1
|
Singh M, Dhanwal A, Verma A, Augustin L, Kumari N, Chakraborti S, Agarwal N, Sriram D, Dey RJ. Discovery of potent antimycobacterial agents targeting lumazine synthase (RibH) of Mycobacterium tuberculosis. Sci Rep 2024; 14:12170. [PMID: 38806590 PMCID: PMC11133327 DOI: 10.1038/s41598-024-63051-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Accepted: 05/24/2024] [Indexed: 05/30/2024] Open
Abstract
Tuberculosis (TB) continues to be a global health crisis, necessitating urgent interventions to address drug resistance and improve treatment efficacy. In this study, we validate lumazine synthase (RibH), a vital enzyme in the riboflavin biosynthetic pathway, as a potential drug target against Mycobacterium tuberculosis (M. tb) using a CRISPRi-based conditional gene knockdown strategy. We employ a high-throughput molecular docking approach to screen ~ 600,000 compounds targeting RibH. Through in vitro screening of 55 shortlisted compounds, we discover 3 compounds that exhibit potent antimycobacterial activity. These compounds also reduce intracellular burden of M. tb during macrophage infection and prevent the resuscitation of the nutrient-starved persister bacteria. Moreover, these three compounds enhance the bactericidal effect of first-line anti-TB drugs, isoniazid and rifampicin. Corroborating with the in silico predicted high docking scores along with favourable ADME and toxicity profiles, all three compounds demonstrate binding affinity towards purified lumazine synthase enzyme in vitro, in addition these compounds exhibit riboflavin displacement in an in vitro assay with purified lumazine synthase indicative of specificity of these compounds to the active site. Further, treatment of M. tb with these compounds indicate reduced production of flavin adenine dinucleotide (FAD), the ultimate end product of the riboflavin biosynthetic pathway suggesting the action of these drugs on riboflavin biosynthesis. These compounds also show acceptable safety profile in mammalian cells, with a high selective index. Hence, our study validates RibH as an important drug target against M. tb and identifies potent antimycobacterial agents.
Collapse
Affiliation(s)
- Monica Singh
- Department of Biological Sciences, Birla Institute of Technology and Science Pilani, Hyderabad Campus, Hyderabad, Telangana, 500078, India
| | - Anannya Dhanwal
- Department of Biological Sciences, Birla Institute of Technology and Science Pilani, Hyderabad Campus, Hyderabad, Telangana, 500078, India
| | - Arpita Verma
- Department of Biological Sciences, Birla Institute of Technology and Science Pilani, Hyderabad Campus, Hyderabad, Telangana, 500078, India
| | - Linus Augustin
- Translational Health Science and Technology Institute, Faridabad, Haryana, 121001, India
| | - Niti Kumari
- National Institute of Animal Biotechnology (NIAB), Hyderabad, Telangana, 500032, India
| | - Soumyananda Chakraborti
- Department of Biological Sciences, Birla Institute of Technology and Science Pilani, Hyderabad Campus, Hyderabad, Telangana, 500078, India
- National Institute of Malaria Research, Indian Council of Medical Research (ICMR), New Delhi, 110077, India
| | - Nisheeth Agarwal
- Translational Health Science and Technology Institute, Faridabad, Haryana, 121001, India
| | - Dharmarajan Sriram
- Department of Pharmacy, Birla Institute of Technology and Science Pilani, Hyderabad Campus, Hyderabad, Telangana, 500078, India
| | - Ruchi Jain Dey
- Department of Biological Sciences, Birla Institute of Technology and Science Pilani, Hyderabad Campus, Hyderabad, Telangana, 500078, India.
| |
Collapse
|
2
|
Islam Z, Kumar P. Inhibitors of riboflavin biosynthetic pathway enzymes as potential antibacterial drugs. Front Mol Biosci 2023; 10:1228763. [PMID: 37496776 PMCID: PMC10366380 DOI: 10.3389/fmolb.2023.1228763] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2023] [Accepted: 07/03/2023] [Indexed: 07/28/2023] Open
Abstract
Multiple drug resistance is the main obstacle in the treatment of bacterial diseases. Resistance against antibiotics demands the exploration of new antimicrobial drug targets. A variety of in silico and genetic approaches show that the enzymes of the riboflavin biosynthetic pathway are crucial for the survival of bacteria. This pathway is absent in humans thus enzymes of the riboflavin biosynthetic pathway are emerging drug targets for resistant pathogenic bacterial strains. Exploring the structural details, their mechanism of action, intermediate elucidation, and interaction analysis would help in designing suitable inhibitors of these enzymes. The riboflavin biosynthetic pathway consists of seven distinct enzymes, namely, 3,4-dihydroxy-2-butanone 4-phosphate synthase, GTP cyclohydrolase II, pyrimidine deaminase/reductase, phosphatase, lumazine synthase, and riboflavin synthase. The present review summarizes the research work that has been carried out on these enzymes in terms of their structures, active site architectures, and molecular mechanism of catalysis. This review also walks through small molecule inhibitors that have been developed against several of these enzymes.
Collapse
Affiliation(s)
- Zeyaul Islam
- Qatar Biomedical Research Institute (QBRI), Qatar Foundation, Hamad Bin Khalifa University, Doha, Qatar
| | - Pankaj Kumar
- Department of Biochemistry, Jamia Hamdard, New Delhi, India
| |
Collapse
|
3
|
Farah N, Chin VK, Chong PP, Lim WF, Lim CW, Basir R, Chang SK, Lee TY. Riboflavin as a promising antimicrobial agent? A multi-perspective review. CURRENT RESEARCH IN MICROBIAL SCIENCES 2022; 3:100111. [PMID: 35199072 PMCID: PMC8848291 DOI: 10.1016/j.crmicr.2022.100111] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Revised: 02/05/2022] [Accepted: 02/07/2022] [Indexed: 12/29/2022] Open
Abstract
Riboflavin demonstrates antioxidant and photosensitizing properties. Riboflavin is able to induce ROS and modulate immune response. Riboflavin possesses potent antimicrobial activity when used alone or combined with other anti-infectives. The riboflavin biosynthesis pathway serves as an ideal drug target against microbes. UVA combination with riboflavin exhibits remarkable antimicrobial effects.
Riboflavin, or more commonly known as vitamin B2, forms part of the component of vitamin B complex. Riboflavin consisting of two important cofactors, flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD), which are involved in multiple oxidative-reduction processes and energy metabolism. Besides maintaining human health, different sources reported that riboflavin can inhibit or inactivate the growth of different pathogens including bacteria, viruses, fungi and parasites, highlighting the possible role of riboflavin as an antimicrobial agent. Moreover, riboflavin and flavins could produce reactive oxygen species (ROS) when exposed to light, inducing oxidative damage in cells and tissues, and thus are excellent natural photosensitizers. Several studies have illustrated the therapeutic efficacy of photoactivated riboflavin against nosocomial infections and multidrug resistant bacterial infections as well as microbial associated biofilm infections, revealing the potential role of riboflavin as a promising antimicrobial candidate, which could serve as one of the alternatives in fighting the global crisis of the emergence of antimicrobial resistance seen in different pathogenic microbes. Riboflavin could also be involved in modulating host immune responses, which might increase the pathogen clearance from host cells and increase host defense against microbial infections. Thus, the dual effects of riboflavin on both pathogens and host immunity, reflected by its potent bactericidal effect and alleviation of inflammation in host cells further imply that riboflavin could be a potential candidate for therapeutic intervention in resolving microbial infections. Hence, this review aimed to provide some insights on the promising role of riboflavin as an antimicrobial candidate and also a host immune-modulator from a multi-perspective view as well as to discuss the application and challenges on using riboflavin in photodynamic therapy against various pathogens and microbial biofilm-associated infections.
Collapse
Affiliation(s)
- Nuratiqah Farah
- Department of Human Anatomy, Faculty of Medicine and Health Sciences, UPM, 43400, Serdang, Selangor, Malaysia
| | - Voon Kin Chin
- Department of Medical Microbiology, Faculty of Medicine and Health Sciences, UPM, 43400, Serdang, Selangor, Malaysia
| | - Pei Pei Chong
- School of Biosciences, Taylor's University, No 1, Jalan Taylor's, 47500 Subang Jaya, Selangor, Malaysia
| | - Wai Feng Lim
- Integrative Pharmacogenomics Institute (iPROMISE), Universiti Teknologi MARA, Puncak Alam Campus, 42300 Bandar Puncak Alam, Selangor, Malaysia
| | - Chee Woei Lim
- Department of Medicine, Faculty of Medicine and Health Sciences, UPM, 43400, Serdang, Selangor, Malaysia
| | - Rusliza Basir
- Department of Human Anatomy, Faculty of Medicine and Health Sciences, UPM, 43400, Serdang, Selangor, Malaysia
| | - Sui Kiat Chang
- Department of Horticulture, Key Laboratory of South China Agricultural Plant Molecular Analysis and Genetic Improvement, Key Laboratory of Post-Harvest Handling of Fruits, Ministry of Agriculture. South China Botanical Garden, Chinese Academy of Sciences. Guangzhou, 510650 China
| | - Tze Yan Lee
- Perdana University School of Liberal Arts, Science and Technology (PUScLST), Suite 9.2, 9th Floor, Wisma Chase Perdana, Changkat Semantan, Damansara Heights, 50490 Kuala Lumpur, Malaysia
- Corresponding author.
| |
Collapse
|
4
|
Abstract
To resolve the growing problem of drug resistance in the treatment of bacterial and fungal pathogens, specific cellular targets and pathways can be used as targets for new antimicrobial agents. Endogenous riboflavin biosynthesis is a conserved pathway that exists in most bacteria and fungi. In this review, the roles of endogenous and exogenous riboflavin in infectious disease as well as several antibacterial agents, which act as analogues of the riboflavin biosynthesis pathway, are summarized. In addition, the effects of exogenous riboflavin on immune cells, cytokines, and heat shock proteins are described. Moreover, the immune response of endogenous riboflavin metabolites in infectious diseases, recognized by MHC-related protein-1, and then presented to mucosal associated invariant T cells, is highlighted. This information will provide a strategy to identify novel drug targets as well as highlight the possible clinical use of riboflavin.
Collapse
Affiliation(s)
- Junwen Lei
- Molecular Biotechnology Platform, Public Center of Experimental Technology, School of Basic Medical Sciences, Southwest Medical University, Luzhou People's Republic of China
| | - Caiyan Xin
- Molecular Biotechnology Platform, Public Center of Experimental Technology, School of Basic Medical Sciences, Southwest Medical University, Luzhou People's Republic of China
| | - Wei Xiao
- Molecular Biotechnology Platform, Public Center of Experimental Technology, School of Basic Medical Sciences, Southwest Medical University, Luzhou People's Republic of China
| | - Wenbi Chen
- Molecular Biotechnology Platform, Public Center of Experimental Technology, School of Basic Medical Sciences, Southwest Medical University, Luzhou People's Republic of China
| | - Zhangyong Song
- Molecular Biotechnology Platform, Public Center of Experimental Technology, School of Basic Medical Sciences, Southwest Medical University, Luzhou People's Republic of China
| |
Collapse
|
5
|
Eberl M, Oldfield E, Herrmann T. Immuno-antibiotics: targeting microbial metabolic pathways sensed by unconventional T cells. IMMUNOTHERAPY ADVANCES 2021; 1:ltab005. [PMID: 35919736 PMCID: PMC9327107 DOI: 10.1093/immadv/ltab005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Revised: 03/17/2021] [Accepted: 04/01/2021] [Indexed: 12/15/2022] Open
Abstract
Human Vγ9/Vδ2 T cells, mucosal-associated invariant T (MAIT) cells, and other unconventional T cells are specialised in detecting microbial metabolic pathway intermediates that are absent in humans. The recognition by such semi-invariant innate-like T cells of compounds like (E)-4-hydroxy-3-methyl-but-2-enyl pyrophosphate (HMB-PP), the penultimate metabolite in the MEP isoprenoid biosynthesis pathway, and intermediates of the riboflavin biosynthesis pathway and their metabolites allows the immune system to rapidly sense pathogen-associated molecular patterns that are shared by a wide range of micro-organisms. Given the essential nature of these metabolic pathways for microbial viability, they have emerged as promising targets for the development of novel antibiotics. Here, we review recent findings that link enzymatic inhibition of microbial metabolism with alterations in the levels of unconventional T cell ligands produced by treated micro-organisms that have given rise to the concept of 'immuno-antibiotics': combining direct antimicrobial activity with an immunotherapeutic effect via modulation of unconventional T cell responses.
Collapse
Affiliation(s)
- Matthias Eberl
- Division of Infection and Immunity, School of Medicine, Cardiff University, Cardiff, UK,Systems Immunity Research Institute, Cardiff University, Cardiff, UK,Correspondence: Matthias Eberl, Division of Infection and Immunity, Henry Wellcome Building, School of Medicine, Cardiff University, Heath Park, Cardiff CF14 4XN, Wales, UK. Tel: +44-29206-87011;
| | - Eric Oldfield
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Thomas Herrmann
- Institut für Virologie und Immunbiologie, Julius-Maximilians-Universität Würzburg, Würzburg, Germany
| |
Collapse
|
6
|
Kundu B, Sarkar D, Ray N, Talukdar A. Understanding the riboflavin biosynthesis pathway for the development of antimicrobial agents. Med Res Rev 2019; 39:1338-1371. [PMID: 30927319 DOI: 10.1002/med.21576] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2018] [Revised: 02/14/2019] [Accepted: 03/08/2019] [Indexed: 12/13/2022]
Abstract
Life on earth depends on the biosynthesis of riboflavin, which plays a vital role in biological electron transport processes. Higher mammals obtain riboflavin from dietary sources; however, various microorganisms, including Gram-negative pathogenic bacteria and yeast, lack an efficient riboflavin-uptake system and are dependent on endogenous riboflavin biosynthesis. Consequently, the inhibition of enzymes in the riboflavin biosynthesis pathway would allow selective toxicity to a pathogen and not the host. Thus, the riboflavin biosynthesis pathway is an attractive target for designing novel antimicrobial drugs, which are urgently needed to address the issue of multidrug resistance seen in various pathogens. The enzymes involved in riboflavin biosynthesis are lumazine synthase (LS) and riboflavin synthase (RS). Understanding the details of the mechanisms of the enzyme-catalyzed reactions and the structural changes that occur in the enzyme active sites during catalysis can facilitate the design and synthesis of suitable analogs that can specifically inhibit the relevant enzymes and stop the generation of riboflavin in pathogenic bacteria. The present review is the first compilation of the work that has been carried out over the last 25 years focusing on the design of inhibitors of the biosynthesis of riboflavin based on an understanding of the mechanisms of LS and RS. This review aimed to address the fundamental advances in our understanding of riboflavin biosynthesis as applied to the rational design of a novel class of inhibitors. These advances have been aided by X-ray structures of ligand-enzyme complexes, rotational-echo, double-resonance nuclear magnetic resonance spectroscopy, high-throughput screening, virtual screenings, and various mechanistic probes.
Collapse
Affiliation(s)
- Biswajit Kundu
- Department of Organic and Medicinal Chemistry, CSIR-Indian Institute of Chemical Biology, Kolkata, India
| | - Dipayan Sarkar
- Department of Organic and Medicinal Chemistry, CSIR-Indian Institute of Chemical Biology, Kolkata, India.,Academy of Scientific and Innovative Research, Kolkata, India
| | - Namrata Ray
- Department of Organic and Medicinal Chemistry, CSIR-Indian Institute of Chemical Biology, Kolkata, India.,Department of Chemistry, Adamas University, Kolkata, India
| | - Arindam Talukdar
- Department of Organic and Medicinal Chemistry, CSIR-Indian Institute of Chemical Biology, Kolkata, India.,Academy of Scientific and Innovative Research, Kolkata, India
| |
Collapse
|
7
|
Meir Z, Osherov N. Vitamin Biosynthesis as an Antifungal Target. J Fungi (Basel) 2018; 4:E72. [PMID: 29914189 PMCID: PMC6023522 DOI: 10.3390/jof4020072] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2018] [Revised: 06/12/2018] [Accepted: 06/13/2018] [Indexed: 12/18/2022] Open
Abstract
The large increase in the population of immunosuppressed patients, coupled with the limited efficacy of existing antifungals and rising resistance toward them, have dramatically highlighted the need to develop novel drugs for the treatment of invasive fungal infections. An attractive possibility is the identification of possible drug targets within essential fungal metabolic pathways not shared with humans. Here, we review the vitamin biosynthetic pathways (vitamins A⁻E, K) as candidates for the development of antifungals. We present a set of ranking criteria that identify the vitamin B2 (riboflavin), B5 (pantothenic acid), and B9 (folate) biosynthesis pathways as being particularly rich in new antifungal targets. We propose that recent scientific advances in the fields of drug design and fungal genomics have developed sufficiently to merit a renewed look at these pathways as promising sources for the development of novel classes of antifungals.
Collapse
Affiliation(s)
- Zohar Meir
- Department of Clinical Microbiology and Immunology, Sackler School of Medicine, Tel-Aviv University, Ramat-Aviv, Tel-Aviv 69978, Israel.
| | - Nir Osherov
- Department of Clinical Microbiology and Immunology, Sackler School of Medicine, Tel-Aviv University, Ramat-Aviv, Tel-Aviv 69978, Israel.
| |
Collapse
|
8
|
Dietl AM, Meir Z, Shadkchan Y, Osherov N, Haas H. Riboflavin and pantothenic acid biosynthesis are crucial for iron homeostasis and virulence in the pathogenic mold Aspergillus fumigatus. Virulence 2018; 9:1036-1049. [PMID: 30052132 PMCID: PMC6068542 DOI: 10.1080/21505594.2018.1482181] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2018] [Accepted: 05/22/2018] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND Aspergillus fumigatus is the most prevalent airborne fungal pathogen, causing invasive fungal infections mainly in immunosuppressed individuals. Death rates from invasive aspergillosis remain high because of limited treatment options and increasing antifungal resistance. The aim of this study was to identify key fungal-specific genes participating in vitamin B biosynthesis in A. fumigatus. Because these genes are absent in humans they can serve as possible novel targets for antifungal drug development. METHODS By sequence homology we identified, deleted and analysed four key A. fumigatus genes (riboB, panA, pyroA, thiB) involved respectively in the biosynthesis of riboflavin (vitamin B2), pantothenic acid (vitamin B5), pyridoxine (vitamin B6) and thiamine (vitamin B1). RESULTS Deletion of riboB, panA, pyroA or thiB resulted in respective vitamin auxotrophy. Lack of riboflavin and pantothenic acid biosynthesis perturbed many cellular processes including iron homeostasis. Virulence in murine pulmonary and systemic models of infection was severely attenuated following deletion of riboB and panA, strongly reduced after pyroA deletion and weakly attenuated after thiB deletion. CONCLUSIONS This study reveals the biosynthetic pathways of the vitamins riboflavin and pantothenic acid as attractive targets for novel antifungal therapy. Moreover, the virulence studies with auxotrophic mutants serve to identify the availability of nutrients to pathogens in host niches. ABBREVIATIONS BPS: bathophenanthrolinedisulfonate; BSA: bovine serum albumin; CFU: colony forming unit; -Fe: iron starvation; +Fe: iron sufficiency; hFe: high iron; NRPSs: nonribosomal peptide synthetases; PKSs: polyketide synthaseses; wt: wild type.
Collapse
Affiliation(s)
- Anna-Maria Dietl
- Division of Molecular Biology, Biocenter, Medical University of Innsbruck, Innsbruck, Austria
| | - Zohar Meir
- Department of Clinical Microbiology and Immunology, Sackler School of Medicine Ramat-Aviv, Tel-Aviv, Israel
| | - Yona Shadkchan
- Department of Clinical Microbiology and Immunology, Sackler School of Medicine Ramat-Aviv, Tel-Aviv, Israel
| | - Nir Osherov
- Department of Clinical Microbiology and Immunology, Sackler School of Medicine Ramat-Aviv, Tel-Aviv, Israel
| | - Hubertus Haas
- Division of Molecular Biology, Biocenter, Medical University of Innsbruck, Innsbruck, Austria
| |
Collapse
|
9
|
Wei Y, Wahome N, Kumar P, Whitaker N, Picking WL, Middaugh CR. Effect of Phosphate Ion on the Structure of Lumazine Synthase, an Antigen Presentation System From Bacillus anthracis. J Pharm Sci 2017; 107:814-823. [PMID: 29045884 DOI: 10.1016/j.xphs.2017.10.013] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2017] [Revised: 10/06/2017] [Accepted: 10/09/2017] [Indexed: 12/20/2022]
Abstract
Lumazine synthase (LS) is an oligomeric enzyme involved in the biosynthesis of riboflavin in microorganisms, fungi, and plants. LS has become of significant interest to biomedical science because of its critical biological role and attractive structural properties for antigen presentation in vaccines. LS derived from Bacillus anthracis (BaLS) consists of 60 identical subunits forming an icosahedron. Its crystal structure has been solved, but its dynamic conformational properties have not yet been studied. We investigated the conformation of BaLS in response to different stress conditions (e.g., chemical denaturants, pH, and temperature) using a variety of biophysical techniques. The physical basis for these thermal transitions was studied, indicating that a molten globular state was present during chemical unfolding by guanidine HCl. In addition, BaLS showed 2 distinct thermal transitions in phosphate-containing buffers. The first transition was due to the dissociation of phosphate ions from BaLS and the second one came from the dissociation and conformational alteration of its icosahedral structure. A small conformational alteration was induced by the binding/dissociation of phosphate ions to BaLS. This work provides a closer view of the conformational behavior of BaLS and provides important information for the formulation of vaccines which use this protein.
Collapse
Affiliation(s)
- Yangjie Wei
- Macromolecule and Vaccine Stabilization Center, Department of Pharmaceutical Chemistry, University of Kansas, 2030 Becker Drive, Lawrence, Kansas 66047; Department of Pharmaceutical Chemistry, University of Kansas, 2030 Becker Drive, Lawrence, Kansas 66047
| | - Newton Wahome
- Macromolecule and Vaccine Stabilization Center, Department of Pharmaceutical Chemistry, University of Kansas, 2030 Becker Drive, Lawrence, Kansas 66047; Department of Pharmaceutical Chemistry, University of Kansas, 2030 Becker Drive, Lawrence, Kansas 66047
| | - Prashant Kumar
- Macromolecule and Vaccine Stabilization Center, Department of Pharmaceutical Chemistry, University of Kansas, 2030 Becker Drive, Lawrence, Kansas 66047; Department of Pharmaceutical Chemistry, University of Kansas, 2030 Becker Drive, Lawrence, Kansas 66047
| | - Neal Whitaker
- Macromolecule and Vaccine Stabilization Center, Department of Pharmaceutical Chemistry, University of Kansas, 2030 Becker Drive, Lawrence, Kansas 66047; Department of Pharmaceutical Chemistry, University of Kansas, 2030 Becker Drive, Lawrence, Kansas 66047
| | - Wendy L Picking
- Department of Pharmaceutical Chemistry, University of Kansas, 2030 Becker Drive, Lawrence, Kansas 66047
| | - C Russell Middaugh
- Macromolecule and Vaccine Stabilization Center, Department of Pharmaceutical Chemistry, University of Kansas, 2030 Becker Drive, Lawrence, Kansas 66047; Department of Pharmaceutical Chemistry, University of Kansas, 2030 Becker Drive, Lawrence, Kansas 66047.
| |
Collapse
|
10
|
Han J, Zou HY, Gao MX, Huang CZ. A graphitic carbon nitride based fluorescence resonance energy transfer detection of riboflavin. Talanta 2016; 148:279-84. [DOI: 10.1016/j.talanta.2015.10.038] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2015] [Revised: 10/10/2015] [Accepted: 10/14/2015] [Indexed: 12/27/2022]
|
11
|
Haase I, Gräwert T, Illarionov B, Bacher A, Fischer M. Recent advances in riboflavin biosynthesis. Methods Mol Biol 2014; 1146:15-40. [PMID: 24764086 DOI: 10.1007/978-1-4939-0452-5_2] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Riboflavin is biosynthesized from GTP and ribulose 5-phosphate. Whereas the early reactions conducing to 5-amino-6-ribitylamino-2,4(1H,3H)-pyrimidinedione 5'-phosphate show significant taxonomic variation, the subsequent reaction steps are universal in all taxonomic kingdoms. With the exception of a hitherto elusive phosphatase, all enzymes of the pathway have been characterized in some detail at the structural and mechanistic level. Some of the pathway enzymes (GTP cycloyhdrolase II, 3,4-dihydroxy-2-butanone 4-phosphate synthase, riboflavin synthase) have exceptionally complex reaction mechanisms. The commercial production of the vitamin is now entirely based on highly productive fermentation processes. Due to their absence in animals, the pathway enzymes are potential targets for the development of novel anti-infective drugs.
Collapse
Affiliation(s)
- Ilka Haase
- Hamburg School of Food Science, Institute of Food Chemistry, University of Hamburg, Grindelallee 117, 20146, Hamburg, Germany
| | | | | | | | | |
Collapse
|
12
|
Ladenstein R, Fischer M, Bacher A. The lumazine synthase/riboflavin synthase complex: shapes and functions of a highly variable enzyme system. FEBS J 2013; 280:2537-63. [PMID: 23551830 DOI: 10.1111/febs.12255] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2012] [Revised: 03/01/2013] [Accepted: 03/04/2013] [Indexed: 11/30/2022]
Abstract
The xylene ring of riboflavin (vitamin B2 ) is assembled from two molecules of 3,4-dihydroxy-2-butanone 4-phosphate by a mechanistically complex process that is jointly catalyzed by lumazine synthase and riboflavin synthase. In Bacillaceae, these enzymes form a structurally unique complex comprising an icosahedral shell of 60 lumazine synthase subunits and a core of three riboflavin synthase subunits, whereas many other bacteria have empty lumazine synthase capsids, fungi, Archaea and some eubacteria have pentameric lumazine synthases, and the riboflavin synthases of Archaea are paralogs of lumazine synthase. The structures of the molecular ensembles have been studied in considerable detail by X-ray crystallography, X-ray small-angle scattering and electron microscopy. However, certain mechanistic aspects remain unknown. Surprisingly, the quaternary structure of the icosahedral β subunit capsids undergoes drastic changes, resulting in formation of large, quasi-spherical capsids; this process is modulated by sequence mutations. The occurrence of large shells consisting of 180 or more lumazine synthase subunits has recently generated interest for protein engineering topics, particularly the construction of encapsulation systems.
Collapse
Affiliation(s)
- Rudolf Ladenstein
- Department of Bioscience and Nutrition, Karolinska Institutet NOVUM, SE-14183 Huddinge, Sweden.
| | | | | |
Collapse
|
13
|
Abstract
The biosynthesis of riboflavin requires 1 equivalent of GTP and 2 equivalents of ribulose phosphate. The first committed reactions of the convergent pathway are catalyzed by GTP hydrolase II and 3,4-dihydroxy-2-butanone 4-phosphate synthase. The initial reaction steps afford 5-amino-6-ribitylaminopyrimidine 5'-phosphate, which needs to be dephosphorylated by a hitherto elusive hydrolase. The dephosphorylated pyrimidine is condensed with the carbohydrate precursor, 3,4-dihydroxy-2-butanone 4-phosphate. The resulting 6,7-dimethyl-8-ribityllumazine affords riboflavin by a mechanistically unique dismutation, i.e., by formation of a pentacyclic dimer that is subsequently fragmented.
Collapse
|
14
|
Morgunova E, Illarionov B, Saller S, Popov A, Sambaiah T, Bacher A, Cushman M, Fischer M, Ladenstein R. Structural study and thermodynamic characterization of inhibitor binding to lumazine synthase from Bacillus anthracis. ACTA CRYSTALLOGRAPHICA. SECTION D, BIOLOGICAL CRYSTALLOGRAPHY 2010; 66:1001-11. [PMID: 20823551 PMCID: PMC2935281 DOI: 10.1107/s0907444910029690] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/23/2010] [Accepted: 07/26/2010] [Indexed: 11/10/2022]
Abstract
The crystal structure of lumazine synthase from Bacillus anthracis was solved by molecular replacement and refined to R(cryst) = 23.7% (R(free) = 28.4%) at a resolution of 3.5 A. The structure reveals the icosahedral symmetry of the enzyme and specific features of the active site that are unique in comparison with previously determined orthologues. The application of isothermal titration calorimetry in combination with enzyme kinetics showed that three designed pyrimidine derivatives bind to lumazine synthase with micromolar dissociation constants and competitively inhibit the catalytic reaction. Structure-based modelling suggested the binding modes of the inhibitors in the active site and allowed an estimation of the possible contacts formed upon binding. The results provide a structural framework for the design of antibiotics active against B. anthracis.
Collapse
Affiliation(s)
- Ekaterina Morgunova
- Karolinska Institutet NOVUM, Center of Structural Biochemistry, Hälsovägen 7–9, 141 57 Huddinge, Sweden
| | - Boris Illarionov
- Institut für Lebensmittelchemie, Universität Hamburg, Grindelallee 117, 20146 Hamburg, Germany
| | - Sabine Saller
- Institut für Lebensmittelchemie, Universität Hamburg, Grindelallee 117, 20146 Hamburg, Germany
| | - Aleksander Popov
- European Synchrotron Radiation Facility, BP 220, F-38043 Grenoble CEDEX 09, France
| | - Thota Sambaiah
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, USA
| | - Adelbert Bacher
- Chemistry Department, Technical University of Munich, 85747 Garching, Germany
| | - Mark Cushman
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, USA
| | - Markus Fischer
- Institut für Lebensmittelchemie, Universität Hamburg, Grindelallee 117, 20146 Hamburg, Germany
| | - Rudolf Ladenstein
- Karolinska Institutet NOVUM, Center of Structural Biochemistry, Hälsovägen 7–9, 141 57 Huddinge, Sweden
| |
Collapse
|
15
|
A new ELISA plate based microtiter well assay for mycobacterial topoisomerase I for the direct screening of enzyme inhibitory monoclonal antibody supernatants. J Immunol Methods 2010; 357:26-32. [DOI: 10.1016/j.jim.2010.03.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2009] [Revised: 03/06/2010] [Accepted: 03/09/2010] [Indexed: 11/18/2022]
|
16
|
Long Q, Ji L, Wang H, Xie J. Riboflavin Biosynthetic and Regulatory Factors as Potential Novel Anti-Infective Drug Targets. Chem Biol Drug Des 2010; 75:339-47. [DOI: 10.1111/j.1747-0285.2010.00946.x] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
|
17
|
Talukdar A, Breen M, Bacher A, Illarionov B, Fischer M, Georg G, Ye QZ, Cushman M. Discovery and development of a small molecule library with lumazine synthase inhibitory activity. J Org Chem 2009; 74:5123-34. [PMID: 19552377 PMCID: PMC2760403 DOI: 10.1021/jo900238q] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
(E)-5-Nitro-6-(2-hydroxystyryl)pyrimidine-2,4(1H,3H)-dione (9) was identified as a novel inhibitor of Schizosaccharomyces pombe lumazine synthase by high-throughput screening of a 100000 compound library. The K(i) of 9 vs Mycobacterium tuberculosis lumazine synthase was 95 microM. Compound 9 is a structural analogue of the lumazine synthase substrate 5-amino-6-(d-ribitylamino)-2,4-(1H,3H)pyrimidinedione (1). This indicates that the ribitylamino side chain of the substrate is not essential for binding to the enzyme. Optimization of the enzyme inhibitory activity through systematic structure modification of the lead compound 9 led to (E)-5-nitro-6-(4-nitrostyryl)pyrimidine-2,4(1H,3H)-dione (26), which has a K(i) of 3.7 microM vs M. tuberculosis lumazine synthase.
Collapse
Affiliation(s)
- Arindam Talukdar
- Department of Medicinal Chemistry and Molecular Pharmacology, School of Pharmacy and Pharmaceutical Sciences, and The Purdue Cancer Center, Purdue University, West Lafayette, Indiana 47907
| | - Megan Breen
- Department of Medicinal Chemistry and Molecular Pharmacology, School of Pharmacy and Pharmaceutical Sciences, and The Purdue Cancer Center, Purdue University, West Lafayette, Indiana 47907
| | | | - Boris Illarionov
- Institute of Food Chemistry, University of Hamburg, D-20146 Hamburg, Germany
| | - Markus Fischer
- Institute of Food Chemistry, University of Hamburg, D-20146 Hamburg, Germany
| | - Gunda Georg
- Department of Medicinal Chemistry, University of Kansas, Lawrence, Kansas 66047
| | - Qi-Zhuang Ye
- Department of Medicinal Chemistry, University of Kansas, Lawrence, Kansas 66047
| | - Mark Cushman
- Department of Medicinal Chemistry and Molecular Pharmacology, School of Pharmacy and Pharmaceutical Sciences, and The Purdue Cancer Center, Purdue University, West Lafayette, Indiana 47907
| |
Collapse
|
18
|
Hu L, Yang X, Wang C, Yuan H, Xiao D. Determination of riboflavin in urine and beverages by capillary electrophoresis with in-column optical fiber laser-induced fluorescence detection. J Chromatogr B Analyt Technol Biomed Life Sci 2007; 856:245-51. [PMID: 17625992 DOI: 10.1016/j.jchromb.2007.06.011] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2006] [Revised: 05/28/2007] [Accepted: 06/12/2007] [Indexed: 11/28/2022]
Abstract
A simple, rapid and sensitive method was developed for routine analysis of riboflavin in beverage, green tea and urine by capillary electrophoresis with in-column optical fiber laser-induced fluorescence detection (LIF). The difference between the present detector in the study and others is that an optical fiber was adopted in the former, which can guide the excitation light into the capillary right at the detection window. The linearity of the method (r(2)=0.998) was good over the concentration range from 0.05 to 20 microM for riboflavin. The limit of detection (LOD) was determined using linear regression analysis and was found to be 3.0 nM. The percent recoveries of riboflavin in beverage, green tea and urine samples were 95.3+/-2.9, 105.5+/-3.9 and 94.3+/-1.7, respectively. These results of quantitative analysis of riboflavin in beverage and green tea samples is in agreement with that of obtained by the AOAC of fluorometric method. In the analysis of urine samples, all electropherograms of urine samples and corresponding concentrations of riboflavin in the period of 13 h after orally administrating the ingestion of vitamin B(2) tablets were illustrated.
Collapse
Affiliation(s)
- Li Hu
- College of Chemistry, Sichuan University, Chengdu 610065, China
| | | | | | | | | |
Collapse
|
19
|
Zhang Y, Illarionov B, Bacher A, Fischer M, Georg GI, Ye QZ, Velde DV, Fanwick PE, Song Y, Cushman M. A novel lumazine synthase inhibitor derived from oxidation of 1,3,6,8-tetrahydroxy-2,7-naphthyridine to a tetraazaperylenehexaone derivative. J Org Chem 2007; 72:2769-76. [PMID: 17348709 PMCID: PMC2526313 DOI: 10.1021/jo062246d] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Air oxidation of 1,3,6,8-tetrahydroxy-2,7-naphthyridine afforded 2,5,8,11-tetraaza-5,11-dihydro-4,10-dihydroxyperylene-1,3,6,7,9,12-hexaone. X-ray crystallography of the product revealed that it exists in the meso form in the solid state. The mechanism of product formation most likely involves oxidative phenolic coupling and oxidation. The product proved to be a competitive inhibitor of Schizosaccharomyces pombe lumazine synthase with a Ki of 66+/-13 microM in Tris buffer and 22+/-4 microM in phosphate buffer. This is significantly more potent than the reactant (Ki 350+/-76 microM, competitive inhibition), which had previously been identified as a lumazine synthase inhibitor by high-throughput screening. Ab initio calculations indicate that the meso form is slightly less stable than the enantiomeric form, and that the two forms interconvert rapidly at room temperature.
Collapse
|
20
|
Mack M, Grill S. Riboflavin analogs and inhibitors of riboflavin biosynthesis. Appl Microbiol Biotechnol 2006; 71:265-75. [PMID: 16607521 DOI: 10.1007/s00253-006-0421-7] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2006] [Revised: 03/06/2006] [Accepted: 03/06/2006] [Indexed: 11/30/2022]
Abstract
Flavins are active components of many enzymes. In most cases, riboflavin (vitamin B(2)) as a coenzyme represents the catalytic part of the holoenzyme. Riboflavin is an amphiphatic molecule and allows a large variety of different interactions with the enzyme itself and also with the substrate. A great number of active riboflavin analogs can readily be synthesized by chemical methods and, thus, a large number of possible inhibitors for many different enzyme targets is conceivable. As mammalian and especially human biochemistry depends on flavins as well, the target of the inhibiting flavin analog has to be carefully selected to avoid unwanted effects. In addition to flavoproteins, enzymes, which are involved in the biosynthesis of flavins, are possible targets for anti-infectives. Only a few flavin analogs or inhibitors of flavin biosynthesis have been subjected to detailed studies to evaluate their biological activity. Nevertheless, flavin analogs certainly have the potential to serve as basic structures for the development of novel anti-infectives and it is possible that, in the future, the urgent need for new molecules to fight multiresistant microorganisms will be met.
Collapse
Affiliation(s)
- Matthias Mack
- Institute for Technical Microbiology, Mannheim University of Applied Sciences, Germany.
| | | |
Collapse
|
21
|
Ramsperger A, Augustin M, Schott AK, Gerhardt S, Krojer T, Eisenreich W, Illarionov B, Cushman M, Bacher A, Huber R, Fischer M. Crystal Structure of an Archaeal Pentameric Riboflavin Synthase in Complex with a Substrate Analog Inhibitor. J Biol Chem 2006; 281:1224-32. [PMID: 16272154 DOI: 10.1074/jbc.m509440200] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Whereas eubacterial and eukaryotic riboflavin synthases form homotrimers, archaeal riboflavin synthases from Methanocaldococcus jannaschii and Methanothermobacter thermoautrophicus are homopentamers with sequence similarity to the 6,7-dimethyl-8-ribityllumazine synthase catalyzing the penultimate step in riboflavin biosynthesis. Recently it could be shown that the complex dismutation reaction catalyzed by the pentameric M. jannaschii riboflavin synthase generates riboflavin with the same regiochemistry as observed for trimeric riboflavin synthases. Here we present crystal structures of the pentameric riboflavin synthase from M. jannaschii and its complex with the substrate analog inhibitor, 6,7-dioxo-8-ribityllumazine. The complex structure shows five active sites located between adjacent monomers of the pentamer. Each active site can accommodate two substrate analog molecules in anti-parallel orientation. The topology of the two bound ligands at the active site is well in line with the known stereochemistry of a pentacyclic adduct of 6,7-dimethyl-8-ribityllumazine that has been shown to serve as a kinetically competent intermediate. The pentacyclic intermediates of trimeric and pentameric riboflavin synthases are diastereomers.
Collapse
Affiliation(s)
- Arne Ramsperger
- Max-Planck-Institut für Biochemie, Abteilung für Strukturforschung, Martinsried, Germany.
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
22
|
Glickman JF, Auld D. Literature Search and Review. Assay Drug Dev Technol 2005. [DOI: 10.1089/adt.2005.3.227] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
| | - Doug Auld
- National Institutes of Health, Bethesda, MD
| |
Collapse
|
23
|
Abstract
The biosynthesis of one riboflavin molecule requires one molecule of GTP and two molecules of ribulose 5-phosphate. The imidazole ring of GTP is hydrolytically opened, yielding a 2,5-diaminopyrimidine that is converted to 5-amino-6-ribitylamino-2,4(1H,3H)-pyrimidinedione by a sequence of deamination, side chain reduction, and dephosphorylation. Condensation of 5-amino-6-ribitylamino-2,4(1H,3H)-pyrimidinedione with 3,4-dihydroxy-2-butanone 4-phosphate obtained from ribulose 5-phosphate affords 6,7-dimethyl-8-ribityllumazine. Dismutation of the lumazine derivative yields riboflavin and 5-amino-6-ribitylamino-2,4(1H,3H)-pyrimidinedione, which is recycled in the biosynthetic pathway. The enzymes of the riboflavin pathway are potential targets for antibacterial agents.
Collapse
Affiliation(s)
- Markus Fischer
- Lehrstuhl für Organische Chemie und Biochemie, Technische Universität München, Lichtenbergstr. 4, D-85747, Garching, Germany.
| | | |
Collapse
|