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Opravil J, Pejchal J, Finger V, Korabecny J, Rozsypal T, Hrabinova M, Muckova L, Hepnarova V, Konecny J, Soukup O, Jun D. A-agents, misleadingly known as "Novichoks": a narrative review. Arch Toxicol 2023; 97:2587-2607. [PMID: 37612377 PMCID: PMC10475003 DOI: 10.1007/s00204-023-03571-8] [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] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Accepted: 08/02/2023] [Indexed: 08/25/2023]
Abstract
"Novichok" refers to a new group of nerve agents called the A-series agents. Their existence came to light in 2018 after incidents in the UK and again in 2020 in Russia. They are unique organophosphorus-based compounds developed during the Cold War in a program called Foliant in the USSR. This review is based on original chemical entities from Mirzayanov's memoirs published in 2008. Due to classified research, a considerable debate arose about their structures, and hence, various structural moieties were speculated. For this reason, the scientific literature is highly incomplete and, in some cases, contradictory. This review critically assesses the information published to date on this class of compounds. The scope of this work is to summarize all the available and relevant information, including the physicochemical properties, chemical synthesis, mechanism of action, toxicity, pharmacokinetics, and medical countermeasures used to date. The environmental stability of A-series agents, the lack of environmentally safe decontamination, their high toxicity, and the scarcity of information on post-contamination treatment pose a challenge for managing possible incidents.
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Affiliation(s)
- Jakub Opravil
- Faculty of Military Health Sciences, University of Defence, Trebesska 1575, 500 01 Hradec Kralove, Czech Republic
| | - Jaroslav Pejchal
- Faculty of Military Health Sciences, University of Defence, Trebesska 1575, 500 01 Hradec Kralove, Czech Republic
| | - Vladimir Finger
- Faculty of Military Health Sciences, University of Defence, Trebesska 1575, 500 01 Hradec Kralove, Czech Republic
- Faculty of Pharmacy in Hradec Kralove, Charles University, Akademika Heyrovskeho 1203, 500 05 Hradec Kralove, Czech Republic
- Biomedical Research Center, University Hospital Hradec Kralove, Sokolska 581, 500 05 Hradec Kralove, Czech Republic
| | - Jan Korabecny
- Faculty of Military Health Sciences, University of Defence, Trebesska 1575, 500 01 Hradec Kralove, Czech Republic
- Biomedical Research Center, University Hospital Hradec Kralove, Sokolska 581, 500 05 Hradec Kralove, Czech Republic
| | - Tomas Rozsypal
- Nuclear, Biological and Chemical Defence Institute, University of Defence, Vita Nejedleho 1, 682 03 Vyskov, Czech Republic
| | - Martina Hrabinova
- Faculty of Military Health Sciences, University of Defence, Trebesska 1575, 500 01 Hradec Kralove, Czech Republic
| | - Lubica Muckova
- Faculty of Military Health Sciences, University of Defence, Trebesska 1575, 500 01 Hradec Kralove, Czech Republic
- Biomedical Research Center, University Hospital Hradec Kralove, Sokolska 581, 500 05 Hradec Kralove, Czech Republic
| | - Vendula Hepnarova
- Faculty of Military Health Sciences, University of Defence, Trebesska 1575, 500 01 Hradec Kralove, Czech Republic
| | - Jan Konecny
- Faculty of Military Health Sciences, University of Defence, Trebesska 1575, 500 01 Hradec Kralove, Czech Republic
- Biomedical Research Center, University Hospital Hradec Kralove, Sokolska 581, 500 05 Hradec Kralove, Czech Republic
| | - Ondrej Soukup
- Biomedical Research Center, University Hospital Hradec Kralove, Sokolska 581, 500 05 Hradec Kralove, Czech Republic
| | - Daniel Jun
- Faculty of Military Health Sciences, University of Defence, Trebesska 1575, 500 01 Hradec Kralove, Czech Republic
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Shcherbakov A, Synnatschke K, Bodnar S, Zerhoch J, Eyre L, Rauh F, Heindl MW, Liu S, Konecny J, Sharp ID, Sofer Z, Backes C, Deschler F. Solution-Processed NiPS 3 Thin Films from Liquid Exfoliated Inks with Long-Lived Spin-Entangled Excitons. ACS Nano 2023. [PMID: 37220255 DOI: 10.1021/acsnano.3c01119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Antiferromagnets are promising materials for future opto-spintronic applications since they show spin dynamics in the THz range and no net magnetization. Recently, layered van der Waals (vdW) antiferromagnets have been reported, which combine low-dimensional excitonic properties with complex spin-structure. While various methods for the fabrication of vdW 2D crystals exist, formation of large area and continuous thin films is challenging because of either limited scalability, synthetic complexity, or low opto-spintronic quality of the final material. Here, we fabricate centimeter-scale thin films of the van der Waals 2D antiferromagnetic material NiPS3, which we prepare using a crystal ink made from liquid phase exfoliation (LPE). We perform statistical atomic force microscopy (AFM) and scanning electron microscopy (SEM) to characterize and control the lateral size and number of layers through this ink-based fabrication. Using ultrafast optical spectroscopy at cryogenic temperatures, we resolve the dynamics of photoexcited excitons. We find antiferromagnetic spin arrangement and spin-entangled Zhang-Rice multiplet excitons with lifetimes in the nanosecond range, as well as ultranarrow emission line widths, despite the disordered nature of our films. Thus, our findings demonstrate scalable thin-film fabrication of high-quality NiPS3, which is crucial for translating this 2D antiferromagnetic material into spintronic and nanoscale memory devices and further exploring its complex spin-light coupled states.
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Affiliation(s)
- Andrii Shcherbakov
- Institute for Physical Chemistry, Heidelberg University, Im Neuenheimer Feld 229, 69120 Heidelberg, Germany
- Walter Schottky Institute and Physics Department, Technical University of Munich, Am Coulombwall 4, 85748 Garching by Munich, Germany
| | - Kevin Synnatschke
- School of Physics, Trinity College Dublin, The University of Dublin, Dublin 2, Ireland
- Applied Physical Chemistry, Heidelberg University, Im Neuenheimer Feld 253, 69120 Heidelberg, Germany
| | - Stanislav Bodnar
- Institute for Physical Chemistry, Heidelberg University, Im Neuenheimer Feld 229, 69120 Heidelberg, Germany
- Walter Schottky Institute and Physics Department, Technical University of Munich, Am Coulombwall 4, 85748 Garching by Munich, Germany
| | - Jonathan Zerhoch
- Institute for Physical Chemistry, Heidelberg University, Im Neuenheimer Feld 229, 69120 Heidelberg, Germany
- Walter Schottky Institute and Physics Department, Technical University of Munich, Am Coulombwall 4, 85748 Garching by Munich, Germany
| | - Lissa Eyre
- Walter Schottky Institute and Physics Department, Technical University of Munich, Am Coulombwall 4, 85748 Garching by Munich, Germany
- Electrical Engineering Division, University of Cambridge, 9 JJ Thomson Ave, Cambridge CB3 0FA, United Kingdom
| | - Felix Rauh
- Walter Schottky Institute and Physics Department, Technical University of Munich, Am Coulombwall 4, 85748 Garching by Munich, Germany
| | - Markus W Heindl
- Institute for Physical Chemistry, Heidelberg University, Im Neuenheimer Feld 229, 69120 Heidelberg, Germany
- Walter Schottky Institute and Physics Department, Technical University of Munich, Am Coulombwall 4, 85748 Garching by Munich, Germany
| | - Shangpu Liu
- Institute for Physical Chemistry, Heidelberg University, Im Neuenheimer Feld 229, 69120 Heidelberg, Germany
- Walter Schottky Institute and Physics Department, Technical University of Munich, Am Coulombwall 4, 85748 Garching by Munich, Germany
| | - Jan Konecny
- Department of Inorganic Chemistry, Faculty of Chemical Technology, University of Chemistry and Technology Prague, Technická 5, 166 28 Prague 6, Czech Republic
| | - Ian D Sharp
- Walter Schottky Institute and Physics Department, Technical University of Munich, Am Coulombwall 4, 85748 Garching by Munich, Germany
| | - Zdeněk Sofer
- Department of Inorganic Chemistry, Faculty of Chemical Technology, University of Chemistry and Technology Prague, Technická 5, 166 28 Prague 6, Czech Republic
| | - Claudia Backes
- Applied Physical Chemistry, Heidelberg University, Im Neuenheimer Feld 253, 69120 Heidelberg, Germany
- Physical Chemistry of Nanomaterials, University of Kassel, Heinrich-Plett-Straße 40, 34132 Kassel, Germany
| | - Felix Deschler
- Institute for Physical Chemistry, Heidelberg University, Im Neuenheimer Feld 229, 69120 Heidelberg, Germany
- Walter Schottky Institute and Physics Department, Technical University of Munich, Am Coulombwall 4, 85748 Garching by Munich, Germany
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Novak M, Svobodova B, Konecny J, Kuratkova A, Nevosadova L, Prchal L, Korabecny J, Lauschke VM, Soukup O, Kučera R. UHPLC-Orbitrap study of the first phase tacrine in vitro metabolites and related Alzheimer's drug candidates using human liver microsomes. J Pharm Biomed Anal 2023; 224:115154. [PMID: 36442458 DOI: 10.1016/j.jpba.2022.115154] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [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: 08/26/2022] [Revised: 10/16/2022] [Accepted: 11/08/2022] [Indexed: 11/13/2022]
Abstract
Tacrine was the first drug used in the therapy of Alzheimer's disease (AD) and is one of the leading structures frequently pursued in the drug discovery of novel candidates for tackling AD. However, because tacrine has been withdrawn from the market due to its hepatotoxicity, ascribed to specific metabolites, concerns are high about the toxicity profile of newly developed compounds related to tacrine. From the point of view of drug safety, the formation of metabolites must be uncovered and analyzed. Bearing in mind that the main culprit of tacrine hepatotoxicity is its biotransformation to hydroxylated metabolites, human liver microsomes were used as a biotransformation model. Our study aims to clarify phase I metabolites of three potentially non-toxic tacrine derivatives (7-methoxytacrine, 6-chlorotacrine, 7-phenoxytacrine) and to semi-quantitatively determine the relative amount of individual metabolites as potential culprits of tacrine-based hepatotoxicity. For this purpose, a new selective UHPLC-Orbitrap method has been developed. Applying UHPLC-Orbitrap method, two as yet unpublished tacrine and 7-methoxytacrine monohydroxylated metabolites have been found and completely characterized, and the separation of ten dihydroxylated tacrine and 7-methoxytacrine metabolites was achieved for the first time. Moreover, the structures of several new metabolites of 7-phenoxytacrine and 6-chlorotacrine have been identified. In addition, the relative amount of these newly observed metabolites was determined. Based on the results and known facts about the toxicity of tacrine metabolites published so far, it appears that 7-phenoxytacrine and 6-chlorotacrine could be substantially less hepatotoxic compared to tacrine, and could potentially pave the way for metabolically safe molecules applicable in AD therapy.
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Affiliation(s)
- M Novak
- Department of Pharmaceutical Chemistry and Pharmaceutical Analysis, Faculty of Pharmacy in Hradec Kralove, Charles University, Heyrovskeho 1203, 50005 Hradec Kralove, Czech Republic; Biomedical Research Centre, University Hospital Hradec Kralove, Sokolska 581, 50005 Hradec Kralove, Czech Republic.
| | - B Svobodova
- Biomedical Research Centre, University Hospital Hradec Kralove, Sokolska 581, 50005 Hradec Kralove, Czech Republic; Department of Toxicology and Military Pharmacy, Trebesska 1575, 50005 Hradec Kralove, Czech Republic.
| | - J Konecny
- Biomedical Research Centre, University Hospital Hradec Kralove, Sokolska 581, 50005 Hradec Kralove, Czech Republic; Department of Toxicology and Military Pharmacy, Trebesska 1575, 50005 Hradec Kralove, Czech Republic.
| | - A Kuratkova
- Department of Pharmaceutical Chemistry and Pharmaceutical Analysis, Faculty of Pharmacy in Hradec Kralove, Charles University, Heyrovskeho 1203, 50005 Hradec Kralove, Czech Republic.
| | - L Nevosadova
- Department of Pharmaceutical Chemistry and Pharmaceutical Analysis, Faculty of Pharmacy in Hradec Kralove, Charles University, Heyrovskeho 1203, 50005 Hradec Kralove, Czech Republic.
| | - L Prchal
- Biomedical Research Centre, University Hospital Hradec Kralove, Sokolska 581, 50005 Hradec Kralove, Czech Republic.
| | - J Korabecny
- Biomedical Research Centre, University Hospital Hradec Kralove, Sokolska 581, 50005 Hradec Kralove, Czech Republic; Department of Toxicology and Military Pharmacy, Trebesska 1575, 50005 Hradec Kralove, Czech Republic.
| | - V M Lauschke
- Department of Physiology and Pharmacology, Karolinska Institutet, 17177 Stockholm, Sweden; Dr Margarete Fischer-Bosch Institute of Clinical Pharmacology, 70376 Stuttgart, Germany; University of Tübingen, 72074 Tübingen, Germany.
| | - O Soukup
- Biomedical Research Centre, University Hospital Hradec Kralove, Sokolska 581, 50005 Hradec Kralove, Czech Republic.
| | - R Kučera
- Department of Pharmaceutical Chemistry and Pharmaceutical Analysis, Faculty of Pharmacy in Hradec Kralove, Charles University, Heyrovskeho 1203, 50005 Hradec Kralove, Czech Republic.
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Konecny J, Konecny T. Sleep Apnea, Septal Myectomy, and the Valsalva/Mueller Maneuvers: Who Can Resist Loving Hemodynamic Physiology? Mayo Clin Proc 2021; 96:2298-2300. [PMID: 34481593 DOI: 10.1016/j.mayocp.2021.07.014] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Accepted: 07/23/2021] [Indexed: 11/15/2022]
Affiliation(s)
- Jan Konecny
- First Department of Surgery, St. Anne's Hospital, Masaryk University, Brno, Czech Republic
| | - Thomas Konecny
- Department of Medicine, Division of Cardiovascular Diseases, Malcom Randall Veterans Affairs Medical Center, University of Florida Medical Center, Gainesville, FL.
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Konecny J, Mezeiova E, Soukup O, Korabecny J. Review of Synthetic Approaches to Dizocilpine. CURR ORG CHEM 2021. [DOI: 10.2174/1385272824999201230205835] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
N-Methyl-D-aspartate (NMDA) receptors, together with AMPA and kainite receptors,
belong to the family of ionotropic glutamate receptors. NMDA receptors play a crucial
role in neuronal plasticity and cognitive functions. Overactivation of those receptors leads to
glutamate-induced excitotoxicity, which could be suppressed by NMDA antagonists. Dizocilpine
was firstly reported in 1982 as an NMDA receptor antagonist with anticonvulsive properties,
but due to serious side effects like neuronal vacuolization, its use in human medicine is
restricted. However, dizocilpine is still used as a validated tool to induce the symptoms of
schizophrenia in animal models and also as a standard for comparative purposes to newly
developed NMDA receptor antagonists. For this reason, the synthesis of dizocilpine and especially
its more active enantiomer (+)-dizocilpine is still relevant. In this review, we bring a
collection of various synthetic approaches leading to dizocilpine and its analogues.
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Affiliation(s)
- Jan Konecny
- Biomedical Research Centre, University Hospital Hradec Kralove, Sokolska 581, 500 05 Hradec Kralove, Czech Republic
| | - Eva Mezeiova
- Biomedical Research Centre, University Hospital Hradec Kralove, Sokolska 581, 500 05 Hradec Kralove, Czech Republic
| | - Ondrej Soukup
- Biomedical Research Centre, University Hospital Hradec Kralove, Sokolska 581, 500 05 Hradec Kralove, Czech Republic
| | - Jan Korabecny
- Biomedical Research Centre, University Hospital Hradec Kralove, Sokolska 581, 500 05 Hradec Kralove, Czech Republic
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Konecny J, Misiachna A, Hrabinova M, Pulkrabkova L, Benkova M, Prchal L, Kucera T, Kobrlova T, Finger V, Kolcheva M, Kortus S, Jun D, Valko M, Horak M, Soukup O, Korabecny J. Pursuing the Complexity of Alzheimer's Disease: Discovery of Fluoren-9-Amines as Selective Butyrylcholinesterase Inhibitors and N-Methyl-d-Aspartate Receptor Antagonists. Biomolecules 2020; 11:biom11010003. [PMID: 33375115 PMCID: PMC7822176 DOI: 10.3390/biom11010003] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Revised: 12/14/2020] [Accepted: 12/18/2020] [Indexed: 12/13/2022] Open
Abstract
Alzheimer’s disease (AD) is a complex disorder with unknown etiology. Currently, only symptomatic therapy of AD is available, comprising cholinesterase inhibitors and N-methyl-d-aspartate (NMDA) receptor antagonists. Drugs targeting only one pathological condition have generated only limited efficacy. Thus, combining two or more therapeutic interventions into one molecule is believed to provide higher benefit for the treatment of AD. In the presented study, we designed, synthesized, and biologically evaluated 15 novel fluoren-9-amine derivatives. The in silico prediction suggested both the oral availability and permeation through the blood–brain barrier (BBB). An initial assessment of the biological profile included determination of the cholinesterase inhibition and NMDA receptor antagonism at the GluN1/GluN2A and GluN1/GluN2B subunits, along with a low cytotoxicity profile in the CHO-K1 cell line. Interestingly, compounds revealed a selective butyrylcholinesterase (BChE) inhibition pattern with antagonistic activity on the NMDARs. Their interaction with butyrylcholinesterase was elucidated by studying enzyme kinetics for compound 3c in tandem with the in silico docking simulation. The docking study showed the interaction of the tricyclic core of new derivatives with Trp82 within the anionic site of the enzyme in a similar way as the template drug tacrine. From the kinetic analysis, it is apparent that 3c is a competitive inhibitor of BChE.
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Affiliation(s)
- Jan Konecny
- Department of Toxicology and Military Pharmacy, Faculty of Military Health Sciences, Trebesska 1575, 500 01 Hradec Kralove, Czech Republic; (J.K.); (M.H.); (L.P.); (T.K.); (D.J.)
- Biomedical Research Centre, University Hospital Hradec Kralove, Sokolska 581, 500 05 Hradec Kralove, Czech Republic; (M.B.); (L.P.); (T.K.); (V.F.)
| | - Anna Misiachna
- Institute of Experimental Medicine of the Czech Academy of Sciences, Videnska 1083, 142 20 Prague, Czech Republic; (A.M.); (M.K.); (S.K.); (M.H.)
- Institute of Physiology of the Czech Academy of Sciences, Videnska 1083, 142 20 Prague, Czech Republic
- Department of Physiology, Faculty of Science, Charles University in Prague, Albertov 6, 128 43 Prague, Czech Republic
| | - Martina Hrabinova
- Department of Toxicology and Military Pharmacy, Faculty of Military Health Sciences, Trebesska 1575, 500 01 Hradec Kralove, Czech Republic; (J.K.); (M.H.); (L.P.); (T.K.); (D.J.)
- Biomedical Research Centre, University Hospital Hradec Kralove, Sokolska 581, 500 05 Hradec Kralove, Czech Republic; (M.B.); (L.P.); (T.K.); (V.F.)
| | - Lenka Pulkrabkova
- Department of Toxicology and Military Pharmacy, Faculty of Military Health Sciences, Trebesska 1575, 500 01 Hradec Kralove, Czech Republic; (J.K.); (M.H.); (L.P.); (T.K.); (D.J.)
- Biomedical Research Centre, University Hospital Hradec Kralove, Sokolska 581, 500 05 Hradec Kralove, Czech Republic; (M.B.); (L.P.); (T.K.); (V.F.)
| | - Marketa Benkova
- Biomedical Research Centre, University Hospital Hradec Kralove, Sokolska 581, 500 05 Hradec Kralove, Czech Republic; (M.B.); (L.P.); (T.K.); (V.F.)
| | - Lukas Prchal
- Biomedical Research Centre, University Hospital Hradec Kralove, Sokolska 581, 500 05 Hradec Kralove, Czech Republic; (M.B.); (L.P.); (T.K.); (V.F.)
| | - Tomas Kucera
- Department of Toxicology and Military Pharmacy, Faculty of Military Health Sciences, Trebesska 1575, 500 01 Hradec Kralove, Czech Republic; (J.K.); (M.H.); (L.P.); (T.K.); (D.J.)
- Biomedical Research Centre, University Hospital Hradec Kralove, Sokolska 581, 500 05 Hradec Kralove, Czech Republic; (M.B.); (L.P.); (T.K.); (V.F.)
| | - Tereza Kobrlova
- Biomedical Research Centre, University Hospital Hradec Kralove, Sokolska 581, 500 05 Hradec Kralove, Czech Republic; (M.B.); (L.P.); (T.K.); (V.F.)
| | - Vladimir Finger
- Biomedical Research Centre, University Hospital Hradec Kralove, Sokolska 581, 500 05 Hradec Kralove, Czech Republic; (M.B.); (L.P.); (T.K.); (V.F.)
- Department of Organic and Bioorganic Chemistry, Faculty of Pharmacy in Hradec Kralove, Charles University, Akademika Heyrovskeho 1203, 500 05 Hradec Kralove, Czech Republic
| | - Marharyta Kolcheva
- Institute of Experimental Medicine of the Czech Academy of Sciences, Videnska 1083, 142 20 Prague, Czech Republic; (A.M.); (M.K.); (S.K.); (M.H.)
- Institute of Physiology of the Czech Academy of Sciences, Videnska 1083, 142 20 Prague, Czech Republic
| | - Stepan Kortus
- Institute of Experimental Medicine of the Czech Academy of Sciences, Videnska 1083, 142 20 Prague, Czech Republic; (A.M.); (M.K.); (S.K.); (M.H.)
- Institute of Physiology of the Czech Academy of Sciences, Videnska 1083, 142 20 Prague, Czech Republic
| | - Daniel Jun
- Department of Toxicology and Military Pharmacy, Faculty of Military Health Sciences, Trebesska 1575, 500 01 Hradec Kralove, Czech Republic; (J.K.); (M.H.); (L.P.); (T.K.); (D.J.)
- Biomedical Research Centre, University Hospital Hradec Kralove, Sokolska 581, 500 05 Hradec Kralove, Czech Republic; (M.B.); (L.P.); (T.K.); (V.F.)
| | - Marian Valko
- Faculty of Chemical and Food Technology, Slovak University of Technology, Radlinskeho 9, 812 37 Bratislava, Slovakia;
| | - Martin Horak
- Institute of Experimental Medicine of the Czech Academy of Sciences, Videnska 1083, 142 20 Prague, Czech Republic; (A.M.); (M.K.); (S.K.); (M.H.)
- Institute of Physiology of the Czech Academy of Sciences, Videnska 1083, 142 20 Prague, Czech Republic
| | - Ondrej Soukup
- Department of Toxicology and Military Pharmacy, Faculty of Military Health Sciences, Trebesska 1575, 500 01 Hradec Kralove, Czech Republic; (J.K.); (M.H.); (L.P.); (T.K.); (D.J.)
- Biomedical Research Centre, University Hospital Hradec Kralove, Sokolska 581, 500 05 Hradec Kralove, Czech Republic; (M.B.); (L.P.); (T.K.); (V.F.)
- Correspondence: (O.S.); (J.K.); Tel.: +420-495-833-447 (O.S. & J.K.)
| | - Jan Korabecny
- Department of Toxicology and Military Pharmacy, Faculty of Military Health Sciences, Trebesska 1575, 500 01 Hradec Kralove, Czech Republic; (J.K.); (M.H.); (L.P.); (T.K.); (D.J.)
- Biomedical Research Centre, University Hospital Hradec Kralove, Sokolska 581, 500 05 Hradec Kralove, Czech Republic; (M.B.); (L.P.); (T.K.); (V.F.)
- Correspondence: (O.S.); (J.K.); Tel.: +420-495-833-447 (O.S. & J.K.)
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Mezeiova E, Janockova J, Konecny J, Kobrlova T, Benkova M, Dolezal R, Prchal L, Karasova-Zdarova J, Soukup O, Korabecny J. From orexin receptor agonist YNT-185 to novel antagonists with drug-like properties for the treatment of insomnia. Bioorg Chem 2020; 103:104179. [PMID: 32891860 DOI: 10.1016/j.bioorg.2020.104179] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [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: 05/18/2020] [Revised: 06/29/2020] [Accepted: 08/02/2020] [Indexed: 12/31/2022]
Abstract
YNT-185 is the first known small molecule acting as orexin 2 receptor (OX2R) agonist with implication to narcolepsy treatment, served as a template scaffold in generating a small set of seven compounds with predictive affinity to OX2R. The design of the new small molecules was driven mostly by improving physicochemical properties of the parent drug YNT-185 in parallel with in silico studies, later suggesting their favorable binding modes within the active site of OX2R. We obtained seven new potential OX2R binders that were evaluated in vitro for their CNS availability, cytotoxicity, and behavior pattern on OX2R. Out of them, 15 emerged as the most potent modulator of OX2R, which, contrary to YNT-185, displayed inverse mode of action, i.e. antagonist profile. 15 was also submitted to an in vivo experiment revealing its ability to permeate through BBB into the brain with a short half-life.
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Affiliation(s)
- Eva Mezeiova
- Biomedical Research Centre, University Hospital Hradec Kralove, Sokolska 581, 500 05 Hradec Kralove, Czech Republic
| | - Jana Janockova
- Biomedical Research Centre, University Hospital Hradec Kralove, Sokolska 581, 500 05 Hradec Kralove, Czech Republic
| | - Jan Konecny
- Biomedical Research Centre, University Hospital Hradec Kralove, Sokolska 581, 500 05 Hradec Kralove, Czech Republic
| | - Tereza Kobrlova
- Biomedical Research Centre, University Hospital Hradec Kralove, Sokolska 581, 500 05 Hradec Kralove, Czech Republic
| | - Marketa Benkova
- Biomedical Research Centre, University Hospital Hradec Kralove, Sokolska 581, 500 05 Hradec Kralove, Czech Republic
| | - Rafael Dolezal
- Biomedical Research Centre, University Hospital Hradec Kralove, Sokolska 581, 500 05 Hradec Kralove, Czech Republic
| | - Lukas Prchal
- Biomedical Research Centre, University Hospital Hradec Kralove, Sokolska 581, 500 05 Hradec Kralove, Czech Republic
| | - Jana Karasova-Zdarova
- Biomedical Research Centre, University Hospital Hradec Kralove, Sokolska 581, 500 05 Hradec Kralove, Czech Republic
| | - Ondrej Soukup
- Biomedical Research Centre, University Hospital Hradec Kralove, Sokolska 581, 500 05 Hradec Kralove, Czech Republic.
| | - Jan Korabecny
- Biomedical Research Centre, University Hospital Hradec Kralove, Sokolska 581, 500 05 Hradec Kralove, Czech Republic.
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Nepovimova E, Janockova J, Misik J, Kubik S, Stuchlik A, Vales K, Korabecny J, Mezeiova E, Dolezal R, Soukup O, Kobrlova T, Pham NL, Nguyen TD, Konecny J, Kuca K. Orexin supplementation in narcolepsy treatment: A review. Med Res Rev 2018; 39:961-975. [PMID: 30426515 DOI: 10.1002/med.21550] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [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: 06/17/2018] [Revised: 09/20/2018] [Accepted: 10/19/2018] [Indexed: 12/22/2022]
Abstract
Narcolepsy is a rare, chronic neurological disease characterized by excessive daytime sleepiness, cataplexy, vivid hallucinations, and sleep paralysis. Narcolepsy occurs in approximately 1 of 3000 people, affecting mainly adolescents aged 15 to 30 years. Recently, people with narcolepsy were shown to exhibit extensive orexin/hypocretin neuronal loss. The orexin system regulates sleep/wake control via complex interactions with monoaminergic, cholinergic and GABA-ergic neuronal systems. Currently, no cure for narcolepsy exists, but some symptoms can be controlled with medication (eg, stimulants, antidepressants, etc). Orexin supplementation represents a more sophisticated way to treat narcolepsy because it addresses the underlying cause of the disease and not just the symptoms. Research on orexin supplementation in the treatment of sleep disorders has strongly increased over the past two decades. This review focuses on a brief description of narcolepsy, the mechanisms by which the orexin system regulates sleep/wake cycles, and finally, possible therapeutic options based on orexin supplementation in animal models and patients with narcolepsy.
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Affiliation(s)
- Eugenie Nepovimova
- Department of Chemistry, Faculty of Science, University of Hradec Kralove, Hradec Kralove, Czech Republic
| | - Jana Janockova
- Biomedical Research Centre, University Hospital Hradec Kralove, Hradec Kralove, Czech Republic
| | - Jan Misik
- Biomedical Research Centre, University Hospital Hradec Kralove, Hradec Kralove, Czech Republic.,Department of Toxicology and Military Pharmacy, Faculty of Military Health Sciences, University of Defence, Hradec Kralove, Czech Republic
| | - Stepan Kubik
- Institute of Physiology, Academy of Sciences of the Czech Republic, Prague 4, Czech Republic
| | - Ales Stuchlik
- Institute of Physiology, Academy of Sciences of the Czech Republic, Prague 4, Czech Republic
| | - Karel Vales
- Institute of Physiology, Academy of Sciences of the Czech Republic, Prague 4, Czech Republic
| | - Jan Korabecny
- Biomedical Research Centre, University Hospital Hradec Kralove, Hradec Kralove, Czech Republic.,Department of Toxicology and Military Pharmacy, Faculty of Military Health Sciences, University of Defence, Hradec Kralove, Czech Republic
| | - Eva Mezeiova
- Biomedical Research Centre, University Hospital Hradec Kralove, Hradec Kralove, Czech Republic
| | - Rafael Dolezal
- Department of Chemistry, Faculty of Science, University of Hradec Kralove, Hradec Kralove, Czech Republic.,Biomedical Research Centre, University Hospital Hradec Kralove, Hradec Kralove, Czech Republic
| | - Ondrej Soukup
- Biomedical Research Centre, University Hospital Hradec Kralove, Hradec Kralove, Czech Republic
| | - Tereza Kobrlova
- Biomedical Research Centre, University Hospital Hradec Kralove, Hradec Kralove, Czech Republic
| | - Ngoc Lam Pham
- Department of Chemistry, Faculty of Science, University of Hradec Kralove, Hradec Kralove, Czech Republic.,Biomedical Research Centre, University Hospital Hradec Kralove, Hradec Kralove, Czech Republic
| | - Thuy Duong Nguyen
- Department of Chemistry, Faculty of Science, University of Hradec Kralove, Hradec Kralove, Czech Republic.,Biomedical Research Centre, University Hospital Hradec Kralove, Hradec Kralove, Czech Republic
| | - Jan Konecny
- Biomedical Research Centre, University Hospital Hradec Kralove, Hradec Kralove, Czech Republic.,Department of Toxicology and Military Pharmacy, Faculty of Military Health Sciences, University of Defence, Hradec Kralove, Czech Republic
| | - Kamil Kuca
- Department of Chemistry, Faculty of Science, University of Hradec Kralove, Hradec Kralove, Czech Republic.,Biomedical Research Centre, University Hospital Hradec Kralove, Hradec Kralove, Czech Republic
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Janockova J, Dolezal R, Nepovimova E, Kobrlova T, Benkova M, Kuca K, Konecny J, Mezeiova E, Melikova M, Hepnarova V, Ring A, Soukup O, Korabecny J. Investigation of New Orexin 2 Receptor Modulators Using In Silico and In Vitro Methods. Molecules 2018; 23:molecules23112926. [PMID: 30423961 PMCID: PMC6278354 DOI: 10.3390/molecules23112926] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [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: 10/05/2018] [Revised: 11/02/2018] [Accepted: 11/08/2018] [Indexed: 11/16/2022] Open
Abstract
The neuropeptides, orexin A and orexin B (also known as hypocretins), are produced in hypothalamic neurons and belong to ligands for orphan G protein-coupled receptors. Generally, the primary role of orexins is to act as excitatory neurotransmitters and regulate the sleep process. Lack of orexins may lead to sleep disorder narcolepsy in mice, dogs, and humans. Narcolepsy is a neurological disorder of alertness characterized by a decrease of ability to manage sleep-wake cycles, excessive daytime sleepiness, and other symptoms, such as cataplexy, vivid hallucinations, and paralysis. Thus, the discovery of orexin receptors, modulators, and their causal implication in narcolepsy is the most important advance in sleep-research. The presented work is focused on the evaluation of compounds L1–L11 selected by structure-based virtual screening for their ability to modulate orexin receptor type 2 (OX2R) in comparison with standard agonist orexin-A together with their blood-brain barrier permeability and cytotoxicity. We can conclude that the studied compounds possess an affinity towards the OX2R. However, the compounds do not have intrinsic activity and act as the antagonists of this receptor. It was shown that L4 was the most potent antagonistic ligand to orexin A and displayed an IC50 of 2.2 µM, offering some promise mainly for the treatment of insomnia.
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Affiliation(s)
- Jana Janockova
- Biomedical Research Centre, University Hospital Hradec Kralove, Sokolska 581, 500 05 Hradec Kralove, Czech Republic.
- Department of Chemistry, Faculty of Science, University of Hradec Kralove, Rokitanskeho 62, 500 03 Hradec Kralove, Czech Republic.
| | - Rafael Dolezal
- Biomedical Research Centre, University Hospital Hradec Kralove, Sokolska 581, 500 05 Hradec Kralove, Czech Republic.
- Department of Chemistry, Faculty of Science, University of Hradec Kralove, Rokitanskeho 62, 500 03 Hradec Kralove, Czech Republic.
- Center for Basic and Applied Research, University of Hradec Kralove, Rokitanskeho 62, 500 03 Hradec Kralove, Czech Republic.
| | - Eugenie Nepovimova
- Department of Chemistry, Faculty of Science, University of Hradec Kralove, Rokitanskeho 62, 500 03 Hradec Kralove, Czech Republic.
| | - Tereza Kobrlova
- Biomedical Research Centre, University Hospital Hradec Kralove, Sokolska 581, 500 05 Hradec Kralove, Czech Republic.
- Department of Toxicology and Military Pharmacy, Faculty of Military Health Sciences, University of Defence, Trebesska 1575, 500 05 Hradec Kralove, Czech Republic.
| | - Marketa Benkova
- Biomedical Research Centre, University Hospital Hradec Kralove, Sokolska 581, 500 05 Hradec Kralove, Czech Republic.
| | - Kamil Kuca
- Biomedical Research Centre, University Hospital Hradec Kralove, Sokolska 581, 500 05 Hradec Kralove, Czech Republic.
- Department of Chemistry, Faculty of Science, University of Hradec Kralove, Rokitanskeho 62, 500 03 Hradec Kralove, Czech Republic.
| | - Jan Konecny
- Biomedical Research Centre, University Hospital Hradec Kralove, Sokolska 581, 500 05 Hradec Kralove, Czech Republic.
- Department of Chemistry, Faculty of Science, University of Hradec Kralove, Rokitanskeho 62, 500 03 Hradec Kralove, Czech Republic.
| | - Eva Mezeiova
- Biomedical Research Centre, University Hospital Hradec Kralove, Sokolska 581, 500 05 Hradec Kralove, Czech Republic.
| | - Michaela Melikova
- Department of Chemistry, Faculty of Science, University of Hradec Kralove, Rokitanskeho 62, 500 03 Hradec Kralove, Czech Republic.
| | - Vendula Hepnarova
- Biomedical Research Centre, University Hospital Hradec Kralove, Sokolska 581, 500 05 Hradec Kralove, Czech Republic.
- Department of Toxicology and Military Pharmacy, Faculty of Military Health Sciences, University of Defence, Trebesska 1575, 500 05 Hradec Kralove, Czech Republic.
| | - Avi Ring
- Norwegian Defence Research Establishment, Gunnar Randersvei 42, 2007 Kjeller, Norway.
| | - Ondrej Soukup
- Biomedical Research Centre, University Hospital Hradec Kralove, Sokolska 581, 500 05 Hradec Kralove, Czech Republic.
- Department of Toxicology and Military Pharmacy, Faculty of Military Health Sciences, University of Defence, Trebesska 1575, 500 05 Hradec Kralove, Czech Republic.
| | - Jan Korabecny
- Biomedical Research Centre, University Hospital Hradec Kralove, Sokolska 581, 500 05 Hradec Kralove, Czech Republic.
- Department of Toxicology and Military Pharmacy, Faculty of Military Health Sciences, University of Defence, Trebesska 1575, 500 05 Hradec Kralove, Czech Republic.
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Konecny J, Krajča P. On attribute reduction in concept lattices: Experimental evaluation shows discernibility matrix based methods inefficient. Inf Sci (N Y) 2018. [DOI: 10.1016/j.ins.2018.08.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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Konecny J. On attribute reduction in concept lattices: Methods based on discernibility matrix are outperformed by basic clarification and reduction. Inf Sci (N Y) 2017. [DOI: 10.1016/j.ins.2017.06.013] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Konecny J, Klvacek A, Simek M, Lonsky V, Santavy P. Complex gunshot injury to the heart as a consequence of suicide attempt in a schizophrenic patient. Int J Surg Case Rep 2016; 24:80-2. [PMID: 27232290 PMCID: PMC4885112 DOI: 10.1016/j.ijscr.2016.05.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Revised: 05/09/2016] [Accepted: 05/09/2016] [Indexed: 11/11/2022] Open
Abstract
Self- inflicted gunshot injury to the heart is uncommon in Western Europe. Up to 40% of schizophrenic patients have history of suicide attempt. Discontinuation of antipsychotic medications is one of the major risk factor for suicide among individuals with schizophrenia. Midline sternotomy provides superior access to the heart and large vessels, pulmonary hilum as well as for access for extracorporeal circulation.
Introduction Self-inflicted gunshot injury to the heart is uncommon in Western Europe countries. However it is considered to have a high mortality through cardiac tamponade or exsanguination and concomitant chest or abdominal cavity injury. Case presentation We present a 39-year-old schizophrenic woman who attempted suicide with the aid of a 6.35 mm caliber handgun, after self-discontinuing of antipsychotic treatment. Lower third of sternum, right heart atrium and ventricle and inferior caval vein were hit by the bullet which consequently got lodged in the right paravertebral muscle mass at the lower thoracic vertebral level. As she was hemodynamically unstable due to hemopericardium and a huge right hemothorax, she underwent emergent surgery. Heart and inferior vena caval injuries were repaired on extracorporeal circulation. The postoperative course was uneventful and she was transferred to a psychiatric facility on the 7th postoperative day. One year after the surgery she is well, compliant to antipsychotic medications and on periodic follow-up by psychiatrists. Conclusion This case represents management of complex self-inflicted gunshot cardiac injury in a schizophrenic patient who discontinued antipsychotic medication. Liaison between themedical rescue service and high level trauma center essentially reduced injury-to-surgery time. Complex heart injury was successfully repaired on extracorporeal circulation.
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Affiliation(s)
- J Konecny
- Department of Cardiac Surgery, University Hospital, Olomouc, Czech Republic.
| | - A Klvacek
- Department of Cardiac Surgery, University Hospital, Olomouc, Czech Republic
| | - M Simek
- Department of Cardiac Surgery, University Hospital, Olomouc, Czech Republic
| | - V Lonsky
- Department of Cardiac Surgery, University Hospital, Olomouc, Czech Republic
| | - P Santavy
- Department of Cardiac Surgery, University Hospital, Olomouc, Czech Republic
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Klvacek A, Konecny J, Santavy P, Lonsky V, Simek M, Hanak V. An unusual symptoms caused by huge pseudoaneurysm formation of ascending aorta. J Cardiothorac Surg 2015. [PMCID: PMC4695752 DOI: 10.1186/1749-8090-10-s1-a337] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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Konecny J, Klvacek A, Santavy P, Lonsky V, Simek M. A case report of an unusual firearm injury: projectile lodged between thoracic aorta and vertebral column. J Cardiothorac Surg 2013. [PMCID: PMC3845072 DOI: 10.1186/1749-8090-8-s1-p28] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Belohlavek R, Konecny J. Concept lattices of isotone vs. antitone Galois connections in graded setting: Mutual reducibility revisited. Inf Sci (N Y) 2012. [DOI: 10.1016/j.ins.2012.02.064] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Affiliation(s)
- Jan Konecny
- Pharmaceutical Division, CIBA‐GEIGY Limited, CH‐4002 Basel, Switzerland
| | - M. Sieber
- Pharmaceutical Division, CIBA‐GEIGY Limited, CH‐4002 Basel, Switzerland
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Palaj J, Konecny J, Petras L, Babiak L, Kukla K, Ciganak J, Moravekova E. Radical D2 surgery for patients with gastric cancer. BRATISL MED J 2003; 103:424-7. [PMID: 12585358] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/28/2023]
Abstract
UNLABELLED The authors analyzed and prepared a report concerning 18 radical surgeries for gastric cancer that were performed between 1999-2001. Overall, 55 operation were performed, 32 radical, 18 palliative and 5 explorative laparatomies. D2 resections were performed 18 times, while D1 type 14 times. The group undergoing D2 surgery comprised of 10 men and 8 women with average age of 64.3. D2 resection included partial (8 times), or total (10) gastrectomy and lymfadenectomy of perigastric nodes, supra and infrapyloric nodes and nodes along common hepatic artery, truncus coeliacus, lienal artery, left paracardial nodes and removing capsula of pancreas. Splenectomy was performed twice. On average, 37.5 lymphnodes were removed for every operation (25-69). Operative mortality was none (0%) and morbidity was 22%. As of January 1, 2002 relaps was noted in six patients, and 5 patients died. CONCLUSION D2 resection surgeries performed by an experienced surgeon show low morbidity as well as better outcome and higher perspective for long-term survival in patients with gastric cancer. (Tab. 1, Ref. 19.).
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Affiliation(s)
- J Palaj
- Surgical Department, Hospital Bojnice, Slovakia.
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Abstract
Messenger RNA sequences often have to preserve functional secondary structure elements in addition to coding for proteins. We present a statistical analysis of retroviral mRNA which supports the hypothesis that the natural genetic code is adapted to such complementary coding. These sequences are still able to explore efficiently the space of possible proteins by point mutations. This is borne out by the observation that, in stem regions of retroviral mRNA foldings, silent mutations on one strand are preferentially accompanied by conservative mutations on the other. Distances between amino acids based on physicochemical properties are used to quantify the conservation of protein function under the constraint of maintained RNA secondary structure. We find that preservation of RNA secondary structure by compensatory mutations is evolutionary compatible with the efficient search for new variants on the protein level.
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Affiliation(s)
- J Konecny
- Theorectical Chemistry, Tech University Munich, Lichtenbergstr. 4, D 85747 Garching, Germany
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Abstract
The hypothesis that the universal genetic code is adapted to double-strand coding is supported by its remarkable compatibility with the RNY comma-less hypothesis. Coding by a triplet code on a polynucleotide double-strand allows for enciphering of five additional messages with reference to a chosen primary reading frame. Assuming the acceptance of coupled mutations on both strands, the best codon register for two overlapping messages can be inferred. The idea of evolutionarily compatible coding of two proteins by one nucleotide double-strand is extended to complementary coding for one protein in folded, single-stranded RNA.
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Abstract
We lay new foundations to the hypothesis that the genetic code is adapted to evolutionary retention of information in the antisense strands of natural DNA/RNA sequences. In particular, we show that the genetic code exhibits, beyond the neutral replacement patterns of amino acid substitutions, optimal properties by favoring simultaneous evolution of proteins encoded in DNA/RNA sense-antisense strands. This is borne out in the sense-antisense transformations of the codons of every amino acid which target amino acids physicochemically similar to each other. Moreover, silent mutations in the sense strand generate conservative ones in its antisense counterpart and vice versa. Coevolution of proteins coded by complementary strands is shown to be a definite possibility, a result which does not depend on any physical interaction between the coevolving proteins. Likewise, the degree to which the present genetic code is dedicated to evolutionary sense-antisense tolerance is demonstrated by comparison with many randomized codes. Double-strand coding is quantified from an information-theoretical point of view.
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Affiliation(s)
- J Konecny
- Tech University Munich, Garching, Federal Republic of Germany
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Abstract
Alkalimetric pH-stat titrations of cephalosporin C, cephacetril and their deacetyl derivatives using an acetyl esterase and beta-lactamase are described. The esterase was used to assay highly purified samples of cephalosporin C and cephacetril, and also to prepare analytically defined solutions of the deacetyl cephalosporins. Lactamase-catalyzed hydrolysis of the parent compounds was then found to generate exactly 2 equivalents of acid per mole; that of the deacetyl derivatives exactly 1 equivalent.
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Abstract
A very stable esterase (EC 3.1.1.-), which hydrolyses ethyl acetate, cephalosporin C and other acetyl esters with a maximum turnover number of 3-10(2) s-1, was isolated from Bacillus subtilis ATCC 6633 and immobilized on two supports: controlled-pore glass and powdered brick, a representative of carriers having a wide pore-size distribution. Carrier morphology determines diffusion rates and the expression of activity. Rate-limiting mass transfer of buffer leads to apparent losses of activity, gross distortions of molecular pH vs. activity profiles and to apparent deviations from Michaelis-Menten kinetics.
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Konecny J, Slanicka J. Proceedings: The effect of buffer diffusion on the activity of an immobilized esterase. Pathobiology 1975; 42:245-7. [PMID: 6931 DOI: 10.1159/000162768] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
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Konecny J. Eigenschaften einer trägergebundenen Esterase. Pathobiology 1974. [DOI: 10.1159/000162590] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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