1
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Baranova AA, Tyurin AP, Korshun VA, Alferova VA. Sensing of Antibiotic-Bacteria Interactions. Antibiotics (Basel) 2023; 12:1340. [PMID: 37627760 PMCID: PMC10451291 DOI: 10.3390/antibiotics12081340] [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: 07/05/2023] [Revised: 08/15/2023] [Accepted: 08/17/2023] [Indexed: 08/27/2023] Open
Abstract
Sensing of antibiotic-bacteria interactions is an important area of research that has gained significant attention in recent years. Antibiotic resistance is a major public health concern, and it is essential to develop new strategies for detecting and monitoring bacterial responses to antibiotics in order to maintain effective antibiotic development and antibacterial treatment. This review summarizes recent advances in sensing strategies for antibiotic-bacteria interactions, which are divided into two main parts: studies on the mechanism of action for sensitive bacteria and interrogation of the defense mechanisms for resistant ones. In conclusion, this review provides an overview of the present research landscape concerning antibiotic-bacteria interactions, emphasizing the potential for method adaptation and the integration of machine learning techniques in data analysis, which could potentially lead to a transformative impact on mechanistic studies within the field.
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Affiliation(s)
| | | | | | - Vera A. Alferova
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Miklukho-Maklaya 16/10, 117997 Moscow, Russia; (A.A.B.); (A.P.T.); (V.A.K.)
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2
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Hilpert K, Rumancev C, Gani J, Collis DWP, Lopez-Perez PM, Garamus VM, Mikut R, Rosenhahn A. Can BioSAXS detect ultrastructural changes of antifungal compounds in Candida albicans?-an exploratory study. Front Pharmacol 2023; 14:1141785. [PMID: 37533629 PMCID: PMC10393279 DOI: 10.3389/fphar.2023.1141785] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2023] [Accepted: 07/06/2023] [Indexed: 08/04/2023] Open
Abstract
The opportunistic yeast Candida albicans is the most common cause of candidiasis. With only four classes of antifungal drugs on the market, resistance is becoming a problem in the treatment of fungal infections, especially in immunocompromised patients. The development of novel antifungal drugs with different modes of action is urgent. In 2016, we developed a groundbreaking new medium-throughput method to distinguish the effects of antibacterial agents. Using small-angle X-ray scattering for biological samples (BioSAXS), it is now possible to screen hundreds of new antibacterial compounds and select those with the highest probability for a novel mode of action. However, yeast (eukaryotic) cells are highly structured compared to bacteria. The fundamental question to answer was if the ultrastructural changes induced by the action of an antifungal drug can be detected even when most structures in the cell stay unchanged. In this exploratory work, BioSAXS was used to measure the ultrastructural changes of C. albicans that were directly or indirectly induced by antifungal compounds. For this, the well-characterized antifungal drug Flucytosine was used. BioSAXS measurements were performed on the synchrotron P12 BioSAXS beamline, EMBL (DESY, Hamburg) on treated and untreated yeast C. albicans. BioSAXS curves were analysed using principal component analysis (PCA). The PCA showed that Flucytosine-treated and untreated yeast were separated. Based on that success further measurements were performed on five antifungal peptides {1. Cecropin A-melittin hybrid [CA (1-7) M (2-9)], KWKLFKKIGAVLKVL; 2. Lasioglossin LL-III, VNWKKILGKIIKVVK; 3. Mastoparan M, INLKAIAALAKKLL; 4. Bmkn2, FIGAIARLLSKIFGKR; and 5. optP7, KRRVRWIIW}. The ultrastructural changes of C. albicans indicate that the peptides may have different modes of action compared to Flucytosine as well as to each other, except for the Cecropin A-melittin hybrid [CA (1-7) M (2-9)] and optP7, showing very similar effects on C. albicans. This very first study demonstrates that BioSAXS shows promise to be used for antifungal drug development. However, this first study has limitations and further experiments are necessary to establish this application.
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Affiliation(s)
- Kai Hilpert
- Institute of Infection and Immunology, St. George’s, University of London (SGUL), London, United Kingdom
| | - Christoph Rumancev
- Laboratory Analytical Chemistry—Biointerfaces, Ruhr-University Bochum, Bochum, Germany
| | - Jurnorain Gani
- Institute of Infection and Immunology, St. George’s, University of London (SGUL), London, United Kingdom
| | | | | | | | - Ralf Mikut
- Institute for Automation and Applied Informatics (IAI), Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany
| | - Axel Rosenhahn
- Laboratory Analytical Chemistry—Biointerfaces, Ruhr-University Bochum, Bochum, Germany
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3
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Cheung E, Xia Y, Caporini MA, Gilmore JL. Tools shaping drug discovery and development. BIOPHYSICS REVIEWS 2022; 3:031301. [PMID: 38505278 PMCID: PMC10903431 DOI: 10.1063/5.0087583] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Accepted: 06/21/2022] [Indexed: 03/21/2024]
Abstract
Spectroscopic, scattering, and imaging methods play an important role in advancing the study of pharmaceutical and biopharmaceutical therapies. The tools more familiar to scientists within industry and beyond, such as nuclear magnetic resonance and fluorescence spectroscopy, serve two functions: as simple high-throughput techniques for identification and purity analysis, and as potential tools for measuring dynamics and structures of complex biological systems, from proteins and nucleic acids to membranes and nanoparticle delivery systems. With the expansion of commercial small-angle x-ray scattering instruments into the laboratory setting and the accessibility of industrial researchers to small-angle neutron scattering facilities, scattering methods are now used more frequently in the industrial research setting, and probe-less time-resolved small-angle scattering experiments are now able to be conducted to truly probe the mechanism of reactions and the location of individual components in complex model or biological systems. The availability of atomic force microscopes in the past several decades enables measurements that are, in some ways, complementary to the spectroscopic techniques, and wholly orthogonal in others, such as those related to nanomechanics. As therapies have advanced from small molecules to protein biologics and now messenger RNA vaccines, the depth of biophysical knowledge must continue to serve in drug discovery and development to ensure quality of the drug, and the characterization toolbox must be opened up to adapt traditional spectroscopic methods and adopt new techniques for unraveling the complexities of the new modalities. The overview of the biophysical methods in this review is meant to showcase the uses of multiple techniques for different modalities and present recent applications for tackling particularly challenging situations in drug development that can be solved with the aid of fluorescence spectroscopy, nuclear magnetic resonance spectroscopy, atomic force microscopy, and small-angle scattering.
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Affiliation(s)
- Eugene Cheung
- Moderna, 200 Technology Square, Cambridge, Massachusetts 02139, USA
| | - Yan Xia
- Moderna, 200 Technology Square, Cambridge, Massachusetts 02139, USA
| | - Marc A. Caporini
- Moderna, 200 Technology Square, Cambridge, Massachusetts 02139, USA
| | - Jamie L. Gilmore
- Moderna, 200 Technology Square, Cambridge, Massachusetts 02139, USA
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4
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Rumancev C, Rosenhahn A, Hilpert K. BioSAXS–an emerging method to accelerate, enrich and de-risk antimicrobial drug development. Front Pharmacol 2022; 13:947005. [PMID: 36081947 PMCID: PMC9445215 DOI: 10.3389/fphar.2022.947005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Accepted: 06/27/2022] [Indexed: 11/13/2022] Open
Abstract
Antimicrobial resistance is a worldwide threat to modern health care. Low-profit margin and high risk of cross-resistance resulted in a loss of interest in big pharma, contributing to the increasing threat. Strategies to address the problem are starting to emerge. Novel antimicrobial compounds with novel modes of action are especially valued because they have a lower risk of cross-resistance. Up to now determining the mode of action has been very time and resource consuming and will be performed once drug candidates were already progressed in preclinical development. BioSAXS is emerging as a new method to test up to thousands of compounds to classify them into groups based on ultra-structural changes that correlate to their modes of action. First experiments in E. coli (gram-negative) have demonstrated that using conventional and experimental antimicrobials a classification of compounds according to their mode of action was possible. Results were backed up by transmission electron microscopy. Further work showed that also gram-positive bacteria (Staphylococcus aureus) can be used and the effects of novel antimicrobial peptides on both types of bacteria were studied. Preliminary experiments also show that BioSAXS can be used to classify antifungal drugs, demonstrated on Candida albicans. In summary, BioSAXS can accelerate and enrich the discovery of antimicrobial compounds from screening projects with a novel mode of action and hence de-risk the development of urgently needed antimicrobial drugs.
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Affiliation(s)
- Christoph Rumancev
- Analytical Chemistry, Biointerfaces, Ruhr-University Bochum, Bochum, Germany
| | - Axel Rosenhahn
- Analytical Chemistry, Biointerfaces, Ruhr-University Bochum, Bochum, Germany
- *Correspondence: Axel Rosenhahn,
| | - Kai Hilpert
- Institute of Infection and Immunology, University of London, London, United Kingdom
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5
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Duarte H, Gummel J, Robles E, Berti D, Fratini E. Ultra-/Small Angle X-ray Scattering (USAXS/SAXS) and Static Light Scattering (SLS) Modeling as a Tool to Determine Structural Changes and Effect on Growth in S. epidermidis. ACS APPLIED BIO MATERIALS 2022; 5:3703-3712. [PMID: 35905477 PMCID: PMC9940853 DOI: 10.1021/acsabm.2c00218] [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] [Indexed: 11/29/2022]
Abstract
Usually, to characterize bacterial cells' susceptibility to antimicrobials, basic microbiology techniques such as serial dilutions or disk assays are used. In this work, we present an approach focused on combining static light scattering (SLS) and ultra-/small angle X-ray scattering (USAXS/SAXS). This approach was used to support microbiology techniques, with the aim of understanding the structural changes caused to bacteria when they are exposed to different stresses like pH, oxidation, and surfactants. Using USAXS/SAXS and SLS data, we developed a detailed multiscale model for a Gram-positive bacterium, S. epidermidis, and we extracted information regarding changes in the overall size and cell thickness induced by different stresses (i.e., pH and hydrogen peroxide). Increasing the concentration of hydrogen peroxide leads to a progressive reduction in cell wall thickness. Moreover, the concomitant use of pH and hydrogen peroxide provides evidence for a synergy in inhibiting the S. epidermidis growth. These promising results will be used as a starting base to further investigate more complex formulations and improve/refine the data modeling of bacteria in the small angle scattering regime.
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Affiliation(s)
- Hugo Duarte
- Department
of Chemistry “Ugo Schiff” and CSGI, University of Florence, Sesto
Fiorentino, Florence I-50019, Italy,
| | - Jeremie Gummel
- Brussels
Innovation Centre, Temselaan
100, Strombeek-bever B-1853, Belgium
| | - Eric Robles
- Household
Care Analytical, Procter & Gamble Newcastle
Innovation Centre, Newcastle NE12 9TS, United Kingdom
| | - Debora Berti
- Department
of Chemistry “Ugo Schiff” and CSGI, University of Florence, Sesto
Fiorentino, Florence I-50019, Italy
| | - Emiliano Fratini
- Department
of Chemistry “Ugo Schiff” and CSGI, University of Florence, Sesto
Fiorentino, Florence I-50019, Italy,
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6
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Hilpert K, Gani J, Rumancev C, Simpson N, Lopez-Perez PM, Garamus VM, von Gundlach AR, Markov P, Scocchi M, Mikut R, Rosenhahn A. Rational Designed Hybrid Peptides Show up to a 6-Fold Increase in Antimicrobial Activity and Demonstrate Different Ultrastructural Changes as the Parental Peptides Measured by BioSAXS. Front Pharmacol 2021; 12:769739. [PMID: 34966279 PMCID: PMC8711299 DOI: 10.3389/fphar.2021.769739] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2021] [Accepted: 11/12/2021] [Indexed: 11/27/2022] Open
Abstract
Antimicrobial peptides (AMPs) are a promising class of compounds being developed against multi-drug resistant bacteria. Hybridization has been reported to increase antimicrobial activity. Here, two proline-rich peptides (consP1: VRKPPYLPRPRPRPL-CONH2 and Bac5-v291: RWRRPIRRRPIRPPFWR-CONH2) were combined with two arginine-isoleucine-rich peptides (optP1: KIILRIRWR-CONH2 and optP7: KRRVRWIIW-CONH2). Proline-rich antimicrobial peptides (PrAMPs) are known to inhibit the bacterial ribosome, shown also for Bac5-v291, whereas it is hypothesized a “dirty drug” model for the arginine-isoleucine-rich peptides. That hypothesis was underpinned by transmission electron microscopy and biological small-angle X-ray scattering (BioSAXS). The strength of BioSAXS is the power to detect ultrastructural changes in millions of cells in a short time (seconds) in a high-throughput manner. This information can be used to classify antimicrobial compounds into groups according to the ultrastructural changes they inflict on bacteria and how the bacteria react towards that assault. Based on previous studies, this correlates very well with different modes of action. Due to the novelty of this approach direct identification of the target of the antimicrobial compound is not yet fully established, more research is needed. More research is needed to address this limitation. The hybrid peptides showed a stronger antimicrobial activity compared to the proline-rich peptides, except when compared to Bac5-v291 against E. coli. The increase in activity compared to the arginine-isoleucine-rich peptides was up to 6-fold, however, it was not a general increase but was dependent on the combination of peptides and bacteria. BioSAXS experiments revealed that proline-rich peptides and arginine-isoleucine-rich peptides induce very different ultrastructural changes in E. coli, whereas a hybrid peptide (hyP7B5GK) shows changes, different to both parental peptides and the untreated control. These different ultrastructural changes indicated that the mode of action of the parental peptides might be different from each other as well as from the hybrid peptide hyP7B5GK. All peptides showed very low haemolytic activity, some of them showed a 100-fold or larger therapeutic window, demonstrating the potential for further drug development.
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Affiliation(s)
- Kai Hilpert
- Institute of Infection and Immunology, St. George's, University of London, London, United Kingdom
| | - Jurnorain Gani
- Institute of Infection and Immunology, St. George's, University of London, London, United Kingdom
| | - Christoph Rumancev
- Laboratory Analytical Chemistry - Biointerfaces, Ruhr University Bochum, Bochum, Germany
| | - Nathan Simpson
- Institute of Infection and Immunology, St. George's, University of London, London, United Kingdom
| | | | | | | | - Petar Markov
- European Molecular Biology Laboratory, Hamburg Outstation, Hamburg, Germany
| | - Marco Scocchi
- Department of Life Sciences, University of Trieste, Trieste, Italy
| | - Ralf Mikut
- Institute for Automation and Applied Informatics (IAI), Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany
| | - Axel Rosenhahn
- Laboratory Analytical Chemistry - Biointerfaces, Ruhr University Bochum, Bochum, Germany
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7
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Kursula P. Small-angle X-ray scattering for the proteomics community: current overview and future potential. Expert Rev Proteomics 2021; 18:415-422. [PMID: 34210208 DOI: 10.1080/14789450.2021.1951242] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Introduction: Proteins are biological nanoparticles. For structural proteomics and hybrid structural biology, complementary methods are required that allow both high throughput and accurate automated data analysis. Small-angle X-ray scattering (SAXS) is a method for observing the size and shape of particles, such as proteins and complexes, in solution. SAXS data can be used to model both the structure, oligomeric state, conformational changes, and flexibility of biomolecular samples.Areas covered: The key principles of SAXS, its sample requirements, and its current and future applications for structural proteomics are briefly reviewed. Recent technical developments in SAXS experiments are discussed, and future potential of the method in structural proteomics is evaluated.Expert opinion: SAXS is a method suitable for several aspects of integrative structural proteomics, with current technical developments allowing for higher throughput and time-resolved studies, as well as the analysis of complex samples, such as membrane proteins. Increasing automation and streamlined data analysis are expected to equip SAXS for structure-based screening workflows. Originally, structural genomics had a heavy focus on folded, crystallizable proteins and complexes - SAXS is a method allowing an expansion of this focus to flexible and disordered systems.
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Affiliation(s)
- Petri Kursula
- Department of Biomedicine, University of Bergen, Bergen, Norway.,Biocenter Oulu & Faculty of Biochemistry and Molecular Medicine, University of Oulu, Oulu, Finland
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8
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Comparison of a Short Linear Antimicrobial Peptide with Its Disulfide-Cyclized and Cyclotide-Grafted Variants against Clinically Relevant Pathogens. Microorganisms 2021; 9:microorganisms9061249. [PMID: 34201398 PMCID: PMC8228819 DOI: 10.3390/microorganisms9061249] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Accepted: 06/04/2021] [Indexed: 12/14/2022] Open
Abstract
According to the World Health Organization (WHO) the development of resistance against antibiotics by microbes is one of the most pressing health concerns. The situation will intensify since only a few pharmacological companies are currently developing novel antimicrobial compounds. Discovery and development of novel antimicrobial compounds with new modes of action are urgently needed. Antimicrobial peptides (AMPs) are known to be able to kill multidrug-resistant bacteria and, therefore, of interest to be developed into antimicrobial drugs. Proteolytic stability and toxicities of these peptides are challenges to overcome, and one strategy frequently used to address stability is cyclization. Here we introduced a disulfide-bond to cyclize a potent and nontoxic 9mer peptide and, in addition, as a proof-of-concept study, grafted this peptide into loop 6 of the cyclotide MCoTI-II. This is the first time an antimicrobial peptide has been successfully grafted onto the cyclotide scaffold. The disulfide-cyclized and grafted cyclotide showed moderate activity in broth and strong activity in 1/5 broth against clinically relevant resistant pathogens. The linear peptide showed superior activity in both conditions. The half-life time in 100% human serum was determined, for the linear peptide, to be 13 min, for the simple disulfide-cyclized peptide, 9 min, and, for the grafted cyclotide 7 h 15 min. The addition of 10% human serum led to a loss of antimicrobial activity for the different organisms, ranging from 1 to >8-fold for the cyclotide. For the disulfide-cyclized version and the linear version, activity also dropped to different degrees, 2 to 18-fold, and 1 to 30-fold respectively. Despite the massive difference in stability, the linear peptide still showed superior antimicrobial activity. The cyclotide and the disulfide-cyclized version demonstrated a slower bactericidal effect than the linear version. All three peptides were stable at high and low pH, and had very low hemolytic and cytotoxic activity.
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9
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Rumancev C, Vöpel T, Stuhr S, Gundlach AR, Senkbeil T, Osterhoff M, Sprung M, Garamus VM, Ebbinghaus S, Rosenhahn A. In Cellulo Analysis of Huntingtin Inclusion Bodies by Cryogenic Nanoprobe SAXS. CHEMSYSTEMSCHEM 2021. [DOI: 10.1002/syst.202000050] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Christoph Rumancev
- Analytical Chemistry – Biointerfaces Ruhr University Bochum Universitätsstr. 150 44780 Bochum Germany
| | - Tobias Vöpel
- Department of Physical Chemistry II Ruhr University Bochum Universitätsstr. 150 44780 Bochum Germany
| | - Susan Stuhr
- Analytical Chemistry – Biointerfaces Ruhr University Bochum Universitätsstr. 150 44780 Bochum Germany
| | - Andreas R. Gundlach
- Analytical Chemistry – Biointerfaces Ruhr University Bochum Universitätsstr. 150 44780 Bochum Germany
| | - Tobias Senkbeil
- Analytical Chemistry – Biointerfaces Ruhr University Bochum Universitätsstr. 150 44780 Bochum Germany
| | - Markus Osterhoff
- Deutsches Elektronen-Synchrotron DESY Notkestr. 85 22607 Hamburg Germany
| | - Michael Sprung
- Deutsches Elektronen-Synchrotron DESY Notkestr. 85 22607 Hamburg Germany
| | - Vasil M. Garamus
- Helmholtz-Zentrum Geesthacht: Centre for Materials and Coast Research Institute of Materials Research Max-Planck-Str. 1 21502 Geesthacht Germany
| | - Simon Ebbinghaus
- Department of Physical Chemistry II Ruhr University Bochum Universitätsstr. 150 44780 Bochum Germany
- Institute of Physical and Theoretical Chemistry TU Braunschweig Rebenring 56 38106 Braunschweig Germany
| | - Axel Rosenhahn
- Analytical Chemistry – Biointerfaces Ruhr University Bochum Universitätsstr. 150 44780 Bochum Germany
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10
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Semeraro EF, Marx L, Mandl J, Frewein MPK, Scott HL, Prévost S, Bergler H, Lohner K, Pabst G. Evolution of the analytical scattering model of live Escherichia coli. J Appl Crystallogr 2021; 54:473-485. [PMID: 33953653 PMCID: PMC8056759 DOI: 10.1107/s1600576721000169] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Accepted: 01/05/2021] [Indexed: 11/10/2022] Open
Abstract
A previously reported multi-scale model for (ultra-)small-angle X-ray (USAXS/SAXS) and (very) small-angle neutron scattering (VSANS/SANS) of live Escherichia coli was revised on the basis of compositional/metabolomic and ultrastructural constraints. The cellular body is modeled, as previously described, by an ellipsoid with multiple shells. However, scattering originating from flagella was replaced by a term accounting for the oligosaccharide cores of the lipopolysaccharide leaflet of the outer membrane including its cross-term with the cellular body. This was mainly motivated by (U)SAXS experiments showing indistinguishable scattering for bacteria in the presence and absence of flagella or fimbrae. The revised model succeeded in fitting USAXS/SAXS and differently contrasted VSANS/SANS data of E. coli ATCC 25922 over four orders of magnitude in length scale. Specifically, this approach provides detailed insight into structural features of the cellular envelope, including the distance of the inner and outer membranes, as well as the scattering length densities of all bacterial compartments. The model was also successfully applied to E. coli K12, used for the authors' original modeling, as well as for two other E. coli strains. Significant differences were detected between the different strains in terms of bacterial size, intermembrane distance and its positional fluctuations. These findings corroborate the general applicability of the approach outlined here to quantitatively study the effect of bactericidal compounds on ultrastructural features of Gram-negative bacteria without the need to resort to any invasive staining or labeling agents.
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Affiliation(s)
- Enrico F Semeraro
- University of Graz, Institute of Molecular Biosciences, NAWI Graz, 8010 Graz, Austria.,BioTechMed Graz, 8010 Graz, Austria.,Field of Excellence BioHealth - University of Graz, Graz, Austria
| | - Lisa Marx
- University of Graz, Institute of Molecular Biosciences, NAWI Graz, 8010 Graz, Austria.,BioTechMed Graz, 8010 Graz, Austria.,Field of Excellence BioHealth - University of Graz, Graz, Austria
| | - Johannes Mandl
- University of Graz, Institute of Molecular Biosciences, NAWI Graz, 8010 Graz, Austria.,BioTechMed Graz, 8010 Graz, Austria.,Field of Excellence BioHealth - University of Graz, Graz, Austria
| | - Moritz P K Frewein
- University of Graz, Institute of Molecular Biosciences, NAWI Graz, 8010 Graz, Austria.,BioTechMed Graz, 8010 Graz, Austria.,Field of Excellence BioHealth - University of Graz, Graz, Austria.,Institut Laue-Langevin, 38043 Grenoble, France
| | - Haden L Scott
- University of Tennessee, Center for Environmental Biotechnology, Knoxville, Tennessee, USA
| | | | - Helmut Bergler
- University of Graz, Institute of Molecular Biosciences, NAWI Graz, 8010 Graz, Austria.,BioTechMed Graz, 8010 Graz, Austria.,Field of Excellence BioHealth - University of Graz, Graz, Austria
| | - Karl Lohner
- University of Graz, Institute of Molecular Biosciences, NAWI Graz, 8010 Graz, Austria.,BioTechMed Graz, 8010 Graz, Austria.,Field of Excellence BioHealth - University of Graz, Graz, Austria
| | - Georg Pabst
- University of Graz, Institute of Molecular Biosciences, NAWI Graz, 8010 Graz, Austria.,BioTechMed Graz, 8010 Graz, Austria.,Field of Excellence BioHealth - University of Graz, Graz, Austria
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11
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Semeraro EF, Marx L, Frewein MPK, Pabst G. Increasing complexity in small-angle X-ray and neutron scattering experiments: from biological membrane mimics to live cells. SOFT MATTER 2021; 17:222-232. [PMID: 32104874 DOI: 10.1039/c9sm02352f] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Small-angle X-ray and neutron scattering are well-established, non-invasive experimental techniques to interrogate global structural properties of biological membrane mimicking systems under physiologically relevant conditions. Recent developments, both in bottom-up sample preparation techniques for increasingly complex model systems, and in data analysis techniques have opened the path toward addressing long standing issues of biological membrane remodelling processes. These efforts also include emerging quantitative scattering studies on live cells, thus enabling a bridging of molecular to cellular length scales. Here, we review recent progress in devising compositional models for joint small-angle X-ray and neutron scattering studies on diverse membrane mimics - with a specific focus on membrane structural coupling to amphiphatic peptides and integral proteins - and live Escherichia coli. In particular, we outline the present state-of-the-art in small-angle scattering methods applied to complex membrane systems, highlighting how increasing system complexity must be followed by an advance in compositional modelling and data-analysis tools.
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Affiliation(s)
- Enrico F Semeraro
- University of Graz, Institute of Molecular Biosciences, Biophysics Division, NAWI Graz, 8010 Graz, Austria. and BioTechMed Graz, 8010 Graz, Austria
| | - Lisa Marx
- University of Graz, Institute of Molecular Biosciences, Biophysics Division, NAWI Graz, 8010 Graz, Austria. and BioTechMed Graz, 8010 Graz, Austria
| | - Moritz P K Frewein
- University of Graz, Institute of Molecular Biosciences, Biophysics Division, NAWI Graz, 8010 Graz, Austria. and BioTechMed Graz, 8010 Graz, Austria and Institut Laue-Langevin, 38000 Grenoble, France
| | - Georg Pabst
- University of Graz, Institute of Molecular Biosciences, Biophysics Division, NAWI Graz, 8010 Graz, Austria. and BioTechMed Graz, 8010 Graz, Austria
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12
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Lombardo D, Calandra P, Kiselev MA. Structural Characterization of Biomaterials by Means of Small Angle X-rays and Neutron Scattering (SAXS and SANS), and Light Scattering Experiments. Molecules 2020; 25:E5624. [PMID: 33260426 PMCID: PMC7730346 DOI: 10.3390/molecules25235624] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2020] [Revised: 11/25/2020] [Accepted: 11/26/2020] [Indexed: 12/13/2022] Open
Abstract
Scattering techniques represent non-invasive experimental approaches and powerful tools for the investigation of structure and conformation of biomaterial systems in a wide range of distances, ranging from the nanometric to micrometric scale. More specifically, small-angle X-rays and neutron scattering and light scattering techniques represent well-established experimental techniques for the investigation of the structural properties of biomaterials and, through the use of suitable models, they allow to study and mimic various biological systems under physiologically relevant conditions. They provide the ensemble averaged (and then statistically relevant) information under in situ and operando conditions, and represent useful tools complementary to the various traditional imaging techniques that, on the contrary, reveal more local structural information. Together with the classical structure characterization approaches, we introduce the basic concepts that make it possible to examine inter-particles interactions, and to study the growth processes and conformational changes in nanostructures, which have become increasingly relevant for an accurate understanding and prediction of various mechanisms in the fields of biotechnology and nanotechnology. The upgrade of the various scattering techniques, such as the contrast variation or time resolved experiments, offers unique opportunities to study the nano- and mesoscopic structure and their evolution with time in a way not accessible by other techniques. For this reason, highly performant instruments are installed at most of the facility research centers worldwide. These new insights allow to largely ameliorate the control of (chemico-physical and biologic) processes of complex (bio-)materials at the molecular length scales, and open a full potential for the development and engineering of a variety of nano-scale biomaterials for advanced applications.
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Affiliation(s)
- Domenico Lombardo
- CNR-IPCF, Consiglio Nazionale delle Ricerche, Istituto per i Processi Chimico-Fisici, 98158 Messina, Italy
| | - Pietro Calandra
- CNR-ISMN, Consiglio Nazionale delle Ricerche, Istituto Studio Materiali Nanostrutturati, 00015 Roma, Italy;
| | - Mikhail A. Kiselev
- Frank Laboratory of Neutron Physics, Joint Institute for Nuclear Research, Dubna, 141980 Moscow, Russia;
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13
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Zamani E, Johnson TJ, Chatterjee S, Immethun C, Sarella A, Saha R, Dishari SK. Cationic π-Conjugated Polyelectrolyte Shows Antimicrobial Activity by Causing Lipid Loss and Lowering Elastic Modulus of Bacteria. ACS APPLIED MATERIALS & INTERFACES 2020; 12:49346-49361. [PMID: 33089982 PMCID: PMC8926324 DOI: 10.1021/acsami.0c12038] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Cationic, π-conjugated oligo-/polyelectrolytes (CCOEs/CCPEs) have shown great potential as antimicrobial materials to fight against antibiotic resistance. In this work, we treated wild-type and ampicillin-resistant (amp-resistant) Escherichia coli (E. coli) with a promising cationic, π-conjugated polyelectrolyte (P1) with a phenylene-based backbone and investigated the resulting morphological, mechanical, and compositional changes of the outer membrane of bacteria in great detail. The cationic quaternary amine groups of P1 led to electrostatic interactions with negatively charged moieties within the outer membrane of bacteria. Using atomic force microscopy (AFM), high-resolution transmission electron microscopy (TEM), we showed that due to this treatment, the bacterial outer membrane became rougher, decreased in stiffness/elastic modulus (AFM nanoindentation), formed blebs, and released vesicles near the cells. These evidences, in addition to increased staining of the P1-treated cell membrane by lipophilic dye Nile Red (confocal laser scanning microscopy (CLSM)), suggested loosening/disruption of packing of the outer cell envelope and release and exposure of lipid-based components. Lipidomics and fatty acid analysis confirmed a significant loss of phosphate-based outer membrane lipids and fatty acids, some of which are critically needed to maintain cell wall integrity and mechanical strength. Lipidomics and UV-vis analysis also confirmed that the extracellular vesicles released upon treatment (AFM) are composed of lipids and cationic P1. Such surface alterations (vesicle/bleb formation) and release of lipids/fatty acids upon treatment were effective enough to inhibit further growth of E. coli cells without completely disintegrating the cells and have been known as a defense mechanism of the cells against cationic antimicrobial agents.
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Affiliation(s)
- Ehsan Zamani
- Department of Chemical and Biomolecular Engineering, University of Nebraska-Lincoln, Lincoln, Nebraska 68588, United States
| | - Tyler J. Johnson
- Department of Chemical and Biomolecular Engineering, University of Nebraska-Lincoln, Lincoln, Nebraska 68588, United States
| | - Shyambo Chatterjee
- Department of Chemical and Biomolecular Engineering, University of Nebraska-Lincoln, Lincoln, Nebraska 68588, United States
| | - Cheryl Immethun
- Department of Chemical and Biomolecular Engineering, University of Nebraska-Lincoln, Lincoln, Nebraska 68588, United States
| | - Anandakumar Sarella
- Nebraska Center for Materials and Nanoscience, Voelte-Keegan Nanoscience Research Center, University of Nebraska-Lincoln, Lincoln, NE 68588-0298, United States
| | - Rajib Saha
- Department of Chemical and Biomolecular Engineering, University of Nebraska-Lincoln, Lincoln, Nebraska 68588, United States
| | - Shudipto Konika Dishari
- Department of Chemical and Biomolecular Engineering, University of Nebraska-Lincoln, Lincoln, Nebraska 68588, United States
- Corresponding author’s ; Phone: 402-472-7537
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14
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Malanovic N, Ön A, Pabst G, Zellner A, Lohner K. Octenidine: Novel insights into the detailed killing mechanism of Gram-negative bacteria at a cellular and molecular level. Int J Antimicrob Agents 2020; 56:106146. [DOI: 10.1016/j.ijantimicag.2020.106146] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Revised: 07/28/2020] [Accepted: 08/19/2020] [Indexed: 01/30/2023]
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15
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Chen PC, Masiewicz P, Perez K, Hennig J. Structure-based screening of binding affinities via small-angle X-ray scattering. IUCRJ 2020; 7:644-655. [PMID: 32695411 PMCID: PMC7340254 DOI: 10.1107/s2052252520004169] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/10/2019] [Accepted: 03/26/2020] [Indexed: 06/11/2023]
Abstract
Protein-protein and protein-ligand interactions often involve conformational changes or structural rearrangements that can be quantified by solution small-angle X-ray scattering (SAXS). These scattering intensity measurements reveal structural details of the bound complex, the number of species involved and, additionally, the strength of interactions if carried out as a titration. Although a core part of structural biology workflows, SAXS-based titrations are not commonly used in drug discovery contexts. This is because prior knowledge of expected sample requirements, throughput and prediction accuracy is needed to develop reliable ligand screens. This study presents the use of the histidine-binding protein (26 kDa) and other periplasmic binding proteins to benchmark ligand screen performance. Sample concentrations and exposure times were varied across multiple screening trials at four beamlines to investigate the accuracy and precision of affinity prediction. The volatility ratio between titrated scattering curves and a common apo reference is found to most reliably capture the extent of structural and population changes. This obviates the need to explicitly model scattering intensities of bound complexes, which can be strongly ligand-dependent. Where the dissociation constant is within 102 of the protein concentration and the total exposure times exceed 20 s, the titration protocol presented at 0.5 mg ml-1 yields affinities comparable to isothermal titration calorimetry measurements. Estimated throughput ranges between 20 and 100 ligand titrations per day at current synchrotron beamlines, with the limiting step imposed by sample handling and cleaning procedures.
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Affiliation(s)
- Po-chia Chen
- Structural and Computational Biology Unit, EMBL Heidelberg, Meyerhofstrasse 1, 69126 Heidelberg, Germany
| | - Pawel Masiewicz
- Structural and Computational Biology Unit, EMBL Heidelberg, Meyerhofstrasse 1, 69126 Heidelberg, Germany
| | - Kathryn Perez
- Protein Expression and Purification Core Facility, EMBL Heidelberg, Meyerhofstrasse 1, 69126 Heidelberg, Germany
| | - Janosch Hennig
- Structural and Computational Biology Unit, EMBL Heidelberg, Meyerhofstrasse 1, 69126 Heidelberg, Germany
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16
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Malanovic N, Marx L, Blondelle SE, Pabst G, Semeraro EF. Experimental concepts for linking the biological activities of antimicrobial peptides to their molecular modes of action. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2020; 1862:183275. [PMID: 32173291 DOI: 10.1016/j.bbamem.2020.183275] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Revised: 03/09/2020] [Accepted: 03/10/2020] [Indexed: 02/07/2023]
Abstract
The search for novel compounds to combat multi-resistant bacterial infections includes exploring the potency of antimicrobial peptides and derivatives thereof. Complementary to high-throughput screening techniques, biophysical and biochemical studies of the biological activity of these compounds enable deep insight, which can be exploited in designing antimicrobial peptides with improved efficacy. This approach requires the combination of several techniques to study the effect of such peptides on both bacterial cells and simple mimics of their cell envelope, such as lipid-only vesicles. These efforts carry the challenge of bridging results across techniques and sample systems, including the proper choice of membrane mimics. This review describes some important concepts toward the development of potent antimicrobial peptides and how they translate to frequently applied experimental techniques, along with an outline of the biophysics pertaining to the killing mechanism of antimicrobial peptides.
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Affiliation(s)
- Nermina Malanovic
- University of Graz, Institute of Molecular Biosciences, Biophysics Division, Graz, Austria.
| | - Lisa Marx
- University of Graz, Institute of Molecular Biosciences, Biophysics Division, Graz, Austria
| | | | - Georg Pabst
- University of Graz, Institute of Molecular Biosciences, Biophysics Division, Graz, Austria
| | - Enrico F Semeraro
- University of Graz, Institute of Molecular Biosciences, Biophysics Division, Graz, Austria
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17
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Grimsey E, Collis DWP, Mikut R, Hilpert K. The effect of lipidation and glycosylation on short cationic antimicrobial peptides. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2020; 1862:183195. [PMID: 32130974 DOI: 10.1016/j.bbamem.2020.183195] [Citation(s) in RCA: 50] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Revised: 01/08/2020] [Accepted: 01/10/2020] [Indexed: 01/16/2023]
Abstract
The global health threat surrounding bacterial resistance has resulted in antibiotic researchers shifting their focus away from 'traditional' antibiotics and concentrating on other antimicrobial agents, including antimicrobial peptides. These low molecular weight "mini-proteins" exhibit broad-spectrum activity against bacteria, including multi-drug resistant strains, viruses, fungi and protozoa and constitute a major element of the innate-immune system of many multicellular organisms. Some naturally occurring antimicrobial peptides are lipidated and/or glycosylated and almost all antimicrobial peptides in clinical use are either lipopeptides (Daptomycin and Polymyxin E and B) or glycopeptides (Vancomycin). Lipidation, glycosylation and PEGylation are an option for improving stability and activity in serum and for reducing the rapid clearing via the kidneys and liver. Two broad-spectrum antimicrobial peptides NH2-RIRIRWIIR-CONH2 (A1) and NH2-KRRVRWIIW-CONH2 (B1) were conjugated via a linker, producing A2 and B2, to individual fatty acids of C8, C10, C12 and C14 and in addition, A2 was conjugated to either glucose, N-acetyl glucosamine, galactose, mannose, lactose or polyethylene glycol (PEG). Antimicrobial activity against two Gram-positive strains (methicillin resistant Staphylococcus aureus (MRSA) and vancomycin resistant Enterococcus faecalis (VRE)) and three Gram-negative strains (Salmonella typhimurium, E. coli and Pseudomonas aeruginosa) were determined. Activity patterns for the lipidated versions are very complex, dependent on sequence, bacteria and fatty acid. Two reciprocal effects were measured; compared to the parental peptides, some combinations led to a 16-fold improvement whereas other combinations let to a 32-fold reduction in antimicrobial activity. Glycosylation decreased antimicrobial activity by 2 to 16-fold in comparison to A1, respectively on the sugar-peptide combination. PEGylation rendered the peptide inactive. Antimicrobial activity in the presence of 25% human serum of A1 and B1 was reduced 32-fold and 8-fold, respectively. The longer chain fatty acids almost completely restored this activity; however, these fatty acids increased hemolytic activity. B1 modified with C8 increased the therapeutic index by 2-fold for four bacterial strains. Our results suggest that finding the right lipid-peptide combination can lead to improved activity in the presence of serum and potentially more effective drug candidates for animal studies. Glycosylation with the optimal sugar and numbers of sugars at the right peptide position could be an alternative route or could be used in addition to lipidation to counteract solubility and toxicity issues.
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Affiliation(s)
- Elizabeth Grimsey
- Institute for Infection and Immunity, St. George's University of London, London, UK
| | | | - Ralf Mikut
- Karlsruhe Institute of Technology (KIT), Institute for Automation and Applied Informatics (IAI), Eggenstein-Leopoldshafen, Germany
| | - Kai Hilpert
- Institute for Infection and Immunity, St. George's University of London, London, UK.
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18
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Cardoso MH, Orozco RQ, Rezende SB, Rodrigues G, Oshiro KGN, Cândido ES, Franco OL. Computer-Aided Design of Antimicrobial Peptides: Are We Generating Effective Drug Candidates? Front Microbiol 2020; 10:3097. [PMID: 32038544 PMCID: PMC6987251 DOI: 10.3389/fmicb.2019.03097] [Citation(s) in RCA: 108] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2019] [Accepted: 12/20/2019] [Indexed: 11/16/2022] Open
Abstract
Antimicrobial peptides (AMPs), especially antibacterial peptides, have been widely investigated as potential alternatives to antibiotic-based therapies. Indeed, naturally occurring and synthetic AMPs have shown promising results against a series of clinically relevant bacteria. Even so, this class of antimicrobials has continuously failed clinical trials at some point, highlighting the importance of AMP optimization. In this context, the computer-aided design of AMPs has put together crucial information on chemical parameters and bioactivities in AMP sequences, thus providing modes of prediction to evaluate the antibacterial potential of a candidate sequence before synthesis. Quantitative structure-activity relationship (QSAR) computational models, for instance, have greatly contributed to AMP sequence optimization aimed at improved biological activities. In addition to machine-learning methods, the de novo design, linguistic model, pattern insertion methods, and genetic algorithms, have shown the potential to boost the automated design of AMPs. However, how successful have these approaches been in generating effective antibacterial drug candidates? Bearing this in mind, this review will focus on the main computational strategies that have generated AMPs with promising activities against pathogenic bacteria, as well as anti-infective potential in different animal models, including sepsis and cutaneous infections. Moreover, we will point out recent studies on the computer-aided design of antibiofilm peptides. As expected from automated design strategies, diverse candidate sequences with different structural arrangements have been generated and deposited in databases. We will, therefore, also discuss the structural diversity that has been engendered.
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Affiliation(s)
- Marlon H Cardoso
- S-Inova Biotech, Programa de Pós-Graduação em Biotecnologia, Universidade Católica Dom Bosco, Campo Grande, Brazil.,Centro de Análises Proteômicas e Bioquímicas, Pós-Graduação em Ciências Genômicas e Biotecnologia, Universidade Católica de Brasília, Brasília, Brazil
| | - Raquel Q Orozco
- S-Inova Biotech, Programa de Pós-Graduação em Biotecnologia, Universidade Católica Dom Bosco, Campo Grande, Brazil.,Instituto de Ciências Biológicas, Departamento de Biologia, Programa de Pós-Graduação em Ciências Biológicas (Imunologia/Genética e Biotecnologia), Universidade Federal de Juiz de Fora, Juiz de Fora, Brazil
| | - Samilla B Rezende
- S-Inova Biotech, Programa de Pós-Graduação em Biotecnologia, Universidade Católica Dom Bosco, Campo Grande, Brazil
| | - Gisele Rodrigues
- Centro de Análises Proteômicas e Bioquímicas, Pós-Graduação em Ciências Genômicas e Biotecnologia, Universidade Católica de Brasília, Brasília, Brazil
| | - Karen G N Oshiro
- S-Inova Biotech, Programa de Pós-Graduação em Biotecnologia, Universidade Católica Dom Bosco, Campo Grande, Brazil.,Programa de Pós-Graduação em Patologia Molecular, Faculdade de Medicina, Universidade de Brasília, Brasília, Brazil
| | - Elizabete S Cândido
- S-Inova Biotech, Programa de Pós-Graduação em Biotecnologia, Universidade Católica Dom Bosco, Campo Grande, Brazil.,Centro de Análises Proteômicas e Bioquímicas, Pós-Graduação em Ciências Genômicas e Biotecnologia, Universidade Católica de Brasília, Brasília, Brazil
| | - Octávio L Franco
- S-Inova Biotech, Programa de Pós-Graduação em Biotecnologia, Universidade Católica Dom Bosco, Campo Grande, Brazil.,Centro de Análises Proteômicas e Bioquímicas, Pós-Graduação em Ciências Genômicas e Biotecnologia, Universidade Católica de Brasília, Brasília, Brazil.,Instituto de Ciências Biológicas, Departamento de Biologia, Programa de Pós-Graduação em Ciências Biológicas (Imunologia/Genética e Biotecnologia), Universidade Federal de Juiz de Fora, Juiz de Fora, Brazil.,Programa de Pós-Graduação em Patologia Molecular, Faculdade de Medicina, Universidade de Brasília, Brasília, Brazil
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19
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Ruden S, Rieder A, Chis Ster I, Schwartz T, Mikut R, Hilpert K. Synergy Pattern of Short Cationic Antimicrobial Peptides Against Multidrug-Resistant Pseudomonas aeruginosa. Front Microbiol 2019; 10:2740. [PMID: 31849888 PMCID: PMC6901909 DOI: 10.3389/fmicb.2019.02740] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2019] [Accepted: 11/11/2019] [Indexed: 12/18/2022] Open
Abstract
With the rise of various multidrug-resistant (MDR) pathogenic bacteria, worldwide health care is under pressure to respond. Conventional antibiotics are failing and the development of novel classes and alternative strategies is a major priority. Antimicrobial peptides (AMPs) cannot only kill MDR bacteria, but also can be used synergistically with conventional antibiotics. We selected 30 short AMPs from different origins and measured their synergy in combination with polymyxin B, piperacillin, ceftazidime, cefepime, meropenem, imipenem, tetracycline, erythromycin, kanamycin, tobramycin, amikacin, gentamycin, and ciprofloxacin. In total, 403 unique combinations were tested against an MDR Pseudomonas aeruginosa isolate (PA910). As a measure of the synergistic effects, fractional inhibitory concentrations (FICs) were determined using microdilution assays with FICs ranges between 0.25 and 2. A high number of combinations between peptides and polymyxin B, erythromycin, and tetracycline were found to be synergistic. Novel variants of indolicidin also showed a high frequency in synergist interaction. Single amino acid substitutions within the peptides can have a very strong effect on the ability to synergize, making it possible to optimize future drugs toward synergistic interaction.
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Affiliation(s)
- Serge Ruden
- Institute of Biological Interfaces, Karlsruhe Institute of Technology, Karlsruhe, Germany.,Institute of Functional Interfaces, Karlsruhe Institute of Technology, Karlsruhe, Germany
| | - Annika Rieder
- Institute of Functional Interfaces, Karlsruhe Institute of Technology, Karlsruhe, Germany
| | - Irina Chis Ster
- Institute of Infection and Immunity, St George's, University of London, London, United Kingdom
| | - Thomas Schwartz
- Institute of Functional Interfaces, Karlsruhe Institute of Technology, Karlsruhe, Germany
| | - Ralf Mikut
- Institute for Automation and Applied Informatics, Karlsruhe Institute of Technology, Karlsruhe, Germany
| | - Kai Hilpert
- Institute of Functional Interfaces, Karlsruhe Institute of Technology, Karlsruhe, Germany.,Institute of Infection and Immunity, St George's, University of London, London, United Kingdom.,Institute of Microstructure Technology, Karlsruhe Institute of Technology, Karlsruhe, Germany
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20
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von Gundlach A, Ashby MP, Gani J, Lopez-Perez PM, Cookson AR, Ann Huws S, Rumancev C, Garamus VM, Mikut R, Rosenhahn A, Hilpert K. BioSAXS Measurements Reveal That Two Antimicrobial Peptides Induce Similar Molecular Changes in Gram-Negative and Gram-Positive Bacteria. Front Pharmacol 2019; 10:1127. [PMID: 31616307 PMCID: PMC6775230 DOI: 10.3389/fphar.2019.01127] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2019] [Accepted: 08/30/2019] [Indexed: 01/10/2023] Open
Abstract
Two highly active short broad-spectrum AMPs (14D and 69D) with unknown mode of action have been investigated in regards to their effect against the Gram-negative bacteria Escherichia coli and the Gram-positive bacteria methicillin-resistant Staphylococcus aureus (MRSA). Minimal inhibitory concentration (MIC) measurements using a cell density of 108 cfu/ml resulted in values between 16 and 32 µg/ml. Time-kill experiments using 108 cfu/ml revealed complete killing, except for 69D in combination with MRSA, where bacterial load was reduced a million times. Small-angle X-ray scattering of biological samples (BioSAXS) at 108 cfu/ml was applied to investigate the ultrastructural changes in E. coli and MRSA in response to these two broad-spectrum AMPs. In addition, electron microscopy (EM) was performed to visualize the treated and non-treated bacteria. As expected, the scattering curves generated using BioSAXS show the ultrastructure of the Gram-positive and Gram-negative bacteria to be very different (BioSAXS is not susceptible to the outer shape). After treatment with either peptide, the scattering curves of E. coli and MRSA cells are much more alike. Whereas in EM, it is notoriously difficult to observe changes for spherical Gram-positives; the BioSAXS results are superior and reveal strongly similar effects for both peptides induced in Gram-positive as well as Gram-negative bacteria. Given the high-throughput possibility and robust statistics, BioSAXS can support and speed up mode of action research in AMPs and other antimicrobial compounds, making a contribution toward the development of urgently needed drugs against resistant bacteria.
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Affiliation(s)
| | - Martin P Ashby
- Institute of Infection and Immunology, St. George's University of London (SGUL), London, United Kingdom
| | - Jurnorain Gani
- Institute of Infection and Immunology, St. George's University of London (SGUL), London, United Kingdom
| | | | - Alan Roy Cookson
- Institute of Biological, Environmental & Rural Sciences (IBERS), Aberystwyth University, Aberystwyth, United Kingdom
| | - Sharon Ann Huws
- Institute of Global Food Security, School of Biological Sciences, Queens University Belfast, Medical Biology Centre, Belfast, United Kingdom
| | - Christoph Rumancev
- Analytical Chemistry - Biointerfaces, Ruhr-University Bochum, Bochum, Germany
| | - Vasil M Garamus
- Helmholtz-Zentrum Geesthacht, Zentrum für Material- und Küstenforschung GmbH, Geesthacht, Germany
| | - Ralf Mikut
- Institute for Automation and Applied Informatics (IAI), Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany
| | - Axel Rosenhahn
- Analytical Chemistry - Biointerfaces, Ruhr-University Bochum, Bochum, Germany
| | - Kai Hilpert
- Institute of Infection and Immunology, St. George's University of London (SGUL), London, United Kingdom
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21
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Chen PC, Hennig J. The role of small-angle scattering in structure-based screening applications. Biophys Rev 2018; 10:1295-1310. [PMID: 30306530 PMCID: PMC6233350 DOI: 10.1007/s12551-018-0464-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2018] [Accepted: 09/04/2018] [Indexed: 12/16/2022] Open
Abstract
In many biomolecular interactions, changes in the assembly states and structural conformations of participants can act as a complementary reporter of binding to functional and thermodynamic assays. This structural information is captured by a number of structural biology and biophysical techniques that are viable either as primary screens in small-scale applications or as secondary screens to complement higher throughput methods. In particular, small-angle X-ray scattering (SAXS) reports the average distance distribution between all atoms after orientational averaging. Such information is important when for example investigating conformational changes involved in inhibitory and regulatory mechanisms where binding events do not necessarily cause functional changes. Thus, we summarise here the current and prospective capabilities of SAXS-based screening in the context of other methods that yield structural information. Broad guidelines are also provided to assist readers in preparing screening protocols that are tailored to available X-ray sources.
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Affiliation(s)
- Po-Chia Chen
- Structural and Computational Biology Unit, European Molecular Biology Laboratory Heidelberg, Meyerhofstrasse 1, 69126, Heidelberg, Germany.
| | - Janosch Hennig
- Structural and Computational Biology Unit, European Molecular Biology Laboratory Heidelberg, Meyerhofstrasse 1, 69126, Heidelberg, Germany.
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22
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Lutz-Bueno V, Arboleda C, Leu L, Blunt MJ, Busch A, Georgiadis A, Bertier P, Schmatz J, Varga Z, Villanueva-Perez P, Wang Z, Lebugle M, David C, Stampanoni M, Diaz A, Guizar-Sicairos M, Menzel A. Model-free classification of X-ray scattering signals applied to image segmentation. J Appl Crystallogr 2018; 51:1378-1386. [PMID: 30279640 PMCID: PMC6157705 DOI: 10.1107/s1600576718011032] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2018] [Accepted: 08/02/2018] [Indexed: 11/17/2022] Open
Abstract
This article describes a modeling framework to relate the molecular orientation of nanostructures to polarized resonant soft X-ray scattering measurements using the Born approximation and a full tensor treatment. In most cases, the analysis of small-angle and wide-angle X-ray scattering (SAXS and WAXS, respectively) requires a theoretical model to describe the sample’s scattering, complicating the interpretation of the scattering resulting from complex heterogeneous samples. This is the reason why, in general, the analysis of a large number of scattering patterns, such as are generated by time-resolved and scanning methods, remains challenging. Here, a model-free classification method to separate SAXS/WAXS signals on the basis of their inflection points is introduced and demonstrated. This article focuses on the segmentation of scanning SAXS/WAXS maps for which each pixel corresponds to an azimuthally integrated scattering curve. In such a way, the sample composition distribution can be segmented through signal classification without applying a model or previous sample knowledge. Dimensionality reduction and clustering algorithms are employed to classify SAXS/WAXS signals according to their similarity. The number of clusters, i.e. the main sample regions detected by SAXS/WAXS signal similarity, is automatically estimated. From each cluster, a main representative SAXS/WAXS signal is extracted to uncover the spatial distribution of the mixtures of phases that form the sample. As examples of applications, a mudrock sample and two breast tissue lesions are segmented.
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Affiliation(s)
- V Lutz-Bueno
- Paul Scherrer Institut, 5232 Villigen PSI, Switzerland
| | - C Arboleda
- Paul Scherrer Institut, 5232 Villigen PSI, Switzerland.,ETH Zurich, 8092 Zurich, Switzerland
| | - L Leu
- Department of Earth Science and Engineering, Imperial College London, London SW7 2BP, UK.,Shell Global Solutions International B.V., 2288 GS, Rijswijk, The Netherlands
| | - M J Blunt
- Department of Earth Science and Engineering, Imperial College London, London SW7 2BP, UK
| | - A Busch
- Lyell Centre for Marine and Earth Science and Technology, Heriot-Watt University, Edinburgh EH14 4AP, UK
| | - A Georgiadis
- Shell Global Solutions International B.V., 2288 GS, Rijswijk, The Netherlands.,Department of Chemical Engineering, Imperial College London, London SW7 2BP, UK
| | - P Bertier
- Clay and Interface Mineralogy, RWTH Aachen, 52062 Aachen, Germany
| | - J Schmatz
- Microstructure and Pores GmbH, 52064 Aachen, Germany
| | - Z Varga
- Institute of Pathology and Molecular Pathology, University Hospital Zurich, 8092 Zurich, Switzerland
| | - P Villanueva-Perez
- Paul Scherrer Institut, 5232 Villigen PSI, Switzerland.,Deutsches Elektronen-Synchrotron, Center for Free-Electron Laser Science, 22607 Hamburg, Germany
| | - Z Wang
- Paul Scherrer Institut, 5232 Villigen PSI, Switzerland.,ETH Zurich, 8092 Zurich, Switzerland
| | - M Lebugle
- Paul Scherrer Institut, 5232 Villigen PSI, Switzerland
| | - C David
- Paul Scherrer Institut, 5232 Villigen PSI, Switzerland
| | - M Stampanoni
- Paul Scherrer Institut, 5232 Villigen PSI, Switzerland.,ETH Zurich, 8092 Zurich, Switzerland
| | - A Diaz
- Paul Scherrer Institut, 5232 Villigen PSI, Switzerland
| | | | - A Menzel
- Paul Scherrer Institut, 5232 Villigen PSI, Switzerland
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23
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Chen PC, Masiewicz P, Rybin V, Svergun D, Hennig J. A General Small-Angle X-ray Scattering-Based Screening Protocol Validated for Protein-RNA Interactions. ACS COMBINATORIAL SCIENCE 2018; 20:197-202. [PMID: 29553252 DOI: 10.1021/acscombsci.8b00007] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We present a screening protocol utilizing small-angle X-ray scattering (SAXS) to obtain structural information on biomolecular interactions independent of prior knowledge, so as to complement affinity-based screening and provide leads for further exploration. This protocol categorizes ligand titrations by computing pairwise agreement between curves, and separately estimates affinities by quantifying complex formation as a departure from the linear sum properties of solution SAXS. The protocol is validated by sparse sequence search around the native poly uridine RNA motifs of the two-RRM domain Sex-lethal protein (Sxl). The screening of 35 RNA motifs between 4 to 10 nucleotides reveals a strong variation of resulting complexes, revealed to be preference-switching between 1:1 and 2:2 binding stoichiometries upon addition of structural modeling. Validation of select sequences in isothermal calorimetry and NMR titration retrieves domain-specific roles and function of a guanine anchor. These findings reinforce the suitability of SAXS as a complement in lead identification.
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Affiliation(s)
- Po-chia Chen
- Structural and Computational Biology Unit, EMBL Heidelberg, Meyerhofstrasse 1, 69126 Heidelberg, Germany
| | - Pawel Masiewicz
- Structural and Computational Biology Unit, EMBL Heidelberg, Meyerhofstrasse 1, 69126 Heidelberg, Germany
| | - Vladimir Rybin
- Structural and Computational Biology Unit, EMBL Heidelberg, Meyerhofstrasse 1, 69126 Heidelberg, Germany
| | - Dmitri Svergun
- EMBL Hamburg, DESY, Building 25A, Notkestraße 85, 22607 Hamburg, Germany
| | - Janosch Hennig
- Structural and Computational Biology Unit, EMBL Heidelberg, Meyerhofstrasse 1, 69126 Heidelberg, Germany
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24
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Mikulskis P, Hook A, Dundas AA, Irvine D, Sanni O, Anderson D, Langer R, Alexander MR, Williams P, Winkler DA. Prediction of Broad-Spectrum Pathogen Attachment to Coating Materials for Biomedical Devices. ACS APPLIED MATERIALS & INTERFACES 2018; 10:139-149. [PMID: 29191009 PMCID: PMC7613461 DOI: 10.1021/acsami.7b14197] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
Bacterial infections in healthcare settings are a frequent accompaniment to both routine procedures such as catheterization and surgical site interventions. Their impact is becoming even more marked as the numbers of medical devices that are used to manage chronic health conditions and improve quality of life increases. The resistance of pathogens to multiple antibiotics is also increasing, adding an additional layer of complexity to the problems of employing safe and effective medical procedures. One approach to reducing the rate of infections associated with implanted and indwelling medical devices is the use of polymers that resist the formation of bacterial biofilms. To significantly accelerate the discovery of such materials, we show how state of the art machine learning methods can generate quantitative predictions for the attachment of multiple pathogens to a large library of polymers in a single model for the first time. Such models facilitate design of polymers with very low pathogen attachment across different bacterial species that will be candidate materials for implantable or indwelling medical devices such as urinary catheters, cochlear implants, and pacemakers.
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Affiliation(s)
- Paulius Mikulskis
- School of Pharmacy, University of Nottingham, Nottingham NG7 2RD, United Kingdom
| | - Andrew Hook
- School of Pharmacy, University of Nottingham, Nottingham NG7 2RD, United Kingdom
| | - Adam A. Dundas
- School of Pharmacy, University of Nottingham, Nottingham NG7 2RD, United Kingdom
- Faculty of Engineering, University of Nottingham, Nottingham NG7 2RD, United Kingdom
| | - Derek Irvine
- Faculty of Engineering, University of Nottingham, Nottingham NG7 2RD, United Kingdom
| | - Olutoba Sanni
- School of Pharmacy, University of Nottingham, Nottingham NG7 2RD, United Kingdom
| | - Daniel Anderson
- Koch Institute for Integrative Cancer Research, MIT, Cambridge, Massachusetts 02139-4307, United States
| | - Robert Langer
- Koch Institute for Integrative Cancer Research, MIT, Cambridge, Massachusetts 02139-4307, United States
| | - Morgan R. Alexander
- School of Pharmacy, University of Nottingham, Nottingham NG7 2RD, United Kingdom
- Corresponding Authors; ;
| | - Paul Williams
- Centre for Biomolecular Sciences, School of Life Sciences, University of Nottingham, Nottingham NG7 2RD, United Kingdom
| | - David A. Winkler
- School of Pharmacy, University of Nottingham, Nottingham NG7 2RD, United Kingdom
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Kingsbury Drive, Melbourne, Victoria 3086, Australia
- Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria 3052, Australia
- School of Chemical and Physical Sciences, Flinders University, Bedford Park, South Australia 5046, Australia
- Corresponding Authors; ;
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25
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Heberle FA, Pabst G. Complex biomembrane mimetics on the sub-nanometer scale. Biophys Rev 2017; 9:353-373. [PMID: 28717925 PMCID: PMC5578918 DOI: 10.1007/s12551-017-0275-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2017] [Accepted: 06/26/2017] [Indexed: 12/12/2022] Open
Abstract
Biomimetic lipid vesicles are indispensable tools for gaining insight into the biophysics of cell physiology on the molecular level. The level of complexity of these model systems has steadily increased, and now spans from domain-forming lipid mixtures to asymmetric lipid bilayers. Here, we review recent progress in the development and application of elastic neutron and X-ray scattering techniques for studying these systems in situ and under physiologically relevant conditions on the nanometer to sub-nanometer length scales. In particular, we focus on: (1) structural details of coexisting liquid-ordered and liquid-disordered domains, including their thickness and lipid packing mismatch as a function of a size transition from nanoscopic to macroscopic domains; (2) membrane-mediated protein partitioning into lipid domains; (3) the role of the aqueous medium in tuning interactions between membranes and domains; and (4) leaflet-specific structure in asymmetric bilayers and passive lipid flip-flop.
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Affiliation(s)
- Frederick A Heberle
- The Bredesen Center, University of Tennessee, Knoxville, TN, 37996, USA.,Joint Institute for Biological Sciences and Biology and Soft Matter Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Georg Pabst
- Institute of Molecular Biosciences, Biophysics Division, NAWI Graz, University of Graz, 8010, Graz, Austria. .,BioTechMed-Graz, 8010, Graz, Austria.
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26
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Rumancev C, von Gundlach AR, Baier S, Wittstock A, Shi J, Benzi F, Senkbeil T, Stuhr S, Garamusx VM, Grunwaldt JD, Rosenhahn A. Morphological analysis of cerium oxide stabilized nanoporous gold catalysts by soft X-ray ASAXS. RSC Adv 2017. [DOI: 10.1039/c7ra05396g] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Soft X-ray SAXS and ASAXS reveal nanostructural properties and temperature induced morphological changes in catalyst materials. The stabilizing effect of cerium oxide deposits on the gold catalyst and the morphological properties of the cerium oxide were determined.
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Affiliation(s)
- C. Rumancev
- Analytical Chemistry – Biointerfaces
- Ruhr-University Bochum
- 44780 Bochum
- Germany
| | - A. R. von Gundlach
- Analytical Chemistry – Biointerfaces
- Ruhr-University Bochum
- 44780 Bochum
- Germany
| | - S. Baier
- Institute for Chemical Technology and Polymer Chemistry
- Karlsruher Institut für Technologie (KIT)
- 76131 Karlsruhe
- Germany
| | - A. Wittstock
- Institute of Applied and Physical Chemistry
- University of Bremen
- 28359 Bremen
- Germany
| | - J. Shi
- Institute of Applied and Physical Chemistry
- University of Bremen
- 28359 Bremen
- Germany
| | - F. Benzi
- Institute for Chemical Technology and Polymer Chemistry
- Karlsruher Institut für Technologie (KIT)
- 76131 Karlsruhe
- Germany
| | - T. Senkbeil
- Analytical Chemistry – Biointerfaces
- Ruhr-University Bochum
- 44780 Bochum
- Germany
| | - S. Stuhr
- Analytical Chemistry – Biointerfaces
- Ruhr-University Bochum
- 44780 Bochum
- Germany
| | - V. M. Garamusx
- Helmholtz-Zentrum Geesthacht
- Zentrum für Material und Küstenforschung GmbH
- 21502 Geesthacht
- Germany
| | - J.-D. Grunwaldt
- Institute for Chemical Technology and Polymer Chemistry
- Karlsruher Institut für Technologie (KIT)
- 76131 Karlsruhe
- Germany
| | - A. Rosenhahn
- Analytical Chemistry – Biointerfaces
- Ruhr-University Bochum
- 44780 Bochum
- Germany
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27
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von Gundlach AR, Garamus VM, Willey TM, Ilavsky J, Hilpert K, Rosenhahn A. Use of small-angle X-ray scattering to resolve intracellular structure changes of Escherichia coli cells induced by antibiotic treatment. J Appl Crystallogr 2016; 49:2210-2216. [PMID: 27980516 PMCID: PMC5139998 DOI: 10.1107/s1600576716018562] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2016] [Accepted: 11/19/2016] [Indexed: 12/22/2022] Open
Abstract
The application of small-angle X-ray scattering (SAXS) to whole Escherichia coli cells is challenging owing to the variety of internal constituents. To resolve their contributions, the outer shape was captured by ultra-small-angle X-ray scattering and combined with the internal structure resolved by SAXS. Building on these data, a model for the major structural components of E. coli was developed. It was possible to deduce information on the occupied volume, occurrence and average size of the most important intracellular constituents: ribosomes, DNA and proteins. E. coli was studied after treatment with three different antibiotic agents (chloramphenicol, tetracycline and rifampicin) and the impact on the intracellular constituents was monitored.
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Affiliation(s)
- A. R. von Gundlach
- Analytical Chemistry – Biointerfaces, Ruhr-University Bochum, Universitätsstrasse 150, 44780 Bochum, Germany
| | - V. M. Garamus
- Helmholtz-Zentrum Geesthacht, Zentrum für Material- und Küstenforschung GmbH, Max-Planck-Strasse 1, 21502 Geesthacht, Germany
| | - T. M. Willey
- Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, CA 94550, USA
| | - J. Ilavsky
- X-ray Science Division, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439, USA
| | - K. Hilpert
- Institute of Infection and Immunity, St George’s University of London (SGUL), Cranmer Terrace, London SW17 0RE, UK
| | - A. Rosenhahn
- Analytical Chemistry – Biointerfaces, Ruhr-University Bochum, Universitätsstrasse 150, 44780 Bochum, Germany
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