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Soon TN, Chia AYY, Yap WH, Tang YQ. Anticancer Mechanisms of Bioactive Peptides. Protein Pept Lett 2021; 27:823-830. [PMID: 32271692 DOI: 10.2174/0929866527666200409102747] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2020] [Revised: 02/24/2020] [Accepted: 03/04/2020] [Indexed: 02/07/2023]
Abstract
Despite technological advancement, there is no 100% effective treatment against metastatic cancer. Increasing resistance of cancer cells towards chemotherapeutic drugs along with detrimental side effects remained a concern. Thus, the urgency in developing new anticancer agents has been raised. Anticancer peptides have been proven to display potent activity against a wide variety of cancer cells. Several mode of actions describing their cytostatic and cytotoxic effect on cancer cells have been proposed which involves cell surface binding leading to membranolysis or internalization to reach their intracellular target. Understanding the mechanism of action of these anticancer peptides is important in achieving full therapeutic success. In the present article, we discuss the anticancer action of peptides accompanied by the mechanisms underpinning their toxicity to cancer cells.
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Affiliation(s)
- Tsuey Ning Soon
- School of Biosciences, Faculty of Medical and Health Sciences, Taylor's University, 47500 Subang Jaya, Selangor Darul Ehsan, Malaysia
| | - Adeline Yoke Yin Chia
- School of Biosciences, Faculty of Medical and Health Sciences, Taylor's University, 47500 Subang Jaya, Selangor Darul Ehsan, Malaysia
| | - Wei Hsum Yap
- School of Biosciences, Faculty of Medical and Health Sciences, Taylor's University, 47500 Subang Jaya, Selangor Darul Ehsan, Malaysia
| | - Yin-Quan Tang
- School of Biosciences, Faculty of Medical and Health Sciences, Taylor's University, 47500 Subang Jaya, Selangor Darul Ehsan, Malaysia
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2
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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: 1] [Impact Index Per Article: 0.3] [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: 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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Desales-Salazar E, Khusro A, Cipriano-Salazar M, Barbabosa-Pliego A, Rivas-Caceres RR. Scorpion venoms and associated toxins as anticancer agents: update on their application and mechanism of action. J Appl Toxicol 2020; 40:1310-1324. [PMID: 32249452 DOI: 10.1002/jat.3976] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Revised: 03/01/2020] [Accepted: 03/05/2020] [Indexed: 12/29/2022]
Abstract
Cancer remains one of the deadliest non-infectious diseases of the 21st century, causing millions of mortalities per year worldwide. Analyses of conventional treatments, such as radiotherapy and chemotherapy, have shown not only a lower therapeutic efficiency rate but also plethora of side-effects. Considering the desperate need to identify promising anticancer agents, researchers are in quest to design and develop new tumoricidal drugs from natural sources. Over the past few years, scorpion venoms have shown exemplary roles as pivotal anticancer agents. Scorpion venoms associated metabolites, particularly toxins demonstrated in vitro anticancer attributes against diversified cell lines by inhibiting the growth and progression of the cell cycle, inhibiting metastasis by blocking ion channels such as K+ and Cl- , and/or inducing apoptosis by intrinsic and extrinsic pathways. This review sheds light not only on in vitro anticancer properties of distinct scorpion venoms and their toxins, but also on their mechanism of action for designing and developing new therapeutic drugs in future.
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Affiliation(s)
- Erasto Desales-Salazar
- Centro de Investigación y Estudios Avanzados en Salud Animal (CIESA), Facultad de Medicina Veterinaria y Zootecnia, Universidad Autónoma del Estado de México (UAEM), Toluca, Mexico
| | - Ameer Khusro
- Research Department of Plant Biology and Biotechnology, Loyola College, Nungambakkam, Chennai, Tamil Nadu, India
| | - Moisés Cipriano-Salazar
- Unidad Académica de Medicina Veterinaria y Zootecnia, Universidad Autónoma de Guerrero, Guerrero, Mexico
| | - Alberto Barbabosa-Pliego
- Centro de Investigación y Estudios Avanzados en Salud Animal (CIESA), Facultad de Medicina Veterinaria y Zootecnia, Universidad Autónoma del Estado de México (UAEM), Toluca, Mexico
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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] [What about the content of this article? (0)] [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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Moradi M, Najafi R, Amini R, Solgi R, Tanzadehpanah H, Esfahani AM, Saidijam M. Remarkable apoptotic pathway of Hemiscorpius lepturus scorpion venom on CT26 cell line. Cell Biol Toxicol 2019; 35:373-385. [PMID: 30617443 DOI: 10.1007/s10565-018-09455-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2018] [Accepted: 11/29/2018] [Indexed: 02/07/2023]
Abstract
OBJECTIVE Scorpion venom, considered as a treasure trove of various bioactive molecules, is a new approach to induce cancer cell death via apoptosis pathways. In the present study, we evaluated for first time the anti-proliferative efficacy of Hemiscorpius lepturus scorpion venom and its pathway on a colon carcinoma cell. MATERIALS AND METHODS The CT26 and VERO cell lines were treated with various concentrations of the venom. The IC50 values were estimated by MTT assay test, and the apoptosis was evaluated by flow cytometry. Moreover, RT-PCR analysis was used to investigate the levels of Bax, Bcl2, Trp53, and Casp3 mRNA expression. The mice xenograft model was established to evaluate the therapy efficiency of venom. Some valuable exponential growth parameters were evaluated in treated mice. RESULT The scorpion venom inhibited the growth of CT26 cells with an IC50 value about 120 μg/ml. However, VERO cells increased to 896 μg/ml under the same condition. A remarkable apoptotic cells in CT26 cells were revealed by flow cytometry assay. A significant over-expression was observed in Bax, Casp3, and Trp53 and downregulated in Bcl2 mRNA level in tumor tissue after treatment with scorpion venom (p < 0.05). All changes of valuable exponential growth parameters showed a shrinking tumor size. CONCLUSION Our findings indicated that Hemiscorpius lepturus venom has a special anti-proliferative effect on CT26 cells via Trp53/Bcl2/Casp3 pathway. Considering its powerful cytotoxic vigor against a colon cancer cell (CT26) and low toxicity to non-tumorigenic cell (VERO), we propose that this venom probably has a specific effect on other colon cancer cells and may turn out to be a novel therapeutic strategy in treating colon cancer.
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Affiliation(s)
- Mohammadreza Moradi
- Research Center for Molecular Medicine, Hamadan University of Medical Sciences, Hamadan, Iran
- Hamadan University of Medical Sciences, Pejohesh Crossroads, Hamadan, 65178-38678, Iran
| | - Rezvan Najafi
- Research Center for Molecular Medicine, Hamadan University of Medical Sciences, Hamadan, Iran
- Hamadan University of Medical Sciences, Pejohesh Crossroads, Hamadan, 65178-38678, Iran
| | - Razieh Amini
- Research Center for Molecular Medicine, Hamadan University of Medical Sciences, Hamadan, Iran
- Hamadan University of Medical Sciences, Pejohesh Crossroads, Hamadan, 65178-38678, Iran
| | - Reza Solgi
- Legal Medicine Research Center, Legal Medicine Organization of Iran, Hamadan, Iran
- Felestin Square, General Office of Legal Medicine, Ghobare Hamadani Blvd, Hamadan, 65187-53141, Iran
| | - Hamid Tanzadehpanah
- Research Center for Molecular Medicine, Hamadan University of Medical Sciences, Hamadan, Iran
- Hamadan University of Medical Sciences, Pejohesh Crossroads, Hamadan, 65178-38678, Iran
| | - Alireza Monsef Esfahani
- Hamadan University of Medical Sciences, Pejohesh Crossroads, Hamadan, 65178-38678, Iran
- Department of Pathology, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Massoud Saidijam
- Research Center for Molecular Medicine, Hamadan University of Medical Sciences, Hamadan, Iran.
- Hamadan University of Medical Sciences, Pejohesh Crossroads, Hamadan, 65178-38678, Iran.
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Takahashi K, Umebayashi C, Numata T, Honda A, Ichikawa J, Hu Y, Yamaura K, Inoue R. TRPM7-mediated spontaneous Ca 2+ entry regulates the proliferation and differentiation of human leukemia cell line K562. Physiol Rep 2018; 6:e13796. [PMID: 30033625 PMCID: PMC6055029 DOI: 10.14814/phy2.13796] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2018] [Revised: 06/20/2018] [Accepted: 06/24/2018] [Indexed: 11/30/2022] Open
Abstract
Continuous Ca2+ influx is essential to maintain intracellular Ca2+ homeostasis and its dysregulation leads to a variety of cellular dysfunctions. In this study, we explored the functional roles of spontaneous Ca2+ influx for the proliferation and differentiation of a human erythromyeloid leukemia cell line K562. mRNA/protein expressions were assessed by the real-time RT-PCR, western blotting, and immunocytochemical staining. Intracellular Ca2+ concentration ([Ca2+ ]i ) and ionic currents were measured by fluorescent imaging and patch clamping techniques, respectively. Cell counting/viability and colorimetric assays were applied to assess proliferation rate and hemoglobin synthesis, respectively. Elimination of extracellular Ca2+ decreased basal [Ca2+ ]i in proliferating K562 cells. Cation channel blockers such as SK&F96365, 2-APB, Gd3+ , and FTY720 dose dependently decreased basal [Ca2+ ]i . A spontaneously active inward current (Ispont ) contributive to basal [Ca2+ ]i was identified by the nystatin-perforated whole-cell recording. Ispont permeated Ca2+ comparably to Na+ , and was greatly eliminated by siRNA targeting TRPM7, a melastatin member of the transient receptor potential (TRP) superfamily. Consistent with these findings, TRPM7 immune reactivity was detected by western blotting, and immunofluorescence representing TRPM7 was found localized to the K562 cell membrane. Strikingly, all these procedures, that is, Ca2+ removal, TRPM7 blockers and siRNA-mediated TRPM7 knockdown significantly retarded the growth and suppressed hemin-induced γ-globin and hemoglobin syntheses in K562 cells, respectively, both of which appeared associated with the inhibition of ERK activation. These results collectively suggest that spontaneous Ca2+ influx through constitutively active TRPM7 channels may critically regulate both proliferative and erythroid differentiation potentials of K562 cells.
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Affiliation(s)
- Kiriko Takahashi
- Department of PhysiologyFukuoka University School of MedicineFukuokaJapan
- Department of AnesthesiologyFukuoka University School of MedicineFukuokaJapan
| | - Chisato Umebayashi
- Department of PhysiologyFukuoka University School of MedicineFukuokaJapan
| | - Tomohiro Numata
- Department of PhysiologyFukuoka University School of MedicineFukuokaJapan
| | - Akira Honda
- Department of PhysiologyFukuoka University School of MedicineFukuokaJapan
| | - Jun Ichikawa
- Department of PhysiologyFukuoka University School of MedicineFukuokaJapan
| | - Yaopeng Hu
- Department of PhysiologyFukuoka University School of MedicineFukuokaJapan
| | - Ken Yamaura
- Department of AnesthesiologyFukuoka University School of MedicineFukuokaJapan
| | - Ryuji Inoue
- Department of PhysiologyFukuoka University School of MedicineFukuokaJapan
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Zhang Y, Chi D. Overexpression of SIRT2 Alleviates Neuropathic Pain and Neuroinflammation Through Deacetylation of Transcription Factor Nuclear Factor-Kappa B. Inflammation 2018; 41:569-78. [DOI: 10.1007/s10753-017-0713-3] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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Song J, Yoon SR, Kim OY. miR-Let7A Controls the Cell Death and Tight Junction Density of Brain Endothelial Cells under High Glucose Condition. Oxid Med Cell Longev 2017; 2017:6051874. [PMID: 28680530 DOI: 10.1155/2017/6051874] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/27/2017] [Revised: 05/07/2017] [Accepted: 05/21/2017] [Indexed: 12/13/2022]
Abstract
Hyperglycemia-induced stress in the brain of patients with diabetes triggers the disruption of blood-brain barrier (BBB), leading to diverse neurological diseases including stroke and dementia. Recently, the role of microRNA becomes an interest in the research for deciphering the mechanism of brain endothelial cell damage under hyperglycemia. Therefore, we investigated whether mircoRNA Let7A (miR-Let7A) controls the damage of brain endothelial (bEnd.3) cells against high glucose condition. Cell viability, cell death marker expressions (p-53, Bax, and cleaved poly ADP-ribose polymerase), the loss of tight junction proteins (ZO-1 and claudin-5), proinflammatory response (interleukin-6, tumor necrosis factor-α), inducible nitric oxide synthase, and nitrite production were confirmed using MTT, reverse transcription-PCR, quantitative-PCR, Western blotting, immunofluorescence, and Griess reagent assay. miR-Let7A overexpression significantly prevented cell death and loss of tight junction proteins and attenuated proinflammatory response and nitrite production in the bEnd.3 cells under high glucose condition. Taken together, we suggest that miR-Let7A may attenuate brain endothelial cell damage by controlling cell death signaling, loss of tight junction proteins, and proinflammatory response against high glucose stress. In the future, the manipulation of miR-Let7A may be a novel solution in controlling BBB disruption which leads to the central nervous system diseases.
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Rapôso C. Scorpion and spider venoms in cancer treatment: state of the art, challenges, and perspectives. J Clin Transl Res 2017; 3:233-249. [PMID: 30873475 PMCID: PMC6410669] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2016] [Revised: 03/01/2017] [Accepted: 05/17/2017] [Indexed: 11/12/2022] Open
Abstract
Background and Aim: Animal venoms comprise a mix of bioactive molecules with high affinity for multiple targets in cells and tissues. Scorpion and spider venoms and purified peptides exhibit significant effects on cancer cells, encompassing four potential mechanisms: 1) induction of cell cycle arrest, growth inhibition, and apoptosis; 2) inhibition of angiogenesis; 3) inhibition of invasion and metastasis; and 4) blocking of specific transmembrane channels. Tumor biology is complex and entails many intertwined processes, as reflected in the putative hallmarks of cancer. This complexity, however, gives rise to numerous (potential) pharmacological intervention sites. Molecules that target multiple proteins or pathways, such as components of animal venoms, may therefore be effective anti-cancer agents. The objective of this review was to address the anti-cancer properties and in vitro mechanisms of scorpion and spider venoms and toxins, and highlight current obstacles in translating the preclinical research to a clinical setting. Relevance for patients: Cancer is a considerable global contributor to disease-related death. Despite some advances being made, therapy remains palliative rather than curative for the majority of cancer indications. Consequently, more effective therapies need to be devised for poorly responding cancer types to optimize clinical cancer management. Scorpion and spider venoms may occupy a role in the development of improved anti-cancer modalities.
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Affiliation(s)
- Catarina Rapôso
- Department of Structural and Functional Biology, Institute of Biology, State University of Campinas (UNICAMP), Campinas, SP, Brazil
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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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: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 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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Abstract
The determination of membrane protein (MP) structures has always trailed that of soluble proteins due to difficulties in their overexpression, reconstitution into membrane mimetics, and subsequent structure determination. The percentage of MP structures in the protein databank (PDB) has been at a constant 1-2% for the last decade. In contrast, over half of all drugs target MPs, only highlighting how little we understand about drug-specific effects in the human body. To reduce this gap, researchers have attempted to predict structural features of MPs even before the first structure was experimentally elucidated. In this review, we present current computational methods to predict MP structure, starting with secondary structure prediction, prediction of trans-membrane spans, and topology. Even though these methods generate reliable predictions, challenges such as predicting kinks or precise beginnings and ends of secondary structure elements are still waiting to be addressed. We describe recent developments in the prediction of 3D structures of both α-helical MPs as well as β-barrels using comparative modeling techniques, de novo methods, and molecular dynamics (MD) simulations. The increase of MP structures has (1) facilitated comparative modeling due to availability of more and better templates, and (2) improved the statistics for knowledge-based scoring functions. Moreover, de novo methods have benefited from the use of correlated mutations as restraints. Finally, we outline current advances that will likely shape the field in the forthcoming decade.
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Affiliation(s)
- Julia Koehler Leman
- Department of Chemical and Biomolecular Engineering, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Martin B. Ulmschneider
- Department of Materials Science and Engineering, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Jeffrey J. Gray
- Department of Chemical and Biomolecular Engineering, Johns Hopkins University, Baltimore, MD 21218, USA
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