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Infrared nanospectroscopic imaging of DNA molecules on mica surface. Sci Rep 2022; 12:18972. [PMID: 36348038 PMCID: PMC9643503 DOI: 10.1038/s41598-022-23637-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Accepted: 11/02/2022] [Indexed: 11/09/2022] Open
Abstract
Significant efforts have been done in last two decades to develop nanoscale spectroscopy techniques owning to their great potential for single-molecule structural detection and in addition, to resolve open questions in heterogeneous biological systems, such as protein-DNA complexes. Applying IR-AFM technique has become a powerful leverage for obtaining simultaneous absorption spectra with a nanoscale spatial resolution for studied proteins, however the AFM-IR investigation of DNA molecules on surface, as a benchmark for a nucleoprotein complexes nanocharacterization, has remained elusive. Herein, we demonstrate methodological approach for acquisition of AFM-IR mapping modalities with corresponding absorption spectra based on two different DNA deposition protocols on spermidine and Ni2+ pretreated mica surface. The nanoscale IR absorbance of distinctly formed DNA morphologies on mica are demonstrated through series of AFM-IR absorption maps with corresponding IR spectrum. Our results thus demonstrate the sensitivity of AFM-IR nanospectroscopy for a nucleic acid research with an open potential to be employed in further investigation of nucleoprotein complexes.
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2
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Fate of Bioactive Compounds during Lactic Acid Fermentation of Fruits and Vegetables. Foods 2022; 11:foods11050733. [PMID: 35267366 PMCID: PMC8909232 DOI: 10.3390/foods11050733] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Revised: 02/27/2022] [Accepted: 02/28/2022] [Indexed: 01/27/2023] Open
Abstract
Consumption of lactic acid fermented fruits and vegetables has been correlated with a series of health benefits. Some of them have been attributed to the probiotic potential of lactic acid microbiota, while others to its metabolic potential and the production of bioactive compounds. The factors that affect the latter have been in the epicenter of intensive research over the last decade. The production of bioactive peptides, vitamins (especially of the B-complex), gamma-aminobutyric acid, as well as phenolic and organosulfur compounds during lactic acid fermentation of fruits and vegetables has attracted specific attention. On the other hand, the production of biogenic amines has also been intensively studied due to the adverse health effects caused by their consumption. The data that are currently available indicate that the production of these compounds is a strain-dependent characteristic that may also be affected by the raw materials used as well as the fermentation conditions. The aim of the present review paper is to collect all data referring to the production of the aforementioned compounds and to present and discuss them in a concise and comprehensive way.
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3
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Banerji R, Iyer P, Saroj SD. Spermidine enhances the survival of Streptococcus pyogenes M3 under oxidative stress. Mol Oral Microbiol 2022; 37:53-62. [PMID: 34994090 DOI: 10.1111/omi.12360] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Revised: 12/23/2021] [Accepted: 12/30/2021] [Indexed: 12/17/2022]
Abstract
Streptococcus pyogenes, a host-restricted gram-positive pathogen during infection, initially adheres to the epithelia of the nasopharynx and respiratory tract of the human host, followed by disseminating to other organs and evading the host immune system. Upon phagocytosis, S. pyogenes encounters oxidative stress inside the macrophages. The role of polyamines in regulating various physiological functions including stress resistance in bacteria has been reported widely. Since S. pyogenes lacks the machinery for the biosynthesis of polyamines, the study aimed to understand the role of extracellular polyamines in the survival of S. pyogenes under oxidative stress environments. S. pyogenes being a catalase-negative organism, we report that its survival within the macrophages and H2 O2 is enhanced by the presence of spermidine. The increased survival can be attributed to the upregulation of oxidative stress response genes such as sodM, npx, and mtsABC. In addition, spermidine influences the upregulation of virulence factors such as sagA, slo, and hasA. Also, spermidine leads to a decrease in hydrophobicity of the cell membrane and an increase in hyaluronic acid. This study suggests a role for extracellular spermidine in the survival of S. pyogenes under oxidative stress environments. Recognizing the factors that modulate S. pyogenes survival and virulence under stress will assist in understanding its interactions with the host.
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Affiliation(s)
- Rajashri Banerji
- Symbiosis School of Biological Sciences, Symbiosis International (Deemed University), Pune, Maharashtra, India
| | - Parvati Iyer
- Symbiosis School of Biological Sciences, Symbiosis International (Deemed University), Pune, Maharashtra, India
| | - Sunil D Saroj
- Symbiosis School of Biological Sciences, Symbiosis International (Deemed University), Pune, Maharashtra, India
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4
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Banerji R, Kanojiya P, Patil A, Saroj SD. Polyamines in the virulence of bacterial pathogens of respiratory tract. Mol Oral Microbiol 2020; 36:1-11. [PMID: 32979241 DOI: 10.1111/omi.12315] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Revised: 08/24/2020] [Accepted: 09/16/2020] [Indexed: 12/11/2022]
Abstract
Polyamines are positively charged hydrocarbons that are essential for the growth and cellular maintenance in prokaryotes and eukaryotes. Polyamines have been demonstrated to play a role in bacterial pathogenicity and biofilm formation. However, the role of extracellular polyamines as a signaling molecule in the regulation of virulence is not investigated in detail. The bacterial pathogens residing in the respiratory tract remain asymptomatic for an extended period; however, the factors that lead to symptomatic behavior are poorly understood. Further investigation to understand the relation between the host-secreted factors and virulence of pathogenic bacteria in the respiratory tract may provide insights into the pathogenesis of respiratory tract infections. Polyamines produced within the bacterial cell are generally sequestered. Therefore, the pool of extracellular polyamines formed by secretion of the commensals and the host may be one of the signaling molecules that might contribute toward the alterations in the expression of virulence factors in bacterial pathogens. Besides, convergent mechanisms of polyamine biosynthesis do exist across the border of species and genus level. Also, several novel polyamine transporters in the host and bacteria remain yet to be identified. The review focuses on the role of polyamines in the expression of virulence phenotypes and biofilm formation of the respiratory tract pathogens.
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Affiliation(s)
- Rajashri Banerji
- Symbiosis School of Biological Sciences, Symbiosis International (Deemed University), Pune, India
| | - Poonam Kanojiya
- Symbiosis School of Biological Sciences, Symbiosis International (Deemed University), Pune, India
| | - Amrita Patil
- Symbiosis School of Biological Sciences, Symbiosis International (Deemed University), Pune, India
| | - Sunil D Saroj
- Symbiosis School of Biological Sciences, Symbiosis International (Deemed University), Pune, India
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5
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Shek R, Dattmore DA, Stives DP, Jackson AL, Chatfield CH, Hicks KA, French JB. Structural and Functional Basis for Targeting Campylobacter jejuni Agmatine Deiminase To Overcome Antibiotic Resistance. Biochemistry 2017; 56:6734-6742. [PMID: 29190068 DOI: 10.1021/acs.biochem.7b00982] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Campylobacter jejuni is the most common bacterial cause of gastroenteritis and a major contributor to infant mortality in the developing world. The increasing incidence of antibiotic-resistant C. jejuni only adds to the urgency to develop effective therapies. Because of the essential role that polyamines play, particularly in protection from oxidative stress, enzymes involved in the biosynthesis of these metabolites are emerging as promising antibiotic targets. The recent description of an alternative pathway for polyamine synthesis, distinct from that in human cells, in C. jejuni suggests this pathway could be a target for novel therapies. To that end, we determined X-ray crystal structures of C. jejuni agmatine deiminase (CjADI) and demonstrated that loss of CjADI function contributes to antibiotic sensitivity, likely because of polyamine starvation. The structures provide details of key molecular features of the active site of this protein. Comparison of the unliganded structure (2.1 Å resolution) to that of the CjADI-agmatine complex (2.5 Å) reveals significant structural rearrangements that occur upon substrate binding. The shift of two helical regions of the protein and a large conformational change in a loop near the active site generate a narrow binding pocket around the bound substrate. This change optimally positions the substrate for catalysis. In addition, kinetic analysis of this enzyme demonstrates that CjADI is an iminohydrolase that effectively deiminates agmatine. Our data suggest that C. jejuni agmatine deiminase is a potentially important target for combatting antibiotic resistance, and these results provide a valuable framework for guiding future drug development.
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Affiliation(s)
- Roger Shek
- Department of Biochemistry and Cell Biology, Stony Brook University , Stony Brook, New York 11794, United States
| | - Devon A Dattmore
- Department of Chemistry, SUNY Cortland , Cortland, New York 13045, United States
| | - Devin P Stives
- Department of Chemistry, SUNY Cortland , Cortland, New York 13045, United States
| | - Ashley L Jackson
- Department of Chemistry, SUNY Cortland , Cortland, New York 13045, United States
| | - Christa H Chatfield
- Department of Biological Sciences, SUNY Cortland , Cortland, New York 13045, United States
| | - Katherine A Hicks
- Department of Chemistry, SUNY Cortland , Cortland, New York 13045, United States
| | - Jarrod B French
- Department of Biochemistry and Cell Biology, Stony Brook University , Stony Brook, New York 11794, United States.,Department of Chemistry, Stony Brook University , Stony Brook, New York 11794, United States
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6
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Arias-Gonzalez JR. Single-molecule portrait of DNA and RNA double helices. Integr Biol (Camb) 2015; 6:904-25. [PMID: 25174412 DOI: 10.1039/c4ib00163j] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The composition and geometry of the genetic information carriers were described as double-stranded right helices sixty years ago. The flexibility of their sugar-phosphate backbones and the chemistry of their nucleotide subunits, which give rise to the RNA and DNA polymers, were soon reported to generate two main structural duplex states with biological relevance: the so-called A and B forms. Double-stranded (ds) RNA adopts the former whereas dsDNA is stable in the latter. The presence of flexural and torsional stresses in combination with environmental conditions in the cell or in the event of specific sequences in the genome can, however, stabilize other conformations. Single-molecule manipulation, besides affording the investigation of the elastic response of these polymers, can test the stability of their structural states and transition models. This approach is uniquely suited to understanding the basic features of protein binding molecules, the dynamics of molecular motors and to shedding more light on the biological relevance of the information blocks of life. Here, we provide a comprehensive single-molecule analysis of DNA and RNA double helices in the context of their structural polymorphism to set a rigorous interpretation of their material response both inside and outside the cell. From early knowledge of static structures to current dynamic investigations, we review their phase transitions and mechanochemical behaviour and harness this fundamental knowledge not only through biological sciences, but also for Nanotechnology and Nanomedicine.
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Affiliation(s)
- J Ricardo Arias-Gonzalez
- Instituto Madrileño de Estudios Avanzados en Nanociencia (IMDEA Nanociencia), Calle Faraday no. 9, Cantoblanco, 28049 Madrid, Spain.
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7
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γ-glutamyl Spermine Synthetase PauA2 as a potential target of antibiotic development against Pseudomonas aeruginosa. Antimicrob Agents Chemother 2012; 56:5309-14. [PMID: 22869561 DOI: 10.1128/aac.01158-12] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Polyamines are absolute requirements for cell growth. When in excess, Pseudomonas aeruginosa possesses six γ-glutamylpolyamine synthetases (GPSs) encoded by the pauA1-pauA7 genes to initiate polyamine catabolism. Recently, the pauA2 mutant was reported to lose the capability to grow on spermine (Spm) and spermidine (Spd) as sole carbon and nitrogen sources. Although this mutant grew normally in defined minimal medium and LB broth, growth was completely abolished by the addition of Spm or Spd. These two compounds exert a bactericidal effect (Spm > Spd) on the mutants as demonstrated by MIC measurements (over 500-fold reduction) and time-killing curves. Spm toxicity in the pauA2 mutant was attenuated when the major uptake system was further deleted from the strain, suggesting cytoplasmic targets of toxicity. In addition, the synergistic effect of Spm and carbenicillin in the wild-type strain PAO1 was diminished in mutants without functional PauA2. Furthermore, Spm MIC was reduced by 8-fold when the Spm uptake system was deleted from the wild-type strain, suggesting a second target of Spm toxicity in the periplasm. Experiments were also conducted to test the hypothesis that native Spm and Spd in human serum may be sufficient to kill the pauA2 mutant. Growth of the mutant was completely inhibited by 40% (vol/vol) human serum, whereas the parental strain required 80%. Colony counts indicated that the mutant but not the parent was in fact killed by human plasma. In addition, carbenicillin MIC against the mutant was reduced by 16-fold in the presence of 20% human serum while that of the parental strain remained unchanged. Taking PauA2 as the template, sequence comparison indicates that putative PauA2 homologues are widespread in a variety of Gram-negative bacteria. In summary, this study reveals the importance of GPS in alleviation of polyamine toxicity when in excess, and it provides strong support to the feasibility of GPS as a molecular target for new antibiotic development.
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8
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Hoffmann GR, Laterza AM, Sylvia KE, Tartaglione JP. Potentiation of the mutagenicity and recombinagenicity of bleomycin in yeast by unconventional intercalating agents. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2011; 52:130-144. [PMID: 20839230 DOI: 10.1002/em.20592] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Interactions between bleomycin (BLM) and conventional or unconventional intercalating agents were analyzed in an assay for mitotic gene conversion at the trp5 locus and reversion of the ilv1-92 allele in Saccharomyces cerevisiae strain D7. BLM is a potent recombinagen and mutagen in the assay. Various chemicals modulate the genetic activity of BLM, producing either antimutagenic effects or enhanced genotoxicity. Effects of cationic amino compounds include enhancement of BLM activity by aminoacridines and protection against BLM by aliphatic amines. The potentiation of BLM is similar to findings in a micronucleus-based BLM amplification assay in Chinese hamster V79 cells. In this study, the amplification of BLM activity was explored in yeast using known intercalators, compounds structurally related to known intercalators, and unconventional intercalators that were identified on the basis of computer modeling or results in the Chinese hamster BLM amplification assay. As shown in previous studies, the classical intercalator 9-aminoacridine (9AA) caused dose-dependent enhancement of BLM activity. Other compounds found to enhance the induction of mitotic recombination and point mutations in strain D7 were chlorpromazine, chloroquine, mefloquine, tamoxifen, diphenhydramine, benzophenone, and 3-hydroxybenzophenone. The increased activity was detectable by cotreatment of yeast with BLM and the modulator compound in growth medium or by separate interaction of the intercalator with DNA followed by BLM treatment of nongrowing cells in buffer. The data support the interpretation drawn from micronucleus assays in mammalian cells that BLM enhancement results from DNA intercalation and may be useful in detecting noncovalent interactions with DNA. Environ.
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Affiliation(s)
- George R Hoffmann
- Department of Biology, College of Holy Cross, Worcester, Massachusetts 01610-2395, USA.
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9
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Xie S, Wang J, Zhang Y, Wang C. Antitumor conjugates with polyamine vectors and their molecular mechanisms. Expert Opin Drug Deliv 2010; 7:1049-61. [DOI: 10.1517/17425247.2010.504205] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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10
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Wortham BW, Oliveira MA, Fetherston JD, Perry RD. Polyamines are required for the expression of key Hms proteins important for Yersinia pestis biofilm formation. Environ Microbiol 2010; 12:2034-47. [PMID: 20406298 DOI: 10.1111/j.1462-2920.2010.02219.x] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
We previously showed that mutations in the genes encoding the two main biosynthetic enzymes responsible for polyamine production, arginine decarboxylase (SpeA) and ornithine decarboxylase (SpeC) cause a loss of biofilm formation in Yersinia pestis. In Y. pestis the development of a biofilm is dependent on 6 Hms (hemin storage) proteins (HmsH, F, R, S, T and P) grouped into 3 operons; hmsHFRS, hmsT and hmsP. In this article we show that polyamines are necessary to maintain the levels of key Hms proteins. In the absence of polyamines there is an approximately 93%, approximately 43% and approximately 90% reduction in protein levels of HmsR, HmsS and HmsT respectively. Overexpression of hmsR and hmsT from plasmids alone can restore biofilm formation to a SpeA(-)SpeC(-) mutant. Addition of exogenous putrescine also restores normal levels of HmsR, HmsS, HmsT and biofilm production. Analyses using transcriptional reporters and quantitative RT-PCR indicate that the initiation of transcription and mRNA stability are not reduced by polyamine deficiency. Instead, translational reporters indicate that polyamines function at least in part by modulating the translation of HmsR and HmsT. Although construction of a consensus Shine-Dalgarno sequence upstream of hmsT modestly reduced the stimulation of translation by putrescine, additional mechanisms likely contribute to the polyamine-dependent expression of HmsT. Finally, we have shown that polyamines play a role in bubonic plague.
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Affiliation(s)
- Brian W Wortham
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, Lexington, KY 40536, USA
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11
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Pavan GM, Kostiainen MA, Danani A. Computational Approach for Understanding the Interactions of UV-Degradable Dendrons with DNA and siRNA. J Phys Chem B 2010; 114:5686-93. [DOI: 10.1021/jp911439q] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Affiliation(s)
- Giovanni M. Pavan
- Mathematical and Physical Sciences Research Unit (SMF), University for Applied Sciences of Southern Switzerland (SUPSI), Centro Galleria 2, Manno, CH-6928, Switzerland, and Institute for Molecules and Materials, Radboud University Nijmegen, Toernooiveld 1, 6525 ED Nijmegen, The Netherlands
| | - Mauri A. Kostiainen
- Mathematical and Physical Sciences Research Unit (SMF), University for Applied Sciences of Southern Switzerland (SUPSI), Centro Galleria 2, Manno, CH-6928, Switzerland, and Institute for Molecules and Materials, Radboud University Nijmegen, Toernooiveld 1, 6525 ED Nijmegen, The Netherlands
| | - Andrea Danani
- Mathematical and Physical Sciences Research Unit (SMF), University for Applied Sciences of Southern Switzerland (SUPSI), Centro Galleria 2, Manno, CH-6928, Switzerland, and Institute for Molecules and Materials, Radboud University Nijmegen, Toernooiveld 1, 6525 ED Nijmegen, The Netherlands
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12
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Jones SP, Pavan GM, Danani A, Pricl S, Smith DK. Quantifying the effect of surface ligands on dendron-DNA interactions: insights into multivalency through a combined experimental and theoretical approach. Chemistry 2010; 16:4519-32. [PMID: 20235240 DOI: 10.1002/chem.200902546] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2009] [Revised: 01/27/2010] [Indexed: 11/10/2022]
Abstract
We report the synthesis, DNA binding ability and preliminary gene delivery profiles of dendrons with different amine surface groups, 1,3-diaminopropane (DAP), N,N-di-(3-aminopropyl)-N-(methyl)amine (DAPMA) and spermine (SPM). By using a combination of ethidium bromide displacement, gel electrophoresis and transfection assays, it is shown that the dendrons with SPM groups are the most effective DNA binders, while the DAPMA-functionalised dendrons were the most effective systems for gene delivery (although the gene delivery profiles were still modest). In order to provide deeper insight into the experimental data, we performed a molecular dynamics simulation of the interactions between the dendrons and DNA. The results of these simulations demonstrated that, in general terms, the enthalpic contribution to binding was roughly proportional to the dendron surface charge, but that dendrons with DAP (and DAPMA) surface amines had significant entropic costs of binding to DNA. In the case of DAP, this is a consequence of the fact that the entire dendron structure has to be organised in order for each individual monoamine charge to make effective contact with DNA. For SPM, however, each surface ligand is already a multivalent triamine, therefore, each individual charge has a much lower entropic cost of binding. For DAPMA, we observed that strong binding of the hindered tertiary amine to the DNA double helix led to ligand back-folding and significant geometric distortion of DNA. Although this weakens the overall binding, we suggest that this distortion might be an explanation for the experimentally observed enhanced gene delivery, in which DNA compaction is an important step. Overall, this paper demonstrates how structure-activity relationships can be developed for multivalent dendritic ligands and provides insights into the thermodynamics of multivalent interactions.
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Affiliation(s)
- Simon P Jones
- Department of Chemistry, University of York, Heslington, York, YO10 5DD (UK), Fax: (+44) 1904 432516
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13
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Posocco P, Pricl S, Jones S, Barnard A, Smith DK. Less is more – multiscale modelling of self-assembling multivalency and its impact on DNA binding and gene delivery. Chem Sci 2010. [DOI: 10.1039/c0sc00291g] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
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14
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The polyamine transport system as a target for anticancer drug development. Amino Acids 2009; 38:415-22. [DOI: 10.1007/s00726-009-0400-2] [Citation(s) in RCA: 78] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2009] [Accepted: 10/28/2009] [Indexed: 10/20/2022]
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15
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Pavan GM, Danani A, Pricl S, Smith DK. Modeling the Multivalent Recognition between Dendritic Molecules and DNA: Understanding How Ligand “Sacrifice” and Screening Can Enhance Binding. J Am Chem Soc 2009; 131:9686-94. [DOI: 10.1021/ja901174k] [Citation(s) in RCA: 109] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Affiliation(s)
- Giovanni M. Pavan
- Molecular Simulations Engineering (MOSE) Laboratory, Department of Chemical Engineering (DICAMP), University of Trieste, Piazzale Europa 1, 34127 Trieste, Italy, Institute of Computer Integrated Manufacturing for Sustainable Innovation (ICIMSI), University for Applied Sciences of Southern Switzerland (SUPSI), Centro Galleria 2, Manno, CH-6928, Switzerland, and Department of Chemistry, University of York, Heslington, York, YO10 5DD, U.K
| | - Andrea Danani
- Molecular Simulations Engineering (MOSE) Laboratory, Department of Chemical Engineering (DICAMP), University of Trieste, Piazzale Europa 1, 34127 Trieste, Italy, Institute of Computer Integrated Manufacturing for Sustainable Innovation (ICIMSI), University for Applied Sciences of Southern Switzerland (SUPSI), Centro Galleria 2, Manno, CH-6928, Switzerland, and Department of Chemistry, University of York, Heslington, York, YO10 5DD, U.K
| | - Sabrina Pricl
- Molecular Simulations Engineering (MOSE) Laboratory, Department of Chemical Engineering (DICAMP), University of Trieste, Piazzale Europa 1, 34127 Trieste, Italy, Institute of Computer Integrated Manufacturing for Sustainable Innovation (ICIMSI), University for Applied Sciences of Southern Switzerland (SUPSI), Centro Galleria 2, Manno, CH-6928, Switzerland, and Department of Chemistry, University of York, Heslington, York, YO10 5DD, U.K
| | - David K. Smith
- Molecular Simulations Engineering (MOSE) Laboratory, Department of Chemical Engineering (DICAMP), University of Trieste, Piazzale Europa 1, 34127 Trieste, Italy, Institute of Computer Integrated Manufacturing for Sustainable Innovation (ICIMSI), University for Applied Sciences of Southern Switzerland (SUPSI), Centro Galleria 2, Manno, CH-6928, Switzerland, and Department of Chemistry, University of York, Heslington, York, YO10 5DD, U.K
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16
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Regulation of gene expression by PrrA in Rhodobacter sphaeroides 2.4.1: role of polyamines and DNA topology. J Bacteriol 2009; 191:4341-52. [PMID: 19411327 DOI: 10.1128/jb.00243-09] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
In the present study, we show in vitro binding of PrrA, a global regulator in Rhodobacter sphaeroides 2.4.1, to the PrrA site 2, within the RSP3361 locus. Specific binding, as shown by competition experiments, requires the phosphorylation of PrrA. The binding affinity of PrrA for site 2 was found to increase 4- to 10-fold when spermidine was added to the binding reaction. The presence of extracellular concentrations of spermidine in growing cultures of R. sphaeroides gave rise to a twofold increase in the expression of the photosynthesis genes pucB and pufB, as well as the RSP3361 gene, under aerobic growth conditions, as shown by the use of lacZ transcriptional fusions, and led to the production of light-harvesting spectral complexes. In addition, we show that negative supercoiling positively regulates the expression of the RSP3361 gene, as well as pucB. We show the importance of supercoiling through an evaluation of the regulation of gene expression in situ by supercoiling, in the case of the former gene, as well as using the DNA gyrase inhibitor novobiocin. We propose that polyamines and DNA supercoiling act synergistically to regulate expression of the RSP3361 gene, partly by affecting the affinity of PrrA binding to the PrrA site 2 within the RSP3361 gene.
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Mechulam A, Chernov KG, Mucher E, Hamon L, Curmi PA, Pastré D. Polyamine sharing between tubulin dimers favours microtubule nucleation and elongation via facilitated diffusion. PLoS Comput Biol 2009; 5:e1000255. [PMID: 19119409 PMCID: PMC2599886 DOI: 10.1371/journal.pcbi.1000255] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2008] [Accepted: 11/17/2008] [Indexed: 12/18/2022] Open
Abstract
We suggest for the first time that the action of multivalent cations on microtubule dynamics can result from facilitated diffusion of GTP-tubulin to the microtubule ends. Facilitated diffusion can promote microtubule assembly, because, upon encountering a growing nucleus or the microtubule wall, random GTP-tubulin sliding on their surfaces will increase the probability of association to the target sites (nucleation sites or MT ends). This is an original explanation for understanding the apparent discrepancy between the high rate of microtubule elongation and the low rate of tubulin association at the microtubule ends in the viscous cytoplasm. The mechanism of facilitated diffusion requires an attraction force between two tubulins, which can result from the sharing of multivalent counterions. Natural polyamines (putrescine, spermidine, and spermine) are present in all living cells and are potent agents to trigger tubulin self-attraction. By using an analytical model, we analyze the implication of facilitated diffusion mediated by polyamines on nucleation and elongation of microtubules. In vitro experiments using pure tubulin indicate that the promotion of microtubule assembly by polyamines is typical of facilitated diffusion. The results presented here show that polyamines can be of particular importance for the regulation of the microtubule network in vivo and provide the basis for further investigations into the effects of facilitated diffusion on cytoskeleton dynamics.
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Affiliation(s)
- Alain Mechulam
- Laboratoire Structure-Activité des Biomolécules
Normales et Pathologiques, Université Evry-Val d'Essonne,
Evry, France
- INSERM, U829, Evry, France
| | - Konstantin G. Chernov
- Laboratoire Structure-Activité des Biomolécules
Normales et Pathologiques, Université Evry-Val d'Essonne,
Evry, France
- INSERM, U829, Evry, France
- Institute of Protein Research, Russian Academy of Sciences, Pushchino,
Moscow Region, Russia
| | - Elodie Mucher
- Laboratoire Structure-Activité des Biomolécules
Normales et Pathologiques, Université Evry-Val d'Essonne,
Evry, France
- INSERM, U829, Evry, France
| | - Loic Hamon
- Laboratoire Structure-Activité des Biomolécules
Normales et Pathologiques, Université Evry-Val d'Essonne,
Evry, France
- INSERM, U829, Evry, France
| | - Patrick A. Curmi
- Laboratoire Structure-Activité des Biomolécules
Normales et Pathologiques, Université Evry-Val d'Essonne,
Evry, France
- INSERM, U829, Evry, France
| | - David Pastré
- Laboratoire Structure-Activité des Biomolécules
Normales et Pathologiques, Université Evry-Val d'Essonne,
Evry, France
- INSERM, U829, Evry, France
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18
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Mann A, Richa R, Ganguli M. DNA condensation by poly-l-lysine at the single molecule level: Role of DNA concentration and polymer length. J Control Release 2008; 125:252-62. [DOI: 10.1016/j.jconrel.2007.10.019] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2007] [Revised: 10/09/2007] [Accepted: 10/23/2007] [Indexed: 11/25/2022]
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19
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Strekowski L, Wilson B. Noncovalent interactions with DNA: an overview. Mutat Res 2007; 623:3-13. [PMID: 17445837 DOI: 10.1016/j.mrfmmm.2007.03.008] [Citation(s) in RCA: 303] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2006] [Revised: 03/14/2007] [Accepted: 03/15/2007] [Indexed: 05/15/2023]
Abstract
Over the last four decades, intense research has focused on the effects of small organic compounds that noncovalently bind to nucleic acids. These interactions have been shown to disrupt replication and/or transcription culminating in cellular death. Accordingly, DNA binding compounds have potential applications as anti-cancer and anti-viral agents. This report provides an overview of the different DNA-binding modes with an emphasis on DNA groove specificity for the groove-binding and intercalation modes. While most DNA-interacting agents selectively bind to DNA by either groove binding or intercalation, some compounds can exhibit both binding modes. The binding mode with the most favorable free energy for complex formation depends on the DNA sequence and structural features of the bound ligand.
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Affiliation(s)
- Lucjan Strekowski
- Department of Chemistry, Georgia State University, Atlanta, GA 30302-4098, United States.
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20
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Hoffmann GR, Gessner GS, Hughes JF, Ronan MV, Sylvia KE, Willett CJ. Modulation of the genotoxicity of bleomycin by amines through noncovalent DNA interactions and alteration of physiological conditions in yeast. Mutat Res 2007; 623:41-52. [PMID: 17428504 DOI: 10.1016/j.mrfmmm.2007.02.008] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2006] [Revised: 02/24/2007] [Accepted: 02/27/2007] [Indexed: 11/26/2022]
Abstract
The effects of amines on the induction of mitotic gene conversion by bleomycin (BLM) were studied at the trp5 locus in Saccharomyces cerevisiae strain D7. BLM induces double-strand breaks in DNA and is a potent recombinagen in this assay. The polyamine spermidine causes concentration-dependent protection against the genotoxicity of BLM, reducing the convertant frequency by over 90% under the most protective conditions. Spermine, diethylenetriamine, ethylenediamine, putrescine, and ethylamine were also antigenotoxic in combined treatments with BLM. There was a general correspondence between the protective effect and the number of amino groups, suggesting that more strongly cationic amines tend to be stronger antirecombinagens. Electrostatic association of the amines with DNA probably hinders BLM access to the 4' position of deoxyribose where it generates a free radical. Other amines interact with BLM differently from these unbranched aliphatic amines. The aminothiol cysteamine inhibits the genotoxicity of BLM under hypoxic conditions but increases it under euoxic conditions. In contrast, pargyline potentiates the genotoxicity of BLM under hypoxic conditions but not under euoxic conditions. The antirecombinagenic effect of cysteamine apparently involves DNA binding and depletion of oxygen needed for BLM activity, whereas its potentiation of BLM entails its serving as an electron source for the activation of BLM. Pargyline may enhance BLM indirectly by preventing the depletion of oxygen by monoamine and polyamine oxidase. The planar 9-aminoacridine weakly induces gene conversion in strain D7, but it is strongly synergistic with BLM. Enhancement of BLM activity by this compound and by the related nitroacridine Entozon is apparently mediated by intercalation of the acridine ring system into DNA. Thus, the influence of amines on the genotoxicity of BLM in yeast encompasses antigenotoxic, potentiating, and synergistic interactions. The underlying mechanisms involve noncovalent association with DNA, altered BLM access to DNA, and modulation of physiological conditions.
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Affiliation(s)
- George R Hoffmann
- Department of Biology, College of the Holy Cross, One College Street, Worcester, MA 01610-2395, USA.
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21
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Tkachenko AG, Fedotova MV. Dependence of protective functions of Escherichia coli polyamines on strength of stress caused by superoxide radicals. BIOCHEMISTRY (MOSCOW) 2007; 72:109-16. [PMID: 17309444 DOI: 10.1134/s0006297907010130] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Mechanisms of antioxidant effect of polyamines were studied in dependence on the strength of superoxide stress. Under conditions of weak stress, polyamines from Escherichia coli cultures were shown to function mainly as a scavenger of free superoxide radicals, whereas under conditions of strong stress they mainly acted as positive modulators of antioxidant genes. Spectrofluorimetry was used to show that both polyamine-dependent mutants and wild type cells treated with inhibitors of polyamine synthesis contained an elevated amount of free oxygen radicals, which could be decreased to the normal level by addition of exogenous polyamines. Under conditions of strong stress, polyamines positively influenced expression of the soxRS regulon genes of antioxidant defense, which was accompanied by an increase in the quantity (activity) of their gene products, such as glucose-6-phosphate dehydrogenase (Zwf) and fumarase (FumC). These effects led to an increase in the number of live cells in the cultures subjected to superoxide stress.
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Affiliation(s)
- A G Tkachenko
- Institute of Ecology and Genetics of Microorganisms, Ural Branch, Russian Academy of Sciences, Perm, 614081, Russia.
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22
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Wortham BW, Patel CN, Oliveira MA. Polyamines in bacteria: pleiotropic effects yet specific mechanisms. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2007; 603:106-15. [PMID: 17966408 DOI: 10.1007/978-0-387-72124-8_9] [Citation(s) in RCA: 115] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
Abstract
Extensive data in a wide range of organisms point to the importance of polyamine homeostasis for growth. The two most common polyamines found in bacteria are putrescine and spermidine. The investigation of polyamine function in bacteria has revealed that they are involved in a number of functions other than growth, which include incorporation into the cell wall and biosynthesis of siderophores. They are also important in acid resistance and can act as a free radical ion scavenger. More recently it has been suggested that polyamines play a potential role in signaling cellular differentiation in Proteus mirabilis. Polyamines have also been shown to be essential in biofilm formation in Yersinia pestis. The pleiotropic nature of polyamines has made their investigation difficult, particularly in discerning any specific effect from more global growth effects. Here we describe key developments in the investigation of the function of polyamines in bacteria that have revealed new roles for polyamines distinct from growth. We describe the bacterial genes necessary for biosynthesis and transport, with a focus on Y. pestis. Finally we review a novel role for polyamines in the regulation of biofilm development in Y. pestis and provide evidence that the investigation of polyamines in Y. pestis may provide a model for understanding the mechanism through which polyamines regulate biofilm formation.
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Affiliation(s)
- Brian W Wortham
- Department of Pharmaceutical Sciences, University of Kentucky, Lexington, USA
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23
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Zhang Y, McEwen AE, Crothers DM, Levene SD. Analysis of in-vivo LacR-mediated gene repression based on the mechanics of DNA looping. PLoS One 2006; 1:e136. [PMID: 17205140 PMCID: PMC1762422 DOI: 10.1371/journal.pone.0000136] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2006] [Accepted: 11/30/2006] [Indexed: 11/19/2022] Open
Abstract
Interactions of E. coli lac repressor (LacR) with a pair of operator sites on the same DNA molecule can lead to the formation of looped nucleoprotein complexes both in vitro and in vivo. As a major paradigm for loop-mediated gene regulation, parameters such as operator affinity and spacing, repressor concentration, and DNA bending induced by specific or non-specific DNA-binding proteins (e.g., HU), have been examined extensively. However, a complete and rigorous model that integrates all of these aspects in a systematic and quantitative treatment of experimental data has not been available. Applying our recent statistical-mechanical theory for DNA looping, we calculated repression as a function of operator spacing (58-156 bp) from first principles and obtained excellent agreement with independent sets of in-vivo data. The results suggest that a linear extended, as opposed to a closed v-shaped, LacR conformation is the dominant form of the tetramer in vivo. Moreover, loop-mediated repression in wild-type E. coli strains is facilitated by decreased DNA rigidity and high levels of flexibility in the LacR tetramer. In contrast, repression data for strains lacking HU gave a near-normal value of the DNA persistence length. These findings underscore the importance of both protein conformation and elasticity in the formation of small DNA loops widely observed in vivo, and demonstrate the utility of quantitatively analyzing gene regulation based on the mechanics of nucleoprotein complexes.
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Affiliation(s)
- Yongli Zhang
- Departments of Chemistry and Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut, United States of America
- * To whom correspondence should be addressed. E-mail:
| | - Abbye E. McEwen
- Institute of Biomedical Sciences and Technology, University of Texas at Dallas, Richardson, Texas, United States of America
| | - Donald M. Crothers
- Departments of Chemistry and Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut, United States of America
| | - Stephen D. Levene
- Institute of Biomedical Sciences and Technology, University of Texas at Dallas, Richardson, Texas, United States of America
- Department of Molecular and Cell Biology, University of Texas at Dallas, Richardson, Texas, United States of America
- * To whom correspondence should be addressed. E-mail:
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24
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Pastré D, Hamon L, Landousy F, Sorel I, David MO, Zozime A, Le Cam E, Piétrement O. Anionic polyelectrolyte adsorption on mica mediated by multivalent cations: a solution to DNA imaging by atomic force microscopy under high ionic strengths. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2006; 22:6651-60. [PMID: 16831009 DOI: 10.1021/la053387y] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Adsorption of DNA molecules on mica, a highly negatively charged surface, mediated by divalent or trivalent cations is considered. By analyzing atomic force microscope (AFM) images of DNA molecules adsorbed on mica, phase diagrams of DNA molecules interacting with a mica surface are established in terms of concentrations of monovalent salt (NaCl) and divalent (MgCl2) or multivalent (spermidine, cobalt hexamine) salts. These diagrams show two transitions between nonadsorption and adsorption. The first one arises when the concentration of multivalent counterions is larger than a limit value, which is not sensitive to the monovalent salt concentration. The second transition is due to the binding competition between monovalent and multivalent counterions. In addition, we develop a model of polyelectrolyte adsorption on like-charged surfaces with multivalent counterions. This model shows that the correlations of the multivalent counterions at the interface between DNA and mica play a critical role. Furthermore, it appears that DNA adsorption takes place when the energy gain in counterion correlations overcomes an energy barrier. This barrier is induced by the entropy loss in confining DNA in a thin adsorbed layer, the entropy loss in the interpenetration of the clouds of mica and DNA counterions, and the electrostatic repulsion between DNA and mica. The analysis of the experimental results provides an estimation of this energy barrier. We then discuss some important issues, including DNA adsorption under physiological conditions.
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Affiliation(s)
- David Pastré
- Laboratoire Structure et Reconnaissance des Biomolécules, EA 3637, Université d'Evry, Rue du Père Jarlan, 91025 Evry Cedex, France.
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