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Titaux-Delgado G, Lopez-Giraldo AE, Carrillo E, Cofas-Vargas LF, Carranza LE, López-Vera E, García-Hernández E, Del Rio-Portilla F. Beta-KTx14.3, a scorpion toxin, blocks the human potassium channel KCNQ1. Biochim Biophys Acta Proteins Proteom 2023; 1871:140906. [PMID: 36918120 DOI: 10.1016/j.bbapap.2023.140906] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Revised: 02/25/2023] [Accepted: 03/06/2023] [Indexed: 03/14/2023]
Abstract
Potassium channels play a key role in regulating many physiological processes, thus, alterations in their proper functioning can lead to the development of several diseases. Hence, the search for compounds capable of regulating the activity of these channels constitutes an intense field of investigation. Potassium scorpion toxins are grouped into six subfamilies (α, β, γ, κ, δ, and λ). However, experimental structures and functional analyses of the long chain β-KTx subfamily are lacking. In this study, we recombinantly produced the toxins TcoKIK and beta-KTx14.3 present in the venom of Tityus costatus and Lychas mucronatus scorpions, respectively. The 3D structures of these β-KTx toxins were determined by nuclear magnetic resonance. In both toxins, the N-terminal region is unstructured, while the C-terminal possesses the classic CSα/β motif. TcoKIK did not show any clear activity against frog Shaker and human KCNQ1 potassium channels; however, beta-KTx14.3 was able to block the KCNQ1 channel. The toxin-channel interaction mode was investigated using molecular dynamics simulations. The results showed that this toxin could form a stable network of polar-to-polar and hydrophobic interactions with KCNQ1, involving key conserved residues in both molecular partners. The discovery and characterization of a toxin capable of inhibiting KCNQ1 pave the way for the future development of novel drugs for the treatment of human diseases caused by the malfunction of this potassium channel. STATEMENT OF SIGNIFICANCE: Scorpion toxins have been shown to rarely block human KCNQ1 channels, which participate in the regulation of cardiac processes. In this study, we obtained recombinant beta-KTx14.3 and TcoKIK toxins and determined their 3D structures by nuclear magnetic resonance. Electrophysiological studies and molecular dynamics models were employed to examine the interactions between these two toxins and the human KCNQ1, which is the major driver channel of cardiac repolarization; beta-KTx14.3 was found to block effectively this channel. Our findings provide insights for the development of novel toxin-based drugs for the treatment of cardiac channelopathies involving KCNQ1-like channels.
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Affiliation(s)
- Gustavo Titaux-Delgado
- Departamento de Química de Biomacromoléculas, Instituto de Química, Universidad Nacional Autónoma de México, CU, Ciudad de México 04510, Mexico
| | - Andrea Estefanía Lopez-Giraldo
- Departamento de Química de Biomacromoléculas, Instituto de Química, Universidad Nacional Autónoma de México, CU, Ciudad de México 04510, Mexico
| | - Elisa Carrillo
- Department of Biochemistry and Molecular Biology, The University of Texas Health Science Center, Houston, TX 77030, USA
| | - Luis Fernando Cofas-Vargas
- Departamento de Química de Biomacromoléculas, Instituto de Química, Universidad Nacional Autónoma de México, CU, Ciudad de México 04510, Mexico
| | - Luis Enrique Carranza
- Departamento de Química de Biomacromoléculas, Instituto de Química, Universidad Nacional Autónoma de México, CU, Ciudad de México 04510, Mexico
| | - Estuardo López-Vera
- Laboratorio de Toxinología Marina, Unidad Académica de Ecología y Biodiversidad Acuática, Instituto de Ciencias del Mar y Limnología, Universidad Nacional Autónoma de México, Ciudad Universitaria, Ciudad de México 04510, Mexico
| | - Enrique García-Hernández
- Departamento de Química de Biomacromoléculas, Instituto de Química, Universidad Nacional Autónoma de México, CU, Ciudad de México 04510, Mexico.
| | - Federico Del Rio-Portilla
- Departamento de Química de Biomacromoléculas, Instituto de Química, Universidad Nacional Autónoma de México, CU, Ciudad de México 04510, Mexico.
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Titaux-Delgado G, Carrillo E, Mendoza A, Mayorga-Flores M, Escobedo-González FC, Cano-Sánchez P, López-Vera E, Corzo G, Del Rio-Portilla F. Successful refolding and NMR structure of rMagi3: A disulfide-rich insecticidal spider toxin. Protein Sci 2018; 27:692-701. [PMID: 29247580 DOI: 10.1002/pro.3363] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2017] [Revised: 12/12/2017] [Accepted: 12/14/2017] [Indexed: 11/07/2022]
Abstract
The need for molecules with high specificity against noxious insects leads the search towards spider venoms that have evolved highly selective toxins for insect preys. In this respect, spiders as a highly diversified group of almost exclusive insect predators appear to possess infinite potential for the discovery of novel insect-selective toxins. In 2003, a group of toxins was isolated from the spider Macrothele gigas and the amino acid sequence was reported. We obtained, by molecular biology techniques in a heterologous system, one of these toxins. Purification process was optimized by chromatographic methods to determine the three-dimensional structure by nuclear magnetic resonance in solution, and, finally, their biological activity was tested. rMagi3 resulted to be a specific insect toxin with no effect on mice.
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Affiliation(s)
- Gustavo Titaux-Delgado
- Departamento de Química de Biomacromoléculas, Instituto de Química, Universidad Nacional Autónoma de México, CU, Ciudad de México, 04510, México
| | - Elisa Carrillo
- Laboratorio de Toxinología Marina, Unidad Académica de Ecología y Biodiversidad Acuática, Instituto de Ciencias del Mar y Limnología, Universidad Nacional Autónoma de México, Ciudad Universitaria, Ciudad de México, 04510, México
| | - Angeles Mendoza
- División de Ciencias e Ingenierías, Campus León, Universidad de Guanajuato, Loma del Bosque 103, Col. Lomas del Campestre León, Gto, 37150, México
| | - Marlen Mayorga-Flores
- Departamento de Química de Biomacromoléculas, Instituto de Química, Universidad Nacional Autónoma de México, CU, Ciudad de México, 04510, México
| | - Fátima C Escobedo-González
- Departamento de Química de Biomacromoléculas, Instituto de Química, Universidad Nacional Autónoma de México, CU, Ciudad de México, 04510, México
| | - Patricia Cano-Sánchez
- Departamento de Química de Biomacromoléculas, Instituto de Química, Universidad Nacional Autónoma de México, CU, Ciudad de México, 04510, México
| | - Estuardo López-Vera
- Laboratorio de Toxinología Marina, Unidad Académica de Ecología y Biodiversidad Acuática, Instituto de Ciencias del Mar y Limnología, Universidad Nacional Autónoma de México, Ciudad Universitaria, Ciudad de México, 04510, México
| | - Gerardo Corzo
- Departamento de Medicina Molecular y Bioprocesos, Instituto de Biotecnología, Universidad Nacional Autónoma de México, UNAM, Apartado Postal 510-3, Cuernavaca, Morelos, 61500, México
| | - Federico Del Rio-Portilla
- Departamento de Química de Biomacromoléculas, Instituto de Química, Universidad Nacional Autónoma de México, CU, Ciudad de México, 04510, México
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Tello I, Campos-Pena V, Montiel E, Rodriguez V, Aguirre-Moreno A, Leon-Rivera I, Del Rio-Portilla F, Herrera-Ruiz M, Villeda-Hernandez J. Anticonvulsant and neuroprotective effects of oligosaccharides from Lingzhi or Reishi medicinal mushroom, Ganoderma lucidum (Higher Basidiomycetes). Int J Med Mushrooms 2014; 15:555-68. [PMID: 24266379 DOI: 10.1615/intjmedmushr.v15.i6.40] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
An oligosaccharide fraction isolated from the mycelium of the Lingzhi or Reishi medicinal mushroom Ganoderma lucidum (GLOS) was separated by size-exclusion chromatography. The chemical structure of GLOS consists of a disaccharide repeating unit [-4-β-1-Galf(1-6)-O-(β-Glcp)-1-]n (n=3,4). In addition, this study was undertaken to determine the possible anticonvulsant and neuroprotective effects of GLOS (10-80 mg/kg) on kainic acid (KA)-induced seizures. The behavioral alterations and histopathology of hippocampal neurons were studied. Our results show that GLOS inhibited convulsions in rats from KA-induced seizures, reduced the degeneration pattern in the CA3 region of rats, decreased astrocytic reactivity, and reduced the expression of IL-1β and TNF-α induced by KA. These results indicate a potential anticonvulsant and neuroprotective effects of GLOS.
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Affiliation(s)
- Isaac Tello
- Centro de Investigaciones Biologicas, Universidad Autonoma del Estado de Morelos, Avenida Universidad 1001, Col. Chamilpa 62209 Cuernavaca, Morelos, México
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