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Rotsides P, Lee PJ, Webber N, Grasty KC, Beld J, Loll PJ. Diazirine Photoprobes for the Identification of Vancomycin-Binding Proteins. ACS BIO & MED CHEM AU 2024; 4:86-94. [PMID: 38645928 PMCID: PMC11027123 DOI: 10.1021/acsbiomedchemau.3c00067] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/17/2023] [Revised: 11/15/2023] [Accepted: 11/15/2023] [Indexed: 04/23/2024]
Abstract
Vancomycin's interactions with cellular targets drive its antimicrobial activity and also trigger expression of resistance against the antibiotic. Interaction partners for vancomycin have previously been identified using photoaffinity probes, which have proven to be useful tools for exploring vancomycin's interactome. This work seeks to develop diazirine-based vancomycin photoprobes that display enhanced specificity and bear fewer chemical modifications as compared to previous photoprobes. Using proteins fused to vancomycin's main cell-wall target, d-alanyl-d-alanine, we used mass spectrometry to show that these photoprobes specifically label known vancomycin-binding partners within minutes. In a complementary approach, we developed a Western-blot strategy targeting the vancomycin adduct of the photoprobes, eliminating the need for affinity tags and simplifying the analysis of photolabeling reactions. Together, the probes and identification strategy provide a novel and streamlined pipeline for identifying vancomycin-binding proteins.
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Affiliation(s)
- Photis Rotsides
- Department
of Biochemistry & Molecular Biology and Department of Microbiology &
Immunology, Drexel University College of
Medicine, Philadelphia, Pennsylvania 19102, United States
| | - Paula J. Lee
- Department
of Biochemistry & Molecular Biology and Department of Microbiology &
Immunology, Drexel University College of
Medicine, Philadelphia, Pennsylvania 19102, United States
| | - Nakoa Webber
- Department
of Biochemistry & Molecular Biology and Department of Microbiology &
Immunology, Drexel University College of
Medicine, Philadelphia, Pennsylvania 19102, United States
| | - Kimberly C. Grasty
- Department
of Biochemistry & Molecular Biology and Department of Microbiology &
Immunology, Drexel University College of
Medicine, Philadelphia, Pennsylvania 19102, United States
| | - Joris Beld
- Department
of Biochemistry & Molecular Biology and Department of Microbiology &
Immunology, Drexel University College of
Medicine, Philadelphia, Pennsylvania 19102, United States
| | - Patrick J. Loll
- Department
of Biochemistry & Molecular Biology and Department of Microbiology &
Immunology, Drexel University College of
Medicine, Philadelphia, Pennsylvania 19102, United States
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2
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Paredes-Amaya CC, Ulloa MT, García-Angulo VA. Fierce poison to others: the phenomenon of bacterial dependence on antibiotics. J Biomed Sci 2023; 30:67. [PMID: 37574554 PMCID: PMC10424368 DOI: 10.1186/s12929-023-00963-x] [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: 04/25/2023] [Accepted: 08/07/2023] [Indexed: 08/15/2023] Open
Abstract
Beyond the development of resistance, the effects of antibiotics on bacteria and microbial communities are complex and far from exhaustively studied. In the context of the current global antimicrobial resistance crisis, understanding the adaptive and physiological responses of bacteria to antimicrobials is of paramount importance along with the development of new therapies. Bacterial dependence on antibiotics is a phenomenon in which antimicrobials instead of eliminating the pathogens actually provide a boost for their growth. This trait comprises an extreme example of the complexities of responses elicited by microorganisms to these drugs. This compelling evolutionary trait was readily described along with the first wave of antibiotics use and dependence to various antimicrobials has been reported. Nevertheless, current molecular characterizations have been focused on dependence on vancomycin, linezolid and colistin, three critically important antibiotics frequently used as last resource therapy for multi resistant pathogens. Outstanding advances have been made in understanding the molecular basis for the dependence to vancomycin, including specific mutations involved. Regarding linezolid and colistin, the general physiological components affected by the dependence, namely ribosomes and membrane function respectively, have been established. Nonetheless the implications of antibiotic dependence in clinically relevant features, such as virulence, epidemics, relationship with development of resistance, diagnostics and therapy effectiveness require clarification. This review presents a brief introduction of the phenomenon of bacterial dependence to antibiotics and a summary on early and current research concerning the basis for this trait. Furthermore, the available information on the effect of dependence in key clinical aspects is discussed. The studies performed so far underline the need to fully disclose the biological and clinical significance of this trait in pathogens to successfully assess its role in resistance and to design adjusted therapies.
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Affiliation(s)
- Claudia C Paredes-Amaya
- Microbiology Department, Escuela de Ciencias Básicas, Facultad de Salud, Universidad del Valle, Cali, Colombia
| | - María Teresa Ulloa
- Microbiology and Micology Program, Facultad de Medicina, Instituto de Ciencias Biomédicas, Universidad de Chile, Independencia 1027, Independencia, RM, Santiago, Chile
- Vertebral I+D+i - Corporation for Assistance for Burned Children (Coaniquem), Santiago, Chile
| | - Víctor Antonio García-Angulo
- Microbiology and Micology Program, Facultad de Medicina, Instituto de Ciencias Biomédicas, Universidad de Chile, Independencia 1027, Independencia, RM, Santiago, Chile.
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3
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Maciunas LJ, Rotsides P, Brady S, Beld J, Loll PJ. The VanS sensor histidine kinase from type-B VRE recognizes vancomycin directly. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.07.09.548278. [PMID: 37503228 PMCID: PMC10369886 DOI: 10.1101/2023.07.09.548278] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/29/2023]
Abstract
V ancomycin-resistant e nterococci (VRE) are among the most common causes of nosocomial infections, which can be challenging to treat. VRE have acquired a suite of resistance genes that function together to confer resistance to vancomycin. Expression of the resistance phenotype is controlled by the VanRS two-component system. This system senses the presence of the antibiotic, and responds by initiating transcription of resistance genes. VanS is a transmembrane sensor histidine kinase, and plays a fundamental role in antibiotic resistance by detecting vancomycin and then transducing this signal to VanR. Despite the critical role played by VanS, fundamental questions remain about its function, and in particular about how it senses vancomycin. Here, we focus on purified VanRS systems from the two most clinically prevalent forms of VRE, types A and B. We show that in a native-like membrane environment, the enzymatic activities of type-A VanS are insensitive to vancomycin, suggesting that the protein functions by an indirect mechanism that detects a downstream consequence of antibiotic activity. In contrast, the autokinase activity of type-B VanS is strongly stimulated by vancomycin. We additionally demonstrate that this effect is mediated by a direct physical interaction between the antibiotic and the type-B VanS protein, and localize the interacting region to the protein's periplasmic domain. This represents the first time that a direct sensing mechanism has been confirmed for any VanS protein. Significance Statement When v ancomycin-resistant e nterococci (VRE) sense the presence of vancomycin, they remodel their cell walls to block antibiotic binding. This resistance phenotype is controlled by the VanS protein, a sensor histidine kinase that senses the antibiotic and signals for transcription of resistance genes. However, the mechanism by which VanS detects the antibiotic has remained unclear. Here, we show that VanS proteins from the two most common types of VRE use very different sensing mechanisms. Vancomycin does not alter the signaling activity of VanS from type-A VRE, suggesting an indirect sensing mechanism; in contrast, VanS from type-B VRE is activated by direct binding of the antibiotic. Such mechanistic insights will likely prove useful in circumventing vancomycin resistance.
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4
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Grudlewska-Buda K, Skowron K, Bauza-Kaszewska J, Budzyńska A, Wiktorczyk-Kapischke N, Wilk M, Wujak M, Paluszak Z. Assessment of antibiotic resistance and biofilm formation of Enterococcus species isolated from different pig farm environments in Poland. BMC Microbiol 2023; 23:89. [PMID: 36997857 PMCID: PMC10061711 DOI: 10.1186/s12866-023-02834-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2022] [Accepted: 03/22/2023] [Indexed: 04/01/2023] Open
Abstract
BACKGROUND Enteroccocus spp. are human opportunistic pathogens causing a variety of serious and life-threating infections in humans, including urinary tract infection, endocarditis, skin infection and bacteraemia. Farm animals and direct contact with them are important sources of Enterococcus faecalis (EFA) and Enterococcus faecium (EFM) infections among farmers, veterinarians and individuals working in breeding farms and abattoirs. The spread of antibiotic-resistant strains is one of the most serious public health concerns, as clinicians will be left without therapeutic options for the management of enterococcal infections. The aim of the study was to evaluate the occurrence and antimicrobial susceptibility of EFA and EFM strains isolated from a pig farm environment and to determine the biofilm formation ability of identified Enterococcus spp. strains. RESULTS A total numer of 160 enterococcal isolates were obtained from 475 samples collected in total (33.7%). Among them, 110 of genetically different strains were identified and classified into EFA (82; 74.5%) and EFM (28; 25.5%). Genetic similarity analysis revealed the presence of 7 and 1 clusters among the EFA and EFM strains, respectively. The highest percentage of EFA strains (16; 19.5%) was resistant to high concentrations of gentamicin. Among the EFM strains, the most frequent strains were resistant to ampicillin and high concentrations of gentamicin (5 each; 17.9%). Six (7.3%) EFA and 4 (14.3%) EFM strains showed vancomycin resistance (VRE - Vancomycin-Resistant Enterococcus). Linezolid resistance was found in 2 strains of each species. The multiplex PCR analysis was performed to identify the vancomycin resistant enterococci. vanB, vanA and vanD genotypes were detected in 4, 1 and 1 EFA strains, respectively. Four EFA VRE-strains in total, 2 with the vanA and 2 with the vanB genotypes, were identified. The biofilm analysis revealed that all vancomycin-resistant E. faecalis and E. faecium strains demonstrated a higher biofilm-forming capacity, as compared to the susceptible strains. The lowest cell count (5.31 log CFU / cm2) was reisolated from the biofilm produced by the vancomycin-sensitive strain EFM 2. The highest level of re-isolated cells was observed for VRE EFA 25 and VRE EFM 7 strains, for which the number was 7 log CFU / cm2 and 6.75 log CFU / cm2, respectively. CONCLUSIONS The irrational use of antibiotics in agriculture and veterinary practice is considered to be one of the key reasons for the rapid spread of antibiotic resistance among microorganisms. Owing to the fact that piggery environment can be a reservoir of antimicrobial resistance and transmission route of antimicrobial resistance genes from commensal zoonotic bacteria to clinical strains, it is of a great importance to public health to monitor trends in this biological phenomenon.
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Affiliation(s)
- Katarzyna Grudlewska-Buda
- Department of Microbiology, Ludwik Rydygier Collegium Medicum in Bydgoszcz, Nicolaus Copernicus University in Toruń, Toruń, Poland
| | - Krzysztof Skowron
- Department of Microbiology, Ludwik Rydygier Collegium Medicum in Bydgoszcz, Nicolaus Copernicus University in Toruń, Toruń, Poland.
| | - Justyna Bauza-Kaszewska
- Department of Microbiology and Food Technology, Bydgoszcz University of Science and Technology, Bydgoszcz, Poland
| | - Anna Budzyńska
- Department of Microbiology, Ludwik Rydygier Collegium Medicum in Bydgoszcz, Nicolaus Copernicus University in Toruń, Toruń, Poland
| | - Natalia Wiktorczyk-Kapischke
- Department of Microbiology, Ludwik Rydygier Collegium Medicum in Bydgoszcz, Nicolaus Copernicus University in Toruń, Toruń, Poland
| | - Monika Wilk
- Department of Microbiology, Ludwik Rydygier Collegium Medicum in Bydgoszcz, Nicolaus Copernicus University in Toruń, Toruń, Poland
| | - Magdalena Wujak
- Department of Medicinal Chemistry, Ludwik Rydygier Collegium Medicum in Bydgoszcz, Nicolaus Copernicus University in Toruń, Toruń, Poland
| | - Zbigniew Paluszak
- Department of Microbiology and Food Technology, Bydgoszcz University of Science and Technology, Bydgoszcz, Poland
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5
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Self-association of the glycopeptide antibiotic teicoplanin A2 in aqueous solution studied by molecular hydrodynamics. Sci Rep 2023; 13:1969. [PMID: 36737502 PMCID: PMC9895975 DOI: 10.1038/s41598-023-28740-8] [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: 10/31/2022] [Accepted: 01/24/2023] [Indexed: 02/05/2023] Open
Abstract
The natural glycopeptide antibiotic teicoplanin is used for the treatment of serious Gram-positive related bacterial infections and can be administered intravenously, intramuscularly, topically (ocular infections), or orally. It has also been considered for targeting viral infection by SARS-CoV-2. The hydrodynamic properties of teicoplanin A2 (M1 = 1880 g/mol) were examined in phosphate chloride buffer (pH 6.8, I = 0.10 M) using sedimentation velocity and sedimentation equilibrium in the analytical ultracentrifuge together with capillary (rolling ball) viscometry. In the concentration range, 0-10 mg/mL teicoplanin A2 was found to self-associate plateauing > 1 mg/mL to give a molar mass of (35,400 ± 1000) g/mol corresponding to ~ (19 ± 1) mers, with a sedimentation coefficient s20, w = ~ 4.65 S. The intrinsic viscosity [[Formula: see text]] was found to be (3.2 ± 0.1) mL/g: both this, the value for s20,w and the hydrodynamic radius from dynamic light scattering are consistent with a globular macromolecular assembly, with a swelling ratio through dynamic hydration processes of ~ 2.
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6
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Jiang F, Cai C, Gao L, Su X, Han S. Peptidoglycan-Directed Chemical Ligation for Selective Inhibition on Gram-Positive Bacteria. ACS OMEGA 2023; 8:2485-2490. [PMID: 36687063 PMCID: PMC9850734 DOI: 10.1021/acsomega.2c06964] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/29/2022] [Accepted: 12/16/2022] [Indexed: 06/17/2023]
Abstract
Microbicides with distinct antibacterial mechanisms show potential to combat multi-drug resistance bacteria. We herein report peptidoglycan-directed chemical ligation (PGCL) between alkyne-bearing vancomycin and an azide-tagged cationic polymer. The former binds peptidoglycan and inhibits peptidoglycan crosslinking, while the latter interferes the integrity of the bacterial membrane. PGCL results in enhanced bactericidal activity against Gram-positive Staphylococcus aureus (S. aureus) over Gram-negative Escherichia coli (E. coli). These data indicate the potential of PGCL to selectively and synergistically inhibit Gram-positive pathogens via dual modality antibacterial mechanisms of peptidoglycan-inhibiting antibiotics and bacterial membrane-disrupting polycations.
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Affiliation(s)
- Feng Jiang
- Department
of Chemical Biology, College of Chemistry and Chemical Engineering,
State Key Laboratory for Physical Chemistry of Solid Surfaces, State
Key Laboratory of Cellular Stress Biology, the Key Laboratory for
Chemical Biology of Fujian Province, and the MOE Key Laboratory of
Spectrochemical Analysis & Instrumentation, Xiamen University, Xiamen 361005, China
| | - Chengteng Cai
- Department
of Chemical Biology, College of Chemistry and Chemical Engineering,
State Key Laboratory for Physical Chemistry of Solid Surfaces, State
Key Laboratory of Cellular Stress Biology, the Key Laboratory for
Chemical Biology of Fujian Province, and the MOE Key Laboratory of
Spectrochemical Analysis & Instrumentation, Xiamen University, Xiamen 361005, China
| | - Lei Gao
- Department
of Chemical Biology, College of Chemistry and Chemical Engineering,
State Key Laboratory for Physical Chemistry of Solid Surfaces, State
Key Laboratory of Cellular Stress Biology, the Key Laboratory for
Chemical Biology of Fujian Province, and the MOE Key Laboratory of
Spectrochemical Analysis & Instrumentation, Xiamen University, Xiamen 361005, China
| | - Xinhui Su
- PET
center, Department of Nuclear Medicine, The First Affiliated Hospital,
College of Medicine, Zhejiang University, Hangzhou 310027, China
| | - Shoufa Han
- Department
of Chemical Biology, College of Chemistry and Chemical Engineering,
State Key Laboratory for Physical Chemistry of Solid Surfaces, State
Key Laboratory of Cellular Stress Biology, the Key Laboratory for
Chemical Biology of Fujian Province, and the MOE Key Laboratory of
Spectrochemical Analysis & Instrumentation, Xiamen University, Xiamen 361005, China
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7
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Lee D, Lee Y, Hye Shin S, Min Choi S, Hyeon Lee S, Jeong S, Jang S, Kee JM. A simple protein histidine kinase activity assay for high-throughput inhibitor screening. Bioorg Chem 2023; 130:106232. [DOI: 10.1016/j.bioorg.2022.106232] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2022] [Revised: 10/15/2022] [Accepted: 10/26/2022] [Indexed: 11/11/2022]
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8
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Targeting the Holy Triangle of Quorum Sensing, Biofilm Formation, and Antibiotic Resistance in Pathogenic Bacteria. Microorganisms 2022; 10:microorganisms10061239. [PMID: 35744757 PMCID: PMC9228545 DOI: 10.3390/microorganisms10061239] [Citation(s) in RCA: 33] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2022] [Revised: 06/12/2022] [Accepted: 06/14/2022] [Indexed: 12/12/2022] Open
Abstract
Chronic and recurrent bacterial infections are frequently associated with the formation of biofilms on biotic or abiotic materials that are composed of mono- or multi-species cultures of bacteria/fungi embedded in an extracellular matrix produced by the microorganisms. Biofilm formation is, among others, regulated by quorum sensing (QS) which is an interbacterial communication system usually composed of two-component systems (TCSs) of secreted autoinducer compounds that activate signal transduction pathways through interaction with their respective receptors. Embedded in the biofilms, the bacteria are protected from environmental stress stimuli, and they often show reduced responses to antibiotics, making it difficult to eradicate the bacterial infection. Besides reduced penetration of antibiotics through the intricate structure of the biofilms, the sessile biofilm-embedded bacteria show reduced metabolic activity making them intrinsically less sensitive to antibiotics. Moreover, they frequently express elevated levels of efflux pumps that extrude antibiotics, thereby reducing their intracellular levels. Some efflux pumps are involved in the secretion of QS compounds and biofilm-related materials, besides being important for removing toxic substances from the bacteria. Some efflux pump inhibitors (EPIs) have been shown to both prevent biofilm formation and sensitize the bacteria to antibiotics, suggesting a relationship between these processes. Additionally, QS inhibitors or quenchers may affect antibiotic susceptibility. Thus, targeting elements that regulate QS and biofilm formation might be a promising approach to combat antibiotic-resistant biofilm-related bacterial infections.
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9
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King A, Blackledge MS. Evaluation of small molecule kinase inhibitors as novel antimicrobial and antibiofilm agents. Chem Biol Drug Des 2021; 98:1038-1064. [PMID: 34581492 PMCID: PMC8616828 DOI: 10.1111/cbdd.13962] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Revised: 08/24/2021] [Accepted: 09/15/2021] [Indexed: 12/25/2022]
Abstract
Antibiotic resistance is a global and pressing concern. Our current therapeutic arsenal is increasingly limited as bacteria are developing resistance at a rate that far outpaces our ability to create new treatments. Novel approaches to treating and curing bacterial infections are urgently needed. Bacterial kinases have been increasingly explored as novel drug targets and are poised for development into novel therapeutic agents to combat bacterial infections. This review describes several general classes of bacterial kinases that play important roles in bacterial growth, antibiotic resistance, and biofilm formation. General features of these kinase classes are discussed and areas of particular interest for the development of inhibitors will be highlighted. Small molecule kinase inhibitors are described and organized by phenotypic effect, spotlighting particularly interesting inhibitors with novel functions and potential therapeutic benefit. Finally, we provide our perspective on the future of bacterial kinase inhibition as a viable strategy to combat bacterial infections and overcome the pressures of increasing antibiotic resistance.
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Affiliation(s)
- Ashley King
- Department of Chemistry, High Point University, One University Parkway, High Point, NC 27268
| | - Meghan S. Blackledge
- Department of Chemistry, High Point University, One University Parkway, High Point, NC 27268
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10
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Eco-friendly pH detecting paper-based analytical device: Towards process intensification. Anal Chim Acta 2021; 1182:338953. [PMID: 34602199 DOI: 10.1016/j.aca.2021.338953] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2021] [Revised: 07/24/2021] [Accepted: 08/05/2021] [Indexed: 11/21/2022]
Abstract
This work describes the development of a miniaturized paper-based pH detection platform using natural dye extracted from red cabbage (Brassica oleracea). The easily available paper was used as a substrate and the requisite patterned zone was created with the aid of a punching machine. Experimental parameters were optimized to obtain the best signal readout. The performance of the device at different pH values was quantitatively assessed using digital image analysis with various color space models. Regression analysis suggested that a∗ parameter in CIEL∗a∗b∗ color space model, which captures the variations on the red-green scale, exhibited the best fit with experimental data (R2 = 0.9754). This parameter was used for the quantitative estimation of pH variations in a wide range of pH (1-12). A series of real test samples were examined using the paper-based device and results validated with a standard pH meter. The use of paper and natural dye makes the device eco-friendly. The simplicity of fabrication, ease of usage and low reagent and sample volume requirements render the methodology suitable for in situ measurements of pH. The approach demonstrated here would pave the way for the development of clean, sustainable and intensified chemical sensor technologies.
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11
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Regulation of Resistance in Vancomycin-Resistant Enterococci: The VanRS Two-Component System. Microorganisms 2021; 9:microorganisms9102026. [PMID: 34683347 PMCID: PMC8541618 DOI: 10.3390/microorganisms9102026] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Revised: 09/21/2021] [Accepted: 09/22/2021] [Indexed: 01/20/2023] Open
Abstract
Vancomycin-resistant enterococci (VRE) are a serious threat to human health, with few treatment options being available. New therapeutics are urgently needed to relieve the health and economic burdens presented by VRE. A potential target for new therapeutics is the VanRS two-component system, which regulates the expression of vancomycin resistance in VRE. VanS is a sensor histidine kinase that detects vancomycin and in turn activates VanR; VanR is a response regulator that, when activated, directs expression of vancomycin-resistance genes. This review of VanRS examines how the expression of vancomycin resistance is regulated, and provides an update on one of the field’s most pressing questions: How does VanS sense vancomycin?
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12
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Ma P, Phillips-Jones MK. Membrane Sensor Histidine Kinases: Insights from Structural, Ligand and Inhibitor Studies of Full-Length Proteins and Signalling Domains for Antibiotic Discovery. Molecules 2021; 26:molecules26165110. [PMID: 34443697 PMCID: PMC8399564 DOI: 10.3390/molecules26165110] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Revised: 08/02/2021] [Accepted: 08/19/2021] [Indexed: 12/19/2022] Open
Abstract
There is an urgent need to find new antibacterial agents to combat bacterial infections, including agents that inhibit novel, hitherto unexploited targets in bacterial cells. Amongst novel targets are two-component signal transduction systems (TCSs) which are the main mechanism by which bacteria sense and respond to environmental changes. TCSs typically comprise a membrane-embedded sensory protein (the sensor histidine kinase, SHK) and a partner response regulator protein. Amongst promising targets within SHKs are those involved in environmental signal detection (useful for targeting specific SHKs) and the common themes of signal transmission across the membrane and propagation to catalytic domains (for targeting multiple SHKs). However, the nature of environmental signals for the vast majority of SHKs is still lacking, and there is a paucity of structural information based on full-length membrane-bound SHKs with and without ligand. Reasons for this lack of knowledge lie in the technical challenges associated with investigations of these relatively hydrophobic membrane proteins and the inherent flexibility of these multidomain proteins that reduces the chances of successful crystallisation for structural determination by X-ray crystallography. However, in recent years there has been an explosion of information published on (a) methodology for producing active forms of full-length detergent-, liposome- and nanodisc-solubilised membrane SHKs and their use in structural studies and identification of signalling ligands and inhibitors; and (b) mechanisms of signal sensing and transduction across the membrane obtained using sensory and transmembrane domains in isolation, which reveal some commonalities as well as unique features. Here we review the most recent advances in these areas and highlight those of potential use in future strategies for antibiotic discovery. This Review is part of a Special Issue entitled “Interactions of Bacterial Molecules with Their Ligands and Other Chemical Agents” edited by Mary K. Phillips-Jones.
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Affiliation(s)
- Pikyee Ma
- Laboratory of Biomolecular Research, Paul Scherrer Institute, CH-5232 Villigen, Switzerland;
| | - Mary K. Phillips-Jones
- National Centre for Macromolecular Hydrodynamics, School of Biosciences, University of Nottingham, Sutton Bonington LE12 5RD, UK
- Correspondence:
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13
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Matilla MA, Velando F, Martín-Mora D, Monteagudo-Cascales E, Krell T. A catalogue of signal molecules that interact with sensor kinases, chemoreceptors and transcriptional regulators. FEMS Microbiol Rev 2021; 46:6356564. [PMID: 34424339 DOI: 10.1093/femsre/fuab043] [Citation(s) in RCA: 45] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2021] [Accepted: 08/10/2021] [Indexed: 12/12/2022] Open
Abstract
Bacteria have evolved many different signal transduction systems that sense signals and generate a variety of responses. Generally, most abundant are transcriptional regulators, sensor histidine kinases and chemoreceptors. Typically, these systems recognize their signal molecules with dedicated ligand-binding domains (LBDs), which, in turn, generate a molecular stimulus that modulates the activity of the output module. There are an enormous number of different LBDs that recognize a similarly diverse set of signals. To give a global perspective of the signals that interact with transcriptional regulators, sensor kinases and chemoreceptors, we manually retrieved information on the protein-ligand interaction from about 1,200 publications and 3D structures. The resulting 811 proteins were classified according to the Pfam family into 127 groups. These data permit a delineation of the signal profiles of individual LBD families as well as distinguishing between families that recognize signals in a promiscuous manner and those that possess a well-defined ligand range. A major bottleneck in the field is the fact that the signal input of many signaling systems is unknown. The signal repertoire reported here will help the scientific community design experimental strategies to identify the signaling molecules for uncharacterised sensor proteins.
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Affiliation(s)
- Miguel A Matilla
- Department of Environmental Protection, Estación Experimental del Zaidín, Consejo Superior de Investigaciones Científicas, Prof. Albareda 1, 18008 Granada, Spain
| | - Félix Velando
- Department of Environmental Protection, Estación Experimental del Zaidín, Consejo Superior de Investigaciones Científicas, Prof. Albareda 1, 18008 Granada, Spain
| | - David Martín-Mora
- Department of Environmental Protection, Estación Experimental del Zaidín, Consejo Superior de Investigaciones Científicas, Prof. Albareda 1, 18008 Granada, Spain
| | - Elizabet Monteagudo-Cascales
- Department of Environmental Protection, Estación Experimental del Zaidín, Consejo Superior de Investigaciones Científicas, Prof. Albareda 1, 18008 Granada, Spain
| | - Tino Krell
- Department of Environmental Protection, Estación Experimental del Zaidín, Consejo Superior de Investigaciones Científicas, Prof. Albareda 1, 18008 Granada, Spain
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14
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Lockey C, Edwards RJ, Roper DI, Dixon AM. The Extracellular Domain of Two-component System Sensor Kinase VanS from Streptomyces coelicolor Binds Vancomycin at a Newly Identified Binding Site. Sci Rep 2020; 10:5727. [PMID: 32235931 PMCID: PMC7109055 DOI: 10.1038/s41598-020-62557-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Accepted: 03/11/2020] [Indexed: 11/24/2022] Open
Abstract
The glycopeptide antibiotic vancomycin has been widely used to treat infections of Gram-positive bacteria including Clostridium difficile and methicillin-resistant Staphylococcus aureus. However, since its introduction, high level vancomycin resistance has emerged. The genes responsible require the action of the two-component regulatory system VanSR to induce expression of resistance genes. The mechanism of detection of vancomycin by this two-component system has yet to be elucidated. Diverging evidence in the literature supports activation models in which the VanS protein binds either vancomycin, or Lipid II, to induce resistance. Here we investigated the interaction between vancomycin and VanS from Streptomyces coelicolor (VanSSC), a model Actinomycete. We demonstrate a direct interaction between vancomycin and purified VanSSC, and traced these interactions to the extracellular region of the protein, which we reveal adopts a predominantly α-helical conformation. The VanSSC-binding epitope within vancomycin was mapped to the N-terminus of the peptide chain, distinct from the binding site for Lipid II. In targeting a separate site on vancomycin, the effective VanS ligand concentration includes both free and lipid-bound molecules, facilitating VanS activation. This is the first molecular description of the VanS binding site within vancomycin, and could direct engineering of future therapeutics.
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Affiliation(s)
- Christine Lockey
- MOAC Doctoral Training Centre, University of Warwick, Coventry, CV4 7AL, UK
| | - Richard J Edwards
- Medical Research Council Doctoral Training Centre, University of Warwick, Coventry, CV4 7AL, UK
| | - David I Roper
- School of Life Sciences, University of Warwick, Coventry, CV4 7AL, UK
| | - Ann M Dixon
- Department of Chemistry, University of Warwick, Coventry, CV4 7AL, UK.
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15
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Stogios PJ, Savchenko A. Molecular mechanisms of vancomycin resistance. Protein Sci 2020; 29:654-669. [PMID: 31899563 DOI: 10.1002/pro.3819] [Citation(s) in RCA: 112] [Impact Index Per Article: 28.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2019] [Revised: 12/30/2019] [Accepted: 01/02/2020] [Indexed: 12/18/2022]
Abstract
Vancomycin and related glycopeptides are drugs of last resort for the treatment of severe infections caused by Gram-positive bacteria such as Enterococcus species, Staphylococcus aureus, and Clostridium difficile. Vancomycin was long considered immune to resistance due to its bactericidal activity based on binding to the bacterial cell envelope rather than to a protein target as is the case for most antibiotics. However, two types of complex resistance mechanisms, each comprised of a multi-enzyme pathway, emerged and are now widely disseminated in pathogenic species, thus threatening the clinical efficiency of vancomycin. Vancomycin forms an intricate network of hydrogen bonds with the d-Ala-d-Ala region of Lipid II, interfering with the peptidoglycan layer maturation process. Resistance to vancomycin involves degradation of this natural precursor and its replacement with d-Ala-d-lac or d-Ala-d-Ser alternatives to which vancomycin has low affinity. Through extensive research over 30 years after the initial discovery of vancomycin resistance, remarkable progress has been made in molecular understanding of the enzymatic cascades responsible. Progress has been driven by structural studies of the key components of the resistance mechanisms which provided important molecular understanding such as, for example, the ability of this cascade to discriminate between vancomycin sensitive and resistant peptidoglycan precursors. Important structural insights have been also made into the molecular evolution of vancomycin resistance enzymes. Altogether this molecular data can accelerate inhibitor discovery and optimization efforts to reverse vancomycin resistance. Here, we overview our current understanding of this complex resistance mechanism with a focus on the structural and molecular aspects.
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Affiliation(s)
- Peter J Stogios
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Ontario, Canada.,Center for Structural Genomics of Infectious Diseases (CSGID)
| | - Alexei Savchenko
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Ontario, Canada.,Center for Structural Genomics of Infectious Diseases (CSGID).,Department of Microbiology, Immunology and Infectious Diseases, University of Calgary, Calgary, Alberta, Canada
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16
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Dinu V, Lu Y, Weston N, Lithgo R, Coupe H, Channell G, Adams GG, Torcello Gómez A, Sabater C, Mackie A, Parmenter C, Fisk I, Phillips-Jones MK, Harding SE. The antibiotic vancomycin induces complexation and aggregation of gastrointestinal and submaxillary mucins. Sci Rep 2020; 10:960. [PMID: 31969624 PMCID: PMC6976686 DOI: 10.1038/s41598-020-57776-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2018] [Accepted: 12/19/2019] [Indexed: 01/14/2023] Open
Abstract
Vancomycin, a branched tricyclic glycosylated peptide antibiotic, is a last-line defence against serious infections caused by staphylococci, enterococci and other Gram-positive bacteria. Orally-administered vancomycin is the drug of choice to treat pseudomembranous enterocolitis in the gastrointestinal tract. However, the risk of vancomycin-resistant enterococcal infection or colonization is significantly associated with oral vancomycin. Using the powerful matrix-free assay of co-sedimentation analytical ultracentrifugation, reinforced by dynamic light scattering and environmental scanning electron microscopy, and with porcine mucin as the model mucin system, this is the first study to demonstrate strong interactions between vancomycin and gastric and intestinal mucins, resulting in very large aggregates and depletion of macromolecular mucin and occurring at concentrations relevant to oral dosing. In the case of another mucin which has a much lower degree of glycosylation (~60%) - bovine submaxillary mucin - a weaker but still demonstrable interaction is observed. Our demonstration - for the first time - of complexation/depletion interactions for model mucin systems with vancomycin provides the basis for further study on the implications of complexation on glycopeptide transit in humans, antibiotic bioavailability for target inhibition, in situ generation of resistance and future development strategies for absorption of the antibiotic across the mucus barrier.
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Affiliation(s)
- Vlad Dinu
- National Centre for Macromolecular Hydrodynamics, School of Biosciences, University of Nottingham, Sutton Bonington, LE12 5RD, UK
- Division of Food Science, School of Biosciences, Sutton Bonington, LE12 5RD, UK
| | - Yudong Lu
- National Centre for Macromolecular Hydrodynamics, School of Biosciences, University of Nottingham, Sutton Bonington, LE12 5RD, UK
| | - Nicola Weston
- Nottingham Nanoscale and Microscale Research Centre, University of Nottingham, University Park, Nottingham, NG7 2RD, UK
| | - Ryan Lithgo
- National Centre for Macromolecular Hydrodynamics, School of Biosciences, University of Nottingham, Sutton Bonington, LE12 5RD, UK
| | - Hayley Coupe
- National Centre for Macromolecular Hydrodynamics, School of Biosciences, University of Nottingham, Sutton Bonington, LE12 5RD, UK
| | - Guy Channell
- National Centre for Macromolecular Hydrodynamics, School of Biosciences, University of Nottingham, Sutton Bonington, LE12 5RD, UK
- Division of Food Science, School of Biosciences, Sutton Bonington, LE12 5RD, UK
| | - Gary G Adams
- National Centre for Macromolecular Hydrodynamics, School of Biosciences, University of Nottingham, Sutton Bonington, LE12 5RD, UK
- School of Health Sciences, University of Nottingham, Nottingham, NG7 2HA, UK
| | | | - Carlos Sabater
- School of Food Science & Nutrition, University of Leeds, Leeds, LS2 9JT, UK
- Department of Bioactivity and Food Analysis, Institute of Food Science Research (CSIC-UAM), Nicolás Cabrera 9, 28049, Madrid, Spain
| | - Alan Mackie
- School of Food Science & Nutrition, University of Leeds, Leeds, LS2 9JT, UK
| | - Christopher Parmenter
- Nottingham Nanoscale and Microscale Research Centre, University of Nottingham, University Park, Nottingham, NG7 2RD, UK
| | - Ian Fisk
- Division of Food Science, School of Biosciences, Sutton Bonington, LE12 5RD, UK
| | - Mary K Phillips-Jones
- National Centre for Macromolecular Hydrodynamics, School of Biosciences, University of Nottingham, Sutton Bonington, LE12 5RD, UK.
| | - Stephen E Harding
- National Centre for Macromolecular Hydrodynamics, School of Biosciences, University of Nottingham, Sutton Bonington, LE12 5RD, UK.
- Kulturhistorisk Museum, Universitetet i Oslo, Postboks 6762, St. Olavs plass, 0130, Oslo, Norway.
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17
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Yushchuk O, Homoniuk V, Ostash B, Marinelli F, Fedorenko V. Genetic insights into the mechanism of teicoplanin self-resistance in Actinoplanes teichomyceticus. J Antibiot (Tokyo) 2020; 73:255-259. [PMID: 31953525 DOI: 10.1038/s41429-019-0274-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2019] [Revised: 11/25/2019] [Accepted: 12/20/2019] [Indexed: 11/09/2022]
Abstract
Actinoplanes teichomyceticus NRRL B-16726 is the only known producer of the clinically important glycopeptide antibiotic teicoplanin. The producing strain is highly self-resistant to teicoplanin. Although the biosynthesis of teicoplanin has been investigated, much of our understanding of self-resistance in the producing strain is based on the extrapolation of existing data about glycopeptide resistance (mediated by the expression of vanRS-vanHAX genes) in other actinomycetes and cocci. The organization of the operons carrying putative van orthologues in A. teichomyceticus differs from known precedents, further adding up to the uncertainty about teicoplanin self-resistance mechanisms. Here, we determined operon structure of the teicoplanin resistance genes in A. teichomyceticus. Although Tei15* is necessary to activate teicoplanin biosynthetic genes, the expression of van orthologues was shown to be independent of Tei15*. We further showed that tei7 promoter driving the expression of vanHAX orthologues is dependent on Tei2 (VanR). Finally, we demonstrate the utility of the tei2 promoter as a new tool to achieve strong constitutive expression in A. teichomyceticus.
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Affiliation(s)
- Oleksandr Yushchuk
- Department of Genetics and Biotechnology, Ivan Franko National University of Lviv, 4 Hrushevskoho st., Lviv, 79005, Ukraine
| | - Vitalina Homoniuk
- Department of Genetics and Biotechnology, Ivan Franko National University of Lviv, 4 Hrushevskoho st., Lviv, 79005, Ukraine
| | - Bohdan Ostash
- Department of Genetics and Biotechnology, Ivan Franko National University of Lviv, 4 Hrushevskoho st., Lviv, 79005, Ukraine
| | - Flavia Marinelli
- Department of Biotechnology and Life Sciences, University of Insubria, Via J.H. Dunant 3, 21100, Varese, Italy
| | - Victor Fedorenko
- Department of Genetics and Biotechnology, Ivan Franko National University of Lviv, 4 Hrushevskoho st., Lviv, 79005, Ukraine.
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18
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Enzyme-Ligand Interaction Monitored by Synchrotron Radiation Circular Dichroism. Methods Mol Biol 2019. [PMID: 31773649 DOI: 10.1007/978-1-0716-0163-1_6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
Abstract
CD spectroscopy is the essential tool to quickly ascertain in the far-UV region the global conformational changes, the secondary structure content, and protein folding and in the near-UV region the local tertiary structure changes probed by the local environment of the aromatic side chains, prosthetic groups (hemes, flavones, carotenoids), the dihedral angle of disulfide bonds, and the ligand chromophore moieties, the latter occurring as a result of protein-ligand binding interaction. Qualitative and quantitative investigations into ligand-binding interactions in both the far- and near-UV regions using CD spectroscopy provide unique and direct information whether induced conformational changes upon ligand binding occur and of what nature that are unattainable with other techniques such as fluorescence, ITC, SPR, and AUC.This chapter provides an overview of how to perform circular dichroism (CD) experiments, detailing methods, hints and tips for successful CD measurements. Descriptions of different experimental designs are discussed using CD to investigate ligand-binding interactions. This includes standard qualitative CD measurements conducted in both single-measurement mode and high-throughput 96-well plate mode, CD titrations, and UV protein denaturation assays with and without ligand.The highly collimated micro-beam available at B23 beamline for synchrotron radiation circular dichroism (SRCD) at Diamond Light Source (DLS) offers many advantages to benchtop instruments. The synchrotron light source is ten times brighter than a standard xenon arc light source of benchtop instruments. The small diameter of the synchrotron beam can be up to 160 times smaller than that of benchtop light beams; this has enabled the use of small aperture cuvette cells and flat capillary tubes reducing substantially the amount of volume sample to be investigated. Methods, hints and tips, and golden rules to measure good quality, artifact-free SRCD and CD data will be described in this chapter in particular for the study of protein-ligand interactions and protein photostability.
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19
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Shee PK, Ratnayake ND, Walter T, Goethe O, Onyeozili EN, Walker KD. Exploring the Scope of an α/β-Aminomutase for the Amination of Cinnamate Epoxides to Arylserines and Arylisoserines. ACS Catal 2019. [DOI: 10.1021/acscatal.9b01557] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Affiliation(s)
| | | | | | | | - Edith Ndubuaku Onyeozili
- Department of Chemistry, Florida Agricultural & Mechanical University, Tallahassee, Florida 32307, United States
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20
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Abstract
The study of the genetics of enterococci has focused heavily on mobile genetic elements present in these organisms, the complex regulatory circuits used to control their mobility, and the antibiotic resistance genes they frequently carry. Recently, more focus has been placed on the regulation of genes involved in the virulence of the opportunistic pathogenic species Enterococcus faecalis and Enterococcus faecium. Little information is available concerning fundamental aspects of DNA replication, partition, and division; this article begins with a brief overview of what little is known about these issues, primarily by comparison with better-studied model organisms. A variety of transcriptional and posttranscriptional mechanisms of regulation of gene expression are then discussed, including a section on the genetics and regulation of vancomycin resistance in enterococci. The article then provides extensive coverage of the pheromone-responsive conjugation plasmids, including sections on regulation of the pheromone response, the conjugative apparatus, and replication and stable inheritance. The article then focuses on conjugative transposons, now referred to as integrated, conjugative elements, or ICEs, and concludes with several smaller sections covering emerging areas of interest concerning the enterococcal mobilome, including nonpheromone plasmids of particular interest, toxin-antitoxin systems, pathogenicity islands, bacteriophages, and genome defense.
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21
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Upton EC, Maciunas LJ, Loll PJ. Vancomycin does not affect the enzymatic activities of purified VanSA. PLoS One 2019; 14:e0210627. [PMID: 30677074 PMCID: PMC6345502 DOI: 10.1371/journal.pone.0210627] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2018] [Accepted: 12/29/2018] [Indexed: 11/18/2022] Open
Abstract
VanS is a membrane-bound sensor histidine kinase responsible for sensing vancomycin and activating transcription of vancomycin-resistance genes. In the presence of vancomycin, VanS phosphorylates the transcription factor VanR, converting it to its transcriptionally active form. In the absence of vancomycin, VanS dephosphorylates VanR, thereby maintaining it in a transcriptionally inactive state. To date, the mechanistic details of how vancomycin modulates VanS activity have remained elusive. We have therefore studied these details in an in vitro system, using the full-length VanS and VanR proteins responsible for type-A vancomycin resistance in enterococci. Both detergent- and amphipol-solubilized VanSA display all the enzymatic activities expected for a sensor histidine kinase, with amphipol reconstitution providing a marked boost in overall activity relative to detergent solubilization. A putative constitutively activated VanSA mutant (T168K) was constructed and purified, and was found to exhibit the expected reduction in phosphatase activity, providing confidence that detergent-solubilized VanSA behaves in a physiologically relevant manner. In both detergent and amphipol solutions, VanSA’s enzymatic activities were found to be insensitive to vancomycin, even at levels many times higher than the antibiotic’s minimum inhibitory concentration. This result argues against direct activation of VanSA via formation of a binary antibiotic-kinase complex, suggesting instead that either additional factors are required to form a functional signaling complex, or that activation does not require direct interaction with the antibiotic.
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Affiliation(s)
- Elizabeth C. Upton
- Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, Philadelphia, Pennsylvania, United States of America
| | - Lina J. Maciunas
- Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, Philadelphia, Pennsylvania, United States of America
| | - Patrick J. Loll
- Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, Philadelphia, Pennsylvania, United States of America
- * E-mail:
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22
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Siligardi G, Hughes CS, Hussain R. Characterisation of sensor kinase by CD spectroscopy: golden rules and tips. Biochem Soc Trans 2018; 46:1627-1642. [PMID: 30514767 PMCID: PMC6299240 DOI: 10.1042/bst20180222] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2018] [Revised: 09/19/2018] [Accepted: 09/21/2018] [Indexed: 01/22/2023]
Abstract
This is a review that describes the golden rules and tips on how to characterise the molecular interactions of membrane sensor kinase proteins with ligands using mainly circular dichroism (CD) spectroscopy. CD spectroscopy is essential for this task as any conformational change observed in the far-UV (secondary structures (α-helix, β-strands, poly-proline of type II, β-turns, irregular and folding) and near-UV regions [local environment of the aromatic side-chains of amino acid residues (Phe, Tyr and Trp) and ligands (drugs) and prosthetic groups (porphyrins, cofactors and coenzymes (FMN, FAD, NAD))] upon ligand addition to the protein can be used to determine qualitatively and quantitatively ligand-binding interactions. Advantages of using CD versus other techniques will be discussed. The difference CD spectra of the protein-ligand mixtures calculated subtracting the spectra of the ligand at various molar ratios can be used to determine the type of conformational changes induced by the ligand in terms of the estimated content of the various elements of protein secondary structure. The highly collimated microbeam and high photon flux of Diamond Light Source B23 beamline for synchrotron radiation circular dichroism (SRCD) enable the use of minimal amount of membrane proteins (7.5 µg for a 0.5 mg/ml solution) for high-throughput screening. Several examples of CD titrations of membrane proteins with a variety of ligands are described herein including the protocol tips that would guide the choice of the appropriate parameters to conduct these titrations by CD/SRCD in the best possible way.
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Affiliation(s)
- Giuliano Siligardi
- Diamond Light Source Ltd, Harwell Science and Innovation Campus, Didcot, Oxfordshire, U.K
| | - Charlotte S Hughes
- Diamond Light Source Ltd, Harwell Science and Innovation Campus, Didcot, Oxfordshire, U.K
| | - Rohanah Hussain
- Diamond Light Source Ltd, Harwell Science and Innovation Campus, Didcot, Oxfordshire, U.K.
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Trichlorination of a Teicoplanin-Type Glycopeptide Antibiotic by the Halogenase StaI Evades Resistance. Antimicrob Agents Chemother 2018; 62:AAC.01540-18. [PMID: 30275088 DOI: 10.1128/aac.01540-18] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2018] [Accepted: 09/22/2018] [Indexed: 01/31/2023] Open
Abstract
Glycopeptide antibiotics (GPAs) include clinically important drugs used for the treatment of infections caused by Gram-positive pathogens. These antibiotics are specialized metabolites produced by several genera of actinomycete bacteria. While many GPAs are highly chemically modified, A47934 is a relatively unadorned GPA lacking sugar or acyl modifications, common to other members of the class, but which is chlorinated at three distinct sites. The biosynthesis of A47934 is encoded by a 68-kb gene cluster in Streptomyces toyocaensis NRRL 15009. The cluster includes all necessary genes for the synthesis of A47934, including two predicted halogenase genes, staI and staK In this study, we report that only one of the halogenase genes, staI, is necessary and essential for A47934 biosynthesis. Chlorination of the A47934 scaffold is important for antibiotic activity, as assessed by binding affinity for the target N-acyl-d-Ala-d-Ala. Surprisingly, chlorination is also vital to avoid activation of enterococcal and Streptomyces VanB-type GPA resistance through induction of resistance genes. Phenotypic assays showed stronger induction of GPA resistance by the dechlorinated compared to the chlorinated GPA. Correspondingly, the relative expression of the enterococcal vanA resistance gene was shown to be increased by the dechlorinated compared to the chlorinated compound. These results provide insight into the biosynthesis of GPAs and the biological function of GPA chlorination for this medically important class of antibiotic.
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24
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Production of membrane proteins for characterisation of their pheromone-sensing and antimicrobial resistance functions. EUROPEAN BIOPHYSICS JOURNAL: EBJ 2018; 47:723-737. [PMID: 30066130 PMCID: PMC6182600 DOI: 10.1007/s00249-018-1325-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Revised: 06/08/2018] [Accepted: 07/21/2018] [Indexed: 12/15/2022]
Abstract
Despite the importance of membrane proteins in cellular processes, studies of these hydrophobic proteins present major technical challenges, including expression and purification for structural and biophysical studies. A modified strategy of that proposed previously by Saidijam et al. (2005) and others, for the routine expression of bacterial membrane proteins involved in environmental sensing and antimicrobial resistance (AMR), is proposed which results in purification of sufficient proteins for biophysical experiments. We report expression successes amongst a collection of enterococcal vancomycin resistance membrane proteins: VanTG, VanTG-M transporter domain, VanZ and the previously characterised VanS (A-type) histidine protein kinase (HPK). Using the same strategy, we report on the successful amplification and purification of intact BlpH and ComD2 HPKs of Streptococcus pneumoniae. Near-UV circular dichroism revealed both recombinant proteins bound their pheromone ligands BlpC and CSP2. Interestingly, CSP1 also interacted with ComD. Finally, we evaluate the alternative strategy for studying sensory HPKs involving isolated soluble sensory domain fragments, exemplified by successful production of VicKESD of Enterococcus faecalis VicK. Purified VicKESD possessed secondary structure post-purification. Thermal denaturation experiments using far-UV CD, a technique which can be revealing regarding ligand binding, revealed that: (a) VicKESD denaturation occurs between 15 and 50 °C; and (b) reducing conditions did not detectably affect denaturation profiles suggesting reducing conditions per se are not directly sensed by VicKESD. Our findings provide information on a modified strategy for the successful expression, production and/or storage of bacterial membrane HPKs, AMR proteins and sensory domains for their future crystallisation, and ligand binding studies.
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25
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Phillips-Jones MK, Harding SE. Antimicrobial resistance (AMR) nanomachines-mechanisms for fluoroquinolone and glycopeptide recognition, efflux and/or deactivation. Biophys Rev 2018; 10:347-362. [PMID: 29525835 PMCID: PMC5899746 DOI: 10.1007/s12551-018-0404-9] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2017] [Accepted: 02/05/2018] [Indexed: 12/11/2022] Open
Abstract
In this review, we discuss mechanisms of resistance identified in bacterial agents Staphylococcus aureus and the enterococci towards two priority classes of antibiotics-the fluoroquinolones and the glycopeptides. Members of both classes interact with a number of components in the cells of these bacteria, so the cellular targets are also considered. Fluoroquinolone resistance mechanisms include efflux pumps (MepA, NorA, NorB, NorC, MdeA, LmrS or SdrM in S. aureus and EfmA or EfrAB in the enterococci) for removal of fluoroquinolone from the intracellular environment of bacterial cells and/or protection of the gyrase and topoisomerase IV target sites in Enterococcus faecalis by Qnr-like proteins. Expression of efflux systems is regulated by GntR-like (S. aureus NorG), MarR-like (MgrA, MepR) regulators or a two-component signal transduction system (TCS) (S. aureus ArlSR). Resistance to the glycopeptide antibiotic teicoplanin occurs via efflux regulated by the TcaR regulator in S. aureus. Resistance to vancomycin occurs through modification of the D-Ala-D-Ala target in the cell wall peptidoglycan and removal of high affinity precursors, or by target protection via cell wall thickening. Of the six Van resistance types (VanA-E, VanG), the VanA resistance type is considered in this review, including its regulation by the VanSR TCS. We describe the recent application of biophysical approaches such as the hydrodynamic technique of analytical ultracentrifugation and circular dichroism spectroscopy to identify the possible molecular effector of the VanS receptor that activates expression of the Van resistance genes; both approaches demonstrated that vancomycin interacts with VanS, suggesting that vancomycin itself (or vancomycin with an accessory factor) may be an effector of vancomycin resistance. With 16 and 19 proteins or protein complexes involved in fluoroquinolone and glycopeptide resistances, respectively, and the complexities of bacterial sensing mechanisms that trigger and regulate a wide variety of possible resistance mechanisms, we propose that these antimicrobial resistance mechanisms might be considered complex 'nanomachines' that drive survival of bacterial cells in antibiotic environments.
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Affiliation(s)
- Mary K Phillips-Jones
- National Centre for Macromolecular Hydrodynamics, School of Biosciences, University of Nottingham, Sutton Bonington, LE12 5RD, Loughborough, Leicestershire, UK.
| | - Stephen E Harding
- National Centre for Macromolecular Hydrodynamics, School of Biosciences, University of Nottingham, Sutton Bonington, LE12 5RD, Loughborough, Leicestershire, UK
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26
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Kumar V, Sharma A, Pratap S, Kumar P. Characterization of isoflavonoids as inhibitors of β-hydroxyacyl-acyl carrier protein dehydratase (FabZ) from Moraxella catarrhalis: Kinetics, spectroscopic, thermodynamics and in silico studies. Biochim Biophys Acta Gen Subj 2017; 1862:726-744. [PMID: 29092780 DOI: 10.1016/j.bbagen.2017.10.017] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2017] [Revised: 10/14/2017] [Accepted: 10/26/2017] [Indexed: 01/02/2023]
Abstract
BACKGROUD β-hydroxyacyl-acyl carrier protein dehydratase (FabZ) is an essential component of type II fatty acid biosynthesis (FAS II) pathway in bacteria. It performs dehydration of β-hydroxyacyl-ACP to trans-2-acyl-ACP in the elongation cycle of the FAS II pathway. FabZ is ubiquitously expressed and has uniform distribution, which makes FabZ an excellent target for developing novel drugs against pathogenic bacteria. METHODS We focused on the biochemical and biophysical characterization of FabZ from drug-resistant pathogen Moraxella catarrhalis (McFabZ). More importantly, we have identified and characterized new inhibitors against McFabZ using biochemical, biophysical and in silico based studies. RESULTS We have identified three isoflavones (daidzein, biochanin A and genistein) as novel inhibitors against McFabZ. Mode of inhibition of these compounds is competitive with IC50 values lie in the range of 6.85μΜ to 27.7μΜ. Conformational changes observed in secondary and tertiary structure marked by a decrease in the helical and the sheet content in McFabZ structure upon inhibitors binding. In addition, thermodynamic data suggest that biochanin A has a strong binding affinity for McFabZ as compare to daidzein and genistein. Molecular docking studies have revealed that these inhibitors are interacting with the active site of McFabZ and making contacts with catalytic and substrate binding tunnel residues. CONCLUSION AND GENERAL SIGNIFICANCE Three new inhibitors against McFabZ have been identified and characterized. These biochemical and biophysical findings lead to the identification of chemical scaffolds, which can lead to broad-spectrum antimicrobial drugs targeted against FabZ, and modification to existing FabZ inhibitors to improve affinity and potency.
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Affiliation(s)
- Vijay Kumar
- Department of Biotechnology, Indian Institute of Technology Roorkee, 247667, India
| | - Anchal Sharma
- Department of Biotechnology, Indian Institute of Technology Roorkee, 247667, India
| | - Shivendra Pratap
- Department of Biotechnology, Indian Institute of Technology Roorkee, 247667, India
| | - Pravindra Kumar
- Department of Biotechnology, Indian Institute of Technology Roorkee, 247667, India.
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27
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Phillips-Jones MK, Lithgo R, Dinu V, Gillis RB, Harding JE, Adams GG, Harding SE. Full hydrodynamic reversibility of the weak dimerization of vancomycin and elucidation of its interaction with VanS monomers at clinical concentration. Sci Rep 2017; 7:12697. [PMID: 28983082 PMCID: PMC5629194 DOI: 10.1038/s41598-017-12620-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2017] [Accepted: 08/29/2017] [Indexed: 12/16/2022] Open
Abstract
The reversibility and strength of the previously established dimerization of the important glycopeptide antibiotic vancomycin in four different aqueous solvents (including a medically-used formulation) have been studied using short-column sedimentation equilibrium in the analytical ultracentrifuge and model-independent SEDFIT-MSTAR analysis across a range of loading concentrations. The change in the weight average molar mass M w with loading concentration was consistent with a monomer-dimer equilibrium. Overlap of data sets of point weight average molar masses M w(r) versus local concentration c(r) for different loading concentrations demonstrated a completely reversible equilibrium process. At the clinical infusion concentration of 5 mg.mL-1 all glycopeptide is dimerized whilst at 19 µg.mL-1 (a clinical target trough serum concentration), vancomycin was mainly monomeric (<20% dimerized). Analysis of the variation of M w with loading concentration revealed dissociation constants in the range 25-75 μM, commensurate with a relatively weak association. The effect of two-fold vancomycin (19 µg.mL-1) appears to have no effect on the monomeric enterococcal VanS kinase involved in glycopeptide resistance regulation. Therefore, the 30% increase in sedimentation coefficient of VanS on adding vancomycin observed previously is more likely to be due to a ligand-induced conformational change of VanS to a more compact form rather than a ligand-induced dimerization.
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Affiliation(s)
- Mary K Phillips-Jones
- AMR Biophysics Group, School of Pharmacy & Biomedical Sciences, University of Central Lancashire, Preston, PR1 2HE, United Kingdom.
| | - Ryan Lithgo
- National Centre for Macromolecular Hydrodynamics, School of Biosciences, University of Nottingham, Sutton Bonington, LE12 5RD, United Kingdom
| | - Vlad Dinu
- National Centre for Macromolecular Hydrodynamics, School of Biosciences, University of Nottingham, Sutton Bonington, LE12 5RD, United Kingdom
| | - Richard B Gillis
- National Centre for Macromolecular Hydrodynamics, School of Biosciences, University of Nottingham, Sutton Bonington, LE12 5RD, United Kingdom
- School of Health Sciences, University of Nottingham, Nottingham, NG7 2HA, United Kingdom
| | - John E Harding
- Department of Architecture and the Built Environment, The University of the West of England, Bristol, BS16 1QY, United Kingdom
| | - Gary G Adams
- National Centre for Macromolecular Hydrodynamics, School of Biosciences, University of Nottingham, Sutton Bonington, LE12 5RD, United Kingdom
- School of Health Sciences, University of Nottingham, Nottingham, NG7 2HA, United Kingdom
| | - Stephen E Harding
- National Centre for Macromolecular Hydrodynamics, School of Biosciences, University of Nottingham, Sutton Bonington, LE12 5RD, United Kingdom.
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Abdel Monaim SAH, Jad YE, El-Faham A, de la Torre BG, Albericio F. Teixobactin as a scaffold for unlimited new antimicrobial peptides: SAR study. Bioorg Med Chem 2017; 26:2788-2796. [PMID: 29029900 DOI: 10.1016/j.bmc.2017.09.040] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2017] [Revised: 09/22/2017] [Accepted: 09/29/2017] [Indexed: 11/26/2022]
Abstract
It looks that a new era of antimicrobial peptides (AMPs) started with the discovery of teixobactin, which is a "head to side-chain" cyclodepsipeptide. It was isolated from a soil gram-negative b-proteobacteria by means of a revolutionary technique. Since there, several groups have developed synthetic strategies for efficient synthesis of this peptide and its analogues as well. Herein, all chemistries reported as well as the biological activity of the analogues are analyzed. Finally, some inputs regarding new trends for the next generation of analogues are discussed.
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Affiliation(s)
- Shimaa A H Abdel Monaim
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban 4001, South Africa
| | - Yahya E Jad
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban 4001, South Africa
| | - Ayman El-Faham
- Department of Chemistry, College of Science, King Saud University, P.O. Box 2455, Riyadh 11451, Saudi Arabia; Chemistry Department, Faculty of Science, Alexandria University, P.O. Box 426, Ibrahimia, Alexandria 12321, Egypt
| | - Beatriz G de la Torre
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban 4001, South Africa; KRISP, College of Health Sciences, University of KwaZulu-Natal, Durban 4001, South Africa.
| | - Fernando Albericio
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban 4001, South Africa; Department of Chemistry, College of Science, King Saud University, P.O. Box 2455, Riyadh 11451, Saudi Arabia; School of Chemistry and Physics, University of KwaZulu-Natal, Durban 4001, South Africa; Department of Organic Chemistry, University of Barcelona, Barcelona 08028, Spain; CIBER-BBN, Networking Centre on Bioengineering, Biomaterials and Nanomedicine, Barcelona Science Park, Barcelona 08028, Spain.
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29
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Quality control and biophysical characterisation data of VanSA. Data Brief 2017; 14:41-47. [PMID: 28765830 PMCID: PMC5526436 DOI: 10.1016/j.dib.2017.07.012] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2017] [Revised: 06/13/2017] [Accepted: 07/10/2017] [Indexed: 11/21/2022] Open
Abstract
This data article presents the results from quality control experiments including N-terminal sequencing, SEC-MALS and Mass Spectrometry for purified VanSA used in experiments described in (Hughes et al., 2017) [1]; in addition to ligand interaction measurements and thermal melting curves of VanSA in the presence of screened ligands from circular dichroism measurements as well as UV–vis absorbance spectra for the binding interaction of VanSA in the presence of screened ligands.
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