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Matsumori N, Hieda M, Morito M, Wakamiya Y, Oishi T. Truncated derivatives of amphidinol 3 reveal the functional role of polyol chain in sterol-recognition and pore formation. Bioorg Med Chem Lett 2024; 98:129594. [PMID: 38104905 DOI: 10.1016/j.bmcl.2023.129594] [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: 09/24/2023] [Revised: 12/02/2023] [Accepted: 12/12/2023] [Indexed: 12/19/2023]
Abstract
Here we examined the membrane binding and pore formation of amphidinol 3 (AM3) and its truncated synthetic derivatives. Importantly, both of the membrane affinity and pore formation activity were well correlated with the reported antifungal activity. Our data clearly demonstrated that the C1-C30 moiety of AM3 plays essential roles both in sterol recognition and stable pore formation. Based on the current findings, we updated the interacting model between AM3 and sterol, in which the moiety encompassing from C21 to C67 accommodates a sterol molecule with forming hydrogen bonds with the sterol hydroxy group and van der Waals contact between AM3 polyol and sterol skeleton. Although the conformation of the C1-C20 moiety of AM3 is hard to specify due to its flexibility, the region likely contributes to stabilization of pore structure.
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Affiliation(s)
- Nobuaki Matsumori
- Department of Chemistry, Graduate School of Science, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan.
| | - Manami Hieda
- Department of Chemistry, Graduate School of Science, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan
| | - Masayuki Morito
- Department of Chemistry, Graduate School of Science, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan
| | - Yuma Wakamiya
- Department of Chemistry, Graduate School of Science, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan; Discovery Chemistry Department, Chugai Pharmaceutical Co., Ltd., 200. 216 Totsukacho, Totsuka-ku, Yokohama 244-8602, Japan
| | - Tohru Oishi
- Department of Chemistry, Graduate School of Science, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan
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Ostroumova OS, Efimova SS. Lipid-Centric Approaches in Combating Infectious Diseases: Antibacterials, Antifungals and Antivirals with Lipid-Associated Mechanisms of Action. Antibiotics (Basel) 2023; 12:1716. [PMID: 38136750 PMCID: PMC10741038 DOI: 10.3390/antibiotics12121716] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Revised: 12/05/2023] [Accepted: 12/08/2023] [Indexed: 12/24/2023] Open
Abstract
One of the global challenges of the 21st century is the increase in mortality from infectious diseases against the backdrop of the spread of antibiotic-resistant pathogenic microorganisms. In this regard, it is worth targeting antibacterials towards the membranes of pathogens that are quite conservative and not amenable to elimination. This review is an attempt to critically analyze the possibilities of targeting antimicrobial agents towards enzymes involved in pathogen lipid biosynthesis or towards bacterial, fungal, and viral lipid membranes, to increase the permeability via pore formation and to modulate the membranes' properties in a manner that makes them incompatible with the pathogen's life cycle. This review discusses the advantages and disadvantages of each approach in the search for highly effective but nontoxic antimicrobial agents. Examples of compounds with a proven molecular mechanism of action are presented, and the types of the most promising pharmacophores for further research and the improvement of the characteristics of antibiotics are discussed. The strategies that pathogens use for survival in terms of modulating the lipid composition and physical properties of the membrane, achieving a balance between resistance to antibiotics and the ability to facilitate all necessary transport and signaling processes, are also considered.
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Affiliation(s)
- Olga S. Ostroumova
- Laboratory of Membrane and Ion Channel Modeling, Institute of Cytology, Russian Academy of Sciences, Tikhoretsky Ave. 4, St. Petersburg 194064, Russia;
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Morales-Amador A, Souto ML, Hertweck C, Fernández JJ, García-Altares M. Rapid Screening of Polyol Polyketides from Marine Dinoflagellates. Anal Chem 2022; 94:14205-14213. [PMID: 36190828 PMCID: PMC9583072 DOI: 10.1021/acs.analchem.2c02185] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
Abstract
![]()
Dinoflagellate-derived
polyketides are typically large molecules
(>1000 Da) with complex structures, potent bioactivities, and high
toxicities. Their discovery suffers three major bottlenecks: insufficient
bioavailability, low-yield cultivation of producer organisms, and
production of multiple highly related analogues by a single strain.
Consequently, the biotechnological production of therapeutics or toxicological
standards of dinoflagellate-derived polyketides is also hampered.
Strategies based on sensitive and selective techniques for chemical
prospection of dinoflagellate extracts could aid in overcoming these
limitations, as it allows selecting the most interesting candidates
for discovery and exploitation programs according to the biosynthetic
potential. In this work, we assess the combination of data-dependent
liquid chromatography coupled with high-resolution tandem mass spectrometry
(LC–HRMS2) and molecular networking to screen polyol
polyketides. To demonstrate the power of this approach, we selected
dinoflagellate Amphidinium carterae since it is commonly used as a biotechnological model and produces
amphidinols, a family of polyol-polyene compounds with antifungal
and antimycoplasmal activity. First, we screened families of compounds
with multiple hydroxyl groups by examining MS2 profiles
that contain sequential neutral losses of water. Then, we clustered
MS2 spectra by molecular networking to facilitate the dereplication
and discovery of amphidinols. Finally, we used the MS2 fragmentation
behavior of well-characterized luteophanol D as a model to propose
a structural hypothesis of nine novel amphidinols. We envision that
this strategy is a valuable approach to rapidly monitoring toxin production
of known and unknown polyol polyketides in dinoflagellates, even in
small culture volumes, and distinguishing strains according to their
toxin profiles.
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Affiliation(s)
- Adrián Morales-Amador
- Departamento de Química Orgánica, Instituto Universitario de Bio-Orgánica Antonio González (IUBO AG), Universidad de La Laguna (ULL), Avenida Astrofísico Francisco Sánchez 2, 38206 La Laguna, Tenerife, Spain.,Department of Biomolecular Chemistry, Leibniz Institute for Natural Products Research and Infection Biology, Hans Knöll Institute (HKI), Adolf-Reichwein-Straße 23, 07745 Jena, Germany
| | - María L Souto
- Departamento de Química Orgánica, Instituto Universitario de Bio-Orgánica Antonio González (IUBO AG), Universidad de La Laguna (ULL), Avenida Astrofísico Francisco Sánchez 2, 38206 La Laguna, Tenerife, Spain
| | - Christian Hertweck
- Department of Biomolecular Chemistry, Leibniz Institute for Natural Products Research and Infection Biology, Hans Knöll Institute (HKI), Adolf-Reichwein-Straße 23, 07745 Jena, Germany.,Faculty of Biological Sciences, Friedrich Schiller University Jena, 07743 Jena, Germany
| | - José J Fernández
- Departamento de Química Orgánica, Instituto Universitario de Bio-Orgánica Antonio González (IUBO AG), Universidad de La Laguna (ULL), Avenida Astrofísico Francisco Sánchez 2, 38206 La Laguna, Tenerife, Spain
| | - María García-Altares
- Department of Biomolecular Chemistry, Leibniz Institute for Natural Products Research and Infection Biology, Hans Knöll Institute (HKI), Adolf-Reichwein-Straße 23, 07745 Jena, Germany.,Department of Electronic Engineering, Rovira i Virgili University, 43007 Tarragona, Spain
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4
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Nishimura S. Marine natural products targeting the eukaryotic cell membrane. J Antibiot (Tokyo) 2021; 74:769-785. [PMID: 34493848 DOI: 10.1038/s41429-021-00468-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Revised: 06/16/2021] [Accepted: 07/01/2021] [Indexed: 02/07/2023]
Abstract
The cell membrane, with high fluidity and alternative curvatures, maintains the robust integrity to distinguish inner and outer space of cells or organelles. Lipids are the main components of the cell membrane, but their functions are largely unknown. Even the visualization of lipids is not straightforward since modification of lipids often hampers its correct physical properties. Many natural products target cell membranes, some of which are used as pharmaceuticals and/or research tools. They show specific recognition on lipids, and thus exhibit desired pharmacological effects and unique biological phenotypes. This review is a catalog of marine natural products that target eukaryotic cell membranes. Chemical structures, biological activities, and molecular mechanisms are summarized. I hope that this review will be helpful for readers to notice the potential of marine natural products in the exploration of the function of lipids and the druggability of eukaryotic cell membranes.
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Affiliation(s)
- Shinichi Nishimura
- Department of Biotechnology, Collaborative Research Institute for Innovative Microbiology, The University of Tokyo, Tokyo, Japan.
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Morales-Amador A, Molina-Miras A, López-Rosales L, Sánchez-Mirón A, García-Camacho F, Souto ML, Fernández JJ. Isolation and Structural Elucidation of New Amphidinol Analogues from Amphidinium carterae Cultivated in a Pilot-Scale Photobioreactor. Mar Drugs 2021; 19:432. [PMID: 34436271 PMCID: PMC8399002 DOI: 10.3390/md19080432] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Revised: 07/19/2021] [Accepted: 07/26/2021] [Indexed: 12/12/2022] Open
Abstract
The demand for valuable products from dinoflagellate biotechnology has increased remarkably in recent years due to their many prospective applications. However, there remain many challenges that need to be addressed in order to make dinoflagellate bioactives a commercial reality. In this article, we describe the technical feasibility of producing and recovering amphidinol analogues (AMs) excreted into a culture broth of Amphidinium carterae ACRN03, successfully cultured in an LED-illuminated pilot-scale (80 L) bubble column photobioreactor operated in fed-batch mode with a pulse feeding strategy. We report on the isolation of new structurally related AMs, amphidinol 24 (1, AM24), amphidinol 25 (2, AM25) and amphidinol 26 (3, AM26), from a singular fraction resulting from the downstream processing. Their planar structures were elucidated by extensive NMR and HRMS analysis, whereas the relative configuration of the C-32→C-47 bis-tetrahydropyran core was confirmed to be antipodal in accord with the recently revised configuration of AM3. The hemolytic activities of the new metabolites and other related derivatives were evaluated, and structure-activity conclusions were established. Their isolation was based on a straightforward and high-performance bioprocess that could be suitable for the commercial development of AMs or other high-value compounds from shear sensitive dinoflagellates.
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Affiliation(s)
- Adrián Morales-Amador
- Instituto Universitario de Bio-Orgánica Antonio González (IUBO AG), Universidad de La Laguna (ULL), Avda. Astrofísico F. Sánchez 2, 38206 La Laguna, Spain;
- Departamento de Química Orgánica, Universidad de La Laguna (ULL), Avda. Astrofísico F. Sánchez 2, 38206 La Laguna, Spain
| | - Alejandro Molina-Miras
- Chemical Engineering Department, University of Almería, 04120 Almería, Spain; (A.M.-M.); (L.L.-R.); (A.S.-M.); (F.G.-C.)
- Research Center CIAIMBITAL, University of Almería, 04120 Almería, Spain
| | - Lorenzo López-Rosales
- Chemical Engineering Department, University of Almería, 04120 Almería, Spain; (A.M.-M.); (L.L.-R.); (A.S.-M.); (F.G.-C.)
- Research Center CIAIMBITAL, University of Almería, 04120 Almería, Spain
| | - Asterio Sánchez-Mirón
- Chemical Engineering Department, University of Almería, 04120 Almería, Spain; (A.M.-M.); (L.L.-R.); (A.S.-M.); (F.G.-C.)
- Research Center CIAIMBITAL, University of Almería, 04120 Almería, Spain
| | - Francisco García-Camacho
- Chemical Engineering Department, University of Almería, 04120 Almería, Spain; (A.M.-M.); (L.L.-R.); (A.S.-M.); (F.G.-C.)
- Research Center CIAIMBITAL, University of Almería, 04120 Almería, Spain
| | - María L. Souto
- Instituto Universitario de Bio-Orgánica Antonio González (IUBO AG), Universidad de La Laguna (ULL), Avda. Astrofísico F. Sánchez 2, 38206 La Laguna, Spain;
- Departamento de Química Orgánica, Universidad de La Laguna (ULL), Avda. Astrofísico F. Sánchez 2, 38206 La Laguna, Spain
| | - José J. Fernández
- Instituto Universitario de Bio-Orgánica Antonio González (IUBO AG), Universidad de La Laguna (ULL), Avda. Astrofísico F. Sánchez 2, 38206 La Laguna, Spain;
- Departamento de Química Orgánica, Universidad de La Laguna (ULL), Avda. Astrofísico F. Sánchez 2, 38206 La Laguna, Spain
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Amphidinol 3 preferentially binds to cholesterol in disordered domains and disrupts membrane phase separation. Biochem Biophys Rep 2021; 26:100941. [PMID: 33614998 PMCID: PMC7881217 DOI: 10.1016/j.bbrep.2021.100941] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Revised: 01/29/2021] [Accepted: 01/30/2021] [Indexed: 11/20/2022] Open
Abstract
Amphidinol 3 (AM3), a polyhydroxy-polyene metabolite from the dinoflagellate Amphidinium klebsii, possesses potent antifungal activity. AM3 is known to interact directly with membrane sterols and permeabilize membranes by forming pores. Because AM3 binds to sterols such as cholesterol and ergosterol, it can be assumed that AM3 has some impact on lipid rafts, which are membrane domains rich in sphingolipids and cholesterol. Hence, we first examined the effect of AM3 on phase-separated liposomes, in which raft-like ordered and non-raft-like disordered domains are segregated. Consequently, AM3 disrupted the phase separation at 22 μM, as in the case of methyl-β-cyclodextrin, a well-known raft-disrupter that extracts sterol from membranes. The surface plasmon resonance measurements and dye leakage assays show that AM3 preferentially recognizes cholesterol in the disordered membrane, which may reflect a weaker lipid-cholesterol interaction in disordered membrane than in ordered membrane. Finally, to gain insight into the AM3-induced coalescence of membrane phases, we measured membrane fluidity using fluorescence correlation spectroscopy, demonstrating that AM3 significantly increases the order of disordered phase. Together, AM3 preferentially binds to the disordered phase rather than the ordered phase, and enhances the order of the disordered phase, consequently blending the separated phases.
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Mayer AMS, Guerrero AJ, Rodríguez AD, Taglialatela-Scafati O, Nakamura F, Fusetani N. Marine Pharmacology in 2016-2017: Marine Compounds with Antibacterial, Antidiabetic, Antifungal, Anti-Inflammatory, Antiprotozoal, Antituberculosis and Antiviral Activities; Affecting the Immune and Nervous Systems, and Other Miscellaneous Mechanisms of Action. Mar Drugs 2021; 19:49. [PMID: 33494402 PMCID: PMC7910995 DOI: 10.3390/md19020049] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Revised: 01/13/2021] [Accepted: 01/15/2021] [Indexed: 12/12/2022] Open
Abstract
The review of the 2016-2017 marine pharmacology literature was prepared in a manner similar as the 10 prior reviews of this series. Preclinical marine pharmacology research during 2016-2017 assessed 313 marine compounds with novel pharmacology reported by a growing number of investigators from 54 countries. The peer-reviewed literature reported antibacterial, antifungal, antiprotozoal, antituberculosis, and antiviral activities for 123 marine natural products, 111 marine compounds with antidiabetic and anti-inflammatory activities as well as affecting the immune and nervous system, while in contrast 79 marine compounds displayed miscellaneous mechanisms of action which upon further investigation may contribute to several pharmacological classes. Therefore, in 2016-2017, the preclinical marine natural product pharmacology pipeline generated both novel pharmacology as well as potentially new lead compounds for the growing clinical marine pharmaceutical pipeline, and thus sustained with its contributions the global research for novel and effective therapeutic strategies for multiple disease categories.
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Affiliation(s)
- Alejandro M. S. Mayer
- Department of Pharmacology, College of Graduate Studies, Midwestern University, 555 31st Street, Downers Grove, IL 60515, USA;
| | - Aimee J. Guerrero
- Department of Pharmacology, College of Graduate Studies, Midwestern University, 555 31st Street, Downers Grove, IL 60515, USA;
| | - Abimael D. Rodríguez
- Molecular Sciences Research Center, University of Puerto Rico, 1390 Ponce de León Avenue, San Juan, PR 00926, USA;
| | | | - Fumiaki Nakamura
- Department of Chemistry and Biochemistry, Graduate School of Advanced Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku-ku, Tokyo 169-8555, Japan;
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Zuttion F, Colom A, Matile S, Farago D, Pompeo F, Kokavecz J, Galinier A, Sturgis J, Casuso I. High-speed atomic force microscopy highlights new molecular mechanism of daptomycin action. Nat Commun 2020; 11:6312. [PMID: 33298927 PMCID: PMC7725780 DOI: 10.1038/s41467-020-19710-z] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2020] [Accepted: 10/15/2020] [Indexed: 02/08/2023] Open
Abstract
The increase in speed of the high-speed atomic force microscopy (HS-AFM) compared to that of the conventional AFM made possible the first-ever visualisation at the molecular-level of the activity of an antimicrobial peptide on a membrane. We investigated the medically prescribed but poorly understood lipopeptide Daptomycin under infection-like conditions (37 °C, bacterial lipid composition and antibiotic concentrations). We confirmed so far hypothetical models: Dap oligomerization and the existence of half pores. Moreover, we detected unknown molecular mechanisms: new mechanisms to form toroidal pores or to resist Dap action, and to unprecedently quantify the energy profile of interacting oligomers. Finally, the biological and medical relevance of the findings was ensured by a multi-scale multi-nativeness-from the molecule to the cell-correlation of molecular-level information from living bacteria (Bacillus subtilis strains) to liquid-suspended vesicles and supported-membranes using electron and optical microscopies and the lipid tension probe FliptR, where we found that the cells with a healthier state of their cell wall show smaller membrane deformations.
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Affiliation(s)
| | - Adai Colom
- Biochemistry Department, University of Geneva, Geneva, Switzerland
| | - Stefan Matile
- Organic Chemistry Department, University of Geneva, Geneva, Switzerland
| | - Denes Farago
- Department of Technical Informatics University of Szeged, Szeged, Hungary
| | - Frédérique Pompeo
- Laboratoire de Chimie Bactérienne (LCB), Institut de Microbiologie de la Méditerranée (IMM), CNRS, UMR 7283, Aix Marseille Université, Marseille, France
| | - Janos Kokavecz
- Institute of Environmental Science and Engineering, University of Szeged, Szeged, Hungary
| | - Anne Galinier
- Laboratoire de Chimie Bactérienne (LCB), Institut de Microbiologie de la Méditerranée (IMM), CNRS, UMR 7283, Aix Marseille Université, Marseille, France
| | - James Sturgis
- LISM, UMR 7255, CNRS, Aix Marseille Université, Marseille, France
| | - Ignacio Casuso
- U1067 INSERM, Aix-Marseille Université, Marseille, France.
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Cusick KD, Widder EA. Bioluminescence and toxicity as driving factors in harmful algal blooms: Ecological functions and genetic variability. HARMFUL ALGAE 2020; 98:101850. [PMID: 33129462 DOI: 10.1016/j.hal.2020.101850] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2019] [Revised: 05/29/2020] [Accepted: 06/02/2020] [Indexed: 06/11/2023]
Abstract
Dinoflagellates are an ecologically important group of marine microbial eukaryotes with a remarkable array of adaptive strategies. It is ironic that two of the traits for which dinoflagellates are best known, toxin production and bioluminescence, are rarely linked when considering the ecological significance of either. Although dinoflagellate species that form some of the most widespread and frequent harmful algal blooms (HABs) are bioluminescent, the molecular and eco-evolutionary associations between these two traits has received little attention. Here, the major themes of biochemistry and genetics, ecological functions, signaling mechanisms, and evolution are addressed, with parallels and connections drawn between the two. Of the 17 major classes of dinoflagellate toxins, only two are produced by bioluminescent species: saxitoxin (STX) and yessotoxin. Of these, STX has been extensively studied, including the identification of the STX biosynthetic genes. While numerous theories have been put forward as to the eco-evolutionary roles of both bioluminescence and toxicity, a general consensus is that both function as grazing deterrents. Thus, both bioluminescence and toxicity may aid in HAB initiation as they alleviate grazing pressure on the HAB species. A large gap in our understanding is the genetic variability among natural bloom populations, as both toxic and non-toxic strains have been isolated from the same geographic location. The same applies to bioluminescence, as there exist both bioluminescent and non-bioluminescent strains of the same species. Recent evidence demonstrating that blooms are not monoclonal events necessitates a greater level of understanding as to the genetic variability of these traits among sub-populations as well as the mechanisms by which cells acquire or lose the trait, as sequence analysis of STX+ and STX- species indicate the key gene required for toxicity is lost rather than gained. While the extent of genetic variability for both bioluminescence and toxicity among natural HAB sub-populations remains unknown, it is an area that needs to be explored in order to gain greater insights into the molecular mechanisms and environmental parameters driving HAB evolution.
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Affiliation(s)
- Kathleen D Cusick
- University of Maryland Baltimore County, Department of Biological Sciences, 1000 Hilltop Circle, Baltimore, MD 21250, United States.
| | - Edith A Widder
- Ocean Research and Conservation Association, 1420 Seaway Dr, Fort Pierce, FL 34949, United States.
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10
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Wakamiya Y, Ebine M, Matsumori N, Oishi T. Total Synthesis of Amphidinol 3: A General Strategy for Synthesizing Amphidinol Analogues and Structure-Activity Relationship Study. J Am Chem Soc 2020; 142:3472-3478. [PMID: 31986250 DOI: 10.1021/jacs.9b11789] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Amphidinol 3 (AM3) is a potent antifungal produced by the dinoflagellate Amphidinium klebsii. It was difficult to determine the absolute configuration of AM3 by using the scarce natural product due to the presence of numerous stereogenic centers on the acyclic carbon chain. Since the absolute configuration was partially determined on the basis of insufficient evidence, the originally proposed structure has been revised three times. Although recent progress on structure determination by computational analysis is remarkable, total synthesis is still the most reliable way to confirm structures. The first total synthesis of AM3 was achieved via expeditious assembly of three components in five steps, confirming the revised structure of AM3 after more than 20 years since its first discovery. The established synthetic route would be a general strategy for synthesizing amphidinol congeners. An artificial and simplified analogue of AM3, which elicited antifungal activity comparable to that of AM3, was designed and synthesized. This is the first example of a biologically active artificial analogue possessing a shorter polyol moiety, providing insight on the antifungal mode-of-action.
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Affiliation(s)
- Yuma Wakamiya
- Department of Chemistry, Faculty and Graduate School of Science , Kyushu University , 744 Motooka , Nishi-ku , Fukuoka 819-0395 , Japan
| | - Makoto Ebine
- Department of Chemistry, Faculty and Graduate School of Science , Kyushu University , 744 Motooka , Nishi-ku , Fukuoka 819-0395 , Japan
| | - Nobuaki Matsumori
- Department of Chemistry, Faculty and Graduate School of Science , Kyushu University , 744 Motooka , Nishi-ku , Fukuoka 819-0395 , Japan
| | - Tohru Oishi
- Department of Chemistry, Faculty and Graduate School of Science , Kyushu University , 744 Motooka , Nishi-ku , Fukuoka 819-0395 , Japan
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11
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Nishimura S, Matsumori N. Chemical diversity and mode of action of natural products targeting lipids in the eukaryotic cell membrane. Nat Prod Rep 2020; 37:677-702. [PMID: 32022056 DOI: 10.1039/c9np00059c] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Covering: up to 2019Nature furnishes bioactive compounds (natural products) with complex chemical structures, yet with simple, sophisticated molecular mechanisms. When natural products exhibit their activities in cells or bodies, they first have to bind or react with a target molecule in/on the cell. The cell membrane is a major target for bioactive compounds. Recently, our understanding of the molecular mechanism of interactions between natural products and membrane lipids progressed with the aid of newly-developed analytical methods. New technology reconnects old compounds with membrane lipids, while new membrane-targeting molecules are being discovered through the screening for antimicrobial potential of natural products. This review article focuses on natural products that bind to eukaryotic membrane lipids, and includes clinically important molecules and key research tools. The chemical diversity of membrane-targeting natural products and the molecular basis of lipid recognition are described. The history of how their mechanism was unveiled, and how these natural products are used in research are also mentioned.
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Affiliation(s)
- Shinichi Nishimura
- Department of Biotechnology, Collaborative Research Institute for Innovative Microbiology, The University of Tokyo, Tokyo 113-8657, Japan.
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Urakubo K, Iwamoto M, Oiki S. Drop-in-well chamber for droplet interface bilayer with built-in electrodes. Methods Enzymol 2019; 621:347-363. [PMID: 31128788 DOI: 10.1016/bs.mie.2019.02.012] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Various methods have been developed for the formation of planar lipid bilayers, and recent techniques using water-in-oil droplets, such as droplet interface bilayer (DIB) and contact bubble bilayer (CBB) methods, allow the ready formation of bilayers with arbitrary lipid compositions. Here, we developed a simple and portable DIB system using drop-in-wells, shaping two merging wells for settling electrolyte droplets. An aliquot of the electrolyte solution (1μL) is dropped into an organic solvent, and the droplet sinks to the drop-in-well at the bottom, where two monolayer-lined droplets come in contact to form the bilayer. Pre-installed electrodes allow electrophysiological measurements. The detailed drop-in-well method is presented, and some variations of the method, such as the use of microelectrodes and a sheet with a small hole for low-noise recordings, are extended. Examples of single channel current recordings of the KcsA potassium channel are demonstrated.
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Affiliation(s)
- Kazuhiro Urakubo
- Department of Molecular Physiology and Biophysics, University of Fukui, Fukui, Japan
| | - Masayuki Iwamoto
- Department of Molecular Physiology and Biophysics, University of Fukui, Fukui, Japan
| | - Shigetoshi Oiki
- Department of Molecular Physiology and Biophysics, University of Fukui, Fukui, Japan.
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13
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Constitutive boost of a K + channel via inherent bilayer tension and a unique tension-dependent modality. Proc Natl Acad Sci U S A 2018; 115:13117-13122. [PMID: 30509986 DOI: 10.1073/pnas.1812282115] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Molecular mechanisms underlying channel-membrane interplay have been extensively studied. Cholesterol, as a major component of the cell membrane, participates either in specific binding to channels or via modification of membrane physical features. Here, we examined the action of various sterols (cholesterol, epicholesterol, etc.) on a prototypical potassium channel (KcsA). Single-channel current recordings of the KcsA channel were performed in a water-in-oil droplet bilayer (contact bubble bilayer) with a mixed phospholipid composition (azolectin). Upon membrane perfusion of sterols, the activated gate at acidic pH closed immediately, irrespective of the sterol species. During perfusion, we found that the contacting bubbles changed their shapes, indicating alterations in membrane physical features. Absolute bilayer tension was measured according to the principle of surface chemistry, and inherent bilayer tension was ∼5 mN/m. All tested sterols decreased the tension, and the nonspecific sterol action to the channel was likely mediated by the bilayer tension. Purely mechanical manipulation that reduced bilayer tension also closed the gate, whereas the resting channel at neutral pH never activated upon increased tension. Thus, rather than conventional stretch activation, the channel, once ready to activate by acidic pH, changes the open probability through the action of bilayer tension. This constitutes a channel regulating modality by two successive stimuli. In the contact bubble bilayer, inherent bilayer tension was high, and the channel remained boosted. In the cell membrane, resting tension is low, and it is anticipated that the ready-to-activate channel remains closed until bilayer tension reaches a few millinewton/meter during physiological and pathological cellular activities.
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Oiki S, Iwamoto M. Lipid Bilayers Manipulated through Monolayer Technologies for Studies of Channel-Membrane Interplay. Biol Pharm Bull 2018; 41:303-311. [PMID: 29491206 DOI: 10.1248/bpb.b17-00708] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Fluidity and mosaicity are two critical features of biomembranes, by which membrane proteins function through chemical and physical interactions within a bilayer. To understand this complex and dynamic system, artificial lipid bilayer membranes have served as unprecedented tools for experimental examination, in which some aspects of biomembrane features have been extracted, and to which various methodologies have been applied. Among the lipid bilayers involving liposomes, planar lipid bilayers and nanodiscs, recent developments of lipid bilayer methods and the results of our channel studies are reviewed herein. Principles and techniques of bilayer formation are summarized, which have been extended to the current techniques, where a bilayer is formed from lipid-coated water-in-oil droplets (water-in-oil bilayer). In our newly developed method, termed the contact bubble bilayer (CBB) method, a water bubble is blown from a pipette into a bulk oil phase, and monolayer-lined bubbles are docked to form a bilayer through manipulation by pipette. An asymmetric bilayer can be readily formed, and changes in composition in one leaflet were possible. Taking advantage of the topological configuration of the CBB, such that the membrane's hydrophobic interior is contiguous with the surrounding bulk organic phase, oil-dissolved substances such as cholesterol were delivered directly to the bilayer interior to perfuse around the membrane-embedded channels (membrane perfusion), and current recordings in the single-channel allowed detection of immediate changes in the channels' response to cholesterol. Chemical and mechanical manipulation in each monolayer (monolayer technology) allows the examination of dynamic channel-membrane interplay.
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Affiliation(s)
- Shigetoshi Oiki
- Department of Molecular Physiology & Biophysics, University of Fukui Faculty of Medical Sciences
| | - Masayuki Iwamoto
- Department of Molecular Physiology & Biophysics, University of Fukui Faculty of Medical Sciences
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Iwamoto M, Elfaramawy MA, Yamatake M, Matsuura T, Oiki S. Concurrent In Vitro Synthesis and Functional Detection of Nascent Activity of the KcsA Channel under a Membrane Potential. ACS Synth Biol 2018; 7:1004-1011. [PMID: 29566487 DOI: 10.1021/acssynbio.7b00454] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Processes involved in the functional formation of prokaryotic membrane proteins have remained elusive. Here, we developed a new in vitro membrane protein expression system to detect nascent activities of the KcsA potassium channel in lipid bilayers under an applied membrane potential. The channel was synthesized using a reconstituted Escherichia coli-based in vitro transcription/translation system (IVTT) in a water-in-oil droplet lined by a membrane. The synthesized channels spontaneously incorporated into the membrane even without the translocon machinery (unassisted pathway) and formed functional channels with the correct orientation. The single-channel current of the first appearing nascent channel was captured, followed by the subsequent appearance of multiple channels. Notably, the first appearance time shortened substantially as the membrane potential was hyperpolarized. Under a steadily applied membrane potential, this system serves as a production line of membrane proteins via the unassisted pathway, mimicking the bacterial synthetic membrane.
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Affiliation(s)
- Masayuki Iwamoto
- Department of Molecular Physiology and Biophysics, University of Fukui, Eiheiji-cho, Fukui 910-1193, Japan
| | - Maie A. Elfaramawy
- Department of Biotechnology, Division of Advanced Science and Biotechnology, Graduate School of Engineering, Osaka University, Suita, Osaka 565-0871, Japan
| | - Mariko Yamatake
- Department of Molecular Physiology and Biophysics, University of Fukui, Eiheiji-cho, Fukui 910-1193, Japan
| | - Tomoaki Matsuura
- Department of Biotechnology, Division of Advanced Science and Biotechnology, Graduate School of Engineering, Osaka University, Suita, Osaka 565-0871, Japan
| | - Shigetoshi Oiki
- Department of Molecular Physiology and Biophysics, University of Fukui, Eiheiji-cho, Fukui 910-1193, Japan
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