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Su HL, Lai SJ, Tsai KC, Fung KM, Lung TL, Hsu HM, Wu YC, Liu CH, Lai HX, Lin JH, Tseng TS. Structure-guided identification and characterization of potent inhibitors targeting PhoP and MtrA to combat mycobacteria. Comput Struct Biotechnol J 2024; 23:1477-1488. [PMID: 38623562 PMCID: PMC11016868 DOI: 10.1016/j.csbj.2024.04.005] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2023] [Revised: 04/01/2024] [Accepted: 04/01/2024] [Indexed: 04/17/2024] Open
Abstract
Mycobacteria are causative agents of tuberculosis (TB), which is a global health concern. Drug-resistant TB strains are rapidly emerging, thereby necessitating the urgent development of new drugs. Two-component signal transduction systems (TCSs) are signaling pathways involved in the regulation of various bacterial behaviors and responses to environmental stimuli. Applying specific inhibitors of TCSs can disrupt bacterial signaling, growth, and virulence, and can help combat drug-resistant TB. We conducted a comprehensive pharmacophore-based inhibitor screening and biochemical and biophysical examinations to identify, characterize, and validate potential inhibitors targeting the response regulators PhoP and MtrA of mycobacteria. The constructed pharmacophore model Phar-PR-n4 identified effective inhibitors of formation of the PhoP-DNA complex: ST132 (IC50 = 29 ± 1.6 µM) and ST166 (IC50 = 18 ± 1.3 µM). ST166 (KD = 18.4 ± 4.3 μM) and ST132 (KD = 14.5 ± 0.1 μM) strongly targeted PhoP in a slow-on, slow-off manner. The inhibitory potency and binding affinity of ST166 and ST132 for MtrAC were comparable to those of PhoP. Structural analyses and molecular dynamics simulations revealed that ST166 and ST132 mainly interact with the α8-helix and C-terminal β-hairpin of PhoP, with functionally essential residue hotspots for structure-based inhibitor optimization. Moreover, ST166 has in vitro antibacterial activity against Macrobacterium marinum. Thus, ST166, with its characteristic 1,2,5,6-tetrathiocane and terminal sulphonic groups, has excellent potential as a candidate for the development of novel antimicrobial agents to combat pathogenic mycobacteria.
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Affiliation(s)
- Han-Li Su
- Department of Emergency Medicine, Ditmanson Medical Foundation Chia-Yi Christian Hospital, Chiayi City 600, Taiwan
| | - Shu-Jung Lai
- Graduate Institute of Biomedical Sciences, China Medical University, Taichung, Taiwan
- Research Center for Cancer Biology, China Medical University, Taichung, Taiwan
| | - Keng-Chang Tsai
- National Research Institute of Chinese Medicine, Ministry of Health and Welfare, Taipei, Taiwan
- Ph.D. Program in Medical Biotechnology, College of Medical Science and Technology, Taipei Medical University, Taipei, Taiwan
| | - Kit-Man Fung
- Biomedical Translation Research Center (BioTReC), Academia Sinica, Taipei 11529, Taiwan
| | - Tse-Lin Lung
- Institute of Molecular Biology, National Chung Hsing University, Taichung,Taiwan
| | - Hsing-Mien Hsu
- Institute of Molecular Biology, National Chung Hsing University, Taichung,Taiwan
| | - Yi-Chen Wu
- Institute of Molecular Biology, National Chung Hsing University, Taichung,Taiwan
| | - Ching-Hui Liu
- Institute of Molecular Biology, National Chung Hsing University, Taichung,Taiwan
| | - Hui-Xiang Lai
- Institute of Molecular Biology, National Chung Hsing University, Taichung,Taiwan
| | - Jiun-Han Lin
- Department of Industrial Technology, Ministry of Economic Affairs, Taipei, Taiwan
- Food Industry Research and Development Institute, Hsinchu City, Taiwan
| | - Tien-Sheng Tseng
- Institute of Molecular Biology, National Chung Hsing University, Taichung,Taiwan
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Wu YC, Lai HX, Li JM, Fung KM, Tseng TS. Discovery of a potent inhibitor, D-132, targeting AsfvPolX, via protein-DNA complex-guided pharmacophore screening and in vitro molecular characterizations. Virus Res 2024; 344:199359. [PMID: 38521505 PMCID: PMC10995865 DOI: 10.1016/j.virusres.2024.199359] [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: 01/15/2024] [Revised: 03/15/2024] [Accepted: 03/17/2024] [Indexed: 03/25/2024]
Abstract
The heightened transmissibility and capacity of African swine fever virus (ASFV) induce fatal diseases in domestic pigs and wild boars, posing significant economic repercussions and global threats. Despite extensive research efforts, the development of potent vaccines or treatments for ASFV remains a persistent challenge. Recently, inhibiting the AsfvPolX, a key DNA repair enzyme, emerges as a feasible strategy to disrupt viral replication and control ASFV infections. In this study, a comprehensive approach involving pharmacophore-based inhibitor screening, coupled with biochemical and biophysical analyses, were implemented to identify, characterize, and validate potential inhibitors targeting AsfvPolX. The constructed pharmacophore model, Phar-PolX-S, demonstrated efficacy in identifying a potent inhibitor, D-132 (IC50 = 2.8 ± 0.2 µM), disrupting the formation of the AsfvPolX-DNA complex. Notably, D-132 exhibited strong binding to AsfvPolX (KD = 6.9 ± 2.2 µM) through a slow-on-fast-off binding mechanism. Employing molecular modeling, it was elucidated that D-132 predominantly binds in-between the palm and finger domains of AsfvPolX, with crucial residues (R42, N48, Q98, E100, F102, and F116) identified as hotspots for structure-based inhibitor optimization. Distinctively characterized by a 1,2,5,6-tetrathiocane with modifications at the 3 and 8 positions involving ethanesulfonates, D-132 holds considerable promise as a lead compound for the development of innovative agents to combat ASFV infections.
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Affiliation(s)
- Yi-Chen Wu
- Institute of Molecular Biology, National Chung Hsing University, Taichung, 40202, Taiwan
| | - Hui-Xiang Lai
- Institute of Molecular Biology, National Chung Hsing University, Taichung, 40202, Taiwan
| | - Ji-Min Li
- Institute of Precision Medicine, College of Medicine, National Sun Yat-sen University, Kaohsiung, 80424, Taiwan; Center of Excellence for Metabolic Associated Fatty Liver Disease, National Sun Yat-sen University, Kaohsiung, 80424, Taiwan
| | - Kit-Man Fung
- Biomedical Translation Research Center (BioTReC), Academia Sinica, Taipei, 11529, Taiwan
| | - Tien-Sheng Tseng
- Institute of Molecular Biology, National Chung Hsing University, Taichung, 40202, Taiwan.
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Tseng TS, Lee CC, Chen PJ, Lin CY, Chen WC, Lee YC, Lin JH, Chen KW, Tsai KC. Structure-Guided Discovery of PD-1/PD-L1 Interaction Inhibitors: Peptide Design, Screening, and Optimization via Computation-Aided Phage Display Engineering. J Chem Inf Model 2024; 64:1615-1627. [PMID: 38356220 DOI: 10.1021/acs.jcim.3c01500] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2024]
Abstract
Cancer immunotherapy harnesses the immune system to combat tumors and has emerged as a major cancer treatment modality. The PD-1/PD-L1 immune checkpoint modulates interactions between tumor cells and T cells and has been extensively targeted in cancer immunotherapy. However, the monoclonal antibodies known to target this immune checkpoint have considerable side effects, and novel PD-1/PD-L1 inhibitors are therefore required. Herein, a peptide inhibitor to disrupt PD-1/PD-L1 interactions was designed through structure-driven phage display engineering coupled to computational modification and optimization. BetaPb, a novel peptide library constructed by using the known structure of PD-1/PD-L, was used to develop inhibitors against the immune checkpoint, and specific peptides with high affinity toward PD-1 were screened through enzyme-linked immunosorbent assays, homogeneous time-resolved fluorescence, and biolayer interferometry. A potential inhibitor, B8, was preliminarily screened through biopanning. The binding affinity of B8 toward PD-1 was confirmed through computation-aided optimization. Assessment of B8 variants (B8.1, B8.2, B8.3, B8.4, and B8.5) demonstrated their attenuation of PD-1/PD-L1 interactions. B8.4 exhibited the strongest attenuation efficiency at a half-maximal effective concentration of 0.1 μM and the strongest binding affinity to PD-1 (equilibrium dissociation constant = 0.1 μM). B8.4 outperformed the known PD-1/PD-L1 interaction inhibitor PL120131 in disrupting PD-1/PD-L1 interactions, revealing that B8.4 has remarkable potential for modification to yield an antitumor agent. This study provides valuable information for the future development of peptide-based drugs, therapeutics, and immunotherapies for cancer.
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Affiliation(s)
- Tien-Sheng Tseng
- Institute of Molecular Biology, National Chung Hsing University, Taichung 40202, Taiwan
| | - Chao-Chang Lee
- National Research Institute of Chinese Medicine, Ministry of Health and Welfare, Taipei 11221, Taiwan
| | - Po-Juei Chen
- Institute of Molecular Biology, National Chung Hsing University, Taichung 40202, Taiwan
- National Research Institute of Chinese Medicine, Ministry of Health and Welfare, Taipei 11221, Taiwan
| | - Chiu-Yuen Lin
- National Research Institute of Chinese Medicine, Ministry of Health and Welfare, Taipei 11221, Taiwan
| | - Wang-Chuan Chen
- The School of Chinese Medicine for Post Baccalaureate, I-Shou University, Kaohsiung 824005, Taiwan
- Department of Chinese Medicine, E-Da Hospital, Kaohsiung 824005, Taiwan
| | - Yu-Ching Lee
- TMU Research Center of Cancer Translational Medicine, Taipei Medical University, Taipei 11031, Taiwan
- Ph.D. Program in Medical Biotechnology, College of Medical Science and Technology, Taipei Medical University, Taipei 11031, Taiwan
| | - Jiun-Han Lin
- Department of Industrial Technology, Ministry of Economic Affairs, Taipei 100210, Taiwan
- Food Industry Research and Development Institute, Hsinchu 30062, Taiwan
| | - Kaun-Wen Chen
- Molecular Science and Digital Innovation Center, Genetics Generation Advancement Corporation, Taipei 11949, Taiwan
| | - Keng-Chang Tsai
- National Research Institute of Chinese Medicine, Ministry of Health and Welfare, Taipei 11221, Taiwan
- Ph.D. Program in Medical Biotechnology, College of Medical Science and Technology, Taipei Medical University, Taipei 11031, Taiwan
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Lee YC, Lai GH, Lin TY, Tseng TS, Tsai TH, Chen WC, Lee CC, Tsai KC. Development of anti-aflatoxin B1 nanobodies from a novel mutagenesis-derived synthetic library for traditional Chinese medicine and foods safety testing. J Biol Eng 2023; 17:30. [PMID: 37095503 PMCID: PMC10127376 DOI: 10.1186/s13036-023-00350-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [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: 11/01/2022] [Accepted: 04/17/2023] [Indexed: 04/26/2023] Open
Abstract
BACKGROUND The main commercially available methods for detecting small molecules of mycotoxins in traditional Chinese medicine (TCM) and functional foods are enzyme-linked immunosorbent assay and mass spectrometry. Regarding the development of diagnostic antibody reagents, effective methods for the rapid preparation of specific monoclonal antibodies are inadequate. METHODS In this study, a novel synthetic phage-displayed nanobody Golden Glove (SynaGG) library with a glove-like cavity configuration was established using phage display technology in synthetic biology. We applied this unique SynaGG library on the small molecule aflatoxin B1 (AFB1), which has strong hepatotoxicity, to isolate specific nanobodies with high affinity for AFB1. RESULT These nanobodies exhibit no cross-reactivity with the hapten methotrexate, which is recognized by the original antibody template. By binding to AFB1, two nanobodies can neutralize AFB1-induced hepatocyte growth inhibition. Using molecular docking, we found that the unique non-hypervariable complementarity-determining region 4 (CDR4) loop region of the nanobody was involved in the interaction with AFB1. Specifically, the CDR4's positively charged amino acid arginine directed the binding interaction between the nanobody and AFB1. We then rationally optimized the interaction between AFB1 and the nanobody by mutating serine at position 2 into valine. The binding affinity of the nanobody to AFB1 was effectively improved, and this result supported the use of molecular structure simulation for antibody optimization. CONCLUSION In summary, this study revealed that the novel SynaGG library, which was constructed through computer-aided design, can be used to isolate nanobodies that specifically bind to small molecules. The results of this study could facilitate the development of nanobody materials to detect small molecules for the rapid screening of TCM materials and foods in the future.
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Affiliation(s)
- Yu-Ching Lee
- TMU Research Center of Cancer Translational Medicine, Taipei Medical University, Taipei, Taiwan
- Ph.D. Program for Cancer Molecular Biology and Drug Discovery, College of Medical Science and Technology, Taipei Medical University, Taipei, Taiwan
- Ph.D. Program in Drug Discovery and Development Industry, College of Pharmacy, Taipei Medical University, Taipei, Taiwan
- Ph.D. Program in Medical Biotechnology, College of Medical Science and Technology, Taipei Medical University, Taipei, Taiwan
| | - Gar-Hwa Lai
- Department of Orthopedics, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan
| | - Tsai-Yu Lin
- Ph.D. Program for Cancer Molecular Biology and Drug Discovery, College of Medical Science and Technology, Taipei Medical University, Taipei, Taiwan
| | - Tien-Sheng Tseng
- Institute of Molecular Biology, National Chung Hsing University, Taichung, Taiwan
| | - Tsung-Hsun Tsai
- Department of Psychiatry, Kaohsiung Armed Forces General Hospital, Kaohsiung, Taiwan
| | - Wang-Chuan Chen
- The School of Chinese Medicine for Post Baccalaureate, I-Shou University, Kaohsiung, Taiwan
- Department of Chinese Medicine, E-Da Hospital, Kaohsiung, Taiwan
| | - Cheng-Chung Lee
- The Ph.D. Program for Translational Medicine, College of Medical Science and Technology, Taipei Medical University, Taipei, Taiwan
| | - Keng-Chang Tsai
- Ph.D. Program in Medical Biotechnology, College of Medical Science and Technology, Taipei Medical University, Taipei, Taiwan.
- National Research Institute of Chinese Medicine, Ministry of Health and Welfare, No. 155-1, Sec. 2, Linong St., Beitou District, Taipei, 11221, Taiwan.
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Lai SJ, Tu IF, Tseng TS, Tsai YH, Wu SH. The deficiency of poly-β-1,6-N-acetyl-glucosamine deacetylase trigger A. baumannii to convert to biofilm-independent colistin-tolerant cells. Sci Rep 2023; 13:2800. [PMID: 36797306 PMCID: PMC9935895 DOI: 10.1038/s41598-023-30065-5] [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] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2022] [Accepted: 02/15/2023] [Indexed: 02/18/2023] Open
Abstract
Acinetobacter baumannii is a nosocomial pathogen that can be resistant to antibiotics by rapidly modulating its anti-drug mechanisms. The multidrug-resistant A. baumannii has been considered one of the most threatening pathogens to our society. Biofilm formation and persistent cells within the biofilm matrix are recognized as intractable problems, especially in hospital-acquired infections. Poly-β-1,6-N-acetyl-glucosamine (PNAG) is one of the important building blocks in A. baumannii's biofilm. Here, we discover a protein phosphoryl-regulation on PNAG deacetylase, AbPgaB1, in which residue Ser411 was phosphorylated. The phosphoryl-regulation on AbPgaB1 modulates the product turnover rate in which deacetylated PNAG is produced and reflected in biofilm production. We further uncovered the PgaB deficient A. baumannii strain shows the lowest level of biofilm production but has a high minimal inhibition concentration to antibiotic colistin and tetracycline. Based on bactericidal post-antibiotic effects and time-dependent killing assays with antibacterial drugs, we claim that the PgaB-deficient A. baumannii converts to colistin-tolerant cells. This study utilizes a biofilm-independent colistin-tolerant model of A. baumannii to further investigate its characteristics and mechanisms to better understand clinical outcomes.
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Affiliation(s)
- Shu-Jung Lai
- Graduate Institute of Biomedical Sciences, China Medical University, Taichung, 404333, Taiwan. .,Research Center for Cancer Biology, China Medical University, Taichung, 404333, Taiwan.
| | - I-Fan Tu
- grid.28665.3f0000 0001 2287 1366Institute of Biological Chemistry, Academia Sinica, Taipei, 11529 Taiwan
| | - Tien-Sheng Tseng
- grid.260542.70000 0004 0532 3749Institute of Molecular Biology, National Chung Hsing University, Taichung, Taiwan
| | - Yu-Hsuan Tsai
- grid.510951.90000 0004 7775 6738Institute of Molecular Physiology, Shenzhen Bay Laboratory, Shenzhen, 518132 China
| | - Shih-Hsiung Wu
- Institute of Biological Chemistry, Academia Sinica, Taipei, 11529, Taiwan. .,Department of Chemistry, National Taiwan University, Taipei, 106, Taiwan.
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Tsai KC, Zhang YX, Kao HY, Fung KM, Tseng TS. Pharmacophore-driven identification of human glutaminyl cyclase inhibitors from foods, plants and herbs unveils the bioactive property and potential of Azaleatin in the treatment of Alzheimer's disease. Food Funct 2022; 13:12632-12647. [PMID: 36416361 DOI: 10.1039/d2fo02507h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Alzheimer's disease (AD) is the leading cause of disabilities in old age and a rapidly growing condition in the elderly population. AD brings significant burden and has a devastating impact on public health, society and the global economy. Thus, developing new therapeutics to combat AD is imperative. Human glutaminyl cyclase (hQC), which catalyzes the formation of neurotoxic pyroglutamate (pE)-modified β-amyloid (Aβ) peptides, is linked to the amyloidogenic process that leads to the initiation of AD. Hence, hQC is an essential target for developing anti-AD therapeutics. Here, we systematically screened and identified hQC inhibitors from natural products by pharmacophore-driven inhibitor screening coupled with biochemical and biophysical examinations. We employed receptor-ligand pharmacophore generation to build pharmacophore models and Phar-MERGE and Phar-SEN for inhibitor screening through ligand-pharmacophore mapping. About 11 and 24 hits identified from the Natural Product and Traditional Chinese Medicine databases, respectively, showed diverse hQC inhibitory abilities. Importantly, the inhibitors TCM1 (Azaleatin; IC50 = 1.1 μM) and TCM2 (Quercetin; IC50 = 4.3 μM) found in foods and plants exhibited strong inhibitory potency against hQC. Furthermore, the binding affinity and molecular interactions were analyzed by surface plasmon resonance (SPR) and molecular modeling/simulations to explore the possible modes of action of Azaleatin and Quercetin. Our study successfully screened and characterized the foundational biochemical and biophysical properties of Azaleatin and Quercetin toward targeting hQC, unveiling their bioactive potential in the treatment of AD.
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Affiliation(s)
- Keng-Chang Tsai
- National Research Institute of Chinese Medicine, Ministry of Health and Welfare, Taipei, Taiwan. .,Ph.D. Program in Medical Biotechnology, College of Medical Science and Technology, Taipei Medical University, Taipei, Taiwan
| | - Yi-Xuan Zhang
- Institute of Molecular Biology, National Chung Hsing University, Taichung, Taiwan.
| | - Hsiang-Yun Kao
- Institute of Molecular Biology, National Chung Hsing University, Taichung, Taiwan.
| | - Kit-Man Fung
- Institute of Molecular Biology, National Chung Hsing University, Taichung, Taiwan. .,Institute of Biological Chemistry, Academia Sinica, Taipei 115, Taiwan
| | - Tien-Sheng Tseng
- Institute of Molecular Biology, National Chung Hsing University, Taichung, Taiwan.
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Fung KM, Lai SJ, Lin TL, Tseng TS. Antigen–Antibody Complex-Guided Exploration of the Hotspots Conferring the Immune-Escaping Ability of the SARS-CoV-2 RBD. Front Mol Biosci 2022; 9:797132. [PMID: 35392535 PMCID: PMC8981523 DOI: 10.3389/fmolb.2022.797132] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [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: 10/18/2021] [Accepted: 03/02/2022] [Indexed: 11/24/2022] Open
Abstract
The COVID-19 pandemic resulting from the spread of SARS-CoV-2 spurred devastating health and economic crises around the world. Neutralizing antibodies and licensed vaccines were developed to combat COVID-19, but progress was slow. In addition, variants of the receptor-binding domain (RBD) of the spike protein confer resistance of SARS-CoV-2 to neutralizing antibodies, nullifying the possibility of human immunity. Therefore, investigations into the RBD mutations that disrupt neutralization through convalescent antibodies are urgently required. In this study, we comprehensively and systematically investigated the binding stability of RBD variants targeting convalescent antibodies and revealed that the RBD residues F456, F490, L452, L455, and K417 are immune-escaping hotspots, and E484, F486, and N501 are destabilizing residues. Our study also explored the possible modes of actions of emerging SARS-CoV-2 variants. All results are consistent with experimental observations of attenuated antibody neutralization and clinically emerging SARS-CoV-2 variants. We identified possible immune-escaping hotspots that could further promote resistance to convalescent antibodies. The results provide valuable information for developing and designing novel monoclonal antibody drugs to combat emerging SARS-CoV-2 variants.
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Affiliation(s)
- Kit-Man Fung
- Academia Sinica, Institute of Biological Chemistry, Taipei, Taiwan
- Institute of Molecular Biology, National Chung Hsing University, Taichung, Taiwan
| | - Shu-Jung Lai
- Graduate Institute of Biomedical Sciences, China Medical University, Taichung, Taiwan
| | - Tzu-Lu Lin
- Institute of Molecular Biology, National Chung Hsing University, Taichung, Taiwan
| | - Tien-Sheng Tseng
- Institute of Molecular Biology, National Chung Hsing University, Taichung, Taiwan
- *Correspondence: Tien-Sheng Tseng,
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Tung MC, Fung KM, Hsu HM, Tseng TS. Correction: Discovery of 8-prenylnaringenin from hop ( Humulus lupulus L.) as a potent monoacylglycerol lipase inhibitor for treatments of neuroinflammation and Alzheimer’s disease. RSC Adv 2022; 12:20217. [PMID: 35919583 PMCID: PMC9277420 DOI: 10.1039/d2ra90070j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [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: 07/04/2022] [Accepted: 07/04/2022] [Indexed: 11/21/2022] Open
Abstract
Correction for ‘Discovery of 8-prenylnaringenin from hop (Humulus lupulus L.) as a potent monoacylglycerol lipase inhibitor for treatments of neuroinflammation and Alzheimer’s disease’ by Min-Che Tung et al., RSC Adv., 2021, 11, 31062–31072, https://doi.org/10.1039/D1RA05311F.
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Affiliation(s)
- Min-Che Tung
- Division of Urology, Department of Surgery, Tungs’ Taichung MetroHarbor Hospital, Taichung 435, Taiwan
| | - Kit-Man Fung
- Institute of Biological Chemistry, Academia Sinica, Taipei 115, Taiwan
| | - Hsing-Mien Hsu
- Institute of Molecular Biology, National Chung Hsing University, Taichung, Taiwan
| | - Tien-Sheng Tseng
- Institute of Molecular Biology, National Chung Hsing University, Taichung, Taiwan
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Tung MC, Fung KM, Hsu HM, Tseng TS. Discovery of 8-prenylnaringenin from hop ( Humulus lupulus L.) as a potent monoacylglycerol lipase inhibitor for treatments of neuroinflammation and Alzheimer's disease. RSC Adv 2021; 11:31062-31072. [PMID: 35498911 PMCID: PMC9041313 DOI: 10.1039/d1ra05311f] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [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: 07/10/2021] [Accepted: 09/15/2021] [Indexed: 12/17/2022] Open
Abstract
Monoacylglycerol lipase (MAGL), a serine hydrolase, converts endocannabinoid 2-arachidonoylglycerol (2-AG) to arachidonic acid (AA) and glycerol in the brain and plays a bidirectional role in controlling nueroinflammation. MAGL, involved in Alzheimer's and Parkinson's diseases, is a promising target for treatment of neurodegenerative disorders. However, the irreversible inhibitors of MAGL lead to the desensitization of CB1 receptors further impairing the benefits associated with the indirect CB1 stimulation. Therefore, development of potent reversible inhibitors from natural products (NPs) and traditional chinese medicines (TCMs) are safer and free from adverse side effects and feasible to avoid drawbacks which irreversible inhibitors cause. Here, we employed pharmacophore-based screening of drug candidates coupled with molecular docking, biochemical assay and Ligplot analyses to identify and characterize inhibitors targeting human MAGL (hMAGL). The built pharmacophore model, Phar-MAGL successfully identified inhibitors NP-2 (IC50 = 9.5 ± 1.2 μM), NP-5 (IC50 = 14.5 ± 1.3 μM), and NP-3 (IC50 = 15.2 ± 1.4 μM), which apparently attenuated the activities of hMAGL in vitro. The evident activities of the identified inhibitors against hMAGL showed that the pharmacophore model, Phar-MAGL is reliable and efficient in screening inhibitors against hMAGL. Our study successfully identified a natrual product inhibitor, NP-2 (8-PN), from the plant Humulus lupulus L. (hops) and its positive effects in neurogenesis and neurodifferentiation along with the evident inhibitory potency against hMAGL revealed the potential for further optimizing and developing into drugs to treat neuroinflammation, Alzheimer's and Parkinson's diseases. Discovery of natural product inhibitors against human monoacylglycerol lipase by pharmacophore-based drug screening, LibDock molecular docking and in vitro biochemical examinations.![]()
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Affiliation(s)
- Min-Che Tung
- Division of Urology, Department of Surgery, Tungs' Taichung MetroHarbor Hospital Taichung 435 Taiwan
| | - Kit-Man Fung
- Institute of Biological Chemistry, Academia Sinica Taipei 115 Taiwan
| | - Hsin-Mie Hsu
- Institute of Molecular Biology, National Chung Hsing University Taichung Taiwan
| | - Tien-Sheng Tseng
- Institute of Molecular Biology, National Chung Hsing University Taichung Taiwan
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Tsai KC, Lee YC, Tseng TS. Comprehensive Deep Mutational Scanning Reveals the Immune-Escaping Hotspots of SARS-CoV-2 Receptor-Binding Domain Targeting Neutralizing Antibodies. Front Microbiol 2021; 12:698365. [PMID: 34335530 PMCID: PMC8319916 DOI: 10.3389/fmicb.2021.698365] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [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: 04/21/2021] [Accepted: 06/09/2021] [Indexed: 12/13/2022] Open
Abstract
The rapid spread of SARS-CoV-2 has caused the COVID-19 pandemic, resulting in the collapse of medical care systems and economic depression worldwide. To combat COVID-19, neutralizing antibodies have been investigated and developed. However, the evolutions (mutations) of the receptor-binding domain (RBD) of SARS-CoV-2 enable escape from neutralization by these antibodies, further impairing recognition by the human immune system. Thus, it is critical to investigate and predict the putative mutations of RBD that escape neutralizing immune responses. Here, we employed computational analyses to comprehensively investigate the mutational effects of RBD on binding to neutralizing antibodies and angiotensin-converting enzyme 2 (ACE2) and demonstrated that the RBD residues K417, L452, L455, F456, E484, G485, F486, F490, Q493, and S494 were consistent with clinically emerging variants or experimental observations of attenuated neutralizations. We also revealed common hotspots, Y449, L455, and Y489, that exerted comparable destabilizing effects on binding to both ACE2 and neutralizing antibodies. Our results provide valuable information on the putative effects of RBD variants on interactions with neutralizing antibodies. These findings provide insights into possible evolutionary hotspots that can escape recognition by these antibodies. In addition, our study results will benefit the development and design of vaccines and antibodies to combat the newly emerging variants of SARS-CoV-2.
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Affiliation(s)
- Keng-Chang Tsai
- National Research Institute of Chinese Medicine, Ministry of Health and Welfare, Taipei, Taiwan
- Ph.D. Program in Medical Biotechnology, College of Medical Science and Technology, Taipei Medical University, Taipei, Taiwan
| | - Yu-Ching Lee
- Ph.D. Program in Medical Biotechnology, College of Medical Science and Technology, Taipei Medical University, Taipei, Taiwan
- TMU Research Center of Cancer Translational Medicine, Taipei Medical University, Taipei, Taiwan
- Ph.D. Program for Cancer Molecular Biology and Drug Discovery, College of Medical Science and Technology, Taipei Medical University, Taipei, Taiwan
- Ph.D. Program in Biotechnology Research and Development, College of Pharmacy, Taipei Medical University, Taipei, Taiwan
- TMU Biomedical Commercialization Center, Taipei Medical University, Taipei, Taiwan
| | - Tien-Sheng Tseng
- Institute of Molecular Biology, National Chung Hsing University, Taichung, Taiwan
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Tung MC, Tsai KC, Fung KM, Don MJ, Tseng TS. Characterizing the structure-activity relationships of natural products, tanshinones, reveals their mode of action in inhibiting spleen tyrosine kinase. RSC Adv 2021; 11:2453-2461. [PMID: 35424194 PMCID: PMC8693659 DOI: 10.1039/d0ra08769f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Accepted: 01/05/2021] [Indexed: 11/21/2022] Open
Abstract
The cytosolic non-receptor protein kinase, spleen tyrosine kinase (SYK), is an attractive drug target in autoimmune, inflammatory disorder, and cancers indications. Here, we employed pharmacophore-based drug screening combined with biochemical assay and molecular dynamics (MD) simulations to identify and characterize inhibitors targeting SYK. The built pharmacophore model, phar-TanI, successfully identified tanshinone (TanI (IC50 = 1.72 μM)) and its analogs (TanIIA (IC50 = 3.2 μM), ST32da (IC50 = 46 μM), and ST32db (IC50 = 51 μM)) which apparently attenuated the activities of SYK in vitro. Additionally, the MD simulations followed by Ligplot analyses revealed that TanI and TanIIA interfered SYK activity through binding deeply into the active site. Besides, TanI and TanIIA mainly interact with residues L377, A400, V433, M448, M450, A451, E452, L453, G454, P455, and L501, which are functional hotspots for structure-based inhibitor optimization against SYK. The structure-activity relationships (SAR) study of the identified SYK inhibitors demonstrated that the pharmacophore model, phar-TanI is reliable and precise in screening inhibitors against SYK. This study disclosed the structure-function relationships of tanshinones from Traditional Chinese Medicine (Danshen), revealing their binding site and mode of action in inhibiting SYK and provides applicability in developing new therapeutic agents.
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Affiliation(s)
- Min-Che Tung
- Department of Stomatology, Tung's MetroHarbor Hospital Taichung Taiwan
| | - Keng-Chang Tsai
- National Research Institute of Chinese Medicine, Ministry of Health and Welfare Taipei Taiwan
- PhD Program in Medical Biotechnology, College of Medical Science and Technology, Taipei Medical University Taipei Taiwan
| | - Kit-Man Fung
- Institute of Biological Chemistry, Academia Sinica Taipei 115 Taiwan
| | - Ming-Jaw Don
- National Research Institute of Chinese Medicine, Ministry of Health and Welfare Taipei Taiwan
| | - Tien-Sheng Tseng
- Institute of Molecular Biology, National Chung Hsing University Taichung Taiwan
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12
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Luo T, Li MS, Williams D, Phillippi S, Yu Q, Kantrow S, Kao YH, Celestin M, Lin WT, Tseng TS. Using social media for smoking cessation interventions: a systematic review. Perspect Public Health 2020; 141:50-63. [DOI: 10.1177/1757913920906845] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [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]
Abstract
Background: Previous studies have shown that smoking tobacco significantly increases both incidence and mortality rates for many diseases. Social media has become one of the most influential platforms for various smoking cessation interventions. However, results from smoking cessation interventions have differed from study to study. Limited studies have summarised cessation outcomes from social media–based interventions. Therefore, the objective of this review is to explore the effectiveness of using social media for smoking cessation. Methods: We searched PubMed, MEDLINE, PsycINFO, and CINAHL for articles between June 2008 and June 2018, and also assessed the references of selected articles. We included studies that used social media as intervention platforms, provided a baseline assessment before the intervention, and provided smoking cessation outcomes after the intervention. Results: We identified 13 original studies that enrolled between 16 and 1698 participants; 7-day Point Prevalence Abstinence (PPA) rate was the most frequently used measure of abstinence, with a range of 7%–75%, regardless of the measurement time, study design, and analysis methods. Social media–based smoking cessation interventions were effective, because (1) smokers reported higher 7-day PPA rates after intervention compared to baseline and (2) smokers reported higher 7-day PPA rates in intervention groups than in control groups. Moreover, at each time point, approximately half of all smokers in studies reporting abstinence were found to be biochemically abstinent. There were no significant differences in the effectiveness of smoking cessation outcomes between those that used existing popular social networking platforms (e.g. Pechmann et al’s studies) and those that used individually designed interactive platforms (e.g. MyLastDip, iQuit system, Quitxt system). Conclusions: This review highlights the effectiveness of social media–based smoking cessation intervention studies. Due to the widespread use of social media, as well as its low cost, we suggest embedding smoking cessation interventions within existing popular social media platforms.
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Affiliation(s)
- T Luo
- Behavioral and Community Health Sciences, School of Public Health, Louisiana State University Health Sciences Center, New Orleans, LA, USA
| | - MS Li
- Behavioral and Community Health Sciences, School of Public Health, Louisiana State University Health Sciences Center, New Orleans, LA, USA
- School of Medicine, Louisiana State University Health Sciences Center, New Orleans, LA, USA
| | - D Williams
- Behavioral and Community Health Sciences, School of Public Health, Louisiana State University Health Sciences Center, New Orleans, LA, USA
| | - S Phillippi
- Behavioral and Community Health Sciences, School of Public Health, Louisiana State University Health Sciences Center, New Orleans, LA, USA
| | - Q Yu
- Biostatistics, School of Public Health, Louisiana State University Health Sciences Center, New Orleans, LA, USA
| | - S Kantrow
- School of Medicine, Louisiana State University Health Sciences Center, New Orleans, LA, USA
| | - YH Kao
- Behavioral and Community Health Sciences, School of Public Health, Louisiana State University Health Sciences Center, New Orleans, LA, USA
| | - M Celestin
- Behavioral and Community Health Sciences, School of Public Health, Louisiana State University Health Sciences Center, New Orleans, LA, USA
| | - WT Lin
- Department of Global Community Health and Behavioral Sciences, Tulane University School of Public Health & Tropical Medicine, New Orleans, LA, USA
| | - TS Tseng
- Associate Professor, Behavioral and Community Health Sciences, School of Public Health, Louisiana State University Health Sciences Center, 2020 Gravier Street, Room 213, New Orleans, LA 70112, USA
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13
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Wu PS, Lai SJ, Fung KM, Tseng TS. Characterization of the structure–function relationship of a novel salt-resistant antimicrobial peptide, RR12. RSC Adv 2020; 10:23624-23631. [PMID: 35517355 PMCID: PMC9054785 DOI: 10.1039/d0ra04299d] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [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: 05/14/2020] [Accepted: 06/15/2020] [Indexed: 11/21/2022] Open
Abstract
Antimicrobial peptides (AMPs) are potential candidates in designing new anti-infective agents. However, many AMPs show poor bactericidal activities in physical salt and serum solutions. Here, we disclosed the structure–function relationships of a novel salt-resistant antimicrobial peptide, RR12, which could further explain its mode of action and show its applicability in developing new antibacterial agents. Antimicrobial peptides (AMPs) are potential candidates in designing new anti-infective agents.![]()
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Affiliation(s)
- Ping-Sheng Wu
- Division of Infectious Diseases
- Department of Pediatrics
- Taipei Tzu Chi Hospital
- Buddhist Tzu Chi Medical Foundation
- New Taipei
| | - Shu-Jung Lai
- Institute of Biological Chemistry
- Academia Sinica
- Taipei 115
- Taiwan
- Graduate Institute of Biomedical Sciences
| | - Kit-Man Fung
- Institute of Biological Chemistry
- Academia Sinica
- Taipei 115
- Taiwan
| | - Tien-Sheng Tseng
- Institute of Molecular Biology
- National Chung Hsing University
- Taichung
- Taiwan
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14
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Tsai KC, Hung PP, Cheng CF, Chen C, Tseng TS. Exploring the mode of action of inhibitors targeting the PhoP response regulator of Salmonella enterica through comprehensive pharmacophore approaches. RSC Adv 2019; 9:9308-9312. [PMID: 35517705 PMCID: PMC9062048 DOI: 10.1039/c9ra00620f] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [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: 01/24/2019] [Accepted: 02/28/2019] [Indexed: 11/23/2022] Open
Abstract
The PhoQ/PhoP two-component system regulates the physiological and virulence functions of Salmonella enterica. However, the mode of action of known PhoP inhibitors is unclear. We systematically constructed a pharmacophore model of inhibitors to probe the interface pharmacophore model of the PhoP dimer, coupling it with Ligplot analysis. We found that these inhibitors bind on the α5-helix, altering the conformation and interfering with PhoP binding on DNA. Comprehensive pharmacophore approaches explore the mode of action of inhibitors targeting PhoP response regulator of Salmonella enterica.![]()
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Affiliation(s)
- Keng-Chang Tsai
- National Research Institute of Chinese Medicine, Ministry of Health and Welfare Taipei 112 Taiwan.,The PhD Program in Medical Biotechnology, College of Medical Science and Technology, Taipei Medical University Taipei Taiwan
| | - Po-Pin Hung
- Division of Infectious Disease, Department of Internal Medicine, Taipei Tzu Chi Hospital, The Buddhist Tzu Chi Medical Foundation New Taipei City 231 Taiwan
| | - Ching-Feng Cheng
- Department of Pediatrics, Taipei Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Taipei and Tzu Chi University Hualien Taiwan.,Institute of Biomedical Sciences, Academia Sinica Taipei 115 Taiwan
| | - Chinpan Chen
- Institute of Biomedical Sciences, Academia Sinica Taipei 115 Taiwan
| | - Tien-Sheng Tseng
- Department of Research, Taipei Tzu Chi Hospital, The Buddhist Tzu Chi Medical Foundation New Taipei City 231 Taiwan
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15
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Tseng TS, Tu IF, Chen HT, Lin LC, Tsai KC, Wu SH, Chen C. Protein–DNA complex-guided discovery of the antibacterial lead E1 for restoring the susceptibility ofKlebsiella Pneumoniaeto polymyxin B by targeting the response regulator PmrA. Chem Commun (Camb) 2018; 54:6372-6375. [DOI: 10.1039/c8cc01840e] [Citation(s) in RCA: 5] [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] [Indexed: 11/21/2022]
Abstract
E1, a novel adjuvant lead, restored the susceptibility ofKlebsiella Pneumoniaeto Polymyxin B by targeting the response regulator PmrA.
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Affiliation(s)
| | - I-Fan Tu
- Institute of Biological Chemistry
- Academia Sinica
- Taipei
- Taiwan
| | | | - Lie-Chwen Lin
- National Research Institute of Chinese Medicine
- Ministry of Health and Welfare
- Taipei
- Taiwan
| | - Keng-Chang Tsai
- National Research Institute of Chinese Medicine
- Ministry of Health and Welfare
- Taipei
- Taiwan
- The PhD Program for Medical Biotechnology
| | - Shih-Hsiung Wu
- Institute of Biological Chemistry
- Academia Sinica
- Taipei
- Taiwan
| | - Chinpan Chen
- Institute of Biomedical Sciences
- Academia Sinica
- Taipei
- Taiwan
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16
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Tseng TS, Tsai KC, Chen C. Characterizing the structure-function relationship reveals the mode of action of a novel antimicrobial peptide, P1, from jumper ant Myrmecia pilosula. Mol Biosyst 2017; 13:1193-1201. [PMID: 28470277 DOI: 10.1039/c6mb00810k] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Microbial infections of antibiotic-resistant strains cause serious diseases and have a significant impact on public health worldwide, so novel antimicrobial drugs are urgently needed. Insect venoms, a rich source of bioactive components containing antimicrobial peptides (AMPs), are attractive candidates for new therapeutic agents against microbes. Recently, a novel peptide, P1, identified from the venom of the Australian jumper ant Myrmecia pilosula, showed potent antimicrobial activities against both Gram-negative and Gram-positive bacteria, but its structure-function relationship is unknown. Here, we used biochemical and biophysical techniques coupled with computational simulations to explore the mode of action of P1 interaction with dodecylphosphocholine (DPC) micelles as a model membrane system. Our circular dichroism (CD) and NMR studies revealed an amphipathic α-helical structure for P1 upon interaction with DPC micelles. A paramagnetic relaxation enhancement approach revealed that P1 orients its α-helix segment (F6-G14) into DPC micelles. In addition, the α-helix segment could be essential for membrane permeabilization and antimicrobial activity. Moreover, the arginine residues R8, R11, and R15 significantly contribute to helix formation and membrane-binding affinity. The lysine residue K19 of the C-terminus functionally guides P1 to interact with DPC micelles in the early interaction stage. Our study provides insights into the mode of action of P1, which is valuable in modifying and developing potent AMPs as antibiotic drugs.
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Affiliation(s)
- Tien-Sheng Tseng
- Institute of Biomedical Sciences, Academia Sinica, Taipei 115, Taiwan.
| | - Keng-Chang Tsai
- National Research Institute of Chinese Medicine, Ministry of Health and Welfare, Taipei 112, Taiwan and The Ph.D. Program for Medical Biotechnology, College of Medical Science and Technology, Taipei Medical University, Taipei, Taiwan
| | - Chinpan Chen
- Institute of Biomedical Sciences, Academia Sinica, Taipei 115, Taiwan.
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17
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Tseng TS, Wang SH, Chang TW, Wei HM, Wang YJ, Tsai KC, Liao YD, Chen C. Sarkosyl-Induced Helical Structure of an Antimicrobial Peptide GW-Q6 Plays an Essential Role in the Binding of Surface Receptor OprI in Pseudomonas aeruginosa. PLoS One 2016; 11:e0164597. [PMID: 27727309 PMCID: PMC5058510 DOI: 10.1371/journal.pone.0164597] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2016] [Accepted: 09/27/2016] [Indexed: 12/27/2022] Open
Abstract
The emergence of antibiotic-resistant microbial strains has become a public health issue and there is an urgent need to develop new anti-infective molecules. Although natural antimicrobial peptides (AMPs) can exert bactericidal activities, they have not shown clinical efficacy. The limitations of native peptides may be overcome with rational design and synthesis. Here, we provide evidence that the bactericidal activity of a synthetic peptide, GW-Q6, against Pseudomonas aeruginosa is mediated through outer membrane protein OprI. Hyperpolarization/depolarization of membrane potential and increase of membrane permeability were observed after GW-Q6 treatment. Helical structure as well as hydrophobicity was induced by an amphipathic surfactant, sarkosyl, for binding to OprI and possible to membrane. NMR studies demonstrated GW-Q6 is an amphipathic α-helical structure in DPC micelles. The paramagnetic relaxation enhancement (PRE) approach revealed that GW-Q6 orients its α-helix segment (K7-K17) into DPC micelles. Additionally, this α-helix segment is critical for membrane permeabilization and antimicrobial activity. Moreover, residues K3, K7, and K14 could be critical for helical formation and membrane binding while residues Y19 and W20 for directing the C-terminus of the peptide to the surface of micelle. Taken together, our study provides mechanistic insights into the mode of action of the GW-Q6 peptide and suggests its applicability in modifying and developing potent AMPs as therapeutic agents.
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Affiliation(s)
- Tien-Sheng Tseng
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
| | - Shih-Han Wang
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
| | - Ting-Wei Chang
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
| | - Hung-Mu Wei
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
| | - Yu-June Wang
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
| | - Keng-Chang Tsai
- National Research Institute of Chinese Medicine, Ministry of Health and Welfare, Taipei, Taiwan
- The Ph.D. Program for Medical Biotechnology, College of Medical Science and Technology, Taipei Medical University, Taipei, Taiwan
| | - You-Di Liao
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
- * E-mail: (YDL); (CC)
| | - Chinpan Chen
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
- * E-mail: (YDL); (CC)
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18
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Huang JY, Chiu YF, Ortega JM, Wang HT, Tseng TS, Ke SC, Roncel M, Chu HA. Mutations of Cytochrome b559 and PsbJ on and near the QC Site in Photosystem II Influence the Regulation of Short-Term Light Response and Photosynthetic Growth of the Cyanobacterium Synechocystis sp. PCC 6803. Biochemistry 2016; 55:2214-26. [DOI: 10.1021/acs.biochem.6b00133] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Affiliation(s)
- Jine-Yung Huang
- Institute
of Plant and Microbial Biology, Academia Sinica, Taipei 11529, Taiwan
| | - Yi-Fang Chiu
- Institute
of Plant and Microbial Biology, Academia Sinica, Taipei 11529, Taiwan
| | - José M. Ortega
- Instituto
de Bioquímica Vegetal y Fotosíntesis, Universidad de Sevilla-CSIC, Avda. Américo Vespucio 49, 41092 Seville, Spain
| | - Hsing-Ting Wang
- Institute
of Plant and Microbial Biology, Academia Sinica, Taipei 11529, Taiwan
| | - Tien-Sheng Tseng
- Institute
of Plant and Microbial Biology, Academia Sinica, Taipei 11529, Taiwan
| | - Shyue-Chu Ke
- Department
of Physics, National Dong Hwa University, Hualien 97401, Taiwan
| | - Mercedes Roncel
- Instituto
de Bioquímica Vegetal y Fotosíntesis, Universidad de Sevilla-CSIC, Avda. Américo Vespucio 49, 41092 Seville, Spain
| | - Hsiu-An Chu
- Institute
of Plant and Microbial Biology, Academia Sinica, Taipei 11529, Taiwan
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19
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Tseng TS, Lee YC, Hsiao NW, Liu YR, Tsai KC. Comparative study between 3D-QSAR and Docking-Based Pharmacophore models for potent Plasomodium falciparum dihydroorotate dehydrogenase inhibitors. Bioorg Med Chem Lett 2016; 26:265-271. [DOI: 10.1016/j.bmcl.2015.12.043] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2015] [Revised: 11/03/2015] [Accepted: 12/12/2015] [Indexed: 12/17/2022]
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20
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Tseng TS, Chuang SM, Hsiao NW, Chen YW, Lee YC, Lin CC, Huang C, Tsai KC. Discovery of a potent cyclooxygenase-2 inhibitor, S4, through docking-based pharmacophore screening, in vivo and in vitro estimations. Mol BioSyst 2016; 12:2541-51. [DOI: 10.1039/c6mb00229c] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Cyclooxygenase (COX; EC: 1.14.99.1), the key enzyme in prostaglandin production in the human body, is a major pharmacological target for developing anti-inflammatory agents.
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Affiliation(s)
- Tien-Sheng Tseng
- National Research Institute of Chinese Medicine
- Ministry of Health and Welfare
- Taipei
- Taiwan
- Institute of Biomedical Sciences
| | - Show-Mei Chuang
- Institute of Biomedical Sciences
- National Chung Hsing University
- Taichung
- Taiwan
| | - Nai-Wan Hsiao
- Institute of Biotechnology
- National Changhua University of Education
- Changhua
- Taiwan
| | | | - Yu-Ching Lee
- The Center of Translational Medicine
- Taipei Medical University
- Taipei
- Taiwan
- The Ph.D. Program for Medical Biotechnology
| | - Chi-Chen Lin
- Institute of Biomedical Sciences
- National Chung Hsing University
- Taichung
- Taiwan
| | - Cheng Huang
- National Research Institute of Chinese Medicine
- Ministry of Health and Welfare
- Taipei
- Taiwan
| | - Keng-Chang Tsai
- National Research Institute of Chinese Medicine
- Ministry of Health and Welfare
- Taipei
- Taiwan
- The Ph.D. Program for Medical Biotechnology
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21
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Tseng TS, Tsai KC, Chen WC, Wang YT, Lee YC, Lu CK, Don MJ, Chang CY, Lee CH, Lin HH, Hsu HJ, Hsiao NW. Discovery of Potent Cysteine-Containing Dipeptide Inhibitors against Tyrosinase: A Comprehensive Investigation of 20 × 20 Dipeptides in Inhibiting Dopachrome Formation. J Agric Food Chem 2015; 63:6181-6188. [PMID: 26083974 DOI: 10.1021/acs.jafc.5b01026] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Tyrosinase is an essential copper-containing enzyme required for melanin synthesis. The overproduction and abnormal accumulation of melanin cause hyperpigmentation and neurodegenerative diseases. Thus, tyrosinase is promising for use in medicine and cosmetics. Our previous study identified a natural product, A5, resembling the structure of the dipeptide WY and apparently inhibiting tyrosinase. Here, we comprehensively estimated the inhibitory capability of 20 × 20 dipeptides against mushroom tyrosinase. We found that cysteine-containing dipeptides, directly blocking the active site of tyrosinase, are highly potent in inhibition; in particular, N-terminal cysteine-containing dipeptides markedly outperform the C-terminal-containing ones. The cysteine-containing dipeptides, CE, CS, CY, and CW, show comparative bioactivities, and tyrosine-containing dipeptides are substrate-like inhibitors. The dipeptide PD attenuates 16.5% melanin content without any significant cytotoxicity. This study reveals the functional role of cysteine residue positional preference and the selectivity of specific amino acids in cysteine-containing dipeptides against tyrosinase, aiding in developing skin-whitening products.
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Affiliation(s)
- Tien-Sheng Tseng
- †Institute of Biotechnology, National Changhua University of Education, Changhua, Taiwan
| | - Keng-Chang Tsai
- ‡National Research Institute of Chinese Medicine, Ministry of Health and Welfare, Taipei, Taiwan
| | - Wang-Chuan Chen
- §The School of Chinese Medicine for Post Baccalaureate, I-Shou University, Kaohsiung, Taiwan
- #Department of Chinese Medicine, E-Da Hospital, Kaohsiung, Taiwan
| | - Yeng-Tseng Wang
- ⊥Department of Biochemistry, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Yu-Ching Lee
- ΔThe Center of Translational Medicine, Taipei Medical University, Taipei, Taiwan
- ⊗Ph.D. Program for Biotechnology in Medicine, College of Medical Science and Technology, Taipei Medical University, Taipei, Taiwan
| | - Chung-Kuang Lu
- ‡National Research Institute of Chinese Medicine, Ministry of Health and Welfare, Taipei, Taiwan
| | - Ming-Jaw Don
- ‡National Research Institute of Chinese Medicine, Ministry of Health and Welfare, Taipei, Taiwan
| | - Chang-Yu Chang
- ΠDepartment of Medical Technology, Jen-Teh Junior College of Medicine, Nursing and Management, Miaoli, Taiwan
| | - Ching-Hsiao Lee
- ΠDepartment of Medical Technology, Jen-Teh Junior College of Medicine, Nursing and Management, Miaoli, Taiwan
| | - Hui-Hsiung Lin
- †Institute of Biotechnology, National Changhua University of Education, Changhua, Taiwan
- ‡National Research Institute of Chinese Medicine, Ministry of Health and Welfare, Taipei, Taiwan
| | - Hung-Ju Hsu
- ‡National Research Institute of Chinese Medicine, Ministry of Health and Welfare, Taipei, Taiwan
| | - Nai-Wan Hsiao
- †Institute of Biotechnology, National Changhua University of Education, Changhua, Taiwan
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22
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Lee YC, Hsiao NW, Tseng TS, Chen WC, Lin HH, Leu SJ, Yang EW, Tsai KC. Phage display-mediated discovery of novel tyrosinase-targeting tetrapeptide inhibitors reveals the significance of N-terminal preference of cysteine residues and their functional sulfur atom. Mol Pharmacol 2014; 87:218-30. [PMID: 25403678 DOI: 10.1124/mol.114.094185] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Tyrosinase, a key copper-containing enzyme involved in melanin biosynthesis, is closely associated with hyperpigmentation disorders, cancer, and neurodegenerative diseases, and as such, it is an essential target in medicine and cosmetics. Known tyrosinase inhibitors possess adverse side effects, and there are no safety regulations; therefore, it is necessary to develop new inhibitors with fewer side effects and less toxicity. Peptides are exquisitely specific to their in vivo targets, with high potencies and relatively few off-target side effects. Thus, we systematically and comprehensively investigated the tyrosinase-inhibitory abilities of N- and C-terminal cysteine/tyrosine-containing tetrapeptides by constructing a phage-display random tetrapeptide library and conducting computational molecular docking studies on novel tyrosinase tetrapeptide inhibitors. We found that N-terminal cysteine-containing tetrapeptides exhibited the most potent tyrosinase-inhibitory abilities. The positional preference of cysteine residues at the N terminus in the tetrapeptides significantly contributed to their tyrosinase-inhibitory function. The sulfur atom in cysteine moieties of N- and C-terminal cysteine-containing tetrapeptides coordinated with copper ions, which then tightly blocked substrate-binding sites. N- and C-terminal tyrosine-containing tetrapeptides functioned as competitive inhibitors against mushroom tyrosinase by using the phenol ring of tyrosine to stack with the imidazole ring of His263, thus competing for the substrate-binding site. The N-terminal cysteine-containing tetrapeptide CRVI exhibited the strongest tyrosinase-inhibitory potency (with an IC50 of 2.7 ± 0.5 μM), which was superior to those of the known tyrosinase inhibitors (arbutin and kojic acid) and outperformed kojic acid-tripeptides, mimosine-FFY, and short-sequence oligopeptides at inhibiting mushroom tyrosinase.
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Affiliation(s)
- Yu-Ching Lee
- The Center of Translational Medicine, Antibody and Hybridoma Core Facility (Y.-C.L.), and Graduate Institute of Medical Sciences, Department of Microbiology and Immunology, School of Medicine, College of Medicine (S.-J.L.), Taipei Medical University, Taipei, Taiwan; Institute of Biotechnology, National Changhua University of Education, Changhua, Taiwan (N.-W.H., T.-S.T., H.-H.L.); National Research Institute of Chinese Medicine, Ministry of Health and Welfare, Taipei, Taiwan (T.-S.T., H.-H.L., K.-C.T.); The School of Chinese Medicine for Post Baccalaureate, I-Shou University, Kaohsiung, Taiwan (W.-C.C.); Department of Chinese Medicine, E-Da hospital, Kaohsiung, Taiwan (W.-C.C.); and Department of Computer Science and Engineering, University of California, Riverside, California (E.-W.Y.)
| | - Nai-Wan Hsiao
- The Center of Translational Medicine, Antibody and Hybridoma Core Facility (Y.-C.L.), and Graduate Institute of Medical Sciences, Department of Microbiology and Immunology, School of Medicine, College of Medicine (S.-J.L.), Taipei Medical University, Taipei, Taiwan; Institute of Biotechnology, National Changhua University of Education, Changhua, Taiwan (N.-W.H., T.-S.T., H.-H.L.); National Research Institute of Chinese Medicine, Ministry of Health and Welfare, Taipei, Taiwan (T.-S.T., H.-H.L., K.-C.T.); The School of Chinese Medicine for Post Baccalaureate, I-Shou University, Kaohsiung, Taiwan (W.-C.C.); Department of Chinese Medicine, E-Da hospital, Kaohsiung, Taiwan (W.-C.C.); and Department of Computer Science and Engineering, University of California, Riverside, California (E.-W.Y.)
| | - Tien-Sheng Tseng
- The Center of Translational Medicine, Antibody and Hybridoma Core Facility (Y.-C.L.), and Graduate Institute of Medical Sciences, Department of Microbiology and Immunology, School of Medicine, College of Medicine (S.-J.L.), Taipei Medical University, Taipei, Taiwan; Institute of Biotechnology, National Changhua University of Education, Changhua, Taiwan (N.-W.H., T.-S.T., H.-H.L.); National Research Institute of Chinese Medicine, Ministry of Health and Welfare, Taipei, Taiwan (T.-S.T., H.-H.L., K.-C.T.); The School of Chinese Medicine for Post Baccalaureate, I-Shou University, Kaohsiung, Taiwan (W.-C.C.); Department of Chinese Medicine, E-Da hospital, Kaohsiung, Taiwan (W.-C.C.); and Department of Computer Science and Engineering, University of California, Riverside, California (E.-W.Y.)
| | - Wang-Chuan Chen
- The Center of Translational Medicine, Antibody and Hybridoma Core Facility (Y.-C.L.), and Graduate Institute of Medical Sciences, Department of Microbiology and Immunology, School of Medicine, College of Medicine (S.-J.L.), Taipei Medical University, Taipei, Taiwan; Institute of Biotechnology, National Changhua University of Education, Changhua, Taiwan (N.-W.H., T.-S.T., H.-H.L.); National Research Institute of Chinese Medicine, Ministry of Health and Welfare, Taipei, Taiwan (T.-S.T., H.-H.L., K.-C.T.); The School of Chinese Medicine for Post Baccalaureate, I-Shou University, Kaohsiung, Taiwan (W.-C.C.); Department of Chinese Medicine, E-Da hospital, Kaohsiung, Taiwan (W.-C.C.); and Department of Computer Science and Engineering, University of California, Riverside, California (E.-W.Y.)
| | - Hui-Hsiung Lin
- The Center of Translational Medicine, Antibody and Hybridoma Core Facility (Y.-C.L.), and Graduate Institute of Medical Sciences, Department of Microbiology and Immunology, School of Medicine, College of Medicine (S.-J.L.), Taipei Medical University, Taipei, Taiwan; Institute of Biotechnology, National Changhua University of Education, Changhua, Taiwan (N.-W.H., T.-S.T., H.-H.L.); National Research Institute of Chinese Medicine, Ministry of Health and Welfare, Taipei, Taiwan (T.-S.T., H.-H.L., K.-C.T.); The School of Chinese Medicine for Post Baccalaureate, I-Shou University, Kaohsiung, Taiwan (W.-C.C.); Department of Chinese Medicine, E-Da hospital, Kaohsiung, Taiwan (W.-C.C.); and Department of Computer Science and Engineering, University of California, Riverside, California (E.-W.Y.)
| | - Sy-Jye Leu
- The Center of Translational Medicine, Antibody and Hybridoma Core Facility (Y.-C.L.), and Graduate Institute of Medical Sciences, Department of Microbiology and Immunology, School of Medicine, College of Medicine (S.-J.L.), Taipei Medical University, Taipei, Taiwan; Institute of Biotechnology, National Changhua University of Education, Changhua, Taiwan (N.-W.H., T.-S.T., H.-H.L.); National Research Institute of Chinese Medicine, Ministry of Health and Welfare, Taipei, Taiwan (T.-S.T., H.-H.L., K.-C.T.); The School of Chinese Medicine for Post Baccalaureate, I-Shou University, Kaohsiung, Taiwan (W.-C.C.); Department of Chinese Medicine, E-Da hospital, Kaohsiung, Taiwan (W.-C.C.); and Department of Computer Science and Engineering, University of California, Riverside, California (E.-W.Y.)
| | - Ei-Wen Yang
- The Center of Translational Medicine, Antibody and Hybridoma Core Facility (Y.-C.L.), and Graduate Institute of Medical Sciences, Department of Microbiology and Immunology, School of Medicine, College of Medicine (S.-J.L.), Taipei Medical University, Taipei, Taiwan; Institute of Biotechnology, National Changhua University of Education, Changhua, Taiwan (N.-W.H., T.-S.T., H.-H.L.); National Research Institute of Chinese Medicine, Ministry of Health and Welfare, Taipei, Taiwan (T.-S.T., H.-H.L., K.-C.T.); The School of Chinese Medicine for Post Baccalaureate, I-Shou University, Kaohsiung, Taiwan (W.-C.C.); Department of Chinese Medicine, E-Da hospital, Kaohsiung, Taiwan (W.-C.C.); and Department of Computer Science and Engineering, University of California, Riverside, California (E.-W.Y.)
| | - Keng-Chang Tsai
- The Center of Translational Medicine, Antibody and Hybridoma Core Facility (Y.-C.L.), and Graduate Institute of Medical Sciences, Department of Microbiology and Immunology, School of Medicine, College of Medicine (S.-J.L.), Taipei Medical University, Taipei, Taiwan; Institute of Biotechnology, National Changhua University of Education, Changhua, Taiwan (N.-W.H., T.-S.T., H.-H.L.); National Research Institute of Chinese Medicine, Ministry of Health and Welfare, Taipei, Taiwan (T.-S.T., H.-H.L., K.-C.T.); The School of Chinese Medicine for Post Baccalaureate, I-Shou University, Kaohsiung, Taiwan (W.-C.C.); Department of Chinese Medicine, E-Da hospital, Kaohsiung, Taiwan (W.-C.C.); and Department of Computer Science and Engineering, University of California, Riverside, California (E.-W.Y.)
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23
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Hsiao NW, Tseng TS, Lee YC, Chen WC, Lin HH, Chen YR, Wang YT, Hsu HJ, Tsai KC. Serendipitous discovery of short peptides from natural products as tyrosinase inhibitors. J Chem Inf Model 2014; 54:3099-111. [PMID: 25317506 DOI: 10.1021/ci500370x] [Citation(s) in RCA: 31] [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: 11/29/2022]
Abstract
Tyrosinase, which is the crucial copper-containing enzyme involved in melanin synthesis, is strongly associated with hyperpigmentation disorders, cancer, and neurodegenerative disease; thus, it has attracted considerable interest in the fields of medicine and cosmetics. The known tyrosinase inhibitors show numerous adverse side effects, and there is a lack of safety regulations governing their use. As a result, there is a need to develop novel inhibitors with no toxicity and long-term stability. In this study, we use molecular docking and pharmacophore modeling to construct a reasonable and reliable pharmacophore model, called Hypo 1, that could be used for identifying potent natural products with crucial complementary functional groups for mushroom tyrosinase inhibition. It was observed that, out of 47,263 natural compounds, A5 structurally resembles a dipeptide (WY) and natural compound B16 is the equivalent of a tripeptide (KFY), revealing that the C-terminus tyrosine residues play a key role in tyrosinase inhibition. Tripeptides RCY and CRY, which show high tyrosinase inhibitory potency, revealed a positional and functional preference for the cysteine residue at the N-terminus of the tripeptides, essentially determining the capacity of tyrosinase inhibition. CRY and RCY used the thiol group of cysteine residues to coordinate with the Cu ions in the active site of tyrosinase and showed reduced tyrosinase activity. We discovered the novel tripeptide CRY that shows the most striking inhibitory potency against mushroom tyrosinase (IC50 = 6.16 μM); this tripeptide is more potent than the known oligopeptides and comparable with kojic acid-tripeptides. Our study provides an insight into the structural and functional roles of key amino acids of tripeptides derived from the natural compound B16, and the results are expected to be useful for the development of tyrosinase inhibitors.
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Affiliation(s)
- Nai-Wan Hsiao
- Institute of Biotechnology, National Changhua University of Education , Changhua 500, Taiwan
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24
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Tseng TS, Cheng CS, Hsu STD, Shih MF, He PL, Lyu PC. Residue-specific annotation of disorder-to-order transition and cathepsin inhibition of a propeptide-like crammer from D. melanogaster. PLoS One 2013; 8:e54187. [PMID: 23349821 PMCID: PMC3551606 DOI: 10.1371/journal.pone.0054187] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2012] [Accepted: 12/07/2012] [Indexed: 11/19/2022] Open
Abstract
Drosophila melanogaster crammer is a novel cathepsin inhibitor involved in long-term memory formation. A molten globule-to-ordered structure transition is required for cathepsin inhibition. This study reports the use of alanine scanning to probe the critical residues in the two hydrophobic cores and the salt bridges of crammer in the context of disorder-to-order transition and cathepsin inhibition. Alanine substitution of the aromatic residues W9, Y12, F16, Y20, Y32, and W53 within the hydrophobic cores, and charged residues E8, R28, R29, and E67 in the salt bridges considerably decrease the ability of crammer to inhibit Drosophila cathepsin B (CTSB). Far-UV circular dichroism (CD), intrinsic fluorescence, and nuclear magnetic resonance (NMR) spectroscopies show that removing most of the aromatic and charged side-chains substantially reduces thermostability, alters pH-dependent helix formation, and disrupts the molten globule-to-ordered structure transition. Molecular modeling indicates that W53 in the hydrophobic Core 2 is essential for the interaction between crammer and the prosegment binding loop (PBL) of CTSB; the salt bridge between R28 and E67 is critical for the appropriate alignment of the α-helix 4 toward the CTSB active cleft. The results of this study show detailed residue-specific dissection of folding transition and functional contributions of the hydrophobic cores and salt bridges in crammer, which have hitherto not been characterized for cathepsin inhibition by propeptide-like cysteine protease inhibitors. Because of the involvements of cathepsin inhibitors in neurodegenerative diseases, these structural insights can serve as a template for further development of therapeutic inhibitors against human cathepsins.
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Affiliation(s)
- Tien-Sheng Tseng
- Institute of Bioinformatics and Structural Biology, National Tsing Hua University, Hsinchu, Taiwan
| | - Chao-Sheng Cheng
- Institute of Bioinformatics and Structural Biology, National Tsing Hua University, Hsinchu, Taiwan
| | | | - Min-Fang Shih
- Institute of Bioinformatics and Structural Biology, National Tsing Hua University, Hsinchu, Taiwan
| | - Pei-Lin He
- Institute of Bioinformatics and Structural Biology, National Tsing Hua University, Hsinchu, Taiwan
| | - Ping-Chiang Lyu
- Institute of Bioinformatics and Structural Biology, National Tsing Hua University, Hsinchu, Taiwan
- Graduate Institute of Molecular Systems Biomedicine, China Medical University, Taichung, Taiwan
- * E-mail:
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25
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Izhaki A, Swain SM, Tseng TS, Borochov A, Olszewski NE, Weiss D. The role of SPY and its TPR domain in the regulation of gibberellin action throughout the life cycle of Petunia hybrida plants. Plant J 2001; 28:181-190. [PMID: 11722761 DOI: 10.1046/j.1365-313x.2001.01144.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
SPY acts as a negative regulator of gibberellin (GA) action in Arabidopsis, but its mode of action and regulation are still unknown. SPY over-expression in transgenic petunia plants affected various GA-regulated processes, including seed germination, shoot elongation, flower initiation, flower development and the expression of a GA-induced gene, GIP. A similar phenotype was obtained when wild-type petunia plants were treated with the GA-biosynthesis inhibitor, paclobutrazol. The N-terminus of SPY contains tetratricopeptide repeats (TPR). TPR motifs participate in protein-protein interactions, suggesting that SPY is part of a multiprotein complex. To test this hypothesis, we over-expressed the SPY's TPR region without the catalytic domain in transgenic petunia and generated a dominant-negative SPY mutant. The transgenic seeds were able to germinate on paclobutrazol, suggesting an enhanced GA signal. We cloned the petunia SPY homologue, PhSPY, and showed that its mRNA level is not affected by GA or ABA. The results of this study support the role of SPY as a negative regulator of GA action, suggest that the TPR domain is required for the interaction with other proteins to form an active complex and indicate that different plants use similar mechanisms to transduce the GA signal.
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Affiliation(s)
- A Izhaki
- The Institute of Plant Sciences and Genetics in Agriculture, Faculty of Agricultural, Food and Environmental Quality Sciences, The Hebrew University of Jerusalem, PO Box 12, Rehovot 76100, Israel
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26
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Tseng TS, Swain SM, Olszewski NE. Ectopic expression of the tetratricopeptide repeat domain of SPINDLY causes defects in gibberellin response. Plant Physiol 2001; 126:1250-1258. [PMID: 11457975 PMCID: PMC116481 DOI: 10.1104/pp.126.3.1250] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2000] [Revised: 02/26/2001] [Accepted: 04/10/2001] [Indexed: 05/23/2023]
Abstract
The SPINDLY (SPY) protein of Arabidopsis is a negative regulator of gibberellin (GA) response. The SPY protein has 10 copies of the tetratricopeptide repeat (TPR) at the N terminus. TPR motifs function as protein-protein interaction domains. Several spy alleles are affected only in the TPR region suggesting that protein-protein interactions mediated by this domain are important for proper GA signaling. We have used a reverse genetics approach to further investigate the role of the TPR domain. The TPR domain of SPY was overexpressed in wild-type, gai, and spy plants. Expression of the TPR domain alone is not sufficient to rescue spy mutants. Expression of the TPR domain in a wild-type background produces phenotypes similar to those caused by loss-of-function spy mutants including resistance to GA biosynthesis inhibitors, short hypocotyl length, and early flowering. The dwarfing of the floral shoot internodes caused by the gai mutation was suppressed by expression of the TRP domain. Expression of the TPR domain had no effect on the abundance of endogenous SPY mRNA. The TPR domain was found to interact with SPY both in vitro and in yeast two-hybrid assays. These data indicate that the TPR domain of SPY can participate in protein-protein interactions and that these interactions are important for the proper functioning of SPY.
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Affiliation(s)
- T S Tseng
- Department of Plant Biology and Plant Molecular Genetics Institute, University of Minnesota, St. Paul, Minnesota 55108, USA
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27
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Swain SM, Tseng TS, Olszewski NE. Altered expression of SPINDLY affects gibberellin response and plant development. Plant Physiol 2001; 126:1174-85. [PMID: 11457967 PMCID: PMC116473 DOI: 10.1104/pp.126.3.1174] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2000] [Revised: 01/24/2001] [Accepted: 03/12/2001] [Indexed: 05/19/2023]
Abstract
Gibberellins (GAs) are plant hormones with diverse roles in plant growth and development. SPINDLY (SPY) is one of several genes identified in Arabidopsis that are involved in GA response and it is thought to encode an O-GlcNAc transferase. Genetic analysis suggests that SPY negatively regulates GA response. To test the hypothesis that SPY acts specifically as a negatively acting component of GA signal transduction, spy mutants and plants containing a 35S:SPY construct have been examined. A detailed investigation of the spy mutant phenotype suggests that SPY may play a role in plant development beyond its role in GA signaling. Consistent with this suggestion, the analysis of spy er plants suggests that the ERECTA (ER) gene, which has not been implicated as having a role in GA signaling, appears to enhance the non-GA spy mutant phenotypes. Arabidopsis plants containing a 35S:SPY construct possess reduced GA response at seed germination, but also possess phenotypes consistent with increased GA response, although not identical to spy mutants, during later vegetative and reproductive development. Based on these results, the hypothesis that SPY is specific for GA signaling is rejected. Instead, it is proposed that SPY is a negative regulator of GA response that has additional roles in plant development.
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Affiliation(s)
- S M Swain
- Department of Plant Biology and Plant Molecular Genetics Institute, University of Minnesota, St. Paul, Minnesota 55108, USA.
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28
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Chu NS, Wu CL, Tseng TS, Kuo LL. Sphenoidal EEG recording using acupuncture needle electrode in complex partial seizure. Electroencephalogr Clin Neurophysiol 1991; 79:119-26. [PMID: 1713825 DOI: 10.1016/0013-4694(91)90049-a] [Citation(s) in RCA: 10] [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] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Sphenoidal EEG recording using an uninsulated acupuncture needle electrode were performed in 41 patients with or suspected of complex partial seizures of temporal lobe origin. The anterior temporal spikes were detected by the routine EEG in 17 patients (41%) and by the acupuncture sphenoidal needle in 29 patients (70%). The anterior temporal spikes recorded by the acupuncture needle were almost identical in configuration, amplitude and distribution to those recorded by conventional wire or insulated needle sphenoidal electrodes. The sequence in the frequency of spike detection by these 3 types of sphenoidal electrode were SP1-2, T1-2, F7-8 and A1-2 locations. The spikes of maximal amplitude were most frequently recorded by the SP electrode followed by the T1-2 electrode. The placement of the disposable acupuncture needle was simple and safe. Patients experienced minimal discomfort or pain that lasted at most 0.5 h. No complications occurred. The records were generally free of artifacts. It is concluded that the acupuncture needle can be used as sphenoidal electrode in outpatient EEG recording for the diagnosis of complex partial seizures of anterior temporal-origin.
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Affiliation(s)
- N S Chu
- Department of Neurology, Chang Gung Medical College and Memorial Hospital, Taipei, Taiwan
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