker region on aggregation have been extensively studied. However, little is known about oligomerization effects of sequence variation in other residues within the Aβ linker region. Moreover, modulation effects of the Aβ linker mutants on Aβ aggregation have yet to be characterized. Here, we created and characterized Aβ linker variants containing sequences preferentially found in specific β turn conformations. Our results indicate that a propensity to form oligomers may be changed by local sequence variation in the Aβ linker region without mutating the charged residues. Strikingly, one Aβ linker variant rapidly formed protofibrillar oligomers, which did not convert to fibrillar aggregates in contrast to Aβ aggregating to fibrils under similar incubation conditions. Moreover, our results suggest that molecular forces critical in oligomerization and fibrillization may differ at least for those involved in the linker region. When co-incubated with Aβ, some Aβ linker variants were found to induce accumulation of Aβ oligomers. Our results suggest that engineering of the Aβ linker region as described in this paper may represent a novel approach to control Aβ oligomerization and create Aβ oligomerization modulators.
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Affiliation(s)
- Yang Hu
- Othmer-Jacobs Department of Chemical and Biological Engineering, Polytechnic Institute of New York University, 6 MetroTech Center, Brooklyn, NY 11201, USA
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Hernandez M, Golbert S, Zhang LG, Kim JR. Creation of aggregation-defective α-synuclein variants by engineering the sequence connecting β-strand-forming domains. Chembiochem 2011; 12:2630-9. [PMID: 21998035 DOI: 10.1002/cbic.201100430] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2011] [Indexed: 12/18/2022]
Abstract
The aggregation of α-synuclein (αS), which is implicated in the pathology of Parkinson's disease, produces fibrils in which layers of parallel, in-register β-sheet-loop-β-sheets are formed. The effects of sequence variation in the loop-forming region (referred to as the linker region) on αS aggregation have yet to be systematically studied. In the study described here, we created and characterized αS variants containing mutations in the linker regions. Our results indicate that although the physicochemical properties of the linker region, evaluated based on an intrinsic property of a single amino acid, still play a significant role in aggregation, additional factors can also determine aggregation of αS linker mutants. Our analyses suggest that these factors include a pairwise potential for parallel in-register β-sheet formation. A linker variant displaying significantly reduced self-aggregation interfered with αS aggregation by inhibiting the conversion of αS soluble species to αS insoluble fibrils. We anticipate that linker mutations could serve as a novel method of creating αS variants that are aggregation-defective and/or inhibit αS aggregation.
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Affiliation(s)
- Michael Hernandez
- Othmer-Jacobs Department of Chemical and Biological Engineering, Polytechnic Institute of New York University, 6 MetroTech Center, Brooklyn, NY 11201, USA
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Ahn JH, Hu Y, Hernandez M, Kim JR. Crocetin inhibits beta-amyloid fibrillization and stabilizes beta-amyloid oligomers. Biochem Biophys Res Commun 2011; 414:79-83. [DOI: 10.1016/j.bbrc.2011.09.025] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2011] [Accepted: 09/03/2011] [Indexed: 10/17/2022]
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31
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Guwy AJ, Dinsdale RM, Kim JR, Massanet-Nicolau J, Premier G. Fermentative biohydrogen production systems integration. Bioresour Technol 2011; 102:8534-8542. [PMID: 21621996 DOI: 10.1016/j.biortech.2011.04.051] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/26/2011] [Revised: 04/12/2011] [Accepted: 04/16/2011] [Indexed: 05/30/2023]
Abstract
Acidogenic fermentation can be used to produce hydrogen from a range of biomass sources. The effluent from this process can be utilised in a number of biological processes enabling further recovery of energy from the biomass. In this review a number of candidate technologies are assessed including conventional methanogenic anaerobic digestion, dark fermentative hydrogen production, photo-fermentation, and bioelectrochemical systems. The principles, benefits and challenges associated with integrating these technologies are discussed, with particular emphasis on integration with fermentative hydrogen production, and the current state of integrative development is presented. The various system configurations for potential integrations presented here may simultaneously permit an increase in the conversion efficiency of biomass to energy, improved adaptability to varying operating conditions, and improved stability. Such integration, while increasing system complexity, may mean that these bioprocesses could be deployed in a wider range of scenarios and be used with a greater range of substrates.
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Affiliation(s)
- A J Guwy
- The Sustainable Environment Research Centre, Faculty of Health, Sport and Science, University of Glamorgan, Pontypridd, Mid. Glamorgan CF37 1DL, UK.
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Hu Y, Su B, Kim CS, Hernandez M, Rostagno A, Ghiso J, Kim JR. A strategy for designing a peptide probe for detection of β-amyloid oligomers. Chembiochem 2011; 11:2409-18. [PMID: 21031399 DOI: 10.1002/cbic.201000435] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Aggregation of β-amyloid (Aβ) is implicated in the pathology of Alzheimer's disease. Development of a robust strategy to detect Aβ oligomeric intermediates, which have been identified as significant toxic agents, would be highly beneficial in the screening of drug candidates as well as enhancing our understanding of Aβ oligomerization. Rapid, specific and quantitative detection, currently unavailable, would be highly preferred for accurate and reliable probing of transient Aβ oligomers. Here, we report the development of a novel peptide probe, PG46, based on the nature of Aβ self-assembly and the conformation-sensitive fluorescence of the biarsenical dye, FlAsH. PG46 was found to bind to Aβ oligomers and displayed an increase in FlAsH fluorescence upon binding. No such event was observed when PG46 was co-incubated with Aβ low-molecular-weight species or Aβ fibrils. Aβ oligomer detection was fast, and occurred within one hour without any additional sample incubation or preparation. We anticipate that the development of a strategy for detection of amyloid oligomers described in this study will be directly relevant to a host of other amyloidogenic proteins.
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Affiliation(s)
- Yang Hu
- Othmer-Jacobs Department of Chemical and Biological Engineering, Polytechnic Institute of New York University, 6 MetroTech Center, Brooklyn, NY 11201, USA
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Pierre B, Xiong T, Hayles L, Guntaka VR, Kim JR. Stability of a guest protein depends on stability of a host protein in insertional fusion. Biotechnol Bioeng 2011; 108:1011-20. [DOI: 10.1002/bit.23039] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2010] [Revised: 11/03/2010] [Accepted: 12/06/2010] [Indexed: 11/11/2022]
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Kim JR, Mathew SO, Patel RK, Pertusi RM, Mathew PA. Altered expression of signalling lymphocyte activation molecule (SLAM) family receptors CS1 (CD319) and 2B4 (CD244) in patients with systemic lupus erythematosus. Clin Exp Immunol 2010; 160:348-58. [PMID: 20345977 DOI: 10.1111/j.1365-2249.2010.04116.x] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
CS1 (CRACC, CD319) and 2B4 (CD244), members of the signalling lymphocyte activation molecule (SLAM) family receptors, regulate various immune functions. Genes encoding SLAM family receptors are located at 1q23, implicated in systemic lupus erythematosus (SLE). In this study, we have investigated the expression and alternative splicing of CS1 and 2B4 in immune cells from SLE patients. The surface expression of CS1 and 2B4 on total peripheral blood mononuclear cells (PBMCs), T, B, natural killer (NK) cells and monocytes in 45 patients with SLE and 30 healthy individuals was analysed by flow cytometry. CS1-positive B cell population was increased significantly in SLE patients. Because CS1 is a self-ligand and homophilic interaction of CS1 induces B cell proliferation and autocrine cytokine secretion, this could account for autoreactive B cell proliferation in SLE. The proportion of NK cells and monocytes expressing 2B4 on their surface was significantly lower in patients with SLE compared to healthy controls. Our study demonstrated altered expression of splice variants of CS1 and 2B4 that mediate differential signalling in PBMC from patients with SLE.
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Affiliation(s)
- J R Kim
- Department of Molecular Biology and Immunology and Institute for Cancer Research, University of North Texas Health Science Center, Fort Worth, TX 76107-2699, USA
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Kim YK, Yiu CKY, Kim JR, Gu L, Kim SK, Weller RN, Pashley DH, Tay FR. Failure of a glass ionomer to remineralize apatite-depleted dentin. J Dent Res 2010; 89:230-5. [PMID: 20110510 DOI: 10.1177/0022034509357172] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Remineralization of demineralized dentin lesions adjacent to glass-ionomer cements (GICs) has been reported in the literature. This study tested the hypothesis that a strontium-based GIC can remineralize completely demineralized dentin by nucleation of new apatite crystallites within an apatite-free dentin matrix. Human dentin specimens were acid-etched, bonded with Fuji IX(GP), and immersed in a calcium-and-phosphate-containing 1.5X simulated body fluid (SBF) for 1-4 months. Polyacrylic acid and polyvinylphosphonic acid biomimetic analogs were added to the SBFs to create 2 additional remineralization media. Specimens were processed by transmission electron microscopy (TEM). No apatite deposition could be identified in the completely demineralized dentin in any of the specimens immersed in the 3 remineralization media, despite TEM/EDX evidence of diffusion of ions specific to the strontium-based GIC into the demineralized dentin. The hypothesis was rejected; mineral concentration alone is not a sufficient endpoint for assessing the success of contemporary remineralization strategies.
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Affiliation(s)
- Y K Kim
- Department of Conservative Dentistry, School of Dentistry, Kyungpook National University, Daegu, Korea
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36
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Kim G, Kim H, Kim IJ, Kim JR, Lee JI, Ree M. Bacterial adhesion, cell adhesion and biocompatibility of Nafion films. J Biomater Sci Polym Ed 2009; 20:1687-707. [PMID: 19723436 DOI: 10.1163/156856208x386273] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
We investigated bioadhesion (bacterial and cell adhesion) and biocompatibility of poly(tetrafluoroethylene-co-perfluoro-3,6-dioxa-4-methyl-7-octenesulfonic acid) (Nafion) and compared the results with those obtained with poly(vinylidene fluoride-co-hexafluoropropylene) (PVFHFP). When incubated with bacteria for 4 h to 7 days, Nafion film exhibited scarce bacterial adhesion at 6 h, after which the adhesion gradually increasing to relatively low levels. In contrast, significant bacterial adhesion to PVFHFP film was observed at 4 h, and much higher adhesion levels were shown thereafter. Although HEp-2 human cells adhered normally to both films, reaching confluence in 7-8 days, the cells adhered to Nafion appeared more lively and stable than those to PVFHFP. Subcutaneous implantation in mice revealed that Nafion elicited a mild acute inflammatory reaction without chronic inflammation or tissue necrosis, indicating excellent biocompatibility in mice. PVFHFP, however, provoked a moderate and prolonged acute inflammatory response. These differences in the biological characteristics of Nafion and PVFHFP films may be attributable to the differences in the chemical and physical natures of these polymer films. Nafion film provided a sufficiently solid support, expressing a high surface charge density and good water-wettability. In summary, Nafion is suitable for use in biomedical applications that require biocompatibility with a reduced possibility of post-operative infections.
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Affiliation(s)
- G Kim
- Department of Chemistry, Pohang University of Science and Technology, Pohang 790-784, South Korea
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Khapli S, Kim JR, Montclare JK, Levicky R, Porfiri M, Sofou S. Frozen cyclohexane-in-water emulsion as a sacrificial template for the synthesis of multilayered polyelectrolyte microcapsules. Langmuir 2009; 25:9728-9733. [PMID: 19507842 DOI: 10.1021/la901020j] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
This paper reports the application of frozen cyclohexane-in-water emulsions as sacrificial templates for the fabrication of hollow microcapsules through layer-by-layer assembly of polyelectrolytes, poly(styrenesulfonate sodium salt), and poly(allylamine hydrochloride). Extraction of the cyclohexane phase from frozen emulsions stabilized with 11 polyelectrolyte layers by compatibilization with 30% v/v ethanol leads to the formation of water-filled microcapsules while preserving the spherical geometry. The majority of microcapsules (>90%) are prepared with intact polyelectrolyte membranes as measured by their deformation induced by osmotic pressure. This work provides a new route for the synthesis of hollow multilayered microcapsules under mild operating conditions.
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Affiliation(s)
- Sachin Khapli
- Center for Co-operative Bioactive Systems, Polytechnic Institute of New York University (NYU-POLY), 6 Metrotech Center, Brooklyn, New York 11201, USA.
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Ryoo NH, Ha JS, Jeon DS, Kim JR, Hwang EA. Alternaria peritonitis after contact with a cat. Perit Dial Int 2009; 29:235-236. [PMID: 19293364] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/27/2023] Open
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39
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Jun HS, Kim IK, Lee HJ, Lee HJ, Kang JH, Kim JR, Shin HD, Song J. Effects of UCP2 and UCP3 variants on the manifestation of overweight in Korean children. Obesity (Silver Spring) 2009; 17:355-62. [PMID: 19039313 DOI: 10.1038/oby.2008.531] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
To investigate the associations of uncoupling protein (UCP)2 and UCP3 gene variants with overweight and related traits, we genotyped UCP2-866G>A, UCP2Ala55Val, and UCP3-55C>T in 737 Korean children and 732 adults and collected data regarding anthropometric status and blood biochemistry. Information concerning the children's lifestyles and dietary habits was collected. The UCP2-866G>A and UCP3-55C>T gene variants showed significant associations with BMI level, waist circumference, and body weight in the children but not in the adults. Compared with -866GG carriers, the -866GA and AA carriers showed a strong decreasing trend in the risk for overweight (odds ratio (OR), 0.67; 95% confidence interval (CI), 0.45-1.01; P = 0.053). In comparison with UCP3-55CC carriers, children carrying -55CT and TT showed a significant reduction in the risk of overweight (OR, 0.67; 95% CI, 0.46-0.98; P = 0.039). There was also evidence of interactions between the effects of the combined UCP2-UCP3 genotype and obesity-related metabolic traits. The greatest protective effect against overweight was seen in those with the combined genotype non-UCP2-866GG and non-UCP3-55CC, as compared with those carrying both UCP2-866GG and UCP3-55CC (OR,0.60; 95% CI, 0.38-0.95; P = 0.030). In the subgroup with a low level of physical activity, UCP3-55CC carriers had higher BMI values than UCP3-55T carriers (16.6 +/- 2.3 kg/m(2) vs. 16.1 +/- 1.9 kg/m(2), P = 0.016). Low physical activity may aggravate the susceptibility to overweight in UCP2-866GG and UCP3-55CC carriers.
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Affiliation(s)
- H S Jun
- Division of Metabolic Diseases, Center for Biomedical Sciences, Korean National Institute of Health, Seoul, Republic of Korea
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Moon TS, Kim YJ, Kim JR, Cha JH, Kim DH, Kim CW. Identification of process operating state with operational map in municipal wastewater treatment plant. J Environ Manage 2009; 90:772-778. [PMID: 18313199 DOI: 10.1016/j.jenvman.2008.01.008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2007] [Revised: 12/18/2007] [Accepted: 01/14/2008] [Indexed: 05/26/2023]
Abstract
This work was performed to develop an operational map for the objective diagnosis of the process operating states of a municipal wastewater treatment plant, for which multivariate statistical analysis techniques were applied. PCA (principal component analysis) was used to reduce the dimension of the data sets obtained from the field municipal wastewater treatment plant. A K-means clustering analysis was used to classify the group according to the property of the process operating state. A Fisher's linear discriminant analysis was used to derive the discriminant function of each classified group. An operational map was developed by scatter-plotting the derived principal components (PCs) on a two-dimensional coordinate according to the classified groups. Using the new data sets not used for developing the operational map, the practical usefulness of the operational map and discriminant function in diagnosing the process operating state were evaluated. Hence, the process operating state could be easily and quickly diagnosed and the dynamic trend of the process operating state was also able to be estimated using the operational map.
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Affiliation(s)
- T S Moon
- Department of Environmental Engineering, Pusan National University, Busan, Republic of Korea
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41
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Oh SE, Kim JR, Joo JH, Logan BE. Effects of applied voltages and dissolved oxygen on sustained power generation by microbial fuel cells. Water Sci Technol 2009; 60:1311-7. [PMID: 19717919 DOI: 10.2166/wst.2009.444] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
Oxygen intrusion into the anode chamber through proton exchange membrane can result in positive redox conditions in fed-batch, two chamber MFCs at the end of a cycle when the substrate is depleted. A slight increase in dissolved oxygen to 0.3 mg/L during MFC operation was not found to adversely affect power generation over subsequent cycles if sufficient substrate (acetate) was provided. Purging the anode chamber with air or pure oxygen for up to 10 days and 10 hrs also did not affect power generation, as power rapidly returned to previous levels when the chamber was sparged with nitrogen gas. When MFCs are connected in series, voltage reversal can occur resulting in a positive voltage applied to the anode biofilm. To investigate if this adversely affected the bacteria, voltages of 1, 2, 3, 4, and 9 V, were applied for 1 hr to the MFC before reconnecting it back to a fixed external load (1,000 Omega). A voltage of <2 V did not affect power generation. However, applying 3 V resulted in a 15 h lag phase before recovery, and 9 V produced a 60 h lag phase suggesting substantial damage to the bacteria that required re-growth of bacteria in the biofilm. These results indicate that charge reversal will be a more serious problem than oxygen intrusion into the anode chamber for sustained performance of MFCs.
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Affiliation(s)
- S E Oh
- Department of Biological Environment, Kangwon National University, 192-1, Hyoja 2-dong, Chuncheon, Kangwon-do 200-701, South Korea.
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JU JUNGHUN, Lee JK, Sohn KH, Lee JP, Kim JH, Lim CH, Hong SK, Kim IY, Kim JR, Ock SW, Kim SH, Park KL. Immune related gene expression profiling of UVB‐induced photoaging skin in SKH‐1 hairless mice. FASEB J 2008. [DOI: 10.1096/fasebj.22.2_supplement.414] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- JUNG HUN JU
- Toxicological research DepartmentNITRKFDASeoulRepublic of Korea
| | - JK Lee
- Toxicological research DepartmentNITRKFDASeoulRepublic of Korea
| | - KH Sohn
- Toxicological research DepartmentNITRKFDASeoulRepublic of Korea
| | - JP Lee
- Toxicological research DepartmentNITRKFDASeoulRepublic of Korea
| | - JH Kim
- Toxicological research DepartmentNITRKFDASeoulRepublic of Korea
| | - CH Lim
- Toxicological research DepartmentNITRKFDASeoulRepublic of Korea
| | - SK Hong
- Toxicological research DepartmentNITRKFDASeoulRepublic of Korea
| | - IY Kim
- Toxicological research DepartmentNITRKFDASeoulRepublic of Korea
| | - JR Kim
- Toxicological research DepartmentNITRKFDASeoulRepublic of Korea
| | - SW Ock
- Toxicological research DepartmentNITRKFDASeoulRepublic of Korea
| | - SH Kim
- Toxicological research DepartmentNITRKFDASeoulRepublic of Korea
| | - Kui Lea Park
- Toxicological research DepartmentNITRKFDASeoulRepublic of Korea
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Abstract
Systems biology is a multi-disciplinary approach to the study of the interactions of various cellular mechanisms and cellular components. Owing to the development of new technologies that simultaneously measure the expression of genetic information, systems biological studies involving gene interactions are increasingly prominent. In this regard, reconstructing gene regulatory networks (GRNs) forms the basis for the dynamical analysis of gene interactions and related effects on cellular control pathways. Various approaches of inferring GRNs from gene expression profiles and biological information, including machine learning approaches, have been reviewed, with a brief introduction of DNA microarray experiments as typical tools for measuring levels of messenger ribonucleic acid (mRNA) expression. In particular, the inference methods are classified according to the required input information, and the main idea of each method is elucidated by comparing its advantages and disadvantages with respect to the other methods. In addition, recent developments in this field are introduced and discussions on the challenges and opportunities for future research are provided.
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Affiliation(s)
- K H Cho
- College of Medicine, Seoul National University, Jongnogu, Seoul 110-799, South Korea.
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44
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Lee IP, Kang BH, Roh JK, Kim JR. Lack of carcinogenicity of lyophilized Agaricus blazei Murill in a F344 rat two year bioassay. Food Chem Toxicol 2007; 46:87-95. [PMID: 17707568 DOI: 10.1016/j.fct.2007.07.001] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2007] [Revised: 05/25/2007] [Accepted: 07/06/2007] [Indexed: 11/19/2022]
Abstract
The Brazilian mushroom Agaricus blazei Murill has antimutagenic, antioxidant, immunostimulatory and antitumorigenic activities, and is increasingly consumed as a health food worldwide. We undertook the present study to evaluate the chronic toxicity and oncogenicity of A. blazei Murill in F344 rats. To establish a no-observed-adverse-effect level (NOAEL), four treatment groups of 100 rats each (50 males and 50 females) were fed a powder diet containing lyophilized A. blazei aqueous extract at 0, 6250, 12,500, and 25,000 ppm for up to 2 years. During this period, there was no remarkable change in mean body weight, body weight gain, hematologic or serum chemistry parameters, or absolute or relative organ weights in control or treatment groups. Mortality in male treatment groups (26%, 16%, and 30%), however, was significantly lower than in controls (48%). Histopathological studies showed no increased incidence of tumors in any treatment group, and total tumor incidence across all groups was comparable to historical data. In conclusion, an A. blazei Murill lyophilized powder diet even at 25,000 ppm (1176 mg/kgb x w x /day for male rats and 1518 mg/kgb.w./day for female rats) resulted in no remarkable carcinogenic effects in F344 rats over a 2-year period. Therefore, the dietary NOAEL is 25,000 ppm.
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Affiliation(s)
- I P Lee
- Laboratory of Molecular Toxicology, Toxicological Research Center, Korea Food and Drug Administration, 5 Nokbun-Dong, Unpyong-Ku, Seoul 122-704, Republic of Korea.
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45
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Abstract
A heterotropic allosteric effect involves an effector molecule that is distinct from the substrate or ligand of the protein. How heterotropic allostery originates is an unanswered question. We have previously created several heterotropic allosteric enzymes by recombining the genes for TEM1 beta-lactamase (BLA) and maltose binding protein (MBP) to create BLAs that are positively or negatively regulated by maltose. We show here that one of these engineered enzymes has approximately 10(6) M(-1) affinity for Zn(2+), a property that neither of the parental proteins possesses. Furthermore, Zn(2+) is a negative effector that noncompetitively switches off beta-lactam hydrolysis activity. Mutagenesis experiments indicate that the Zn(2+)-binding site does not involve a histidine or a cysteine, which is atypical of natural Zn(2+)-binding sites. These studies also implicate helices 1 and 12 of the BLA domain in allosteric signal propagation. These results support a model for the evolution of heterotropic allostery in which effector affinity and allosteric signaling emerge simultaneously.
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Affiliation(s)
- Jing Liang
- Program in Molecular and Computational Biophysics, Johns Hopkins University, Baltimore, Maryland 21218, USA
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46
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Lee JJ, Im JH, BenAim R, Kim JR, Kim YJ, Poo KM, Kim CW. Better understanding of the filtration characteristics in the flexible fibre filter module (3FM). Water Sci Technol 2007; 55:77-83. [PMID: 17305126 DOI: 10.2166/wst.2007.049] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
This study is about the particle retention and filtration characteristics of fibre filter. Four laboratory scale fibre filters with different heights were used in parallel at various packing densities and filtration velocities. Of all of the operating parameters studied, filtration velocity had the most influence. Contrary to general theories, pressure drop increases slightly during the filtration in spite of the continuous retention of particles. This may have occurred because of large porosity of the packing (about 93%). This might be considered an advantage of the filter and something that makes it economic. The higher the filtration velocity, the larger the mass of particles retained in the filter. For filtration velocities of 20 and 40 m/h, particles smaller than 5 microm are retained as proven by the particle size distribution at the inlet and outlet.
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Affiliation(s)
- J J Lee
- Department of Environmental Engineering, Pusan National University, Busan, 609-735, Korea
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Park JH, Song HI, Rho JM, Kim MR, Kim JR, Park BH, Park TS, Baek HS. Parathyroid hormone (1-34) augments angiopoietin-1 expression in human osteoblast-like cells. Exp Clin Endocrinol Diabetes 2006; 114:438-43. [PMID: 17039426 DOI: 10.1055/s-2006-924400] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
Parathyroid hormone (PTH) is a major regulatory factor in skeletal physiology. However, the molecular mechanism underlying the effects of PTH on bones has yet to be elucidated in detail. Recently, some reports have demonstrated the crucial role of bone vasculature with regard to bone density. Angiopoietin-1 (Ang-1), along with VEGF, has been established as a primary angiogenic regulatory agent. In this study, we have attempted to characterize the effects of PTH (1-34) on Ang-1 expression and signaling molecules, employing primary-cultured human osteoblast-like cells. Quiescent osteoblasts were exposed to PTH (1-34), after which Ang-1 expression was determined at the mRNA and protein levels. Reverse transcription-polymerase chain reaction (RT-PCR) analyses indicated that Ang-1 mRNA expression increased as the result of PTH (1-34) treatment. The expression of the Ang-1 protein was also augmented as the result of treatment with PTH (1-34). An adenylyl cyclase activator, forskolin, was shown to induce Ang-1 mRNA expression, whereas the protein kinase A inhibitor, H-89, blocked the PTH (1-34)-mediated expression of Ang-1 mRNA. These findings indicate that PTH (1-34)-mediated Ang-1 expression involves adenylyl cyclase-protein kinase A dependent signaling. Our observations also show that Ang-1 may perform a crucial role in the effects of PTH (1-34) on bones, possibly involving alterations in bone vasculature.
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Affiliation(s)
- J H Park
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Chonbuk National University Medical School, Jeonju, Republic of Korea.
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Abstract
Assembly of proteins and peptides into amyloid fibrils is characteristic of the pathology of a number of degenerative diseases, of which perhaps the best known is Alzheimer's. Neuronal death in Alzheimer's disease has been linked to aggregation of beta-amyloid peptide and deposition of the aggregates in brain tissue. Recent studies suggest that soluble intermediate oligomers rather than fully formed fibrils may be responsible for beta-amyloid's toxicity; consistent with this hypothesis, some compounds that inhibited beta-amyloid toxicity were found to accelerate aggregation of the peptide. The degree of increase of aggregation caused by these compounds was shown to correlate strongly with their effect on the surface tension of aqueous buffers (Gibson, T. J.; Murphy, R. M. Biochemistry 2005, 44, 8898-8907). In work reported here, we used group contribution methods to calculate infinite dilution activity coefficients of moieties contained in these compounds. We demonstrate that activity coefficients calculated in this manner are strongly predictive of effects of these peptides on solvent surface tension and on beta-amyloid aggregation. These results suggest that group contribution calculations can be used for a priori design of compounds that modulate aggregation of peptides through their effect on solvent properties.
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Affiliation(s)
- Jin Ryoun Kim
- Department of Chemical and Biological Engineering, University of Wisconsin, Madison, 1415 Engineering Drive, 53706, USA
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49
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Suh MK, Lim JW, Lee YH, Ha GY, Kim H, Kim JR, Yaguchi T, Nishimura K. Subcutaneous hyalohyphomycosis due to Cephalotheca foveolata
in an immunocompetent host. Br J Dermatol 2006; 154:1184-9. [PMID: 16704653 DOI: 10.1111/j.1365-2133.2006.07158.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We report the first case of subcutaneous hyalohyphomycosis caused by the genus Cephalotheca, which has not been reported to cause human infection. A 67-year-old immunocompetent farmer presented with a 10-year history of verrucous erythematous plaques on the right foot dorsum, great toe, heel and sole. Histopathology of the lesions revealed chronic granulomatous inflammation with numerous nonpigmented fungal spores in the dermis. Cultures of biopsy specimens on Sabouraud's dextrose agar for 2 weeks developed into yellowish brown, velvety colonies that subsequently turned black after 8 weeks because of the production of black cleistothecia indicating the teleomorph. On the basis of mycological features, scanning electron microscopic morphology and molecular analysis data, a new species of Cephalotheca was identified and designated Cephalotheca foveolata. Because there was no response to the antifungal agents administered, the patient was successfully treated by surgical excision with skin graft.
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Affiliation(s)
- M K Suh
- Department of Laboratory Medicine, College of Medicine, Gyeongju Hospital of Dongguk University, Seokjang-dong, Gyeongju 780-350, South Korea
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50
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Ko JH, Lee SH, Kim JR, Kim YJ, Hwang IS, Lee TH, Kim CW. Monitoring of pH inhibition on microbial activity in a continuous flow reactor by pseudo toxic concentration (C(PT)) concept and time delay model. Water Sci Technol 2006; 53:367-73. [PMID: 16722088 DOI: 10.2166/wst.2006.142] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
The pseudo toxic concentration (C(PT)) concept was introduced as a quantification method to describe pH as an inhibitor concentration. In this research, the applicability of the C(PT) concept model for the detection of pH inhibitions was expanded for a continuous flow activated sludge reactor. A pilot equipped with an inhibition detection system was installed. Inhibitory wastewater was injected for 1 h and the relative activity was calculated by the maximum respiration rate. At the same time, the coefficients for the C(PT) concept model were estimated. At the dynamic conditions, the estimated relative activity by the C(PT) concept model showed time lag compared to the measured one. However, the time lag problem was successfully resolved by introducing a transfer function into the C(PT) concept model. The C(PT) concept model combined with a transfer function (C(PT) + TF model) successfully tracked the variation of the relative activity under dynamic conditions. The C(PT) + TF model could detect 50% inhibition faster than the respirometry based method by approximately 10 min. Moreover, it had additional advantages such as being inexpensive, easy to install and simple to operate. In conclusion, the C(PT) + TF model was an effective and convenient detection method of pH inhibition.
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Affiliation(s)
- J H Ko
- Research and Engineering Division, Posco Engineering and Construction, 445-810, Korea
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