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de Sousa LO, Oliveira LN, Naves RB, Pereira ALA, Santiago Freitas E Silva K, de Almeida Soares CM, de Sousa Lima P. The dual role of SrbA from Paracoccidioides lutzii: a hypoxic regulator. Braz J Microbiol 2021; 52:1135-1149. [PMID: 34148216 PMCID: PMC8382145 DOI: 10.1007/s42770-021-00527-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Accepted: 05/12/2021] [Indexed: 11/26/2022] Open
Abstract
The fungus Paracoccidioides lutzii is one of the species of the Paracoccidioides genus, responsible for a neglected human mycosis, endemic in Latin America, the paracoccidioidomycosis (PCM). In order to survive in the host, the fungus overcomes a hostile environment under low levels of oxygen (hypoxia) during the infectious process. The hypoxia adaptation mechanisms are variable among human pathogenic fungi and worthy to be investigated in Paracoccidoides spp. Previous proteomic results identified that P. lutzii responds to hypoxia and it has a functional homolog of the SrbA transcription factor, a well-described hypoxic regulator. However, the direct regulation of genes by SrbA and the biological processes it governs while performing protein interactions have not been revealed yet. The goal of this study was to demonstrate the potential of SrbA targets genes in P. lutzii. In addition, to show the SrbA three-dimensional aspects as well as a protein interaction map and important regions of interaction with predicted targets. The results show that SrbA-regulated genes were involved with several biological categories, such as metabolism, energy, basal processes for cell maintenance, fungal morphogenesis, defense, virulence, and signal transduction. Moreover, in order to investigate the SrbA's role as a protein, we performed a 3D simulation and also a protein-protein network linked to this hypoxic regulator. These in silico analyses revealed relevant aspects regarding the biology of this pathogen facing hypoxia and highlight the potential of SrbA as an antifungal target in the future.
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Affiliation(s)
- Lorena Ordones de Sousa
- Unidade Universitária de Itapuranga, Câmpus Cora Coralina, Instituto Acadêmico de Ciências da Saúde e Biológicas, Universidade Estadual de Goiás, Itapuranga, Goiás, Brazil
| | - Lucas Nojosa Oliveira
- Laboratório de Biologia Molecular, Instituto de Ciências Biológicas II, Campus II, Universidade Federal de Goiás, Goiânia, Goiás, Brazil
| | - Raphaela Barbosa Naves
- Unidade Universitária de Itapuranga, Câmpus Cora Coralina, Instituto Acadêmico de Ciências da Saúde e Biológicas, Universidade Estadual de Goiás, Itapuranga, Goiás, Brazil
| | - André Luiz Araújo Pereira
- Unidade Universitária de Itapuranga, Câmpus Cora Coralina, Instituto Acadêmico de Ciências da Saúde e Biológicas, Universidade Estadual de Goiás, Itapuranga, Goiás, Brazil
| | - Kleber Santiago Freitas E Silva
- Laboratório de Biologia Molecular, Instituto de Ciências Biológicas II, Campus II, Universidade Federal de Goiás, Goiânia, Goiás, Brazil
| | - Célia Maria de Almeida Soares
- Laboratório de Biologia Molecular, Instituto de Ciências Biológicas II, Campus II, Universidade Federal de Goiás, Goiânia, Goiás, Brazil
| | - Patrícia de Sousa Lima
- Unidade Universitária de Itapuranga, Câmpus Cora Coralina, Instituto Acadêmico de Ciências da Saúde e Biológicas, Universidade Estadual de Goiás, Itapuranga, Goiás, Brazil.
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2
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Qin C, Yang X, Zuo Z, Yang L, Yang F, Cao Z, Chen Z, Wu Y. BmK86-P1, a New Degradation Peptide with Desirable Thermostability and Kv1.2 Channel-Specific Activity from Traditional Chinese Scorpion Medicinal Material. Toxins (Basel) 2021; 13:toxins13090610. [PMID: 34564614 PMCID: PMC8472965 DOI: 10.3390/toxins13090610] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Revised: 08/23/2021] [Accepted: 08/27/2021] [Indexed: 11/16/2022] Open
Abstract
Thermally processed Buthus martensii Karsch scorpions are a traditional Chinese medical material for treating various diseases. However, their pharmacological foundation remains unclear. Here, a new degraded peptide of scorpion toxin was identified in Chinese scorpion medicinal material by proteomics. It was named BmK86-P1 and has six conserved cysteine residues. Homology modeling and circular dichroism spectra experiments revealed that BmK86-P1 not only contained representative disulfide bond-stabilized α-helical and β-sheet motifs but also showed remarkable stability at test temperatures from 20-95 °C. Electrophysiology experiments indicated that BmK86-P1 was a highly potent and selective inhibitor of the hKv1.2 channel with IC50 values of 28.5 ± 6.3 nM. Structural and functional dissection revealed that two residues of BmK86-P1 (i.e., Lys19 and Ile21) were the key residues that interacted with the hKv1.2 channel. In addition, channel chimeras and mutagenesis experiments revealed that three amino acids (i.e., Gln357, Val381 and Thr383) of the hKv1.2 channel were responsible for BmK86-P1 selectivity. This research uncovered a new bioactive peptide from traditional Chinese scorpion medicinal material that has desirable thermostability and Kv1.2 channel-specific activity, which strongly suggests that thermally processed scorpions are novel peptide resources for new drug discovery for the Kv1.2 channel-related ataxia and epilepsy diseases.
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Affiliation(s)
- Chenhu Qin
- College of Life Sciences, Wuhan University, Wuhan 430072, China; (C.Q.); (X.Y.); (Z.Z.); (L.Y.); (F.Y.); (Z.C.); (Z.C.)
- Department of Biochemistry and Molecular Biology, College of Basic Medicine, Hubei University of Medicine, Shiyan 442000, China
| | - Xuhua Yang
- College of Life Sciences, Wuhan University, Wuhan 430072, China; (C.Q.); (X.Y.); (Z.Z.); (L.Y.); (F.Y.); (Z.C.); (Z.C.)
| | - Zheng Zuo
- College of Life Sciences, Wuhan University, Wuhan 430072, China; (C.Q.); (X.Y.); (Z.Z.); (L.Y.); (F.Y.); (Z.C.); (Z.C.)
| | - Liuting Yang
- College of Life Sciences, Wuhan University, Wuhan 430072, China; (C.Q.); (X.Y.); (Z.Z.); (L.Y.); (F.Y.); (Z.C.); (Z.C.)
| | - Fan Yang
- College of Life Sciences, Wuhan University, Wuhan 430072, China; (C.Q.); (X.Y.); (Z.Z.); (L.Y.); (F.Y.); (Z.C.); (Z.C.)
| | - Zhijian Cao
- College of Life Sciences, Wuhan University, Wuhan 430072, China; (C.Q.); (X.Y.); (Z.Z.); (L.Y.); (F.Y.); (Z.C.); (Z.C.)
| | - Zongyun Chen
- College of Life Sciences, Wuhan University, Wuhan 430072, China; (C.Q.); (X.Y.); (Z.Z.); (L.Y.); (F.Y.); (Z.C.); (Z.C.)
- Department of Biochemistry and Molecular Biology, College of Basic Medicine, Hubei University of Medicine, Shiyan 442000, China
| | - Yingliang Wu
- College of Life Sciences, Wuhan University, Wuhan 430072, China; (C.Q.); (X.Y.); (Z.Z.); (L.Y.); (F.Y.); (Z.C.); (Z.C.)
- Center for BioDrug Research, Wuhan University, Wuhan 430072, China
- Correspondence:
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3
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Xie Z, Zhao Y, Yang W, Li W, Wu Y, Chen Z. Methotrexate, a small molecular scaffold targeting Kv1.3 channel extracellular pore region. Biochem Biophys Res Commun 2020; 532:265-270. [PMID: 32863001 DOI: 10.1016/j.bbrc.2020.08.050] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Revised: 08/14/2020] [Accepted: 08/18/2020] [Indexed: 11/18/2022]
Abstract
Methotrexate (MTX) has been widely used for the treatment of many types of autoimmune diseases, such as rheumatoid arthritis, psoriasis and dermatomyositis. However, its pharmacological mechanism is still unclear completely. In this study, we found that MTX is a potent and selective inhibitor of the Kv1.3 channel, a class of potassium channels highly associated with autoimmune diseases. Electrophysiological experiments showed that MTX inhibited human Kv1.3 channel with an IC50 of 41.5 ± 24.9 nM, and 1 μM MTX inhibited 32.6 ± 1.3% and 25.6 ± 2.2% of human Kv1.1 and Kv1.2 channel currents, respectively. These data implied the unique selectivity of MTX towards the Kv1.3 channel. Excitingly, using channel activation and chimeric experiments, we found that MTX bound to the outer pore region of Kv1.3 channel. Mutagenesis experiments in the Kv.3 channel extracellular pore region further showed that the Dsp371, Thr373 and His399 residues of outer pore region of Kv1.3 channel played important roles in MTX inhibiting activities. In conclusion, MTX inhibited Kv1.3 channel by targeting extracellular pore region, which is different form all the report small molecules, such as PAP-1 and 4-AP, but similar with many natural animal toxin peptides, such as ChTX, ShK and BmKTX. To the best of our knowledge, MTX is the first small molecular scaffold targeting the Kv1.3 channel extracellular pore region, suggesting its potential applications for designing novel Kv1.3 lead drugs and treating Kv1.3 channel-associated autoimmune diseases.
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Affiliation(s)
- Zili Xie
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan, 430072, China
| | - Yonghui Zhao
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan, 430072, China
| | - Weishan Yang
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan, 430072, China
| | - Wenxin Li
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan, 430072, China; Biodrug Research Center, Wuhan University, Wuhan, 430072, China
| | - Yingliang Wu
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan, 430072, China; Biodrug Research Center, Wuhan University, Wuhan, 430072, China.
| | - Zongyun Chen
- Department of Biochemistry and Molecular Biology, Institute of Basic Medical Sciences, College of Basic Medicine, Hubei University of Medicine, Shiyan, 442000, China; State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan, 430072, China; Biodrug Research Center, Wuhan University, Wuhan, 430072, China.
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Shen B, Cao Z, Wu Y, Yi W, Zhu Z, Lv Z, Zhu C, Yu Y. Purlisin, a toxin‐like defensin derived from clinical pathogenic fungus
Purpureocillium lilacinum
with both antimicrobial and potassium channel inhibitory activities. FASEB J 2020; 34:15093-15107. [PMID: 32918769 DOI: 10.1096/fj.202000029rr] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2020] [Revised: 08/16/2020] [Accepted: 08/31/2020] [Indexed: 01/22/2023]
Affiliation(s)
- Bingzheng Shen
- Department of Pharmacy Renmin Hospital of Wuhan University Wuhan China
- State Key Laboratory of Virology, College of Life Sciences Wuhan University Wuhan China
| | - Zhijian Cao
- State Key Laboratory of Virology, College of Life Sciences Wuhan University Wuhan China
| | - Yingliang Wu
- State Key Laboratory of Virology, College of Life Sciences Wuhan University Wuhan China
| | - Wei Yi
- Department of Neurosurgery Renmin Hospital of Wuhan University Wuhan China
| | - Zhanyong Zhu
- Department of Plastic Surgery Renmin Hospital of Wuhan University Wuhan China
| | - Zhihua Lv
- Department of Clinical Laboratory Renmin Hospital of Wuhan University Wuhan China
| | - Chengliang Zhu
- Department of Clinical Laboratory Renmin Hospital of Wuhan University Wuhan China
| | - Yan Yu
- Department of Gastroenterology Tongji Hospital of Tongji Medical College, Huazhong University of Science and Technology Wuhan China
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5
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Mayorga-Flores M, Chantôme A, Melchor-Meneses CM, Domingo I, Titaux-Delgado GA, Galindo-Murillo R, Vandier C, del Río-Portilla F. Novel Blocker of Onco SK3 Channels Derived from Scorpion Toxin Tamapin and Active against Migration of Cancer Cells. ACS Med Chem Lett 2020; 11:1627-1633. [PMID: 32832033 DOI: 10.1021/acsmedchemlett.0c00300] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Accepted: 07/10/2020] [Indexed: 11/28/2022] Open
Abstract
Peptide-based therapy against cancer is a field of great interest for biomedical developments. Since it was shown that SK3 channels promote cancer cell migration and metastatic development, we started using these channels as targets for the development of antimetastatic drugs. Particularly, tamapin (a peptide found in the venom of the scorpion Mesobuthus tamulus) is the most specific toxin against the SK2 channel currently known. Considering this fact, we designed diverse tamapin mutants based on three different hypotheses to discover a new potent molecule to block SK3 channels. We performed in vitro studies to evaluate this new toxin derivative inhibitor of cancer cell migration. Our results can be used to generate a new tamapin-based therapy against cancer cells that express SK3 channels.
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Affiliation(s)
- Marlen Mayorga-Flores
- Departamento de Química de Biomacromoléculas, Instituto de Química, Universidad Nacional Autónoma de México, Circuito Exterior s/n, Ciudad Universitaria, 04510 Ciudad de México, Mexico
| | - Aurélie Chantôme
- N2C UMR 1069, University of Tours, INSERM, Faculté de Pharmacie, Calciscreen Platform, 37032 Tours, France
| | - Carolina Monserrath Melchor-Meneses
- Departamento de Química de Biomacromoléculas, Instituto de Química, Universidad Nacional Autónoma de México, Circuito Exterior s/n, Ciudad Universitaria, 04510 Ciudad de México, Mexico
| | - Isabelle Domingo
- N2C UMR 1069, University of Tours, INSERM, Calciscreen Platform, 37032 Tours, France
| | - Gustavo Alfredo Titaux-Delgado
- Departamento de Química de Biomacromoléculas, Instituto de Química, Universidad Nacional Autónoma de México, Circuito Exterior s/n, Ciudad Universitaria, 04510 Ciudad de México, Mexico
| | - Rodrigo Galindo-Murillo
- Department of Medicinal Chemistry, L. S. Skaggs Pharmacy Institute, University of Utah, Salt Lake City, Utah 84112, United States
| | - Christophe Vandier
- N2C UMR 1069, University of Tours, INSERM, Calciscreen Platform, 37032 Tours, France
| | - Federico del Río-Portilla
- Departamento de Química de Biomacromoléculas, Instituto de Química, Universidad Nacional Autónoma de México, Circuito Exterior s/n, Ciudad Universitaria, 04510 Ciudad de México, Mexico
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6
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Yang F, Wang D, Tong Y, Qin C, Yang L, Yu F, Huang X, Liu S, Cao Z, Guo L, Li W, Wu Y, Zhao X. Thermostable potassium channel-inhibiting neurotoxins in processed scorpion medicinal material revealed by proteomic analysis: Implications of its pharmaceutical basis in traditional Chinese medicine. J Proteomics 2019; 206:103435. [DOI: 10.1016/j.jprot.2019.103435] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2019] [Revised: 06/19/2019] [Accepted: 06/28/2019] [Indexed: 12/28/2022]
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7
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Zhao Y, Chen Z, Cao Z, Li W, Wu Y. Diverse Structural Features of Potassium Channels Characterized by Scorpion Toxins as Molecular Probes. Molecules 2019; 24:molecules24112045. [PMID: 31146335 PMCID: PMC6600638 DOI: 10.3390/molecules24112045] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2019] [Revised: 05/15/2019] [Accepted: 05/26/2019] [Indexed: 12/21/2022] Open
Abstract
Scorpion toxins are well-known as the largest potassium channel peptide blocker family. They have been successfully proven to be valuable molecular probes for structural research on diverse potassium channels. The potassium channel pore region, including the turret and filter regions, is the binding interface for scorpion toxins, and structural features from different potassium channels have been identified using different scorpion toxins. According to the spatial orientation of channel turrets with differential sequence lengths and identities, conformational changes and molecular surface properties, the potassium channel turrets can be divided into the following three states: open state with less hindering effects on toxin binding, half-open state or half-closed state with certain effects on toxin binding, and closed state with remarkable effects on toxin binding. In this review, we summarized the diverse structural features of potassium channels explored using scorpion toxin tools and discuss future work in the field of scorpion toxin-potassium channel interactions.
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Affiliation(s)
- Yonghui Zhao
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan 430072, China.
| | - Zongyun Chen
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan 430072, China.
- Department of Biochemistry and Molecular Biology, Institute of Basic Medical Sciences, College of Basic Medicine, Hubei University of Medicine, Shiyan 442000, China.
| | - Zhijian Cao
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan 430072, China.
- Biodrug Research Center, Wuhan University, Wuhan 430072, China.
| | - Wenxin Li
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan 430072, China.
- Biodrug Research Center, Wuhan University, Wuhan 430072, China.
| | - Yingliang Wu
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan 430072, China.
- Biodrug Research Center, Wuhan University, Wuhan 430072, China.
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8
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Tobassum S, Tahir HM, Arshad M, Zahid MT, Ali S, Ahsan MM. Nature and applications of scorpion venom: an overview. TOXIN REV 2018. [DOI: 10.1080/15569543.2018.1530681] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Affiliation(s)
- Saadia Tobassum
- Department of Zoology, Government College University, Lahore, Pakistan
| | | | - Muhammad Arshad
- Department of Zoology, University of Education Lower Mall Campus, Lahore, Pakistan
| | | | - Shaukat Ali
- Department of Zoology, Government College University, Lahore, Pakistan
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9
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Zou Y, Zhang F, Li Y, Wang Y, Li Y, Long Z, Shi S, Shuai L, Liu J, Di Z, Yin S. Cloning, expression and identification of KTX-Sp4, a selective Kv1.3 peptidic blocker from Scorpiops pococki. Cell Biosci 2017; 7:60. [PMID: 29142737 PMCID: PMC5674823 DOI: 10.1186/s13578-017-0187-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2017] [Accepted: 10/27/2017] [Indexed: 11/10/2022] Open
Abstract
Background Specific and selective peptidic blockers of Kv1.3 channels can serve as a valuable drug lead for treating T cell-mediated autoimmune diseases, and scorpion venom is an important source of kv1.3 channel inhibitors. Through conducting transcriptomic sequencing for the venom gland of Scorpiops pococki from Xizang province of China, this research aims to discover a novel functional gene encoding peptidic blocker of Kv1.3, and identify its function. Results We screened out a new peptide toxin KTX-Sp4 which had 43 amino acids including six cysteine residues. Electrophysiological experiments indicated that recombinant expression products of KTX-Sp4 blocked both endogenous and exogenous Kv1.3 channel concentration-dependently, and exhibited good selectivity on Kv1.3 over Kv1.1, Kv1.2, respectively. Mutation experiments showed that the Kv1 turret region was responsible for the selectivity of KTX-Sp4 peptide on Kv1.3 over Kv1.1. Conclusions This work not only provided a novel lead compound for the development of anti autoimmune disease drugs, but also enriched the molecular basis for the interaction between scorpion toxins and potassium channels, serving as an important theoretical basis for designing high selective Kv1.3 peptide inhibitors.
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Affiliation(s)
- Yan Zou
- School of Pharmaceutical Sciences, South-Central University for Nationalities, Wuhan, 430074 People's Republic of China
| | - Feng Zhang
- School of Pharmaceutical Sciences, South-Central University for Nationalities, Wuhan, 430074 People's Republic of China
| | - Yaxian Li
- School of Pharmaceutical Sciences, South-Central University for Nationalities, Wuhan, 430074 People's Republic of China
| | - Yuanfang Wang
- School of Pharmaceutical Sciences, South-Central University for Nationalities, Wuhan, 430074 People's Republic of China
| | - Yi Li
- School of Pharmaceutical Sciences, South-Central University for Nationalities, Wuhan, 430074 People's Republic of China
| | - Zhengtao Long
- School of Pharmaceutical Sciences, South-Central University for Nationalities, Wuhan, 430074 People's Republic of China
| | - Shujuan Shi
- School of Pharmaceutical Sciences, South-Central University for Nationalities, Wuhan, 430074 People's Republic of China
| | - Li Shuai
- School of Pharmaceutical Sciences, South-Central University for Nationalities, Wuhan, 430074 People's Republic of China.,National Demonstration Center for Experimental Ethnopharmacology Education, South-Central University for Nationalities, Wuhan, 430074 People's Republic of China
| | - Jiukai Liu
- School of Pharmaceutical Sciences, South-Central University for Nationalities, Wuhan, 430074 People's Republic of China.,National Demonstration Center for Experimental Ethnopharmacology Education, South-Central University for Nationalities, Wuhan, 430074 People's Republic of China
| | - Zhiyong Di
- School of Life Sciences, University of Science and Technology of China, Hefei, 230027 People's Republic of China
| | - Shijin Yin
- School of Pharmaceutical Sciences, South-Central University for Nationalities, Wuhan, 430074 People's Republic of China.,National Demonstration Center for Experimental Ethnopharmacology Education, South-Central University for Nationalities, Wuhan, 430074 People's Republic of China
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10
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Zhang HY, Xu Q, Li F, Tian PC, Wang YH, Xiong Y, Zhang YH, Wei DQ. Recent progresses of simulations on passive membrane permeations in China. MOLECULAR SIMULATION 2016. [DOI: 10.1080/08927022.2015.1135333] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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11
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Feng J, Xie Z, Yang W, Zhao Y, Xiang F, Cao Z, Li W, Chen Z, Wu Y. Human beta-defensin 1, a new animal toxin-like blocker of potassium channel. Toxicon 2016; 113:1-6. [PMID: 26854370 DOI: 10.1016/j.toxicon.2016.02.007] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2015] [Revised: 01/26/2016] [Accepted: 02/03/2016] [Indexed: 10/22/2022]
Abstract
The discovery of human β-defensin 2 (hBD2), as a Kv1.3 channel inhibitor with the unique molecular mechanism and novel immune modulatory function, suggests that human β-defensins are a novel class of channel ligands. Here, the function and mechanism of the human β-defensin 1 (hBD1) binding to potassium channels was investigated. Based on the structural similarity between hBD1 and Kv1.3 channel-sensitive hBD2, hBD1 was found to selectively inhibit human and mouse Kv1.3 channels with IC50 values of 11.8 ± 3.1 μM and 13.2 ± 4.0 μM, respectively. Different from hBD2 modifying Kv1.3 channel activation and increasing activation time constant, hBD1 did not affect the activation feature of both human and mouse Kv1.3 channels. In comparison with hBD2 simultaneously interacting with the extracellular S1-S2 linker and pore region of Kv1.3 channel, the chimeric channel and mutagenesis experiments showed that hBD1 only bound to the extracellular pore region of Kv1.3 channel instead of extracellular S1-S2 linker or S3-S4 linker. Together, these findings enhance knowledge of hBD1 as a new immune-related Kv1.3 channel blocker and highlight the major functional differences between hBD1 and hBD2 to explore in future research.
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Affiliation(s)
- Jing Feng
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Zili Xie
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Weishan Yang
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Yonghui Zhao
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Fang Xiang
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Zhijian Cao
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan 430072, China; Center for BioDrug Research, Wuhan University, Wuhan 430072, China
| | - Wenxin Li
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan 430072, China; Center for BioDrug Research, Wuhan University, Wuhan 430072, China
| | - Zongyun Chen
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan 430072, China.
| | - Yingliang Wu
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan 430072, China; Center for BioDrug Research, Wuhan University, Wuhan 430072, China.
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12
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Meng L, Xie Z, Zhang Q, Li Y, Yang F, Chen Z, Li W, Cao Z, Wu Y. Scorpion Potassium Channel-blocking Defensin Highlights a Functional Link with Neurotoxin. J Biol Chem 2016; 291:7097-106. [PMID: 26817841 DOI: 10.1074/jbc.m115.680611] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2015] [Indexed: 01/01/2023] Open
Abstract
The structural similarity between defensins and scorpion neurotoxins suggests that they might have evolved from a common ancestor. However, there is no direct experimental evidence demonstrating a functional link between scorpion neurotoxins and defensins. The scorpion defensin BmKDfsin4 from Mesobuthus martensiiKarsch contains 37 amino acid residues and a conserved cystine-stabilized α/β structural fold. The recombinant BmKDfsin4, a classical defensin, has been found to have inhibitory activity against Gram-positive bacteria such as Staphylococcus aureus, Bacillus subtilis, and Micrococcus luteusas well as methicillin-resistant Staphylococcus aureus Interestingly, electrophysiological experiments showed that BmKDfsin4,like scorpion potassium channel neurotoxins, could effectively inhibit Kv1.1, Kv1.2, and Kv1.3 channel currents, and its IC50value for the Kv1.3 channel was 510.2 nm Similar to the structure-function relationships of classical scorpion potassium channel-blocking toxins, basic residues (Lys-13 and Arg-19) of BmKDfsin4 play critical roles in peptide-Kv1.3 channel interactions. Furthermore, mutagenesis and electrophysiological experiments demonstrated that the channel extracellular pore region is the binding site of BmKDfsin4, indicating that BmKDfsin4 adopts the same mechanism for blocking potassium channel currents as classical scorpion toxins. Taken together, our work identifies scorpion BmKDfsin4 as the first invertebrate defensin to block potassium channels. These findings not only demonstrate that defensins from invertebrate animals are a novel type of potassium channel blockers but also provide evidence of a functional link between defensins and neurotoxins.
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Affiliation(s)
- Lanxia Meng
- From the State Key Laboratory of Virology, College of Life Sciences and
| | - Zili Xie
- From the State Key Laboratory of Virology, College of Life Sciences and
| | - Qian Zhang
- From the State Key Laboratory of Virology, College of Life Sciences and
| | - Yang Li
- From the State Key Laboratory of Virology, College of Life Sciences and
| | - Fan Yang
- From the State Key Laboratory of Virology, College of Life Sciences and
| | - Zongyun Chen
- From the State Key Laboratory of Virology, College of Life Sciences and
| | - Wenxin Li
- From the State Key Laboratory of Virology, College of Life Sciences and Center for BioDrug Research, Wuhan University, Wuhan 430072, China
| | - Zhijian Cao
- From the State Key Laboratory of Virology, College of Life Sciences and Center for BioDrug Research, Wuhan University, Wuhan 430072, China
| | - Yingliang Wu
- From the State Key Laboratory of Virology, College of Life Sciences and Center for BioDrug Research, Wuhan University, Wuhan 430072, China
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Hu Y, Chen J, Wang B, Yang W, Zhang C, Hu J, Xie Z, Cao Z, Li W, Wu Y, Chen Z. Engineering a peptide inhibitor towards the KCNQ1/KCNE1 potassium channel (IKs). Peptides 2015; 71:77-83. [PMID: 26188173 DOI: 10.1016/j.peptides.2015.07.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/10/2015] [Revised: 07/05/2015] [Accepted: 07/07/2015] [Indexed: 11/27/2022]
Abstract
The KCNQ1/KCNE1 channel (IKs) plays important roles in the physiological and pathological process of heart, but no potent peptide acting on this channel has been reported. In this work, we found that the natural scorpion venom hardly inhibited KCNQ1/KCNE1 channel currents. Based on this observation, we attempted to use three natural scorpion toxins ChTX, BmKTX and OmTx2 with two different structural folds as templates to engineer potent peptide inhibitors towards the KCNQ1/KCNE1 channel. Pharmacological experiments showed that when we screen with 1μM MT2 peptide, an analog derived from BmKTX toxin, KCNQ1/KCNE1 channel currents could be effectively inhibited. Concentration-dependent experiments showed that MT2 inhibited the KCNQ1/KCNE1 channel with an IC50 value of 4.6±1.9μM. The mutagenesis experiments indicated that MT2 peptide likely used Lys26 residue to interact with the KCNQ1/KCNE1 channel. With MT2 as a new template, we further designed a more potent MT2-2 peptide, which selectively inhibited the KCNQ1/KCNE1 channel with an IC50 of 1.51±0.62μM. Together, this work provided a much potent KCNQ1/KCNE1 channel peptide inhibitor so far, and highlighted the role of molecular strategy in developing potent peptide inhibitors for the natural toxin-insensitive orphan receptors.
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Affiliation(s)
- Youtian Hu
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Jing Chen
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Bin Wang
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Weishan Yang
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Chuangeng Zhang
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Jun Hu
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Zili Xie
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Zhijian Cao
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan 430072, China; Center for BioDrug Research, Wuhan University, Wuhan 430072, China
| | - Wenxin Li
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan 430072, China; Center for BioDrug Research, Wuhan University, Wuhan 430072, China
| | - Yingliang Wu
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan 430072, China; Center for BioDrug Research, Wuhan University, Wuhan 430072, China.
| | - Zongyun Chen
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan 430072, China; Department of Biochemistry and Molecular Biology, Institute of Basic Medical Sciences, Hubei University of Medicine, Hubei, China.
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Chen Z, Hu Y, Wang B, Cao Z, Li W, Wu Y. A single conserved basic residue in the potassium channel filter region controls KCNQ1 insensitivity toward scorpion toxins. Biochem Biophys Rep 2015; 3:62-67. [PMID: 29124168 PMCID: PMC5668678 DOI: 10.1016/j.bbrep.2015.07.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2015] [Revised: 07/05/2015] [Accepted: 07/07/2015] [Indexed: 02/06/2023] Open
Abstract
Although many studies concerning the sensitivity mechanism of scorpion toxin-potassium channel interactions have been reported, few have explored the biochemical insensitivity mechanisms of potassium channel receptors toward natural scorpion toxin peptides, such as the KCNQ1 channel. Here, by sequence alignment analyses of the human KCNQ1 channel and scorpion potassium channel MmKv2, which is completely insensitive to scorpion toxins, we proposed that the insensitivity mechanism of KCNQ1 toward natural scorpion toxins might involve two functional regions, the turret and filter regions. Based on this observation, a series of KCNQ1 mutants were constructed to study molecular mechanisms of the KCNQ1 channel insensitivity toward natural scorpion toxins. Electrophysiological studies of chimera channels showed that the channel filter region controls KCNQ1 insensitivity toward the classical scorpion toxin ChTX. Interestingly, further residue mutant experiments showed that a single basic residue in the filter region determined the insensitivity of KCNQ1 channels toward scorpion toxins. Our present work showed that amino acid residue diversification at common sites controls the sensitivity and insensitivity of potassium channels toward scorpion toxins. The unique insensitivity mechanism of KCNQ1 toward natural scorpion toxins will accelerate the rational design of potent peptide inhibitors toward this channel. Insensitivity mechanism of KCNQ1 towards scorpion toxins was still unclear. A single basic residue in the KCNQ1 filter region controls its insensitivity. Amino acid residue diversification controls KCNQ1 sensitivity and insensitivity. Our work will accelerate rational design of KCNQ1 peptide inhibitors.
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Affiliation(s)
- Zongyun Chen
- Department of Biochemistry and Molecular Biology, Institute of Basic Medical Sciences, Hubei University of Medicine, Hubei, China.,State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Hubei, China
| | - Youtian Hu
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Hubei, China
| | - Bin Wang
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Hubei, China
| | - Zhijian Cao
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Hubei, China
| | - Wenxin Li
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Hubei, China
| | - Yingliang Wu
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Hubei, China
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Xie Z, Feng J, Yang W, Xiang F, Yang F, Zhao Y, Cao Z, Li W, Chen Z, Wu Y. Human α-defensins are immune-related Kv1.3 channel inhibitors: new support for their roles in adaptive immunity. FASEB J 2015; 29:4324-33. [PMID: 26148969 DOI: 10.1096/fj.15-274787] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2015] [Accepted: 06/22/2015] [Indexed: 12/26/2022]
Abstract
Defensins form a major family of antimicrobial peptides. Recently, human β-defensin 2 and fungal plectasin were shown to be immune-related potassium voltage-gated channel subfamily A member 3 (Kv1.3) channel inhibitors. This work continued to show that the human α-defensins human neutrophil peptide (HNP) 1 and human defensin (HD) 5 are selective Kv1.3 channel inhibitors with 50% inhibition concentration values of 102.0 ± 30.3 nM and 2.2 ± 0.2 μM, respectively. Furthermore, HNP1 was found to inhibit Kv1.3 currents and IL-2 secretion in human CD3(+) T cells. Despite the structural similarity between HNP1 and HD5, HNP1 could simultaneously bind to the S1-S2 linker and the pore region of the Kv1.3 channel as both a toxinlike blocker and a novel modifier, whereas HD5 could only bind to the channel pore region as a toxinlike blocker. As a channel modifier, HNP1 could shift the conductance-voltage relationship curve of the Kv1.3 channel by ∼9.5 mV in the positive direction and could increase the time constant for channel activation through the electrostatic repulsion between the cationic HNP1 anchored in the S1-S2 linker and the positively charged S4 domain of the Kv1.3 channel. Together, these findings reveal that human α-defensins are novel endogenous inhibitors of Kv1.3 channels with distinct interaction mechanisms, which facilitates future research into their adaptive immune functions.
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Affiliation(s)
- Zili Xie
- *State Key Laboratory of Virology, College of Life Sciences, and Center for BioDrug Research, Wuhan University, Wuhan, China
| | - Jing Feng
- *State Key Laboratory of Virology, College of Life Sciences, and Center for BioDrug Research, Wuhan University, Wuhan, China
| | - Weishan Yang
- *State Key Laboratory of Virology, College of Life Sciences, and Center for BioDrug Research, Wuhan University, Wuhan, China
| | - Fang Xiang
- *State Key Laboratory of Virology, College of Life Sciences, and Center for BioDrug Research, Wuhan University, Wuhan, China
| | - Fan Yang
- *State Key Laboratory of Virology, College of Life Sciences, and Center for BioDrug Research, Wuhan University, Wuhan, China
| | - Yonghui Zhao
- *State Key Laboratory of Virology, College of Life Sciences, and Center for BioDrug Research, Wuhan University, Wuhan, China
| | - Zhijian Cao
- *State Key Laboratory of Virology, College of Life Sciences, and Center for BioDrug Research, Wuhan University, Wuhan, China
| | - Wenxin Li
- *State Key Laboratory of Virology, College of Life Sciences, and Center for BioDrug Research, Wuhan University, Wuhan, China
| | - Zongyun Chen
- *State Key Laboratory of Virology, College of Life Sciences, and Center for BioDrug Research, Wuhan University, Wuhan, China
| | - Yingliang Wu
- *State Key Laboratory of Virology, College of Life Sciences, and Center for BioDrug Research, Wuhan University, Wuhan, China
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Chen Z, Hu Y, Hong J, Hu J, Yang W, Xiang F, Yang F, Xie Z, Cao Z, Li W, Lin D, Wu Y. Toxin acidic residue evolutionary function-guided design of de novo peptide drugs for the immunotherapeutic target, the Kv1.3 channel. Sci Rep 2015; 5:9881. [PMID: 25955787 PMCID: PMC4424837 DOI: 10.1038/srep09881] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2014] [Accepted: 03/24/2015] [Indexed: 12/25/2022] Open
Abstract
During the long-term evolution of animal toxins acting on potassium channels, the acidic residues can orientate the toxin binding interfaces by adjusting the molecular polarity. Based on the evolutionary function of toxin acidic residues, de novo peptide drugs with distinct binding interfaces were designed for the immunotherapeutic target, the Kv1.3 channel. Using a natural basic toxin, BmKTX, as a template, which contains 2 acidic residues (Asp19 and Asp33), we engineered two new peptides BmKTX-19 with 1 acidic residue (Asp33), and BmKTX-196 with 2 acidic residues (Asp6 and Asp33) through only adjusting acidic residue distribution for reorientation of BmKTX binding interface. Pharmacological experiments indicated that BmKTX-19 and BmKTX-196 peptides were specific inhibitors of the Kv1.3 channel and effectively suppressed cytokine secretion. In addition to the structural similarity between the designed and native peptides, both experimental alanine-scanning mutagenesis and computational simulation further indicated that the binding interface of wild-type BmKTX was successfully reoriented in BmKTX-19 and BmKTX-196, which adopted distinct toxin surfaces as binding interfaces. Together, these findings indicate not only the promising prospect of BmKTX-19 and BmKTX-196 as drug candidates but also the desirable feasibility of the evolution-guided peptide drug design for discovering numerous peptide drugs for the Kv1.3 channel.
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Affiliation(s)
- Zongyun Chen
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Youtian Hu
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Jing Hong
- College of Biological Science and Technology, Fuzhou University, Fuzhou 350108, China
| | - Jun Hu
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Weishan Yang
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Fang Xiang
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Fan Yang
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Zili Xie
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Zhijian Cao
- 1] State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan 430072, China [2] Center for BioDrug Research, Wuhan University, Wuhan 430072, China
| | - Wenxin Li
- 1] State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan 430072, China [2] Center for BioDrug Research, Wuhan University, Wuhan 430072, China
| | - Donghai Lin
- College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China
| | - Yingliang Wu
- 1] State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan 430072, China [2] Center for BioDrug Research, Wuhan University, Wuhan 430072, China
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Plectasin, first animal toxin-like fungal defensin blocking potassium channels through recognizing channel pore region. Toxins (Basel) 2015; 7:34-42. [PMID: 25568977 PMCID: PMC4303811 DOI: 10.3390/toxins7010034] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2014] [Accepted: 12/24/2014] [Indexed: 12/04/2022] Open
Abstract
The potassium channels were recently found to be inhibited by animal toxin-like human β-defensin 2 (hBD2), the first defensin blocker of potassium channels. Whether there are other defensin blockers from different organisms remains an open question. Here, we reported the potassium channel-blocking plectasin, the first defensin blocker from a fungus. Based on the similar cysteine-stabilized alpha-beta (CSαβ) structure between plectasin and scorpion toxins acting on potassium channels, we found that plectasin could dose-dependently block Kv1.3 channel currents through electrophysiological experiments. Besides Kv1.3 channel, plectasin could less inhibit Kv1.1, Kv1.2, IKCa, SKCa3, hERG and KCNQ channels at the concentration of 1 μΜ. Using mutagenesis and channel activation experiments, we found that outer pore region of Kv1.3 channel was the binding site of plectasin, which is similar to the interacting site of Kv1.3 channel recognized by animal toxin blockers. Together, these findings not only highlight the novel function of plectasin as a potassium channel inhibitor, but also imply that defensins from different organisms functionally evolve to be a novel kind of potassium channel inhibitors.
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Rong M, Yang S, Wen B, Mo G, Kang D, Liu J, Lin Z, Jiang W, Li B, Du C, Yang S, Jiang H, Feng Q, Xu X, Wang J, Lai R. Peptidomics combined with cDNA library unravel the diversity of centipede venom. J Proteomics 2014; 114:28-37. [PMID: 25449838 DOI: 10.1016/j.jprot.2014.10.014] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2014] [Revised: 10/14/2014] [Accepted: 10/18/2014] [Indexed: 01/25/2023]
Abstract
UNLABELLED Centipedes are one of the oldest venomous arthropods using toxin as their weapon to capture prey. But little attention was focused on them and only few centipede toxins were demonstrated with activity on ion channels. Therefore, more deep works are needed to understand the diversity of centipede venom. In the present study, we use peptidomics combined with cDNA library to uncover the diversity of centipede Scolopendra subspinipes mutilans L. Koch. 192 peptides were identified by LC-MS/MS and 79 precursors were deduced by cDNA library. Surprisingly, the signal peptides of centipede toxins were more complicated than any other animal toxins and even exhibited large differences in homologues. Meanwhile, a large number of variants generated by alternative cleavage sites were detected by mass spectra. Odd number of cystein (3, 5, 7) found in the mature peptides were seldom seen in peptide toxins. In additional, two novel cysteine frameworks (C-C-C-CCC, C-C-C-C-CC-CC) were identified from 16 different cysteine frameworks from centipede peptides. Only 29 precursors have clear targets, while others may provide a potential diversity function for centipede. These findings highlight the extensive diversity of centipede toxins and provide powerful tools to understand the capture and defense weapon of centipede. BIOLOGICAL SIGNIFICANCE Peptide toxins from venomous animal have attracted increasing attentions due to their extraordinary chemical and pharmacological diversity. Centipedes are one of the most used Chinese traditional medicines, but little was known about the active components. The venom of Scolopendra subspinipes mutilans L. Koch is first deeply analyzed in this work and most of peptides were never discovered before. Interestingly, the number and arrangement of cysteine showed a larger different to known peptide toxins such spider or scorpion toxins. Moreover, only 29 peptides from this centipede venom were identified with known function. It suggested that our work not only important to understand the composition of centipede venom, but also provide many valuable peptides for potential biological functions.
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Affiliation(s)
- Mingqiang Rong
- Key Laboratory of Animal Models and Human Disease Mechanisms of Chinese Academy of Sciences & Yunnan Province, Kunming Institute of Zoology, Kunming 650223, Yunnan, China
| | - Shilong Yang
- Key Laboratory of Animal Models and Human Disease Mechanisms of Chinese Academy of Sciences & Yunnan Province, Kunming Institute of Zoology, Kunming 650223, Yunnan, China
| | - Bo Wen
- BGI-Shenzhen, Shenzhen 518083, China
| | - Guoxiang Mo
- School of Biological Sciences, Nanjing Agriculture University, Nanjing, Jiangshu 210095, China
| | - Di Kang
- Key Laboratory of Animal Models and Human Disease Mechanisms of Chinese Academy of Sciences & Yunnan Province, Kunming Institute of Zoology, Kunming 650223, Yunnan, China
| | - Jie Liu
- Key Laboratory of Animal Models and Human Disease Mechanisms of Chinese Academy of Sciences & Yunnan Province, Kunming Institute of Zoology, Kunming 650223, Yunnan, China
| | | | - Wenbin Jiang
- College of Life Science and Technology, Kunming University of Science and Technology, China
| | - Bowen Li
- Key Laboratory of Animal Models and Human Disease Mechanisms of Chinese Academy of Sciences & Yunnan Province, Kunming Institute of Zoology, Kunming 650223, Yunnan, China
| | | | - Shuanjuan Yang
- Kunming Biological Diversity Regional Center of Large Apparatuses and Equipment, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming 650223, Yunnan, China
| | - Hui Jiang
- BGI-Shenzhen, Shenzhen 518083, China
| | - Qiang Feng
- BGI-Shenzhen, Shenzhen 518083, China; Kunming Biological Diversity Regional Center of Large Apparatuses and Equipment, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming 650223, Yunnan, China
| | - Xun Xu
- BGI-Shenzhen, Shenzhen 518083, China
| | - Jun Wang
- BGI-Shenzhen, Shenzhen 518083, China; Kunming Biological Diversity Regional Center of Large Apparatuses and Equipment, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming 650223, Yunnan, China; Princess Al Jawhara Center of Excellence in the Research of Hereditary Disorders, King Abdulaziz University, Jeddah, Saudi Arabia; The Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark.
| | - Ren Lai
- Key Laboratory of Animal Models and Human Disease Mechanisms of Chinese Academy of Sciences & Yunnan Province, Kunming Institute of Zoology, Kunming 650223, Yunnan, China.
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Hu Y, Sinha SK, Patel S. Reconciling structural and thermodynamic predictions using all-atom and coarse-grain force fields: the case of charged oligo-arginine translocation into DMPC bilayers. J Phys Chem B 2014; 118:11973-92. [PMID: 25290376 PMCID: PMC4199542 DOI: 10.1021/jp504853t] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Using the translocation of short, charged cationic oligo-arginine peptides (mono-, di-, and triarginine) from bulk aqueous solution into model DMPC bilayers, we explore the question of the similarity of thermodynamic and structural predictions obtained from molecular dynamics simulations using all-atom and Martini coarse-grain force fields. Specifically, we estimate potentials of mean force associated with translocation using standard all-atom (CHARMM36 lipid) and polarizable and nonpolarizable Martini force fields, as well as a series of modified Martini-based parameter sets. We find that we are able to reproduce qualitative features of potentials of mean force of single amino acid side chain analogues into model bilayers. In particular, modifications of peptide-water and peptide-membrane interactions allow prediction of free energy minima at the bilayer-water interface as obtained with all-atom force fields. In the case of oligo-arginine peptides, the modified parameter sets predict interfacial free energy minima as well as free energy barriers in almost quantitative agreement with all-atom force field based simulations. Interfacial free energy minima predicted by a modified coarse-grained parameter set are -2.51, -4.28, and -5.42 for mono-, di-, and triarginine; corresponding values from all-atom simulations are -0.83, -3.33, and -3.29, respectively, all in units of kcal/mol. We found that a stronger interaction between oligo-arginine and the membrane components and a weaker interaction between oligo-arginine and water are crucial for producing such minima in PMFs using the polarizable CG model. The difference between bulk aqueous and bilayer center states predicted by the modified coarse-grain force field are 11.71, 14.14, and 16.53 kcal/mol, and those by the all-atom model are 6.94, 8.64, and 12.80 kcal/mol; those are of almost the same order of magnitude. Our simulations also demonstrate a remarkable similarity in the structural aspects of the ensemble of configurations generated using the all-atom and coarse-grain force fields. Both resolutions show that oligo-arginine peptides adopt preferential orientations as they translocate into the bilayer. The guiding theme centers on charged groups maintaining coordination with polar and charged bilayer components as well as local water. We also observe similar behaviors related with membrane deformations.
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Affiliation(s)
- Yuan Hu
- Department of Chemistry and Biochemistry, University of Delaware , Newark, Delaware 19716, United States
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20
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Chen R, Chung SH. Binding modes of two scorpion toxins to the voltage-gated potassium channel kv1.3 revealed from molecular dynamics. Toxins (Basel) 2014; 6:2149-61. [PMID: 25054783 PMCID: PMC4113748 DOI: 10.3390/toxins6072149] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2014] [Revised: 07/08/2014] [Accepted: 07/10/2014] [Indexed: 12/13/2022] Open
Abstract
Molecular dynamics (MD) simulations are used to examine the binding modes of two scorpion toxins, margatoxin (MgTx) and hongotoxin (HgTx), to the voltage gated K+ channel, Kv1.3. Using steered MD simulations, we insert either Lys28 or Lys35 of the toxins into the selectivity filter of the channel. The MgTx-Kv1.3 complex is stable when the side chain of Lys35 from the toxin occludes the channel filter, suggesting that Lys35 is the pore-blocking residue for Kv1.3. In this complex, Lys28 of the toxin forms one additional salt bridge with Asp449 just outside the filter of the channel. On the other hand, HgTx forms a stable complex with Kv1.3 when the side chain of Lys28 but not Lys35 protrudes into the filter of the channel. A survey of all the possible favorable binding modes of HgTx-Kv1.3 is carried out by rotating the toxin at 3° intervals around the channel axis while the position of HgTx-Lys28 relative to the filter is maintained. We identify two possible favorable binding modes: HgTx-Arg24 can interact with either Asp433 or Glu420 on the vestibular wall of the channel. The dissociation constants calculated from the two binding modes of HgTx-Kv1.3 differ by approximately 20 fold, suggesting that the two modes are of similar energetics.
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Affiliation(s)
- Rong Chen
- Research School of Biology, Australian National University, Canberra, ACT 0200, Australia.
| | - Shin-Ho Chung
- Research School of Biology, Australian National University, Canberra, ACT 0200, Australia.
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Hu YT, Hu J, Li T, Wei JJ, Feng J, Du YM, Cao ZJ, Li WX, Wu YL. Open conformation of hERG channel turrets revealed by a specific scorpion toxin BmKKx2. Cell Biosci 2014; 4:18. [PMID: 24725272 PMCID: PMC4108063 DOI: 10.1186/2045-3701-4-18] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2014] [Accepted: 02/11/2014] [Indexed: 11/23/2022] Open
Abstract
Background The human ether-a-go-go-related gene potassium channel (hERG) has an unusual long turret, whose role in recognizing scorpion toxins remains controversial. Here, BmKKx2, the first specific blocker of hERG channel derived from scorpion Mesobuthus martensii, was identified and the turret role of hERG channel was re-investigated using BmKKx2 as a molecular probe. Results BmKKx2 was found to block hERG channel with an IC50 of 6.7 ± 1.7 nM and share similar functional surface with the known hERG channel inhibitor BeKm-1. The alanine-scanning mutagenesis data indicate that different residue substitutions on hERG channel by alanine decreased the affinities of toxin BmKKx2 by about 10-fold compared with that of wild-type hERG channel, which reveals that channel turrets play a secondary role in toxin binding. Different from channel turret, the pore region of hERG channel was found to exert the conserved and essential function for toxin binding because the mutant hERG-S631A channel remarkably decreased toxin BmKKx2 affinity by about 104-fold. Conclusions Our results not only revealed that channel turrets of hERG channel formed an open conformation in scorpion toxin binding, but also enriched the diversity of structure-function relationships among the different potassium channel turrets.
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Affiliation(s)
- You-Tian Hu
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Jun Hu
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Tian Li
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Jing-Jing Wei
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Jing Feng
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Yi-Mei Du
- Research Center of Ion Channelopathy, Institute of Cardiovascular Diseases, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China
| | - Zhi-Jian Cao
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Wen-Xin Li
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Ying-Liang Wu
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan 430072, China
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22
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Unusual binding mode of scorpion toxin BmKTX onto potassium channels relies on its distribution of acidic residues. Biochem Biophys Res Commun 2014; 447:70-6. [DOI: 10.1016/j.bbrc.2014.03.101] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2014] [Accepted: 03/20/2014] [Indexed: 01/12/2023]
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Liégeois JF, Wouters J, Seutin V, Dilly S. Bis-(1,2,3,4-tetrahydroisoquinolinium): A Chiral Scaffold for Developing High-Affinity Ligands for SK Channels. ChemMedChem 2014; 9:737-40. [DOI: 10.1002/cmdc.201400028] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
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Cao Z, Di Z, Wu Y, Li W. Overview of scorpion species from China and their toxins. Toxins (Basel) 2014; 6:796-815. [PMID: 24577583 PMCID: PMC3968362 DOI: 10.3390/toxins6030796] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2013] [Revised: 01/16/2014] [Accepted: 01/18/2014] [Indexed: 12/29/2022] Open
Abstract
Scorpions are one of the most ancient groups of terrestrial animals. They have maintained a steady morphology over more than 400 million years of evolution. Their venom arsenals for capturing prey and defending against predators may play a critical role in their ancient and conservative appearance. In the current review, we present the scorpion fauna of China: 53 species covering five families and 12 genera. We also systematically list toxins or genes from Chinese scorpion species, involving eight species covering four families. Furthermore, we review the diverse functions of typical toxins from Chinese scorpion species, involving Na+ channel modulators, K+ channel blockers, antimicrobial peptides and protease inhibitors. Using scorpion species and their toxins from China as an example, we build the bridge between scorpion species and their toxins, which helps us to understand the molecular and functional diversity of scorpion venom arsenal, the dynamic and functional evolution of scorpion toxins, and the potential relationships of scorpion species and their toxins.
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Affiliation(s)
- Zhijian Cao
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan 430072, China.
| | - Zhiyong Di
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan 430072, China.
| | - Yingliang Wu
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan 430072, China.
| | - Wenxin Li
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan 430072, China.
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Kv1.3 potassium channel-blocking toxin Ctri9577, novel gating modifier of Kv4.3 potassium channel from the scorpion toxin family. Biochem Biophys Res Commun 2014; 444:406-10. [DOI: 10.1016/j.bbrc.2014.01.094] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2014] [Accepted: 01/19/2014] [Indexed: 01/11/2023]
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Ma J, Hu Y, Guo M, Huang Z, Li W, Wu Y. hERG potassium channel blockage by scorpion toxin BmKKx2 enhances erythroid differentiation of human leukemia cells K562. PLoS One 2013; 8:e84903. [PMID: 24386436 PMCID: PMC3873423 DOI: 10.1371/journal.pone.0084903] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2013] [Accepted: 11/28/2013] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND The hERG potassium channel can modulate the proliferation of the chronic myelogenous leukemic K562 cells, and its role in the erythroid differentiation of K562 cells still remains unclear. PRINCIPAL FINDINGS The hERG potassium channel blockage by a new 36-residue scorpion toxin BmKKx2, a potent hERG channel blocker with IC50 of 6.7 ± 1.7 nM, enhanced the erythroid differentiation of K562 cells. The mean values of GPA (CD235a) fluorescence intensity in the group of K562 cells pretreated by the toxin for 24 h and followed by cytosine arabinoside (Ara-C) treatment for 72 h were about 2-fold stronger than those of K562 cells induced by Ara-C alone. Such unique role of hERG potassium channel was also supported by the evidence that the effect of the toxin BmKKx2 on cell differentiation was nullified in hERG-deficient cell lines. During the K562 cell differentiation, BmKKx2 could also suppress the expression of hERG channels at both mRNA and protein levels. Besides the function of differentiation enhancement, BmKKx2 was also found to promote the differentiation-dependent apoptosis during the differentiation process of K562 cells. In addition, the blockage of hERG potassium channel by toxin BmKKx2 was able to decrease the intracellular Ca(2+) concentration during the K562 cell differentiation, providing an insight into the mechanism of hERG potassium channel regulating this cellular process. CONCLUSIONS/SIGNIFICANCE Our results revealed scorpion toxin BmKKx2 could enhance the erythroid differentiation of leukemic K562 cells via inhibiting hERG potassium channel currents. These findings would not only accelerate the functional research of hERG channel in different leukemic cells, but also present the prospects of natural scorpion toxins as anti-leukemic drugs.
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Affiliation(s)
- Jian Ma
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan, China
| | - Youtian Hu
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan, China
| | - Mingxiong Guo
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan, China
| | - Zan Huang
- Department of Biochemistry and Molecular Biology, College of Life Sciences, Wuhan University, Wuhan, China
| | - Wenxin Li
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan, China
- * E-mail: (WL); (YW)
| | - Yingliang Wu
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan, China
- * E-mail: (WL); (YW)
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