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Nguyen A, Roy JJS, Kim JH, Yun KH, Lee W, Kim KK, Kim T, Chaurasia AK. Repeated Exposure of Vancomycin to Vancomycin-Susceptible Staphylococcus aureus (VSSA) Parent Emerged VISA and VRSA Strains with Enhanced Virulence Potentials. J Microbiol 2024:10.1007/s12275-024-00139-8. [PMID: 38814539 DOI: 10.1007/s12275-024-00139-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2023] [Revised: 04/18/2024] [Accepted: 04/21/2024] [Indexed: 05/31/2024]
Abstract
The emergence of resistance against the last-resort antibiotic vancomycin in staphylococcal infections is a serious concern for human health. Although various drug-resistant pathogens of diverse genetic backgrounds show higher virulence potential, the underlying mechanism behind this is not yet clear due to variability in their genetic dispositions. In this study, we investigated the correlation between resistance and virulence in adaptively evolved isogenic strains. The vancomycin-susceptible Staphylococcus aureus USA300 was exposed to various concentrations of vancomycin repeatedly as a mimic of the clinical regimen to obtain mutation(s)-accrued-clonally-selected (MACS) strains. The phenotypic analyses followed by expression of the representative genes responsible for virulence and resistance of MACS strains were investigated. MACS strains obtained under 2 and 8 µg/ml vancomycin, named Van2 and Van8, respectively; showed enhanced vancomycin minimal inhibitory concentrations (MIC) to 4 and 16 µg/ml, respectively. The cell adhesion and invasion of MACS strains increased in proportion to their MICs. The correlation between resistance and virulence potential was partially explained by the differential expression of genes known to be involved in both virulence and resistance in MACS strains compared to parent S. aureus USA300. Repeated treatment of vancomycin against vancomycin-susceptible S. aureus (VSSA) leads to the emergence of vancomycin-resistant strains with variable levels of enhanced virulence potentials.
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Affiliation(s)
- An Nguyen
- Department of Precision Medicine, Graduate School of Basic Medical Science (GSBMS), Institute for Antimicrobial Resistance Research and Therapeutics, Sungkyunkwan University School of Medicine, Suwon, 16419, Republic of Korea
- Department of Biophysics, Sungkyunkwan University, Suwon, 16419, Republic of Korea
| | - J Jean Sophy Roy
- Department of Precision Medicine, Graduate School of Basic Medical Science (GSBMS), Institute for Antimicrobial Resistance Research and Therapeutics, Sungkyunkwan University School of Medicine, Suwon, 16419, Republic of Korea
| | - Ji-Hoon Kim
- School of Pharmacy, Sungkyunkwan University, Suwon, 16419, Republic of Korea
| | - Kyung-Hee Yun
- Department of Precision Medicine, Graduate School of Basic Medical Science (GSBMS), Institute for Antimicrobial Resistance Research and Therapeutics, Sungkyunkwan University School of Medicine, Suwon, 16419, Republic of Korea
| | - Wonsik Lee
- School of Pharmacy, Sungkyunkwan University, Suwon, 16419, Republic of Korea
| | - Kyeong Kyu Kim
- Department of Precision Medicine, Graduate School of Basic Medical Science (GSBMS), Institute for Antimicrobial Resistance Research and Therapeutics, Sungkyunkwan University School of Medicine, Suwon, 16419, Republic of Korea.
- Department of Biophysics, Sungkyunkwan University, Suwon, 16419, Republic of Korea.
| | - Truc Kim
- Department of Precision Medicine, Graduate School of Basic Medical Science (GSBMS), Institute for Antimicrobial Resistance Research and Therapeutics, Sungkyunkwan University School of Medicine, Suwon, 16419, Republic of Korea.
| | - Akhilesh Kumar Chaurasia
- Department of Precision Medicine, Graduate School of Basic Medical Science (GSBMS), Institute for Antimicrobial Resistance Research and Therapeutics, Sungkyunkwan University School of Medicine, Suwon, 16419, Republic of Korea.
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2
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Cao H, Zhang G, Ma H, Xue Z, Huo R, Wang K, Liu Z. Sensitive and Extraction-Free Detection of Methicillin-Resistant Staphylococcus aureus through Ag + Aptamer-Based Color Reaction. J Microbiol Biotechnol 2024; 34:192-197. [PMID: 37957116 PMCID: PMC10840478 DOI: 10.4014/jmb.2308.08044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2023] [Revised: 09/11/2023] [Accepted: 09/14/2023] [Indexed: 11/15/2023]
Abstract
Refractory infections, such as hospital-acquired pneumonia, can be better diagnosed with the assistance of precise methicillin-resistant Staphylococcus aureus (MRSA) testing. However, traditional methods necessitate high-tech tools, rigorous temperature cycling, and the extraction of genetic material from MRSA cells. Herein, we propose a sensitive, specific, and extraction-free strategy for MRSA detection by integrating allosteric probe-based target recognition and exonuclease-III (Exo-III)-enhanced color reaction. The penicillin-binding protein 2a (PBP2a) aptamer in the allosteric probe binds with MRSA to convert protein signals to nucleic acid signals. This is followed by the DNA polymerase-assisted target recycle and the production of numerous single-strand DNA (ssDNA) chains which bind with silver ion (Ag+) aptamer to form a blunt terminus that can be identified by Exo-III. As a result, the Ag+ aptamer pre-coupled to magnetic nanoparticles is digested. After magnetic separation, the Ag+ in liquid supernatant catalyzes 3,3',5,5'-tetramethylbenzidine (TMB) for a color reaction. In addition, a concentration of 54 cfu/mL is predicted to be the lowest detectable value. Based on this, our assay has a wide linear detection range, covering 5 orders of magnitude and demonstrating a high specificity, which allows it to accurately distinguish the target MRSA from other microorganisms.
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Affiliation(s)
- Hongli Cao
- Emergency Department, Beijing Rehabilitation Hospital, Capital Medical University, Beijing 100144, P.R. China
| | - Guosheng Zhang
- Emergency Department, Beijing Rehabilitation Hospital, Capital Medical University, Beijing 100144, P.R. China
| | - Hui Ma
- Emergency Department, Beijing Rehabilitation Hospital, Capital Medical University, Beijing 100144, P.R. China
| | - Zhongwen Xue
- Emergency Department, Beijing Rehabilitation Hospital, Capital Medical University, Beijing 100144, P.R. China
| | - Ran Huo
- Emergency Department, Beijing Rehabilitation Hospital, Capital Medical University, Beijing 100144, P.R. China
| | - Kun Wang
- Emergency Department, Beijing Rehabilitation Hospital, Capital Medical University, Beijing 100144, P.R. China
| | - Zijin Liu
- Orthopedic Rehabilitation Department, Beijing Rehabilitation Hospital, Capital Medical University, Beijing 100144, P.R. China
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3
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Jacobs LMC, Consol P, Chen Y. Drug Discovery in the Field of β-Lactams: An Academic Perspective. Antibiotics (Basel) 2024; 13:59. [PMID: 38247618 PMCID: PMC10812508 DOI: 10.3390/antibiotics13010059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2023] [Revised: 12/21/2023] [Accepted: 12/23/2023] [Indexed: 01/23/2024] Open
Abstract
β-Lactams are the most widely prescribed class of antibiotics that inhibit penicillin-binding proteins (PBPs), particularly transpeptidases that function in peptidoglycan synthesis. A major mechanism of antibiotic resistance is the production of β-lactamase enzymes, which are capable of hydrolyzing β-lactam antibiotics. There have been many efforts to counter increasing bacterial resistance against β-lactams. These studies have mainly focused on three areas: discovering novel inhibitors against β-lactamases, developing new β-lactams less susceptible to existing resistance mechanisms, and identifying non-β-lactam inhibitors against cell wall transpeptidases. Drug discovery in the β-lactam field has afforded a range of research opportunities for academia. In this review, we summarize the recent new findings on both β-lactamases and cell wall transpeptidases because these two groups of enzymes are evolutionarily and functionally connected. Many efforts to develop new β-lactams have aimed to inhibit both transpeptidases and β-lactamases, while several promising novel β-lactamase inhibitors have shown the potential to be further developed into transpeptidase inhibitors. In addition, the drug discovery progress against each group of enzymes is presented in three aspects: understanding the targets, screening methodology, and new inhibitor chemotypes. This is to offer insights into not only the advancement in this field but also the challenges, opportunities, and resources for future research. In particular, cyclic boronate compounds are now capable of inhibiting all classes of β-lactamases, while the diazabicyclooctane (DBO) series of small molecules has led to not only new β-lactamase inhibitors but potentially a new class of antibiotics by directly targeting PBPs. With the cautiously optimistic successes of a number of new β-lactamase inhibitor chemotypes and many questions remaining to be answered about the structure and function of cell wall transpeptidases, non-β-lactam transpeptidase inhibitors may usher in the next exciting phase of drug discovery in this field.
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Affiliation(s)
| | | | - Yu Chen
- Department of Molecular Medicine, Morsani College of Medicine, University of South Florida, Tampa, FL 33612, USA; (L.M.C.J.); (P.C.)
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Huang LD, Gou XY, Yang MJ, Li MJ, Chen SN, Yan J, Liu XX, Sun AH. Peptidoglycan biosynthesis-associated enzymatic kinetic characteristics and β-lactam antibiotic inhibitory effects of different Streptococcus pneumoniae penicillin-binding proteins. Int J Biol Macromol 2024; 254:127784. [PMID: 37949278 DOI: 10.1016/j.ijbiomac.2023.127784] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2023] [Revised: 09/15/2023] [Accepted: 10/28/2023] [Indexed: 11/12/2023]
Abstract
Penicillin-binding proteins (PBPs) include transpeptidases, carboxypeptidases, and endopeptidases for biosynthesis of peptidoglycans in the cell wall to maintain bacterial morphology and survival in the environment. Streptococcus pneumoniae expresses six PBPs, but their enzymatic kinetic characteristics and inhibitory effects on different β-lactam antibiotics remain poorly understood. In this study, all the six recombinant PBPs of S. pneumoniae displayed transpeptidase activity with different substrate affinities (Km = 1.56-9.11 mM) in a concentration-dependent manner, and rPBP3 showed a greater catalytic efficiency (Kcat = 2.38 s-1) than the other rPBPs (Kcat = 3.20-7.49 × 10-2 s-1). However, only rPBP3 was identified as a carboxypeptidase (Km = 8.57 mM and Kcat = 2.57 s-1). None of the rPBPs exhibited endopeptidase activity. Penicillin and cefotaxime inhibited the transpeptidase and carboxypeptidase activity of all the rPBPs but imipenem did not inhibited the enzymatic activities of rPBP3. Except for the lack of binding of imipenem to rPBP3, penicillin, cefotaxime, and imipenem bound to all the other rPBPs (KD = 3.71-9.35 × 10-4 M). Sublethal concentrations of penicillin, cefotaxime, and imipenem induced a decrease of pneumococcal pbps-mRNA levels (p < 0.05). These results indicated that all six PBPs of S. pneumoniae are transpeptidases, while only PBP3 is a carboxypeptidase. Imipenem has no inhibitory effect on pneumococcal PBP3. The pneumococcal genes for encoding endopeptidases remain to be determined.
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Affiliation(s)
- Li-Dan Huang
- School of Basic Medical Sciences and Forensic Medicine, Hangzhou Medical College, Hangzhou, Zhejiang 310053, PR China; Yiwu Central Blood Station, Yiwu, Zhejiang 322000, PR China
| | - Xiao-Yu Gou
- School of Basic Medical Sciences and Forensic Medicine, Hangzhou Medical College, Hangzhou, Zhejiang 310053, PR China
| | - Mei-Juan Yang
- School of Basic Medical Sciences and Forensic Medicine, Hangzhou Medical College, Hangzhou, Zhejiang 310053, PR China; The First Hospital of Putian City, Putian, Fujian 351100, PR China
| | - Meng-Jie Li
- School of Basic Medical Sciences and Forensic Medicine, Hangzhou Medical College, Hangzhou, Zhejiang 310053, PR China
| | - Sui-Ning Chen
- School of Basic Medical Sciences and Forensic Medicine, Hangzhou Medical College, Hangzhou, Zhejiang 310053, PR China
| | - Jie Yan
- Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, PR China
| | - Xiao-Xiang Liu
- School of Basic Medical Sciences and Forensic Medicine, Hangzhou Medical College, Hangzhou, Zhejiang 310053, PR China.
| | - Ai-Hua Sun
- School of Basic Medical Sciences and Forensic Medicine, Hangzhou Medical College, Hangzhou, Zhejiang 310053, PR China.
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Ambade SS, Gupta VK, Bhole RP, Khedekar PB, Chikhale RV. A Review on Five and Six-Membered Heterocyclic Compounds Targeting the Penicillin-Binding Protein 2 (PBP2A) of Methicillin-Resistant Staphylococcus aureus (MRSA). Molecules 2023; 28:7008. [PMID: 37894491 PMCID: PMC10609489 DOI: 10.3390/molecules28207008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2023] [Revised: 10/05/2023] [Accepted: 10/05/2023] [Indexed: 10/29/2023] Open
Abstract
Staphylococcus aureus is a common human pathogen. Methicillin-resistant Staphylococcus aureus (MRSA) infections pose significant and challenging therapeutic difficulties. MRSA often acquires the non-native gene PBP2a, which results in reduced susceptibility to β-lactam antibiotics, thus conferring resistance. PBP2a has a lower affinity for methicillin, allowing bacteria to maintain peptidoglycan biosynthesis, a core component of the bacterial cell wall. Consequently, even in the presence of methicillin or other antibiotics, bacteria can develop resistance. Due to genes responsible for resistance, S. aureus becomes MRSA. The fundamental premise of this resistance mechanism is well-understood. Given the therapeutic concerns posed by resistant microorganisms, there is a legitimate demand for novel antibiotics. This review primarily focuses on PBP2a scaffolds and the various screening approaches used to identify PBP2a inhibitors. The following classes of compounds and their biological activities are discussed: Penicillin, Cephalosporins, Pyrazole-Benzimidazole-based derivatives, Oxadiazole-containing derivatives, non-β-lactam allosteric inhibitors, 4-(3H)-Quinazolinones, Pyrrolylated chalcone, Bis-2-Oxoazetidinyl macrocycles (β-lactam antibiotics with 1,3-Bridges), Macrocycle-embedded β-lactams as novel inhibitors, Pyridine-Coupled Pyrimidinones, novel Naphthalimide corbelled aminothiazoximes, non-covalent inhibitors, Investigational-β-lactam antibiotics, Carbapenem, novel Benzoxazole derivatives, Pyrazolylpyridine analogues, and other miscellaneous classes of scaffolds for PBP2a. Additionally, we discuss the penicillin-binding protein, a crucial target in the MRSA cell wall. Various aspects of PBP2a, bacterial cell walls, peptidoglycans, different crystal structures of PBP2a, synthetic routes for PBP2a inhibitors, and future perspectives on MRSA inhibitors are also explored.
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Affiliation(s)
- Shraddha S. Ambade
- Department of Pharmaceutical Sciences, Rashtrasant Tukadoji Maharaj Nagpur University, Nagpur 440033, MH, India (P.B.K.)
| | - Vivek Kumar Gupta
- Department of Biochemistry, National JALMA Institute for Leprosy & Other Mycobacterial Diseases (ICMR), Agra 282004, UP, India
| | - Ritesh P. Bhole
- Dr. D. Y. Patil Institute of Pharmaceutical Sciences and Research, Pimpri, Pune 411018, MH, India
- Dr. D. Y. Patil Dental College and Hospital, Dr. D. Y. Patil Vidyapeeth, Pimpri, Pune 411018, MH, India
| | - Pramod B. Khedekar
- Department of Pharmaceutical Sciences, Rashtrasant Tukadoji Maharaj Nagpur University, Nagpur 440033, MH, India (P.B.K.)
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Dai J, Battini N, Zang Z, Luo Y, Zhou C. Novel Thiazolylketenyl Quinazolinones as Potential Anti-MRSA Agents and Allosteric Modulator for PBP2a. Molecules 2023; 28:molecules28104240. [PMID: 37241983 DOI: 10.3390/molecules28104240] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Revised: 05/16/2023] [Accepted: 05/17/2023] [Indexed: 05/28/2023] Open
Abstract
Bacterial infections caused by methicillin-resistant Staphylococcus aureus have seriously threatened public health. There is an urgent need to propose an existing regimen to overcome multidrug resistance of MRSA. A unique class of novel anti-MRSA thiazolylketenyl quinazolinones (TQs) and their analogs were developed. Some synthesized compounds showed good bacteriostatic potency. Especially TQ 4 was found to exhibit excellent inhibition against MRSA with a low MIC of 0.5 μg/mL, which was 8-fold more effective than norfloxacin. The combination of TQ 4 with cefdinir showed stronger antibacterial potency. Further investigation revealed that TQ 4, with low hemolytic toxicity and low drug resistance, was not only able to inhibit biofilm formation but also could reduce MRSA metabolic activity and showed good drug-likeness. Mechanistic explorations revealed that TQ 4 could cause leakage of proteins by disrupting membrane integrity and block DNA replication by intercalated DNA. Furthermore, the synergistic antibacterial effect with cefdinir might be attributed to TQ 4 with the ability to induce PBP2a allosteric regulation of MRSA and further trigger the opening of the active site to promote the binding of cefdinir to the active site, thus inhibiting the expression of PBP2a, thereby overcoming MRSA resistance and significantly enhancing the anti-MRSA activity of cefdinir. A new strategy provided by these findings was that TQ 4, possessing both excellent anti-MRSA activity and allosteric effect of PBP2a, merited further development as a novel class of antibacterial agents to overcome increasingly severe MRSA infections.
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Affiliation(s)
- Jie Dai
- Institute of Bioorganic & Medicinal Chemistry, Key Laboratory of Applied Chemistry of Chongqing Municipality, School of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, China
| | - Narsaiah Battini
- Institute of Bioorganic & Medicinal Chemistry, Key Laboratory of Applied Chemistry of Chongqing Municipality, School of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, China
| | - Zhonglin Zang
- Institute of Bioorganic & Medicinal Chemistry, Key Laboratory of Applied Chemistry of Chongqing Municipality, School of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, China
| | - Yan Luo
- College of Pharmacy, National & Local Joint Engineering Research Center of Targeted and Innovative Therapeutics, Chongqing Key Laboratory of Kinase Modulators as Innovative Medicine, Chongqing University of Arts and Sciences, Chongqing 402160, China
| | - Chenghe Zhou
- Institute of Bioorganic & Medicinal Chemistry, Key Laboratory of Applied Chemistry of Chongqing Municipality, School of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, China
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Hu XL, Gan HQ, Qin ZY, Liu Q, Li M, Chen D, Sessler JL, Tian H, He XP. Phenotyping of Methicillin-Resistant Staphylococcus aureus Using a Ratiometric Sensor Array. J Am Chem Soc 2023; 145:8917-8926. [PMID: 37040584 DOI: 10.1021/jacs.2c12798] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/13/2023]
Abstract
Chemical tools capable of classifying multidrug-resistant bacteria (superbugs) can facilitate early-stage disease diagnosis and help guide precision therapy. Here, we report a sensor array that permits the facile phenotyping of methicillin-resistant Staphylococcus aureus (MRSA), a clinically common superbug. The array consists of a panel of eight separate ratiometric fluorescent probes that provide characteristic vibration-induced emission (VIE) profiles. These probes bear a pair of quaternary ammonium salts in different substitution positions around a known VIEgen core. The differences in the substituents result in varying interactions with the negatively charged cell walls of bacteria. This, in turn, dictates the molecular conformation of the probes and affects their blue-to-red fluorescence intensity ratios (ratiometric changes). Within the sensor array, the differences in the ratiometric changes for the probes result in "fingerprints" for MRSA of different genotypes. This allows them to be identified using principal component analysis (PCA) without the need for cell lysis and nucleic acid isolation. The results obtained with the present sensor array agree well with those obtained using polymerase chain reaction (PCR) analysis.
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Affiliation(s)
- Xi-Le Hu
- Key Laboratory for Advanced Materials and Joint International Research Laboratory of Precision Chemistry and Molecular Engineering, Feringa Nobel Prize Scientist Joint Research Center, Frontiers Center for Materiobiology and Dynamic Chemistry, School of Chemistry and Molecular Engineering, East China University of Science and Technology, 130 Meilong Rd, Shanghai 200237, China
| | - Hui-Qi Gan
- Key Laboratory for Advanced Materials and Joint International Research Laboratory of Precision Chemistry and Molecular Engineering, Feringa Nobel Prize Scientist Joint Research Center, Frontiers Center for Materiobiology and Dynamic Chemistry, School of Chemistry and Molecular Engineering, East China University of Science and Technology, 130 Meilong Rd, Shanghai 200237, China
| | - Zhao-Yang Qin
- Key Laboratory for Advanced Materials and Joint International Research Laboratory of Precision Chemistry and Molecular Engineering, Feringa Nobel Prize Scientist Joint Research Center, Frontiers Center for Materiobiology and Dynamic Chemistry, School of Chemistry and Molecular Engineering, East China University of Science and Technology, 130 Meilong Rd, Shanghai 200237, China
| | - Qian Liu
- Department of Laboratory Medicine, Ren Ji Hospital (Eastern), 160 Pujian Rd, Shanghai 200127, China
| | - Min Li
- Department of Laboratory Medicine, Ren Ji Hospital (Eastern), 160 Pujian Rd, Shanghai 200127, China
| | - Daijie Chen
- School of Pharmacy, Shanghai Jiao Tong University, 800 Dongchuan Rd, Minhang District, Shanghai 200240, China
| | - Jonathan L Sessler
- Department of Chemistry, The University of Texas at Austin, 105 East 24th Street-A5300, Austin, Texas 78712-1224, United States
| | - He Tian
- Key Laboratory for Advanced Materials and Joint International Research Laboratory of Precision Chemistry and Molecular Engineering, Feringa Nobel Prize Scientist Joint Research Center, Frontiers Center for Materiobiology and Dynamic Chemistry, School of Chemistry and Molecular Engineering, East China University of Science and Technology, 130 Meilong Rd, Shanghai 200237, China
| | - Xiao-Peng He
- Key Laboratory for Advanced Materials and Joint International Research Laboratory of Precision Chemistry and Molecular Engineering, Feringa Nobel Prize Scientist Joint Research Center, Frontiers Center for Materiobiology and Dynamic Chemistry, School of Chemistry and Molecular Engineering, East China University of Science and Technology, 130 Meilong Rd, Shanghai 200237, China
- The International Cooperation Laboratory on Signal Transduction, National Center for Liver Cancer, Eastern Hepatobiliary Surgery Hospital, Shanghai 200438, China
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Ma Q, Wang G, Li N, Wang X, Kang X, Mao Y, Wang G. Insights into the Effects and Mechanism of Andrographolide-Mediated Recovery of Susceptibility of Methicillin-Resistant Staphylococcus aureus to β-Lactam Antibiotics. Microbiol Spectr 2023; 11:e0297822. [PMID: 36602386 PMCID: PMC9927479 DOI: 10.1128/spectrum.02978-22] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2022] [Accepted: 12/13/2022] [Indexed: 01/06/2023] Open
Abstract
The frequent resistance associated with β-lactam antibiotics and the high frequency of mutations in β-lactamases constitute a major clinical challenge that can no longer be ignored. Andrographolide (AP), a natural active compound, has been shown to restore susceptibility to β-lactam antibiotics. Fluorescence quenching and molecular simulation showed that AP quenched the intrinsic fluorescence of β-lactamase BlaZ and stably bound to the residues in the catalytic cavity of BlaZ. Of note, AP was found to reduce the stability of the cell wall (CW) in methicillin-resistant Staphylococcus aureus (MRSA), and in combination with penicillin G (PEN), it significantly induced CW roughness and dispersion and even caused its disintegration, while the same concentration of PEN did not. In addition, transcriptome sequencing revealed that AP induced a significant stress response and increased peptidoglycan (PG) synthesis but disrupted its cross-linking, and it repressed the expression of critical genes such as mecA, blaZ, and sarA. We also validated these findings by quantitative reverse transcription-PCR (qRT-PCR). Association analysis using the GEO database showed that the alterations caused by AP were similar to those caused by mutations in the sarA gene. In summary, AP was able to restore the susceptibility of MRSA to β-lactam antibiotics, mainly by inhibiting the β-lactamase BlaZ, by downregulating the expression of critical resistance genes such as mecA and blaZ, and by disrupting CW homeostasis. In addition, restoration of susceptibility to antibiotics could be achieved by inhibiting the global regulator SarA, providing an effective solution to alleviate the problem of bacterial resistance. IMPORTANCE Increasingly, alternatives to antibiotics are being used to mitigate the rapid onset and development of bacterial resistance, and the combination of natural compounds with traditional antibiotics has become an effective therapeutic strategy. Therefore, we attempted to discover more mechanisms to restore susceptibility and effective dosing strategies. Andrographolide (AP), as a natural active ingredient, can mediate recovery of susceptibility of MRSA to β-lactam antibiotics. AP bound stably to the β-lactamase BlaZ and impaired its hydrolytic activity. Notably, AP was able to downregulate the expression of critical resistance genes such as mecA, blaZ, and sarA. Meanwhile, it disrupted the CW cross-linking and homeostasis, while the same concentration of penicillin could not. The multiple inhibitory effect of AP resensitizes intrinsically resistant bacteria to β-lactam antibiotics, effectively prolonging the use cycle of these antibiotics and providing an effective solution to reduce the dosage of antibiotics and providing a theoretical reference for the prevention and control of MRSA.
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Affiliation(s)
- Qiang Ma
- Veterinary Pharmacology Lab, College of Agriculture, Ningxia University, Yinchuan, Ningxia, China
| | - Guilai Wang
- Yinchuan Hospital of Traditional Chinese Medicine, Yinchuan, Ningxia, China
| | - Na Li
- Veterinary Pharmacology Lab, College of Agriculture, Ningxia University, Yinchuan, Ningxia, China
| | - Xin Wang
- Veterinary Pharmacology Lab, College of Agriculture, Ningxia University, Yinchuan, Ningxia, China
| | - Xinyun Kang
- Veterinary Pharmacology Lab, College of Agriculture, Ningxia University, Yinchuan, Ningxia, China
| | - Yanni Mao
- Veterinary Pharmacology Lab, College of Agriculture, Ningxia University, Yinchuan, Ningxia, China
| | - Guiqin Wang
- Veterinary Pharmacology Lab, College of Agriculture, Ningxia University, Yinchuan, Ningxia, China
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9
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Novel Sulfonylurea Derivatives as Potential Antimicrobial Agents: Chemical Synthesis, Biological Evaluation, and Computational Study. Antibiotics (Basel) 2023; 12:antibiotics12020323. [PMID: 36830234 PMCID: PMC9951967 DOI: 10.3390/antibiotics12020323] [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: 01/03/2023] [Revised: 01/28/2023] [Accepted: 02/02/2023] [Indexed: 02/08/2023] Open
Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) is a worldwide health threat and has already tormented humanity during its long history, creating an urgent need for the development of new classes of antibacterial agents. In this study, twenty-one novel sulfonylurea derivatives containing phenyl-5-vinyl and pyrimidinyl-4-aryl moieties were designed and synthesized, among which, nine compounds exhibited inhibitory potencies against Gram-positive bacterial strains: MRSA (Chaoyang clinical isolates), S. aureus ATCC6538, vancomycin-resistant Enterococci-309 (VRE-309), and Bacillus subtilis ATCC 6633. Especially, 9i and 9q demonstrated inhibitory activities against the four bacterial strains with minimum inhibitory concentrations (MICs) of 0.78-1.56 μg/mL, and quite a few of other MRSA clinical strains with MICs of 0.78 μg/mL, superior to those of the positive controls vancomycin (MIC of 1 μg/mL) and methicillin (MIC of >200 μg/mL). This is the very first time that sulfonylurea derivatives have been identified as promising inhibitors against different MRSA clinical isolates. In addition, all the MIC values of the synthesized compounds against Candida albicans were greater than 100 μg/mL. Since the reported anti-Candida activities of sulfonylureas were due to acetohydroxyacid synthase (AHAS) inhibition, the molecular target against MRSA for the target sulfonylureas was thought to be a different mode of action. Density functional theory (DFT) calculations were finally performed to understand the structure-activity relationships, based on which, significant differences were observed between their HOMO maps for compounds with strong antibacterial activities and weak anti-MRSA effects. The present results hence provide valuable guidance for the discovery of novel agents to treat bacterial infections, especially against MRSA.
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Kwan JMC, Qiao Y. Mechanistic Insights into the Activities of Major Families of Enzymes in Bacterial Peptidoglycan Assembly and Breakdown. Chembiochem 2023; 24:e202200693. [PMID: 36715567 DOI: 10.1002/cbic.202200693] [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: 11/24/2022] [Revised: 01/28/2023] [Accepted: 01/30/2023] [Indexed: 01/31/2023]
Abstract
Serving as an exoskeletal scaffold, peptidoglycan is a polymeric macromolecule that is essential and conserved across all bacteria, yet is absent in mammalian cells; this has made bacterial peptidoglycan a well-established excellent antibiotic target. In addition, soluble peptidoglycan fragments derived from bacteria are increasingly recognised as key signalling molecules in mediating diverse intra- and inter-species communication in nature, including in gut microbiota-host crosstalk. Each bacterial species encodes multiple redundant enzymes for key enzymatic activities involved in peptidoglycan assembly and breakdown. In this review, we discuss recent findings on the biochemical activities of major peptidoglycan enzymes, including peptidoglycan glycosyltransferases (PGT) and transpeptidases (TPs) in the final stage of peptidoglycan assembly, as well as peptidoglycan glycosidases, lytic transglycosylase (LTs), amidases, endopeptidases (EPs) and carboxypeptidases (CPs) in peptidoglycan turnover and metabolism. Biochemical characterisation of these enzymes provides valuable insights into their substrate specificity, regulation mechanisms and potential modes of inhibition.
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Affiliation(s)
- Jeric Mun Chung Kwan
- School of Chemistry, Chemical Engineering and Biotechnology (CCEB), 21 Nanyang Link, Singapore, 637371, Singapore.,LKC School of Medicine, Nanyang Technological University (NTU) Singapore, 11 Mandalay Road, Singapore, Singapore, 208232, Singapore
| | - Yuan Qiao
- School of Chemistry, Chemical Engineering and Biotechnology (CCEB), Nanyang Technological University (NTU), Singapore, 21 Nanyang Link, Singapore, 637371, Singapore
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11
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Satishkumar N, Lai LY, Mukkayyan N, Vogel BE, Chatterjee SS. A Nonclassical Mechanism of β-Lactam Resistance in Methicillin-Resistant Staphylococcus aureus and Its Effect on Virulence. Microbiol Spectr 2022; 10:e0228422. [PMID: 36314912 PMCID: PMC9769611 DOI: 10.1128/spectrum.02284-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2022] [Accepted: 10/07/2022] [Indexed: 11/07/2022] Open
Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) is a group of pathogenic bacteria that are infamously resistant to β-lactam antibiotics, a property attributed to the mecA gene. Recent studies have reported that mutations associated with the promoter region of pbp4 demonstrated high levels of β-lactam resistance, suggesting the role of PBP4 as an important non-mecA mediator of β-lactam resistance. The pbp4-promoter-associated mutations have been detected in strains with or without mecA. Our previous studies that were carried out in strains devoid of mecA described that pbp4-promoter-associated mutations lead to PBP4 overexpression and β-lactam resistance. In this study, by introducing various pbp4-promoter-associated mutations in the genome of a MRSA strain, we demonstrate that PBP4 overexpression can supplement mecA-associated resistance in S. aureus and can lead to increased β-lactam resistance. The promoter and regulatory region of pbp4 is shared with a divergently transcribed gene, abcA, which encodes a multidrug exporter. We demonstrate that the promoter mutations caused an upregulation of pbp4 and downregulation of abcA, confirming that the resistant phenotype is associated with PBP4 overexpression. PBP4 has also been associated with staphylococcal pathogenesis, however, its exact role remains unclear. Using a Caenorhabditis elegans model, we demonstrate that strains having increased PBP4 expression are less virulent than wild-type strains, suggesting that β-lactam resistance mediated via PBP4 likely comes at the cost of virulence. IMPORTANCE Our study demonstrates the ability of PBP4 to be an important mediator of β-lactam resistance in not only methicillin-susceptible Staphylococcus aureus (MSSA) background strains as previously demonstrated but also in MRSA strains. When present together, PBP2a and PBP4 overexpression can produce increased levels of β-lactam resistance, causing complications in treatment. Thus, this study suggests the importance of monitoring PBP4-associated resistance in clinical settings, as well as understanding the mechanistic basis of associated resistance, so that treatments targeting PBP4 may be developed. This study also demonstrates that S. aureus strains with increased PBP4 expression are less pathogenic, providing important hints about the role of PBP4 in S. aureus resistance and pathogenesis.
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Affiliation(s)
- Nidhi Satishkumar
- Department of Microbial Pathogenesis, School of Dentistry, University of Maryland, Baltimore, Maryland, USA
- Institute of Marine and Environmental Technology (IMET), Baltimore, Maryland, USA
| | - Li-Yin Lai
- Department of Microbial Pathogenesis, School of Dentistry, University of Maryland, Baltimore, Maryland, USA
- Institute of Marine and Environmental Technology (IMET), Baltimore, Maryland, USA
| | - Nagaraja Mukkayyan
- Department of Microbial Pathogenesis, School of Dentistry, University of Maryland, Baltimore, Maryland, USA
- Institute of Marine and Environmental Technology (IMET), Baltimore, Maryland, USA
| | - Bruce E. Vogel
- Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, University of Maryland, Baltimore, Maryland, USA
| | - Som S. Chatterjee
- Department of Microbial Pathogenesis, School of Dentistry, University of Maryland, Baltimore, Maryland, USA
- Institute of Marine and Environmental Technology (IMET), Baltimore, Maryland, USA
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12
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Divergent Effects of Peptidoglycan Carboxypeptidase DacA on Intrinsic β-Lactam and Vancomycin Resistance. Microbiol Spectr 2022; 10:e0173422. [PMID: 35758683 PMCID: PMC9430164 DOI: 10.1128/spectrum.01734-22] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Vancomycin and β-lactams are clinically important antibiotics that inhibit the formation of peptidoglycan cross-links, but their binding targets are different. The binding target of vancomycin is d-alanine-d-alanine (d-Ala-d-Ala), whereas that of β-lactam is penicillin-binding proteins (PBPs). In this study, we revealed the divergent effects of peptidoglycan (PG) carboxypeptidase DacA on vancomycin and β-lactam resistance in Escherichia coli and Bacillus subtilis. The deletion of DacA induced sensitivity to most β-lactams, whereas it induced strong resistance toward vancomycin. Notably, both phenotypes did not have a strong association with ld-transpeptidases, which are necessary for the formation of PG 3-3 cross-links and covalent bonds between PG and an Lpp outer membrane (OM) lipoprotein. Vancomycin resistance was induced by an increased amount of decoy d-Ala-d-Ala residues within PG, whereas β-lactam sensitivity was associated with physical interactions between DacA and PBPs. The presence of an OM permeability barrier strongly strengthened vancomycin resistance, but it significantly weakened β-lactam sensitivity. Collectively, our results revealed two distinct functions of DacA, which involved inverse modulation of bacterial resistance to clinically important antibiotics, β-lactams and vancomycin, and presented evidence for a link between DacA and PBPs. IMPORTANCE Bacterial PG hydrolases play important roles in various aspects of bacterial physiology, including cytokinesis, PG synthesis, quality control of PG, PG recycling, and stress adaptation. Of all the PG hydrolases, the role of PG carboxypeptidases is poorly understood, especially regarding their impacts on antibiotic resistance. We have revealed two distinct functions of PG carboxypeptidase DacA with respect to antibiotic resistance. The deletion of DacA led to sensitivity to most β-lactams, while it caused strong resistance to vancomycin. Our study provides novel insights into the roles of PG carboxypeptidases in the regulation of antibiotic resistance and a potential clue for the development of a drug to improve the clinical efficacy of β-lactam antibiotics.
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Penicillin-Binding Protein 1 (PBP1) of Staphylococcus aureus Has Multiple Essential Functions in Cell Division. mBio 2022; 13:e0066922. [PMID: 35703435 PMCID: PMC9426605 DOI: 10.1128/mbio.00669-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Bacterial cell division is a complex process requiring the coordination of multiple components to allow the appropriate spatial and temporal control of septum formation and cell scission. Peptidoglycan (PG) is the major structural component of the septum, and our recent studies in the human pathogen Staphylococcus aureus have revealed a complex, multistage PG architecture that develops during septation. Penicillin-binding proteins (PBPs) are essential for the final steps of PG biosynthesis; their transpeptidase activity links the peptide side chains of nascent glycan strands. PBP1 is required for cell division in S. aureus, and here, we demonstrate that it has multiple essential functions associated with its enzymatic activity and as a regulator of division. Loss of PBP1, or just its C-terminal PASTA domains, results in cessation of division at the point of septal plate formation. The PASTA domains can bind PG and thereby potentially coordinate the cell division process. The transpeptidase activity of PBP1 is also essential, but its loss leads to a strikingly different phenotype of thickened and aberrant septa, which is phenocopied by the morphological effects of adding the PBP1-specific β-lactam, meropenem. Together, these results lead to a model for septal PG synthesis where PBP1 enzyme activity is required for the characteristic architecture of the septum and PBP1 protein molecules enable the formation of the septal plate.
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14
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External oxidant-free and transition metal-free synthesis of 5-amino-1,2,4-thiadiazoles as promising antibacterials against ESKAPE pathogen strains. Mol Divers 2022; 27:651-666. [PMID: 35639224 DOI: 10.1007/s11030-022-10445-1] [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: 02/22/2022] [Accepted: 04/18/2022] [Indexed: 10/18/2022]
Abstract
A new route to 5-amino-1,2,4-thiadiazole derivatives via reaction of N-chloroamidines with isothiocyanates has been proposed. The advantages of this method are high product yields (up to 93%), the column chromatography-free workup procedure, scalability and the absence of additive oxidizing agents or transition metal catalysts. The 28 examples of 5-amino-1,2,4-thiadiazole derivatives obtaining via the proposing protocol were evaluated in vitro against ESKAPE pathogens strains (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, Enterobacter cloacae). It was found that compounds 5ba, 5bd, 6a, 6d and 6c have potent antibacterial activity (MIC values 0.09-1.5 μg mL-1), which is superior to the activity of commercial antibiotics such as pefloxacin (MIC 4-8 μg mL-1) and streptomycin (MIC 2-32 μg mL-1). The additional cytotoxic assay of hit compounds on PANC-1 cell line demonstrated the low or non-cytotoxicity activity at the same level of concentrations. Thus, these 5 compounds are promising starting point for further antimicrobial drug development.
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15
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Yaacob SN, Wahab RA, Misson M, Sabullah MK, Huyop F, Zin NM. Lactic acid bacteria and their bacteriocins: new potential weapons in the fight against methicillin-resistant Staphylococcus aureus. Future Microbiol 2022; 17:683-699. [PMID: 35414206 DOI: 10.2217/fmb-2021-0256] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Alternative solutions are eminently needed to combat the escalating number of infections caused by methicillin-resistant Staphylococcus aureus (MRSA). Bacteriocins produced by lactic acid bacteria are promising candidates for next-generation antibiotics. Studies have found that these stable and nontoxic ribosomally synthesized antimicrobial peptides exhibit significant potency against other bacteria, including antibiotic-resistant strains. Here the authors review previous studies on bacteriocins that have been effectively employed to manage MRSA infections. The authors' review focuses on the beneficial traits of bacteriocins for further application as templates for the design of novel drugs. Treatments that combine bacteriocins with other antimicrobials to combat pervasive MRSA infections are also highlighted. In short, future studies should focus on the pharmacodynamics and pharmacokinetics of bacteriocins-antimicrobials to understand their interactions, as this aspect would likely determine their efficacy in MRSA inhibition.
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Affiliation(s)
- Syariffah Ns Yaacob
- Department of Bioscience, Faculty of Science, Universiti Teknologi Malaysia, Johor Bahru, 81310, Malaysia
| | - Roswanira A Wahab
- Department of Chemistry, Faculty of Science, Universiti Teknologi Malaysia, Johor Bahru, 81310, Malaysia
| | - Mailin Misson
- Biotechnology Research Institute, Jalan Universiti Malaysia Sabah, Kota Kinabalu, Sabah, 88400, Malaysia
| | - Mohd K Sabullah
- Faculty of Science and Natural Resources, Jalan Universiti Malaysia Sabah, Kota Kinabalu, Sabah, 88400, Malaysia
| | - Fahrul Huyop
- Department of Bioscience, Faculty of Science, Universiti Teknologi Malaysia, Johor Bahru, 81310, Malaysia
| | - Noraziah M Zin
- Center for Diagnostic, Therapeutic and Investigative Studies, Faculty of Health Sciences, Universiti Kebangsaan Malaysia, Kuala Lumpur, 50300, Malaysia
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16
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Impact of crossbridge structure on peptidoglycan crosslinking: A synthetic stem peptide approach. Methods Enzymol 2022; 665:259-279. [PMID: 35379437 DOI: 10.1016/bs.mie.2021.11.019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The bacterial cell wall, whose main component is peptidoglycan (PG), provides cellular rigidity and prevents lysis from osmotic pressure. Moreover, the cell wall is the main interface between the external environment and internal cellular components. Given its essentiality, many antibiotics target enzymes related to the biosynthesis of cell wall. Of these enzymes, transpeptidases (TPs) are central to proper cell wall assembly and their inactivation is the mechanism of action of many antibiotics including β-lactams. TPs are responsible for stitching together strands of PG to make the crosslinked meshwork of the cell wall. This chapter focuses on the use of solid-phase peptide synthesis to build PG analogs that become site-selectively incorporated into the cell wall of live bacterial cells. This method allows for the design of fluorescent handles on PG probes that will enable the interrogation of substrate preferences of TPs (e.g., amidation at the glutamic acid residue, crossbridge presence) by analyzing the level of probe incorporation within the native cell wall of live bacterial cells.
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17
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Gao J, Guo J, Chen J, Ding C, Wang J, Huang Q, Jian Y, Zhao X, Li M, Gao Y, Yang C, Wang W. d-Amino Acid-Based Metabolic Labeling Enables a Fast Antibiotic Susceptibility Test of Both Isolated Bacteria and Bronchoalveolar Lavage Fluid. Adv Healthc Mater 2022; 11:e2101736. [PMID: 34898025 DOI: 10.1002/adhm.202101736] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Revised: 11/18/2021] [Indexed: 11/07/2022]
Abstract
The threat of multidrug-resistant bacteria has escalated rapidly, increasing the demand for accurate antibiotic susceptibility tests (ASTs). Traditional bacterial growth yield-based ASTs often take overnight to report, delaying the timely guidance of antibiotic use. Here, a fluorescent d-amino acid (FDAA) labeling-based AST (FaAST) is reported, which can quickly provide accurate minimum inhibitory concentrations (MICs). The FDAA-labeling signals that reflect the bacterial metabolic status underlie the flow cytometry-based strategy for MIC determination. Resistant bacteria show a reluctant decline in FDAA-labeling (inhibited metabolism) after treatment with the corresponding antibiotics, whereas susceptible bacteria demonstrate quick responses to low doses of drugs. The MICs are determined based on the changing trends in labeling. After testing 23 clinical isolates and laboratory strains of the most critical drug-resistant bacteria against a panel of representative antibiotics, FaAST shows a high susceptibility category with an accuracy of 98.13%. Moreover, FaAST can also make quick and accurate diagnosis against bronchoalveolar lavage fluids collected from hospital-acquired pneumonia patients, saving 2-4 days in guiding antibiotic use for this life-threatening infection. Thus, the speed, accuracy, and broad applicability of FaAST will be valuable in informing antibiotic decisions when treating critical infections caused by drug-resistant bacteria.
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Affiliation(s)
- Juan Gao
- Institute of Molecular Medicine Renji Hospital Shanghai Jiao Tong University School of Medicine Shanghai 200127 China
| | - Junnan Guo
- Institute of Molecular Medicine Renji Hospital Shanghai Jiao Tong University School of Medicine Shanghai 200127 China
| | - Jianxiao Chen
- Department of Critical Care Medicine Renji Hospital Shanghai Jiao Tong University School of Medicine Shanghai 200127 China
| | - Chenling Ding
- Department of Critical Care Medicine Renji Hospital Shanghai Jiao Tong University School of Medicine Shanghai 200127 China
| | - Jiemin Wang
- Department of Critical Care Medicine Renji Hospital Shanghai Jiao Tong University School of Medicine Shanghai 200127 China
| | - Qian Huang
- Department of Laboratory Medicine Renji Hospital Shanghai Jiao Tong University School of Medicine Shanghai 200127 China
| | - Ying Jian
- Department of Laboratory Medicine Renji Hospital Shanghai Jiao Tong University School of Medicine Shanghai 200127 China
| | - Xianyuan Zhao
- Department of Critical Care Medicine Renji Hospital Shanghai Jiao Tong University School of Medicine Shanghai 200127 China
| | - Min Li
- Department of Laboratory Medicine Renji Hospital Shanghai Jiao Tong University School of Medicine Shanghai 200127 China
| | - Yuan Gao
- Department of Critical Care Medicine Renji Hospital Shanghai Jiao Tong University School of Medicine Shanghai 200127 China
| | - Chaoyong Yang
- Institute of Molecular Medicine Renji Hospital Shanghai Jiao Tong University School of Medicine Shanghai 200127 China
- The MOE Key Laboratory of Spectrochemical Analysis and Instrumentation Key Laboratory for Chemical Biology of Fujian Province State Key Laboratory of Physical Chemistry of Solid Surfaces Department of Chemical Biology College of Chemistry and Chemical Engineering Xiamen University Xiamen 361005 China
| | - Wei Wang
- Institute of Molecular Medicine Renji Hospital Shanghai Jiao Tong University School of Medicine Shanghai 200127 China
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18
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19
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Pan T, Guan J, Li Y, Sun B. LcpB Is a Pyrophosphatase Responsible for Wall Teichoic Acid Synthesis and Virulence in Staphylococcus aureus Clinical Isolate ST59. Front Microbiol 2021; 12:788500. [PMID: 34975809 PMCID: PMC8716876 DOI: 10.3389/fmicb.2021.788500] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2021] [Accepted: 11/30/2021] [Indexed: 11/17/2022] Open
Abstract
The community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) causes severe pandemics primarily consisting of skin and soft tissue infections. However, the underlying pathomechanisms of the bacterium are yet to fully understood. The present study identifies LcpB protein, which belongs to the LytR-A-Psr (LCP) family, is crucial for cell wall synthesis and virulence in S. aureus. The findings revealed that LcpB is a pyrophosphatase responsible for wall teichoic acid synthesis. The results also showed that LcpB regulates enzyme activity through specific key arginine sites in its LCP domain. Furthermore, knockout of lcpB in the CA-MRSA isolate ST59 resulted in enhanced hemolytic activity, enlarged of abscesses, and increased leukocyte infiltration. Meanwhile, we also found that LcpB regulates virulence in agr-independent manner and the key sites for pyrophosphatase of LcpB play critical roles in regulating the virulence. In addition, the results showed that the role of LcpB was different between methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-sensitive Staphylococcus aureus (MSSA). This study therefore highlights the dual role of LcpB in cell wall synthesis and regulation of virulence. These insights on the underlying molecular mechanisms can thus guide the development of novel anti-infective strategies.
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Affiliation(s)
- Ting Pan
- Department of Oncology, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui, China
| | - Jing Guan
- Department of Gastroenterology, The First Affiliated Hospital of Anhui Medical University, Hefei, China
| | - Yujie Li
- Department of Oncology, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui, China
| | - Baolin Sun
- Department of Oncology, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui, China
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20
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Zhang PL, Gopala L, Zhang SL, Cai GX, Zhou CH. An unanticipated discovery towards novel naphthalimide corbelled aminothiazoximes as potential anti-MRSA agents and allosteric modulators for PBP2a. Eur J Med Chem 2021; 229:114050. [PMID: 34922190 DOI: 10.1016/j.ejmech.2021.114050] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2021] [Revised: 11/26/2021] [Accepted: 12/09/2021] [Indexed: 12/14/2022]
Abstract
Available therapeutic strategies are urgently needed to conquer multidrug resistance of MRSA. A visible effort was guided towards the advancement of novel antibacterial framework of naphthalimide corbelled aminothiazoximes, and desired to assert some insight on the conjunction of individual pharmacophore with distinct biological activities and unique action mechanism. Preliminary assessment displayed that dimethylenediamine derivative 13d presented a wonderful inhibition on MRSA (MIC = 0.5 μg/mL), and showed excellent membrane selectivity (HC50 > 200 μg/mL) from an electrostatic distinction of the electronegative bacterial membranes and the electroneutral mammalian membranes. Moreover, 13d could effectually relieve the development of MRSA resistance. Investigations into explaining the mechanism of anti-MRSA disclosed that 13d displayed strong lipase affinity, which facilitated its permeation into cell membrane, causing membrane depolarization, leakage of cytoplasmic contents and lactate dehydrogenase (LDH) inhibition. Meanwhile, 13d could exert interaction with DNA to hinder biological function of DNA, and disrupt the antioxidant defense system of MRSA through up-regulation of ROS subjected the strain to oxidative stress. In particular, the unanticipated mechanism for naphthalimide corbelled aminothiazoximes that 13d could suppress the expression of PBP2a by inducing allosteric modulation of PBP2a and triggering the open of the active site, was discovered for the first time. These findings of naphthalimide corbelled aminothiazoximes as a small-molecule class of anti-MRSA agents held promise in strategies for treatment of MRSA infections.
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Affiliation(s)
- Peng-Li Zhang
- Institute of Bioorganic & Medicinal Chemistry, Key Laboratory of Applied Chemistry of Chongqing Municipality, School of Chemistry and Chemical Engineering, Southwest University, Chongqing, 400715, China
| | - Lavanya Gopala
- Institute of Bioorganic & Medicinal Chemistry, Key Laboratory of Applied Chemistry of Chongqing Municipality, School of Chemistry and Chemical Engineering, Southwest University, Chongqing, 400715, China
| | - Shao-Lin Zhang
- School of Pharmaceutical Sciences, Chongqing Key Laboratory of Natural Product Synthesis and Drug Research, Chongqing University, Chongqing, 401331, China.
| | - Gui-Xin Cai
- Institute of Bioorganic & Medicinal Chemistry, Key Laboratory of Applied Chemistry of Chongqing Municipality, School of Chemistry and Chemical Engineering, Southwest University, Chongqing, 400715, China.
| | - Cheng-He Zhou
- Institute of Bioorganic & Medicinal Chemistry, Key Laboratory of Applied Chemistry of Chongqing Municipality, School of Chemistry and Chemical Engineering, Southwest University, Chongqing, 400715, China.
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21
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Roy S, Dikshit PK, Sherpa KC, Singh A, Jacob S, Chandra Rajak R. Recent nanobiotechnological advancements in lignocellulosic biomass valorization: A review. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2021; 297:113422. [PMID: 34351298 DOI: 10.1016/j.jenvman.2021.113422] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Revised: 07/15/2021] [Accepted: 07/26/2021] [Indexed: 05/22/2023]
Abstract
Increase in human population, rapid industrialization, excessive utilization of fossil fuel utilization and anthropogenic activities have caused serious threats to the environment in terms of greenhouse gas emissions (GHGs), global warming, air pollution, acid rain, etc. This destruction in sustainability can be averted by a paradigm shift in the fuel production from fossil resources to bioenergy. Amongst different forms of bioenergy, lignocellulosic biomass can be utilized as an attractive substrate for the production of several high-value products owing to its renewability, easy availability, and abundance. Additionally, utilization of these waste biomasses reduces the environmental hazards associated with its disposal. Impedance of lignin and crystalline nature of cellulose pose major bottlenecks in biomass based energy. Though, several physio-chemicals processes are recommended as mitigation route but none of them seems to be promising for large scale application. In recent years, a right fusion of biological treatment combined with nanotechnology for efficient pretreatment and subsequent hydrolysis of biomass by ubiquitous enzymes seems to be promising alternative. In addition, to overcome these difficulties, nanotechnology-based methods have been recently adopted in catalytic valorization of lignocellulosic biomass. The present review has critically discussed the application of nano-biotechnology in lignocellulosic biomass valorization in terms of pretreatment and hydrolysis. A detailed discussion on the application of various nanoparticles in these processes, enzyme immobilization and end-production utilization is presented in this review. Finally, the review emphasizes the major challenges of this process along with different routes and recommendations to address the issues.
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Affiliation(s)
- Sharmili Roy
- Division of Oncology, School of Medicine, Stanford University, CA, 94305, USA
| | - Pritam Kumar Dikshit
- Department of Life Sciences, School of Basic Sciences and Research, Sharda University, Greater Noida, 201310, India
| | - Knawang Chhunji Sherpa
- Advanced Technology Development Centre, Indian Institute of Technology, Kharagpur, 721302, India
| | - Anshu Singh
- Agricultural and Food Engineering Department, Indian Institute of Technology, Kharagpur, 721302, India
| | - Samuel Jacob
- Department of Biotechnology, School of Engineering, SRM Institute of Science and Technology, Kattankulathur, India
| | - Rajiv Chandra Rajak
- Department of Botany, Marwari College, Ranchi University, Ranchi, 834008, India.
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22
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Martínez-Caballero S, Mahasenan KV, Kim C, Molina R, Feltzer R, Lee M, Bouley R, Hesek D, Fisher JF, Muñoz IG, Chang M, Mobashery S, Hermoso JA. Integrative structural biology of the penicillin-binding protein-1 from Staphylococcus aureus, an essential component of the divisome machinery. Comput Struct Biotechnol J 2021; 19:5392-5405. [PMID: 34667534 PMCID: PMC8493512 DOI: 10.1016/j.csbj.2021.09.018] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Revised: 09/13/2021] [Accepted: 09/15/2021] [Indexed: 12/18/2022] Open
Abstract
The penicillin-binding proteins are the enzyme catalysts of the critical transpeptidation crosslinking polymerization reaction of bacterial peptidoglycan synthesis and the molecular targets of the penicillin antibiotics. Here, we report a combined crystallographic, small-angle X-ray scattering (SAXS) in-solution structure, computational and biophysical analysis of PBP1 of Staphylococcus aureus (saPBP1), providing mechanistic clues about its function and regulation during cell division. The structure reveals the pedestal domain, the transpeptidase domain, and most of the linker connecting to the "penicillin-binding protein and serine/threonine kinase associated" (PASTA) domains, but not its two PASTA domains, despite their presence in the construct. To address this absence, the structure of the PASTA domains was determined at 1.5 Å resolution. Extensive molecular-dynamics simulations interpret the PASTA domains of saPBP1 as conformationally mobile and separated from the transpeptidase domain. This conclusion was confirmed by SAXS experiments on the full-length protein in solution. A series of crystallographic complexes with β-lactam antibiotics (as inhibitors) and penta-Gly (as a substrate mimetic) allowed the molecular characterization of both inhibition by antibiotics and binding for the donor and acceptor peptidoglycan strands. Mass-spectrometry experiments with synthetic peptidoglycan fragments revealed binding by PASTA domains in coordination with the remaining domains. The observed mobility of the PASTA domain in saPBP1 could play a crucial role for in vivo interaction with its glycosyltransferase partner in the membrane or with other components of the divisome machinery, as well as for coordination of transpeptidation and polymerization processes in the bacterial divisome.
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Affiliation(s)
- Siseth Martínez-Caballero
- Department of Crystallography and Structural Biology, Institute of Physical Chemistry "Rocasolano", CSIC, 28006 Madrid, Spain
| | - Kiran V Mahasenan
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556, USA
| | - Choon Kim
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556, USA
| | - Rafael Molina
- Department of Crystallography and Structural Biology, Institute of Physical Chemistry "Rocasolano", CSIC, 28006 Madrid, Spain
| | - Rhona Feltzer
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556, USA
| | - Mijoon Lee
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556, USA
| | - Renee Bouley
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556, USA
| | - Dusan Hesek
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556, USA
| | - Jed F Fisher
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556, USA
| | - Inés G Muñoz
- Structural Biology Programme, Spanish National Cancer Research Center (CNIO), 28029 Madrid, Spain
| | - Mayland Chang
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556, USA
| | - Shahriar Mobashery
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556, USA
| | - Juan A Hermoso
- Department of Crystallography and Structural Biology, Institute of Physical Chemistry "Rocasolano", CSIC, 28006 Madrid, Spain
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Rahman S, Das AK. Integrated Multi-omics, Virtual Screening and Molecular Docking Analysis of Methicillin-Resistant Staphylococcus aureus USA300 for the Identification of Potential Therapeutic Targets: An In-Silico Approach. Int J Pept Res Ther 2021; 27:2735-2755. [PMID: 34548853 PMCID: PMC8446483 DOI: 10.1007/s10989-021-10287-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/10/2021] [Indexed: 11/28/2022]
Abstract
Staphylococcus aureus infection is a leading cause of mortality and morbidity in community, hospital and live-stock sectors, especially with the widespread emergence of methicillin-resistant S. aureus (MRSA) strains. To identify new drug molecules to treat MRSA patients, we have undertaken to search essential proteins that are indispensable for their survival but non-homologous to human host proteins. The current study utilizes a subtractive genome and proteome approach to screen the possible therapeutic targets against S. aureus USA300. Bacterial essential genes are obtained from the DEG database and are compared to avoid cross-reactivity with human host genes. In silico analysis shows 198 proteins that may be considered as therapeutic candidates. Depending on their sub-cellular localization, proteins are grouped as either vaccine or drug targets or both. Extracellular proteins such as cell division proteins (Q2FZ91, Q2FZ95), penicillin-binding proteins (Q2FZ94, Q2FYI0) of the bacterial cell wall, phosphoglucomutase (Q2FE11) and lipoteichoic acid synthase (Q2FIS2) are considered as vaccine targets, and their epitopes have been mapped. Altogether, 53 drug targets are identified, which have shown similarity with the drug targets available in the DrugBank database. Predicted drug targets belong to the common metabolic pathways of MRSA, such as fatty acid biosynthesis, folate biosynthesis, peptidoglycan biosynthesis, ribosome, etc. Protein-protein interaction analysis emphasizing peptidoglycan biosynthesis reveals the connection between penicillin-binding proteins, mur-family proteins and FemXAB proteins. In this study, staphylococcal FemA protein (P0A0A5) is subjected to structure-based virtual screening for the drug repurposing approach. There are 20 residues missing in the crystal structure of FemA, and 12 of these residues are located at the catalytic site. The missing residues are modelled, and stereochemistry is checked. FDA approved drugs available in the DrugBank database have been used in virtual screening with FemA in search of potential repurposed molecules. This approach provides us with 10 drugs that may be used in the treatment of methicillin-resistant staphylococcal mediated diseases. AutoDock 4.2 is used for in silico screening and shows a comparable inhibition constant (Ki) for all 10 FDA-approved drugs towards FemA. Most of these drugs are used in the treatment of various cancers, migraines and leukaemia. Protein-drug interaction analysis shows that the drugs mostly interact with hydrophobic residues of FemA. Moreover, Tyr328 and Lys383 contribute largely to hydrogen bondings during interactions. All interacting amino acids that bind to the drugs are part of the active site cavity of FemA. Supplementary Information The online version contains supplementary material available at 10.1007/s10989-021-10287-9.
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Affiliation(s)
- Shakilur Rahman
- Department of Biotechnology, Indian Institute of Technology Kharagpur, Kharagpur, West Bengal 721302 India
| | - Amit Kumar Das
- Department of Biotechnology, Indian Institute of Technology Kharagpur, Kharagpur, West Bengal 721302 India
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Lv N, Kong Q, Zhang H, Li J. Discovery of novel Staphylococcus aureus penicillin binding protein 2a inhibitors by multistep virtual screening and biological evaluation. Bioorg Med Chem Lett 2021; 41:128001. [PMID: 33811991 DOI: 10.1016/j.bmcl.2021.128001] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Revised: 03/21/2021] [Accepted: 03/23/2021] [Indexed: 01/27/2023]
Abstract
Penicillin-binding protein 2a (PBP2a) is an essential protein involved in the resistance to β-lactam antibiotics acquired by methicillin-resistant Staphylococcus aureus (MRSA) and is a potential antibacterial target. In the current study, we employed a strategy that combined virtual screening with biological evaluation to discover novel inhibitors of PBP2a. In this investigation, a hybrid virtual screening method, consisting of drug-likeness evaluation (Lipinski's Rule of Five and ADMET) and rigid (LibDock) and semi-flexible (CDOCKER) docking-based virtual screenings, was used for retrieving novel PBP2a inhibitors from commercially available chemical databases. 11 compounds were selected from the final hits and subsequently shifted to experimental studies. Among them, Hit 2, Hit 3, and Hit 10 exhibited excellent anti-MRSA ATCC 33591 activity and weak toxicity in vitro. The affinity of the three compounds to bind to PBP2a was further confirmed by surface plasmon resonance (SPR) experiments and molecular dynamics (MD) simulation. An inter-complex interaction study showed that all hit compounds adapted well to the allosteric site of the PBP2a protein. In addition, Hit 2 (with best binding affinity to PBP2a, KD = 1.29 × 10-7 M) significantly inhibits proliferation of MRSA clinical isolates. Together, the 3 hit compounds, especially Hit 2, may be potential non-β-lactam antibiotics against MRSA and the work will provide clues for the future development of specific compounds that block the interaction of PBP2a with their targets.
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Affiliation(s)
- Na Lv
- Department of Infectious Diseases, The First Affiliated Hospital of Anhui Medical University, Hefei, Anhui 230032, China; Department of Stomatology, The First Affiliated Hospital of Anhui Medical University, Hefei, Anhui 230032, China
| | - Qinxiang Kong
- Department of Infectious Diseases, Chaohu Hospital of Anhui Medical University, Hefei, China
| | - Hui Zhang
- Department of Infectious Diseases, The First Affiliated Hospital of Anhui Medical University, Hefei, Anhui 230032, China
| | - Jiabin Li
- Department of Infectious Diseases, The First Affiliated Hospital of Anhui Medical University, Hefei, Anhui 230032, China; Institute of Bacterial Resistance, Anhui Medical University, Hefei, Anhui 230032, China.
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Fisher JF, Mobashery S. β-Lactams against the Fortress of the Gram-Positive Staphylococcus aureus Bacterium. Chem Rev 2021; 121:3412-3463. [PMID: 33373523 PMCID: PMC8653850 DOI: 10.1021/acs.chemrev.0c01010] [Citation(s) in RCA: 41] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The biological diversity of the unicellular bacteria-whether assessed by shape, food, metabolism, or ecological niche-surely rivals (if not exceeds) that of the multicellular eukaryotes. The relationship between bacteria whose ecological niche is the eukaryote, and the eukaryote, is often symbiosis or stasis. Some bacteria, however, seek advantage in this relationship. One of the most successful-to the disadvantage of the eukaryote-is the small (less than 1 μm diameter) and nearly spherical Staphylococcus aureus bacterium. For decades, successful clinical control of its infection has been accomplished using β-lactam antibiotics such as the penicillins and the cephalosporins. Over these same decades S. aureus has perfected resistance mechanisms against these antibiotics, which are then countered by new generations of β-lactam structure. This review addresses the current breadth of biochemical and microbiological efforts to preserve the future of the β-lactam antibiotics through a better understanding of how S. aureus protects the enzyme targets of the β-lactams, the penicillin-binding proteins. The penicillin-binding proteins are essential enzyme catalysts for the biosynthesis of the cell wall, and understanding how this cell wall is integrated into the protective cell envelope of the bacterium may identify new antibacterials and new adjuvants that preserve the efficacy of the β-lactams.
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Affiliation(s)
- Jed F Fisher
- Department of Chemistry and Biochemistry, McCourtney Hall, University of Notre Dame, Notre Dame Indiana 46556, United States
| | - Shahriar Mobashery
- Department of Chemistry and Biochemistry, McCourtney Hall, University of Notre Dame, Notre Dame Indiana 46556, United States
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Al-Majmaie S, Nahar L, Rahman MM, Nath S, Saha P, Talukdar AD, Sharples GP, Sarker SD. Anti-MRSA Constituents from Ruta chalepensis (Rutaceae) Grown in Iraq, and In Silico Studies on Two of Most Active Compounds, Chalepensin and 6-Hydroxy-rutin 3',7-Dimethyl ether. Molecules 2021; 26:molecules26041114. [PMID: 33669881 PMCID: PMC7923287 DOI: 10.3390/molecules26041114] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Revised: 02/14/2021] [Accepted: 02/18/2021] [Indexed: 01/08/2023] Open
Abstract
Ruta chalepensis L. (Rutaceae), a perennial herb with wild and cultivated habitats, is well known for its traditional uses as an anti-inflammatory, analgesic, antipyretic agent, and in the treatment of rheumatism, nerve diseases, neuralgia, dropsy, convulsions and mental disorders. The antimicrobial activities of the crude extracts from the fruits, leaves, stem and roots of R. chalepensis were initially evaluated against two Gram-positive and two Gram-negative bacterial strains and a strain of the fungus Candida albicans. Phytochemical investigation afforded 19 compounds, including alkaloids, coumarins, flavonoid glycosides, a cinnamic acid derivative and a long-chain alkane. These compounds were tested against a panel of methicillin-resistant Staphylococcus aureus (MRSA) strains, i.e., ATCC 25923, SA-1199B, XU212, MRSA-274819 and EMRSA-15. The MIC values of the active compounds, chalepin (9), chalepensin (10), rutamarin (11), rutin 3′-methyl ether (14), rutin 7,4′-dimethyl ether (15), 6-hydroxy-rutin 3′,7-dimethyl ether (16) and arborinine (18) were in the range of 32–128 µg/mL against the tested MRSA strains. Compounds 10 and 16 were the most active compounds from R. chalepensis, and were active against four out of six tested MRSA strains, and in silico studies were performed on these compounds. The anti-MRSA activity of compound 16 was comparable to that of the positive control norfloxacin (MICs 32 vs 16 μg/mL, respectively) against the MRSA strain XU212, which is a Kuwaiti hospital isolate that possesses the TetK tetracycline efflux pump. This is the first report on the anti-MRSA property of compounds isolated from R. chalepensis and relevant in silico studies on the most active compounds.
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Affiliation(s)
- Shaymaa Al-Majmaie
- Centre for Natural Products Discovery, School of Pharmacy and Biomolecular Sciences, Liverpool John Moores University, James Parsons Building, Byrom Street, Liverpool L3 3AF, UK; (S.A.-M.); (S.N.); (G.P.S.)
| | - Lutfun Nahar
- Laboratory of Growth Regulators, Institute of Experimental Botany ASCR & Palacký University, Šlechtitelů 27, 78371 Olomouc, Czech Republic
- Correspondence: (L.N.); (S.D.S.); Tel.: +44-(0)-15-1231-2096 (S.D.S.)
| | - M. Mukhlesur Rahman
- Medicines Research Group, School of Health, Sport and Bioscience, University of East London, Water Lane, London E15 4LZ, UK;
| | - Sushmita Nath
- Centre for Natural Products Discovery, School of Pharmacy and Biomolecular Sciences, Liverpool John Moores University, James Parsons Building, Byrom Street, Liverpool L3 3AF, UK; (S.A.-M.); (S.N.); (G.P.S.)
| | - Priyanka Saha
- Cancer Biology and Inflammatory Disease Division, CSIR-Indian Institute of Chemical Biology, Kolkata, West Bengal 700032, India;
| | - Anupam Das Talukdar
- Department of Life Science and Bioinformatics, Assam University, Silchar, Assam 788011, India; or
| | - George P. Sharples
- Centre for Natural Products Discovery, School of Pharmacy and Biomolecular Sciences, Liverpool John Moores University, James Parsons Building, Byrom Street, Liverpool L3 3AF, UK; (S.A.-M.); (S.N.); (G.P.S.)
| | - Satyajit D. Sarker
- Centre for Natural Products Discovery, School of Pharmacy and Biomolecular Sciences, Liverpool John Moores University, James Parsons Building, Byrom Street, Liverpool L3 3AF, UK; (S.A.-M.); (S.N.); (G.P.S.)
- Correspondence: (L.N.); (S.D.S.); Tel.: +44-(0)-15-1231-2096 (S.D.S.)
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27
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Gorboletova GG, Bychkova SA, Frolova KO. Thermodynamics of Complexation of Triglycine with Cobalt(II) in Aqueous Solutions. RUSSIAN JOURNAL OF PHYSICAL CHEMISTRY A 2020. [DOI: 10.1134/s0036024420080099] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Apostolos AJ, Pidgeon SE, Pires MM. Remodeling of Cross-bridges Controls Peptidoglycan Cross-linking Levels in Bacterial Cell Walls. ACS Chem Biol 2020; 15:1261-1267. [PMID: 32167281 DOI: 10.1021/acschembio.0c00002] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Cell walls are barriers found in almost all known bacterial cells. These structures establish a controlled interface between the external environment and vital cellular components. A primary component of cell wall is a highly cross-linked matrix called peptidoglycan (PG). PG cross-linking, carried out by transglycosylases and transpeptidases, is necessary for proper cell wall assembly. Transpeptidases, targets of β-lactam antibiotics, stitch together two neighboring PG stem peptides (acyl-donor and acyl-acceptor strands). We recently described a novel class of cellular PG probes that were processed exclusively as acyl-donor strands. Herein, we have accessed the other half of the transpeptidase reaction by developing probes that are processed exclusively as acyl-acceptor strands. The critical nature of the cross-bridge on the PG peptide was demonstrated in live bacterial cells, and surprising promiscuity in cross-bridge primary sequence was found in various bacterial species. Additionally, acyl-acceptor probes provided insight into how chemical remodeling of the PG cross-bridge (e.g., amidation) can modulate cross-linking levels, thus establishing a physiological role of PG structural variations. Together, the acyl-donor and -acceptor probes will provide a versatile platform to interrogate PG cross-linking in physiologically relevant settings.
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Affiliation(s)
- Alexis J. Apostolos
- Department of Chemistry, University of Virginia, Charlotesville, Virginia 22904, United States
| | - Sean E. Pidgeon
- Department of Chemistry, University of Virginia, Charlotesville, Virginia 22904, United States
| | - Marcos M. Pires
- Department of Chemistry, University of Virginia, Charlotesville, Virginia 22904, United States
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29
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Shalaby MAW, Dokla EME, Serya RAT, Abouzid KAM. Penicillin binding protein 2a: An overview and a medicinal chemistry perspective. Eur J Med Chem 2020; 199:112312. [PMID: 32442851 DOI: 10.1016/j.ejmech.2020.112312] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2019] [Revised: 03/28/2020] [Accepted: 04/05/2020] [Indexed: 12/17/2022]
Abstract
Antimicrobial resistance is an imminent threat worldwide. Methicillin-resistant Staphylococcus aureus (MRSA) is one of the "superbug" family, manifesting resistance through the production of a penicillin binding protein, PBP2a, an enzyme that provides its transpeptidase activity to allow cell wall biosynthesis. PBP2a's low affinity to most β-lactams, confers resistance to MRSA against numerous members of this class of antibiotics. An Achilles' heel of MRSA, PBP2a represents a substantial target to design novel antibiotics to tackle MRSA threat via inhibition of the bacterial cell wall biosynthesis. In this review we bring into focus the PBP2a enzyme and examine the various aspects related to its role in conferring resistance to MRSA strains. Moreover, we discuss several antibiotics and antimicrobial agents designed to target PBP2a and their therapeutic potential to meet such a grave threat. In conclusion, we consider future perspectives for targeting MRSA infections.
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Affiliation(s)
- Menna-Allah W Shalaby
- Pharmaceutical Chemistry Department, Faculty of Pharmacy, Ain Shams University, Abbassia, 11566, Cairo, Egypt
| | - Eman M E Dokla
- Pharmaceutical Chemistry Department, Faculty of Pharmacy, Ain Shams University, Abbassia, 11566, Cairo, Egypt.
| | - Rabah A T Serya
- Pharmaceutical Chemistry Department, Faculty of Pharmacy, Ain Shams University, Abbassia, 11566, Cairo, Egypt
| | - Khaled A M Abouzid
- Pharmaceutical Chemistry Department, Faculty of Pharmacy, Ain Shams University, Abbassia, 11566, Cairo, Egypt; Department of Organic and Medicinal Chemistry, Faculty of Pharmacy, University of Sadat City, Sadat City, Egypt.
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30
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Abstract
Dating back to the 1960s, initial studies on the staphylococcal cell wall were driven by the need to clarify the mode of action of the first antibiotics and the resistance mechanisms developed by the bacteria. During the following decades, the elucidation of the biosynthetic path and primary composition of staphylococcal cell walls was propelled by advances in microbial cell biology, specifically, the introduction of high-resolution analytical techniques and molecular genetic approaches. The field of staphylococcal cell wall gradually gained its own significance as the complexity of its chemical structure and involvement in numerous cellular processes became evident, namely its versatile role in host interactions, coordination of cell division and environmental stress signaling.This chapter includes an updated description of the anatomy of staphylococcal cell walls, paying particular attention to information from the last decade, under four headings: high-resolution analysis of the Staphylococcus aureus peptidoglycan; variations in peptidoglycan composition; genetic determinants and enzymes in cell wall synthesis; and complex functions of cell walls. The latest contributions to a more precise picture of the staphylococcal cell envelope were possible due to recently developed state-of-the-art microscopy and spectroscopy techniques and to a wide combination of -omics approaches, that are allowing to obtain a more integrative view of this highly dynamic structure.
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31
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Do T, Page JE, Walker S. Uncovering the activities, biological roles, and regulation of bacterial cell wall hydrolases and tailoring enzymes. J Biol Chem 2020; 295:3347-3361. [PMID: 31974163 DOI: 10.1074/jbc.rev119.010155] [Citation(s) in RCA: 58] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Bacteria account for 1000-fold more biomass than humans. They vary widely in shape and size. The morphological diversity of bacteria is due largely to the different peptidoglycan-based cell wall structures that encase bacterial cells. Although the basic structure of peptidoglycan is highly conserved, consisting of long glycan strands that are cross-linked by short peptide chains, the mature cell wall is chemically diverse. Peptidoglycan hydrolases and cell wall-tailoring enzymes that regulate glycan strand length, the degree of cross-linking, and the addition of other modifications to peptidoglycan are central in determining the final architecture of the bacterial cell wall. Historically, it has been difficult to biochemically characterize these enzymes that act on peptidoglycan because suitable peptidoglycan substrates were inaccessible. In this review, we discuss fundamental aspects of bacterial cell wall synthesis, describe the regulation and diverse biochemical and functional activities of peptidoglycan hydrolases, and highlight recently developed methods to make and label defined peptidoglycan substrates. We also review how access to these substrates has now enabled biochemical studies that deepen our understanding of how bacterial cell wall enzymes cooperate to build a mature cell wall. Such improved understanding is critical to the development of new antibiotics that disrupt cell wall biogenesis, a process essential to the survival of bacteria.
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Affiliation(s)
- Truc Do
- Department of Microbiology, Harvard Medical School, Boston, Massachusetts 02115
| | - Julia E Page
- Department of Microbiology, Harvard Medical School, Boston, Massachusetts 02115
| | - Suzanne Walker
- Department of Microbiology, Harvard Medical School, Boston, Massachusetts 02115.
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32
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Gorboletova GG, Bychkova SA, Frolova KO. Thermodynamics of Mixed-Ligand Complexation of Copper(II) with Triglycine and L-Histidine. RUSSIAN JOURNAL OF PHYSICAL CHEMISTRY A 2019. [DOI: 10.1134/s0036024419070082] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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33
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Maya-Martinez R, Alexander JAN, Otten CF, Ayala I, Vollmer D, Gray J, Bougault CM, Burt A, Laguri C, Fonvielle M, Arthur M, Strynadka NCJ, Vollmer W, Simorre JP. Recognition of Peptidoglycan Fragments by the Transpeptidase PBP4 From Staphylococcus aureus. Front Microbiol 2019; 9:3223. [PMID: 30713527 PMCID: PMC6346638 DOI: 10.3389/fmicb.2018.03223] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2018] [Accepted: 12/11/2018] [Indexed: 11/13/2022] Open
Abstract
Peptidoglycan (PG) is an essential component of the cell envelope, maintaining bacterial cell shape and protecting it from bursting due to turgor pressure. The monoderm bacterium Staphylococcus aureus has a highly cross-linked PG, with ~90% of peptide stems participating in DD-cross-links and up to 15 peptide stems connected with each other. These cross-links are formed in transpeptidation reactions catalyzed by penicillin-binding proteins (PBPs) of classes A and B. Most S. aureus strains have three housekeeping PBPs with this function (PBP1, PBP2, and PBP3) but MRSA strains have acquired a third class B PBP, PBP2a, which is encoded by the mecA gene and required for the expression of high-level resistance to β-lactams. Another housekeeping PBP of S. aureus is PBP4, which belongs to the class C PBPs, and hence would be expected to have PG hydrolase (DD-carboxypeptidase or DD-endopeptidase) activity. However, previous works showed that, unexpectedly, PBP4 has transpeptidase activity that significantly contributes to both the high level of cross-linking in the PG of S. aureus and to the low level of β-lactam resistance in the absence of PBP2a. To gain insights into this unusual activity of PBP4, we studied by NMR spectroscopy its interaction in vitro with different substrates, including intact peptidoglycan, synthetic peptide stems, muropeptides, and long glycan chains with uncross-linked peptide stems. PBP4 showed no affinity for the complex, intact peptidoglycan or the smallest isolated peptide stems. Transpeptidase activity of PBP4 was verified with the disaccharide peptide subunits (muropeptides) in vitro, producing cyclic dimer and multimer products; these assays also showed a designed PBP4(S75C) nucleophile mutant to be inactive. Using this inactive but structurally highly similar variant, liquid-state NMR identified two interaction surfaces in close proximity to the central nucleophile position that can accommodate the potential donor and acceptor stems for the transpeptidation reaction. A PBP4:muropeptide model structure was built from these experimental restraints, which provides new mechanistic insights into mecA independent resistance to β-lactams in S. aureus.
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Affiliation(s)
| | - J Andrew N Alexander
- Department of Biochemistry and Molecular Biology and Centre for Blood Research, The University of British Columbia, Vancouver, BC, Canada
| | - Christian F Otten
- Centre for Bacterial Cell Biology, Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Isabel Ayala
- University Grenoble Alpes, CNRS, CEA, IBS, Grenoble, France
| | - Daniela Vollmer
- Centre for Bacterial Cell Biology, Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Joe Gray
- Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle upon Tyne, United Kingdom
| | | | - Alister Burt
- University Grenoble Alpes, CNRS, CEA, IBS, Grenoble, France
| | - Cédric Laguri
- University Grenoble Alpes, CNRS, CEA, IBS, Grenoble, France
| | - Matthieu Fonvielle
- Centre de Recherche des Cordeliers, LRMA, Equipe 12, Université Sorbone-Paris, Paris, France
| | - Michel Arthur
- Centre de Recherche des Cordeliers, LRMA, Equipe 12, Université Sorbone-Paris, Paris, France
| | - Natalie C J Strynadka
- Department of Biochemistry and Molecular Biology and Centre for Blood Research, The University of British Columbia, Vancouver, BC, Canada
| | - Waldemar Vollmer
- Centre for Bacterial Cell Biology, Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle upon Tyne, United Kingdom
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Rohs PDA, Buss J, Sim SI, Squyres GR, Srisuknimit V, Smith M, Cho H, Sjodt M, Kruse AC, Garner EC, Walker S, Kahne DE, Bernhardt TG. A central role for PBP2 in the activation of peptidoglycan polymerization by the bacterial cell elongation machinery. PLoS Genet 2018; 14:e1007726. [PMID: 30335755 PMCID: PMC6207328 DOI: 10.1371/journal.pgen.1007726] [Citation(s) in RCA: 80] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2018] [Revised: 10/30/2018] [Accepted: 10/01/2018] [Indexed: 01/13/2023] Open
Abstract
Cell elongation in rod-shaped bacteria is mediated by the Rod system, a conserved morphogenic complex that spatially controls cell wall assembly by the glycan polymerase RodA and crosslinking enzyme PBP2. Using Escherichia coli as a model system, we identified a PBP2 variant that promotes Rod system function when essential accessory components of the machinery are inactivated. This PBP2 variant hyperactivates cell wall synthesis in vivo and stimulates the activity of RodA-PBP2 complexes in vitro. Cells with the activated synthase also exhibited enhanced polymerization of the actin-like MreB component of the Rod system. Our results define an activation pathway governing Rod system function in which PBP2 conformation plays a central role in stimulating both glycan polymerization by its partner RodA and the formation of cytoskeletal filaments of MreB to orient cell wall assembly. In light of these results, previously isolated mutations that activate cytokinesis suggest that an analogous pathway may also control cell wall synthesis by the division machinery.
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Affiliation(s)
- Patricia D. A. Rohs
- Department of Microbiology and Immunobiology, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Jackson Buss
- Department of Microbiology and Immunobiology, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Sue I. Sim
- Department of Microbiology and Immunobiology, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Georgia R. Squyres
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, Massachusetts, United States of America
| | - Veerasak Srisuknimit
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts, United States of America
| | - Mandy Smith
- Department of Microbiology and Immunobiology, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Hongbaek Cho
- Department of Biological Sciences, Sungkyunkwan University, Suwon, Gyeonggi, Korea
| | - Megan Sjodt
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Andrew C. Kruse
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Ethan C. Garner
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, Massachusetts, United States of America
| | - Suzanne Walker
- Department of Microbiology and Immunobiology, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Daniel E. Kahne
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts, United States of America
| | - Thomas G. Bernhardt
- Department of Microbiology and Immunobiology, Harvard Medical School, Boston, Massachusetts, United States of America
- Howard Hughes Medical Institute, Boston, Massachusetts, United States of America
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35
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Fonvielle M, Bouhss A, Hoareau C, Patin D, Mengin-Lecreulx D, Iannazzo L, Sakkas N, El Sagheer A, Brown T, Ethève-Quelquejeu M, Arthur M. Synthesis of Lipid-Carbohydrate-Peptidyl-RNA Conjugates to Explore the Limits Imposed by the Substrate Specificity of Cell Wall Enzymes on the Acquisition of Drug Resistance. Chemistry 2018; 24:14911-14915. [PMID: 30020544 DOI: 10.1002/chem.201802360] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2018] [Revised: 07/16/2018] [Indexed: 01/10/2023]
Abstract
Conjugation of RNA with multiple partners to obtain mimics of complex biomolecules is limited by the identification of orthogonal reactions. Here, lipid-carbohydrate-peptidyl-RNA conjugates were obtained by post-functionalization reactions, solid-phase synthesis, and enzymatic steps, to generate molecules mimicking the substrates of FmhB, an essential peptidoglycan synthesis enzyme of Staphylococcus aureus. Mimics of Gly-tRNAGly and lipid intermediate II (undecaprenyl-diphospho-disaccharide-pentapeptide) were combined in a single "bi-substrate" inhibitor (IC50 =56 nm). The synthetic route was exploited to generate substrates and inhibitors containing d-lactate residue (d-Lac) instead of d-Ala at the C-terminus of the pentapeptide stem, a modification responsible for vancomycin resistance in the enterococci. The substitution impaired recognition of peptidoglycan precursors by FmhB. The associated fitness cost may account for limited dissemination of vancomycin resistance genes in S. aureus.
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Affiliation(s)
- Matthieu Fonvielle
- INSERM UMRS 1138, Sorbonne Universités, UPMC Univ Paris 06;, 'Sorbonne Paris Cité, Université Paris Descartes, Université Paris Diderot, Centre de Recherche des Cordeliers, 75006, Paris, France
| | - Ahmed Bouhss
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ Paris-Sud, Université Paris-Saclay, 91198, Gif-sur-Yvette cedex, France.,Present address: Laboratoire Structure-Activité des Biomolécules, Normales et Pathologiques (SABNP), Univ Evry, INSERM U1204, Université Paris-Saclay, 91025, Evry, France
| | - Coralie Hoareau
- INSERM UMRS 1138, Sorbonne Universités, UPMC Univ Paris 06;, 'Sorbonne Paris Cité, Université Paris Descartes, Université Paris Diderot, Centre de Recherche des Cordeliers, 75006, Paris, France
| | - Delphine Patin
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ Paris-Sud, Université Paris-Saclay, 91198, Gif-sur-Yvette cedex, France
| | - Dominique Mengin-Lecreulx
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ Paris-Sud, Université Paris-Saclay, 91198, Gif-sur-Yvette cedex, France
| | - Laura Iannazzo
- Laboratoire de Chimie et de Biochimie Pharmacologiques et Toxicologiques, Université Paris Descartes, UMR 8601, Paris, F-75005, France.,CNRS UMR 8601, Paris, F-75006, France
| | - Nicolas Sakkas
- Laboratoire de Chimie et de Biochimie Pharmacologiques et Toxicologiques, Université Paris Descartes, UMR 8601, Paris, F-75005, France.,CNRS UMR 8601, Paris, F-75006, France
| | - Affaf El Sagheer
- Chemistry Branch, Dept. of Science and Mathematics, Faculty of Petroleum and Mining Engineering, Suez University, Suez, 43721, Egypt.,Department of Chemistry, University of Oxford, 12 Mansfield Road, Oxford, OX1 3TA, UK
| | - Tom Brown
- Department of Chemistry, University of Oxford, 12 Mansfield Road, Oxford, OX1 3TA, UK
| | - Mélanie Ethève-Quelquejeu
- Laboratoire de Chimie et de Biochimie Pharmacologiques et Toxicologiques, Université Paris Descartes, UMR 8601, Paris, F-75005, France.,CNRS UMR 8601, Paris, F-75006, France
| | - Michel Arthur
- INSERM UMRS 1138, Sorbonne Universités, UPMC Univ Paris 06;, 'Sorbonne Paris Cité, Université Paris Descartes, Université Paris Diderot, Centre de Recherche des Cordeliers, 75006, Paris, France
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36
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Santiago M, Lee W, Fayad AA, Coe KA, Rajagopal M, Do T, Hennessen F, Srisuknimit V, Müller R, Meredith TC, Walker S. Genome-wide mutant profiling predicts the mechanism of a Lipid II binding antibiotic. Nat Chem Biol 2018; 14:601-608. [PMID: 29662210 PMCID: PMC5964011 DOI: 10.1038/s41589-018-0041-4] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2017] [Accepted: 02/27/2018] [Indexed: 12/11/2022]
Abstract
Identifying targets of antibacterial compounds remains a challenging step in antibiotic development. We have developed a two-pronged functional genomics approach to predict mechanism of action that uses mutant fitness data from antibiotic-treated transposon libraries containing both upregulation and inactivation mutants. We treated a Staphylococcus aureus transposon library containing 690,000 unique insertions with 32 antibiotics. Upregulation signatures, identified from directional biases in insertions, revealed known molecular targets and resistance mechanisms for the majority of these. Because single gene upregulation does not always confer resistance, we used a complementary machine learning approach to predict mechanism from inactivation mutant fitness profiles. This approach suggested the cell wall precursor Lipid II as the molecular target of the lysocins, a mechanism we have confirmed. We conclude that docking to membrane-anchored Lipid II precedes the selective bacteriolysis that distinguishes these lytic natural products, showing the utility of our approach for nominating antibiotic mechanism of action.
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Affiliation(s)
- Marina Santiago
- Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA, USA
| | - Wonsik Lee
- Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA, USA
| | - Antoine Abou Fayad
- Department of Microbial Natural Products, Helmholtz-Institute for Pharmaceutical Research Saarland (HIPS), Helmholtz Centre for Infection Research (HZI) and Department of Pharmacy, Saarland University, Saarbrücken, Germany
| | - Kathryn A Coe
- Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA, USA
| | - Mithila Rajagopal
- Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA, USA.,Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA
| | - Truc Do
- Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA, USA
| | - Fabienne Hennessen
- Department of Microbial Natural Products, Helmholtz-Institute for Pharmaceutical Research Saarland (HIPS), Helmholtz Centre for Infection Research (HZI) and Department of Pharmacy, Saarland University, Saarbrücken, Germany
| | - Veerasak Srisuknimit
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA
| | - Rolf Müller
- Department of Microbial Natural Products, Helmholtz-Institute for Pharmaceutical Research Saarland (HIPS), Helmholtz Centre for Infection Research (HZI) and Department of Pharmacy, Saarland University, Saarbrücken, Germany.
| | - Timothy C Meredith
- Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA, USA. .,Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, PA, USA.
| | - Suzanne Walker
- Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA, USA. .,Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA.
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37
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Schaefer K, Owens TW, Kahne D, Walker S. Substrate Preferences Establish the Order of Cell Wall Assembly in Staphylococcus aureus. J Am Chem Soc 2018; 140:2442-2445. [PMID: 29402087 DOI: 10.1021/jacs.7b13551] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The Gram-positive bacterial cell wall is a large supramolecular structure and its assembly requires coordination of complex biosynthetic pathways. In the step that merges the two major biosynthetic pathways in Staphylococcus aureus cell wall assembly, conserved protein ligases attach wall teichoic acids to peptidoglycan, but the order of biosynthetic events is a longstanding question. Here, we use a chemical approach to define which of the possible peptidoglycan intermediates are substrates for wall-teichoic acid ligases, thereby establishing the order of cell wall assembly. We have developed a strategy to make defined glycan chain-length polymers of either un-cross-linked or cross-linked peptidoglycan, and we find that wall teichoic acid ligases cannot transfer wall teichoic acid precursors to the cross-linked substrates. A 1.9 Å crystal structure of a LytR-CpsA-Psr (LCP) family ligase in complex with a wall teichoic acid precursor defines the location of the peptidoglycan binding site as a long, narrow groove, and suggests that the basis for selectivity is steric exclusion of cross-linked peptidoglycan. Consistent with this hypothesis, we have found that chitin oligomers are good substrates for transfer, showing that LCPs do not discriminate cross-linked from un-cross-linked peptidoglycan substrates by recognizing features of the un-cross-linked stem peptide. We conclude that wall teichoic acids are coupled to un-cross-linked peptidoglycan chains at an early stage of peptidoglycan synthesis and may create marks that define the proper spacing of subsequent cross-links.
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Affiliation(s)
- Kaitlin Schaefer
- Department of Chemistry and Chemical Biology, Harvard University , Cambridge, Massachusetts 02138, United States.,Department of Microbiology and Immunobiology, Harvard Medical School , Boston, Massachusetts 02115, United States
| | - Tristan W Owens
- Department of Chemistry and Chemical Biology, Harvard University , Cambridge, Massachusetts 02138, United States
| | - Daniel Kahne
- Department of Chemistry and Chemical Biology, Harvard University , Cambridge, Massachusetts 02138, United States
| | - Suzanne Walker
- Department of Microbiology and Immunobiology, Harvard Medical School , Boston, Massachusetts 02115, United States
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38
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Welsh MA, Taguchi A, Schaefer K, Van Tyne D, Lebre-ton F, Gilmore MS, Kahne D, Walker S. Identification of a Functionally Unique Family of Penicillin-Binding Proteins. J Am Chem Soc 2017; 139:17727-17730. [PMID: 29182854 PMCID: PMC5729098 DOI: 10.1021/jacs.7b10170] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Penicillin-binding proteins (PBPs) are enzymes involved in the assembly of the bacterial cell wall, a major target for antibiotics. These proteins are classified by mass into high-molecular-weight PBPs, which are transpeptidases that form peptidoglycan cross-links, and low-molecular-weight PBPs, which are typically hydrolases. We report a functionally unique family of low-molecular-weight PBPs that act as transpeptidases rather than hydrolases, but they do not cross-link peptidoglycan. We show that these PBPs can exchange d-amino acids bearing chemical tags or affinity handles into peptidoglycan precursors, including Lipid II, enabling biochemical studies of proteins involved in cell wall assembly. We report that, in two organisms, the PBPs incorporate lysine into cellular peptidoglycan and that, further, the PBPs have the unprecedented ability to transfer the primary ε-amine of lysine to peptidoglycan.
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Affiliation(s)
- Michael A. Welsh
- Dept. of Microbiology and Immunobiology, Harvard Medical School, Boston, Massachusetts 02115
| | - Atsushi Taguchi
- Dept. of Microbiology and Immunobiology, Harvard Medical School, Boston, Massachusetts 02115
| | - Kaitlin Schaefer
- Dept. of Microbiology and Immunobiology, Harvard Medical School, Boston, Massachusetts 02115
- Dept. of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138
| | - Daria Van Tyne
- Dept. of Ophthalmology, Harvard Medical School, Massachusetts Eye and Ear Infirmary, Boston, Massachusetts, 02114
| | - François Lebre-ton
- Dept. of Ophthalmology, Harvard Medical School, Massachusetts Eye and Ear Infirmary, Boston, Massachusetts, 02114
| | - Michael S. Gilmore
- Dept. of Microbiology and Immunobiology, Harvard Medical School, Boston, Massachusetts 02115
- Dept. of Ophthalmology, Harvard Medical School, Massachusetts Eye and Ear Infirmary, Boston, Massachusetts, 02114
| | - Daniel Kahne
- Dept. of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138
| | - Suzanne Walker
- Dept. of Microbiology and Immunobiology, Harvard Medical School, Boston, Massachusetts 02115
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