1
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Gorgan M, Vanunu Ofri S, Engler ER, Yehuda A, Hutnick E, Hayouka Z, Bertucci MA. The importance of the PapR 7 C-terminus and amide protons in mediating quorum sensing in Bacilluscereus. Res Microbiol 2023; 174:104139. [PMID: 37758114 DOI: 10.1016/j.resmic.2023.104139] [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: 06/29/2023] [Revised: 09/11/2023] [Accepted: 09/21/2023] [Indexed: 10/03/2023]
Abstract
The opportunistic human pathogen Bacillus cereus controls the expression of key infection-promoting phenotypes using bacterial quorum sensing (QS). QS signal transduction within the species is controlled by an autoinducing peptide, PapR7, and its cognate receptor, PlcR, indicating that the PlcR:PapR interface is a prime target for QS inhibitor development. The C-terminal region of the peptide (PapR7; ADLPFEF) has been successfully employed as a scaffold to develop potent QS modulators. Despite the noted importance of the C-terminal carboxylate and amide protons in crystallographic data, their role in QS activity has yet to be explored. In this study, an N-methyl scan of PapR7 was conducted in conjunction with a C-terminal modification of previously identified B. cereus QS inhibitors. The results indicate that the amide proton at Glu6 and the C-terminal carboxylate are important for effective QS inhibition of the PlcR regulon. Through β-galactosidase and hemolysis assays, a series of QS inhibitors were discovered, including several capable of inhibiting QS with nanomolar potency. These inhibitors, along with the structure-activity data reported, will serve as valuable tools for disrupting the B. cereus QS pathway towards developing novel anti-infective strategies.
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Affiliation(s)
- Michael Gorgan
- Department of Chemistry, Lafayette College, 701 Sullivan Rd., Easton, PA 18042, United States
| | - Shahar Vanunu Ofri
- Institute of Biochemistry, Food Science and Nutrition, The Hebrew University of Jerusalem, Rehovot, Israel
| | - Emilee R Engler
- Department of Chemistry, Moravian University, 1200 Main St., Bethlehem, PA 18018, United States
| | - Avishag Yehuda
- Institute of Biochemistry, Food Science and Nutrition, The Hebrew University of Jerusalem, Rehovot, Israel
| | - Elizabeth Hutnick
- Department of Chemistry, Moravian University, 1200 Main St., Bethlehem, PA 18018, United States
| | - Zvi Hayouka
- Institute of Biochemistry, Food Science and Nutrition, The Hebrew University of Jerusalem, Rehovot, Israel.
| | - Michael A Bertucci
- Department of Chemistry, Lafayette College, 701 Sullivan Rd., Easton, PA 18042, United States.
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2
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West KHJ, Ma SV, Pensinger DA, Tucholski T, Tiambeng TN, Eisenbraun EL, Yehuda A, Hayouka Z, Ge Y, Sauer JD, Blackwell HE. Characterization of an Autoinducing Peptide Signal Reveals Highly Efficacious Synthetic Inhibitors and Activators of Quorum Sensing and Biofilm Formation in Listeria monocytogenes. Biochemistry 2023; 62:2878-2892. [PMID: 37699554 PMCID: PMC10676741 DOI: 10.1021/acs.biochem.3c00373] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/14/2023]
Abstract
Bacteria can use chemical signals to assess their local population density in a process called quorum sensing (QS). Many of these bacteria are common pathogens, including Gram-positive bacteria that utilize agr QS systems regulated by macrocyclic autoinducing peptide (AIP) signals. Listeria monocytogenes, an important foodborne pathogen, uses an agr system to regulate a variety of virulence factors and biofilm formation, yet little is known about the specific roles of agr in Listeria infection and its persistence in various environments. Herein, we report synthetic peptide tools that will enable the study of QS in Listeria. We identified a 6-mer AIP signal in L. monocytogenes supernatants and selected it as a scaffold around which a collection of non-native AIP mimics was designed and synthesized. These peptides were evaluated in cell-based agr reporter assays to generate structure-activity relationships for AIP-based agonism and antagonism in L. monocytogenes. We discovered synthetic agonists with increased potency relative to native AIP and a synthetic antagonist capable of reducing agr activity to basal levels. Notably, the latter peptide was able to reduce biofilm formation by over 90%, a first for a synthetic QS modulator in wild-type L. monocytogenes. The lead agr agonist and antagonist in L. monocytogenes were also capable of antagonizing agr signaling in the related pathogen Staphylococcus aureus, further extending their utility and suggesting different mechanisms of agr activation in these two pathogens. This study represents an important first step in the application of chemical methods to modulate QS and concomitant virulence outcomes in L. monocytogenes.
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Affiliation(s)
- Korbin H J West
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Ave., Madison, Wisconsin 53706, United States
| | - Stella V Ma
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Ave., Madison, Wisconsin 53706, United States
| | - Daniel A Pensinger
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, 1550 Linden Dr., Madison, Wisconsin 53706, United States
| | - Trisha Tucholski
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Ave., Madison, Wisconsin 53706, United States
| | - Timothy N Tiambeng
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Ave., Madison, Wisconsin 53706, United States
| | - Emma L Eisenbraun
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Ave., Madison, Wisconsin 53706, United States
| | - Avishag Yehuda
- Institute of Biochemistry, Food Science and Nutrition, Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot 7610001, Israel
| | - Zvi Hayouka
- Institute of Biochemistry, Food Science and Nutrition, Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot 7610001, Israel
| | - Ying Ge
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Ave., Madison, Wisconsin 53706, United States
- Department of Cell and Regenerative Biology, University of Wisconsin-Madison, Wisconsin Institute for Medical Research, 1111 Highland Ave., Madison, Wisconsin 53705, United States
| | - John-Demian Sauer
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, 1550 Linden Dr., Madison, Wisconsin 53706, United States
| | - Helen E Blackwell
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Ave., Madison, Wisconsin 53706, United States
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3
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Brennan AA, Mehrani M, Tal-Gan Y. Modulating streptococcal phenotypes using signal peptide analogues. Open Biol 2022; 12:220143. [PMID: 35920042 PMCID: PMC9346555 DOI: 10.1098/rsob.220143] [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: 12/13/2022] Open
Abstract
Understanding bacterial communication mechanisms is imperative to improve our current understanding of bacterial infectivity and find alternatives to current modes of antibacterial therapeutics. Both Gram-positive and Gram-negative bacteria use quorum sensing (QS) to regulate group behaviours and associated phenotypes in a cell-density-dependent manner. Group behaviours, phenotypic expression and resultant infection and disease can largely be attributed to efficient bacterial communication. Of particular interest are the communication mechanisms of Gram-positive bacteria known as streptococci. This group has demonstrated marked resistance to traditional antibiotic treatment, resulting in increased morbidity and mortality of infected hosts and an ever-increasing burden on the healthcare system. Modulating circuits and mechanisms involved in streptococcal communication has proven to be a promising anti-virulence therapeutic approach that allows managing bacterial phenotypic response but does not affect bacterial viability. Targeting the chemical signals bacteria use for communication is a promising starting point, as manipulation of these signals can dramatically affect resultant bacterial phenotypes, minimizing associated morbidity and mortality. This review will focus on the use of modified peptide signals in modulating the development of proliferative phenotypes in different streptococcal species, specifically regarding how such modification can attenuate bacterial infectivity and aid in developing future alternative therapeutic agents.
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Affiliation(s)
- Alec A Brennan
- Department of Chemistry, University of Nevada, Reno, 1664 N. Virginia St., Reno, NV 89557, USA
| | - Mona Mehrani
- Department of Chemistry, University of Nevada, Reno, 1664 N. Virginia St., Reno, NV 89557, USA
| | - Yftah Tal-Gan
- Department of Chemistry, University of Nevada, Reno, 1664 N. Virginia St., Reno, NV 89557, USA
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4
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Oh MW, Lella M, Kuo SH, Tal-Gan Y, Lau GW. Pharmacological Evaluation of Synthetic Dominant-Negative Peptides Derived from the Competence-Stimulating Peptide of Streptococcus pneumoniae. ACS Pharmacol Transl Sci 2022; 5:299-305. [PMID: 35592433 PMCID: PMC9112410 DOI: 10.1021/acsptsci.2c00037] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Indexed: 11/28/2022]
Abstract
The competence regulon of Streptococcus pneumoniae (pneumococcus) is a quorum-sensing circuitry that regulates the ability of this pathogen to acquire antibiotic resistance or perform serotype switching, leading to vaccine-escape serotypes, via horizontal gene transfer, as well as initiate virulence. Induction of the competence regulon is centered on binding of the competence-stimulating peptide (CSP) to its cognate receptor, ComD. We have recently synthesized multiple dominant-negative peptide analogs capable of inhibiting competence induction and virulence in S. pneumoniae. However, the pharmacodynamics and safety profiles of these peptide drug leads have not been characterized. Therefore, in this study, we compared the biostability of cyanine-7.5-labeled wild-type CSPs versus dominant-negative peptide analogs (dnCSPs) spatiotemporally by using an IVIS Spectrum in vivo imaging system. Moreover, in vitro cytotoxicity and in vivo toxicity were evaluated. We conclude that our best peptide analog, CSP1-E1A-cyc(Dap6E10), is an attractive therapeutic agent against pneumococcal infection with superior safety and pharmacokinetics profiles.
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Affiliation(s)
- Myung Whan Oh
- Department of Pathobiology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61802, United States
| | - Muralikrishna Lella
- Department of Chemistry, University of Nevada, Reno, 1664 North Virginia Street, Reno, Nevada 89557, United States
| | - Shanny Hsuan Kuo
- Department of Pathobiology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61802, United States
| | - Yftah Tal-Gan
- Department of Chemistry, University of Nevada, Reno, 1664 North Virginia Street, Reno, Nevada 89557, United States
| | - Gee W Lau
- Department of Pathobiology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61802, United States
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5
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Lella M, Oh MW, Kuo SH, Lau GW, Tal-Gan Y. Attenuating the Streptococcus pneumoniae Competence Regulon Using Urea-Bridged Cyclic Dominant-Negative Competence-Stimulating Peptide Analogs. J Med Chem 2022; 65:6826-6839. [PMID: 35452241 PMCID: PMC9106926 DOI: 10.1021/acs.jmedchem.2c00148] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Streptococcus pneumoniae (pneumococcus) is a prevalent human pathogen that utilizes the competence regulon quorum sensing circuitry to acquire antibiotic resistance and initiate its attack on the human host. Therefore, targeting the competence regulon can be applied as an anti-infective approach with minimal pressure for resistance development. Herein, we report the construction of a library of urea-bridged cyclic dominant-negative competence-stimulating peptide (dnCSP) derivatives and their evaluation as competitive inhibitors of the competence regulon. Our results reveal the first pneumococcus dual-action CSPs that inhibit the group 1 pneumococcus competence regulon while activating the group 2 pneumococcus competence regulon. Structural analysis indicates that the urea-bridge cyclization stabilizes the bioactive α-helix conformation, while in vivo studies using a mouse model of infection exhibit that the lead dual-action dnCSP, CSP1-E1A-cyc(Dab6Dab10), attenuates group 1-mediated mortality without significantly reducing the bacterial burden. Overall, our results pave the way for developing novel therapeutics against this notorious pathogen.
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Affiliation(s)
- Muralikrishna Lella
- Department of Chemistry, University of Nevada, Reno, 1664 North Virginia Street, Reno, Nevada 89557, United States
| | - Myung Whan Oh
- Department of Pathobiology, University of Illinois at Urbana-Champaign, 2001 South Lincoln Avenue, Urbana, Illinois 61802, United States
| | - Shanny Hsuan Kuo
- Department of Pathobiology, University of Illinois at Urbana-Champaign, 2001 South Lincoln Avenue, Urbana, Illinois 61802, United States
| | - Gee W Lau
- Department of Pathobiology, University of Illinois at Urbana-Champaign, 2001 South Lincoln Avenue, Urbana, Illinois 61802, United States
| | - Yftah Tal-Gan
- Department of Chemistry, University of Nevada, Reno, 1664 North Virginia Street, Reno, Nevada 89557, United States
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6
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Milly TA, Buttner AR, Rieth N, Hutnick E, Engler ER, Campanella AR, Lella M, Bertucci MA, Tal-Gan Y. Optimizing CSP1 Analogs for Modulating Quorum Sensing in Streptococcus pneumoniae with Bulky, Hydrophobic Nonproteogenic Amino Acid Substitutions. RSC Chem Biol 2022; 3:301-311. [PMID: 35359494 PMCID: PMC8905529 DOI: 10.1039/d1cb00224d] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2021] [Accepted: 01/28/2022] [Indexed: 11/21/2022] Open
Abstract
The prompt appearance of multiantibiotic-resistant bacteria necessitates finding alternative treatments that can attenuate bacterial infections while minimizing the rate of antibiotic resistance development. Streptococcus pneumoniae, a notorious human pathogen, is responsible for severe antibiotic-resistant infections. Its pathogenicity is influenced by a cell-density communication system, termed quorum sensing (QS). As a result, controlling QS through the development of peptide-based QS modulators may serve to attenuate pneumococcal infections. Herein, we set out to evaluate the impact of the introduction of bulkier, nonproteogenic side-chain residues on the hydrophobic binding face of CSP1 to optimize receptor-binding interactions in both of the S. pneumoniae specificity groups. Our results indicate that these substitutions optimize the peptide–protein binding interactions, yielding several pneumococcal QS modulators with high potency. Moreover, pharmacological evaluation of lead analogs revealed that the incorporation of nonproteogenic amino acids increased the peptides’ half-life towards enzymatic degradation while remaining nontoxic. Overall, our data convey key considerations for SAR using nonproteogenic amino acids, which provide analogs with better pharmacological properties. The prompt appearance of multiantibiotic-resistant bacteria necessitates finding alternative treatments that can attenuate bacterial infections while minimizing the rate of antibiotic resistance development.![]()
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Affiliation(s)
- Tahmina A Milly
- Department of Chemistry, University of Nevada, Reno 1664 North Virginia Street Reno Nevada 89557 USA
| | - Alec R Buttner
- Department of Chemistry, Moravian University 1200 Main St. Bethlehem PA 18018 USA
| | - Naomi Rieth
- Department of Chemistry, Moravian University 1200 Main St. Bethlehem PA 18018 USA
| | - Elizabeth Hutnick
- Department of Chemistry, Moravian University 1200 Main St. Bethlehem PA 18018 USA
| | - Emilee R Engler
- Department of Chemistry, Moravian University 1200 Main St. Bethlehem PA 18018 USA
| | | | - Muralikrishna Lella
- Department of Chemistry, University of Nevada, Reno 1664 North Virginia Street Reno Nevada 89557 USA
| | - Michael A Bertucci
- Department of Chemistry, Lafayette College 701 Sullivan Rd. Easton PA 18042 USA
| | - Yftah Tal-Gan
- Department of Chemistry, University of Nevada, Reno 1664 North Virginia Street Reno Nevada 89557 USA
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7
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Lella M, Tal-Gan Y. Strategies to Attenuate the Competence Regulon in Streptococcus pneumoniae. Pept Sci (Hoboken) 2021; 113:e24222. [PMID: 34337308 PMCID: PMC8323945 DOI: 10.1002/pep2.24222] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Accepted: 01/19/2021] [Indexed: 12/18/2022]
Abstract
Streptococcus pneumoniae is an opportunistic respiratory human pathogen that poses a continuing threat to human health. Natural competence for genetic transformation in S. pneumoniae plays an important role in aiding pathogenicity and it is the best-characterized feature to acquire antimicrobial resistance genes by a frequent process of recombination. In S. pneumoniae, competence, along with virulence factor production, is controlled by a cell-density communication mechanism termed the competence regulon. In this review, we present the recent advances in the development of alternative methods to attenuate the pathogenicity of S. pneumoniae by targeting the various stages of the non-essential competence regulon communication system. We mainly focus on new developments related to competitively intercepting the competence regulon signaling through the introduction of promising dominant-negative Competence Stimulating Peptide (dnCSP) scaffolds. We also discuss recent reports on antibiotics that can block CSP export by disturbing the proton motive force (PMF) across the membrane and various ways to control the pneumococcal pathogenicity by activating the counter signaling circuit and targeting the pneumococcal proteome.
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Affiliation(s)
- Muralikrishna Lella
- Department of Chemistry, University of Nevada, Reno, 1664 North Virginia Street, Reno, NV 89557 (USA)
| | - Yftah Tal-Gan
- Department of Chemistry, University of Nevada, Reno, 1664 North Virginia Street, Reno, NV 89557 (USA)
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8
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Milly TA, Engler ER, Chichura KS, Buttner AR, Koirala B, Tal-Gan Y, Bertucci MA. Harnessing Multiple, Nonproteogenic Substitutions to Optimize CSP:ComD Hydrophobic Interactions in Group 1 Streptococcus pneumoniae. Chembiochem 2021; 22:1940-1947. [PMID: 33644965 DOI: 10.1002/cbic.202000876] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2020] [Revised: 02/27/2021] [Indexed: 11/12/2022]
Abstract
Streptococcus pneumoniae (pneumococcus) is a human pathobiont that causes drastic antibiotic-resistant infections and is responsible for millions of deaths universally. Pneumococcus pathogenicity relies on the competence-stimulating peptide (CSP)-mediated quorum-sensing (QS) pathway that controls competence development for genetic transformation and, consequently, the spread of antibiotic resistance and virulence genes. Modulation of QS in S. pneumoniae can therefore be used to enervate pneumococcal infectivity as well as minimize the susceptibility to resistance development. In this work, we sought to optimize the interaction of CSP1 with its cognate transmembrane histidine kinase receptor (ComD1) through substitution of proteogenic and nonproteogenic amino acids on the hydrophobic binding face of CSP1. The findings from this study not only provided additional structure-activity data that are significant in optimizing CSP1 potency, but also led to the development of potent QS modulators. These CSP-based QS modulators could be used as privileged scaffolds for the development of antimicrobial agents against pneumococcal infections.
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Affiliation(s)
- Tahmina A Milly
- Department of Chemistry, University of Nevada, Reno, 1664 North Virginia Street, Reno, NV 89557, USA
| | - Emilee R Engler
- Department of Chemistry, Moravian College, 1200 Main Street, Bethlehem, PA 18018, USA
| | - Kylie S Chichura
- Department of Chemistry, Moravian College, 1200 Main Street, Bethlehem, PA 18018, USA
| | - Alec R Buttner
- Department of Chemistry, Moravian College, 1200 Main Street, Bethlehem, PA 18018, USA
| | - Bimal Koirala
- Department of Chemistry, University of Nevada, Reno, 1664 North Virginia Street, Reno, NV 89557, USA
| | - Yftah Tal-Gan
- Department of Chemistry, University of Nevada, Reno, 1664 North Virginia Street, Reno, NV 89557, USA
| | - Michael A Bertucci
- Department of Chemistry, Moravian College, 1200 Main Street, Bethlehem, PA 18018, USA
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9
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Koirala B, Tal-Gan Y. Development of Streptococcus pneumoniae Pan-Group Quorum-Sensing Modulators. Chembiochem 2020; 21:340-345. [PMID: 31291510 PMCID: PMC6952583 DOI: 10.1002/cbic.201900365] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Indexed: 01/24/2023]
Abstract
The rapid increase in multidrug-resistant pathogens is a major health concern that could bring mankind back to the pre-antibiotic era. Streptococcus pneumoniae is a highly recombinogenic opportunistic pathogen that causes a variety of deadly diseases and rapidly develops resistance to current antibiotic treatments. S. pneumoniae pathogenicity is dependent on a cell-density communication mechanism, or quorum sensing (QS), termed the competence regulon. In this work, we set out to design signal-based QS modulators capable of affecting the two specificity groups found in S. pneumoniae. Through systematic analysis and rational design, we were able to construct peptide-based pan-group QS activators and inhibitors with activities in the nanomolar range. These novel analogues are privileged scaffolds for the development of anti-virulence therapeutics against S. pneumoniae infections.
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Affiliation(s)
- Bimal Koirala
- Department of Chemistry, University of Nevada, Reno, 1664 North Virginia Street, Reno, Nevada, 89557, United States
| | - Yftah Tal-Gan
- Department of Chemistry, University of Nevada, Reno, 1664 North Virginia Street, Reno, Nevada, 89557, United States
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10
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Koirala B, Phillips NR, Tal-Gan Y. Unveiling the Importance of Amide Protons in CSP:ComD Interactions in Streptococcus pneumoniae. ACS Med Chem Lett 2019; 10:880-886. [PMID: 31223442 DOI: 10.1021/acsmedchemlett.9b00038] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Accepted: 04/30/2019] [Indexed: 01/06/2023] Open
Abstract
Streptococcus pneumoniae is an opportunistic pathogen that can cause diseases ranging from mild respiratory infections to life-threatening conditions such as pneumonia, meningitis, and bacteremia. S. pneumoniae pathogenicity is dependent on the action of a 17-amino acid peptide pheromone, termed competence stimulating peptide (CSP) that controls the competence regulon, a quorum sensing (QS) circuit. Therefore, intercepting QS could have therapeutic implications in treating pneumococcal infections while avoiding emerging antimicrobial resistance. In this study, we set out to evaluate the impact of amide protons on CSP activity and metabolic stability through systematic N-methylation. Our results indicate that the majority of amide protons are critical for CSP activity, either through direct interactions with the cognate receptor or by stabilizing the bioactive conformation. Importantly, we identified several N-methyl CSP analogs, namely, CSP1(15)-N-Me-K6 and CSP1(15)-N-Me-F7, that retain their biological activity while exhibiting enhanced metabolic stability. These analogs are privileged scaffolds for the design of CSP-based QS modulators with drug-like properties.
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Affiliation(s)
- Bimal Koirala
- Department of Chemistry, University of Nevada, Reno, 1664 North Virginia Street, Reno, Nevada 89557, United States
| | - Naiya R. Phillips
- Department of Chemistry, University of Nevada, Reno, 1664 North Virginia Street, Reno, Nevada 89557, United States
| | - Yftah Tal-Gan
- Department of Chemistry, University of Nevada, Reno, 1664 North Virginia Street, Reno, Nevada 89557, United States
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11
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Yang Y, Tal-Gan Y. Exploring the competence stimulating peptide (CSP) N-terminal requirements for effective ComD receptor activation in group1 Streptococcus pneumoniae. Bioorg Chem 2019; 89:102987. [PMID: 31132605 DOI: 10.1016/j.bioorg.2019.102987] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2019] [Accepted: 05/16/2019] [Indexed: 12/14/2022]
Abstract
The competence stimulating peptide (CSP) plays a key role in the regulation of pneumococcal quorum sensing (QS), a communication system that is critical to the infectivity of pneumococci. CSP functions through binding and activating a transmembrane receptor, ComD. Molecules that can modulate pneumococcal QS through intercepting CSP:ComD interaction may serve as new generation of antibacterial agents to treat pneumococcal infections. In this work, we systematically modified the N-terminus of CSP1, a region that is essential to ComD activation, to identify detailed structural features of the N-terminus that are responsible for its function. Our results revealed structural features that are optimal to achieve receptor activation and structure-activity trends that improve our understanding of CSP:ComD interaction, all of which will contribute to the design of novel pneumococcal QS modulators with higher potency and improved pharmacological properties.
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Affiliation(s)
- Yifang Yang
- Department of Chemistry, University of Nevada, Reno, 1664 North Virginia Street, Reno, Nevada 89557, United States
| | - Yftah Tal-Gan
- Department of Chemistry, University of Nevada, Reno, 1664 North Virginia Street, Reno, Nevada 89557, United States.
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12
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Yang Y, Koirala B, Sanchez LA, Phillips NR, Hamry SR, Tal-Gan Y. Structure-Activity Relationships of the Competence Stimulating Peptides (CSPs) in Streptococcus pneumoniae Reveal Motifs Critical for Intra-group and Cross-group ComD Receptor Activation. ACS Chem Biol 2017; 12:1141-1151. [PMID: 28221753 DOI: 10.1021/acschembio.7b00007] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Streptococcus pneumoniae is a highly recombinogenic human pathogen that utilizes the competence stimulating peptide (CSP)-based quorum sensing (QS) circuitry to acquire antibiotic resistance genes from the environment and initiate its attack on the human host. Modulation of QS in this bacterium, either inhibition or activation, can therefore be used to attenuate S. pneumoniae infectivity and slow down pneumococcal resistance development. In this study, we set to determine the molecular mechanism that drives CSP:receptor binding and identify CSP-based QS modulators with distinct activity profiles. To this end, we conducted systematic replacement of the amino acid residues in the two major CSP signals (CSP1 and CSP2) and assessed the ability of the mutated analogs to modulate QS against both cognate and noncognate ComD receptors. We then evaluated the overall 3D structures of these analogs using circular dichroism (CD) to correlate between the structure and function of these peptides. Our CD analysis revealed a strong correlation between α-helicity and bioactivity for both specificity groups (CSP1 and CSP2). Furthermore, we identified the first pan-group QS activator and the most potent group-II QS inhibitor to date. These chemical probes can be used to study the role of QS in S. pneumoniae and as scaffolds for the design of QS-based anti-infective therapeutics against S. pneumoniae infections.
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Affiliation(s)
- Yifang Yang
- Department of Chemistry, University of Nevada, Reno, 1664 North Virginia Street, Reno, Nevada 89557, United States
| | - Bimal Koirala
- Department of Chemistry, University of Nevada, Reno, 1664 North Virginia Street, Reno, Nevada 89557, United States
| | - Lucia A. Sanchez
- Department of Chemistry, University of Nevada, Reno, 1664 North Virginia Street, Reno, Nevada 89557, United States
| | - Naiya R. Phillips
- Department of Chemistry, University of Nevada, Reno, 1664 North Virginia Street, Reno, Nevada 89557, United States
| | - Sally R. Hamry
- Department of Chemistry, University of Nevada, Reno, 1664 North Virginia Street, Reno, Nevada 89557, United States
| | - Yftah Tal-Gan
- Department of Chemistry, University of Nevada, Reno, 1664 North Virginia Street, Reno, Nevada 89557, United States
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13
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Zhu L, Lau GW. Therapeutic potential of the Streptococcus pneumoniae competence regulon. Expert Rev Anti Infect Ther 2013; 11:227-9. [PMID: 23458762 DOI: 10.1586/eri.13.10] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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