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K M K, N U, S K. Conformational dynamics and ribosomal interactions of Bacillus subtilis Obg in various nucleotide-bound states: Insights from molecular dynamics simulation. Int J Biol Macromol 2024; 279:135337. [PMID: 39241998 DOI: 10.1016/j.ijbiomac.2024.135337] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2024] [Revised: 08/24/2024] [Accepted: 09/03/2024] [Indexed: 09/09/2024]
Abstract
Obg, a GTPase, binds to the premature 50S ribosomal subunit and facilitates recruitment of rproteins and rRNA processing to form the mature 50S subunit. This binding depends on nucleotide-induced conformational changes (GDP/GTP). However, the mechanism by which Obg undergoes conformational changes to associate with the premature 50S subunit is unknown. Therefore, 1000 ns molecular dynamics simulations were conducted to investigate this mechanism. Visualization of the simulated trajectory showed that in GDP and GTP-bound states, the C-domain moved towards the SwI region, while in GTP-Mg2+ and ppGpp-bound states, the C-domain shifted towards the N-tails. Further, positioning these conformations of Obg on the 50S subunit suggests possible mechanisms by which the GTP-Mg2+ bound state is responsible for recruiting rprotein, as well as the impact of the absence of Mg2+ in the GTP-bound state. Furthermore, the study provides insights into the conformational changes that may lead to the dissociation of the GDP-bound state from the 50S subunit and explores the potential role of the ppGpp-bound state in inhibiting 70S ribosome formation. Additionally, RMSF and community network analyses reveal how internal dynamics and intricate connections within Obg affect C-domain motion.
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Affiliation(s)
- Kavya K M
- Department of Studies in Physics, University of Mysore, Mysuru, India.
| | - Upendra N
- Center for Research and Innovations, Faculty of Natural Sciences, Adichunchanagiri University, B.G.Nagara, India.
| | - Krishnaveni S
- Department of Studies in Physics, University of Mysore, Mysuru, India.
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2
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Stoakes E, Turner K, Baker DJ, Suau Sans M, Yasir M, Kalmar L, Costigan R, Lott M, Grant AJ. Application of TraDIS to define the core essential genome of Campylobacter jejuni and Campylobacter coli. BMC Microbiol 2023; 23:97. [PMID: 37024800 PMCID: PMC10077673 DOI: 10.1186/s12866-023-02835-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2022] [Accepted: 03/23/2023] [Indexed: 04/08/2023] Open
Abstract
Campylobacter species are the major cause of bacterial gastroenteritis. As there is no effective vaccine, combined with the rapid increase in antimicrobial resistant strains, there is a need to identify new targets for intervention. Essential genes are those that are necessary for growth and/or survival, making these attractive targets. In this study, comprehensive transposon mutant libraries were created in six C. jejuni strains, four C. coli strains and one C. lari and C. hyointestinalis strain, allowing for those genes that cannot tolerate a transposon insertion being called as essential. Comparison of essential gene lists using core genome analysis can highlight those genes which are common across multiple strains and/or species. Comparison of C. jejuni and C. coli, the two species that cause the most disease, identified 316 essential genes. Genes of interest highlighted members of the purine pathway being essential for C. jejuni whilst also finding that a functional potassium uptake system is essential. Protein-protein interaction networks using these essential gene lists also highlighted proteins in the purine pathway being major 'hub' proteins which have a large number of interactors across the network. When adding in two more species (C. lari and C. hyointestinalis) the essential gene list reduces to 261. Within these 261 essential genes, there are many genes that have been found to be essential in other bacteria. These include htrB and PEB4, which have previously been found as core virulence genes across Campylobacter species in other studies. There were 21 genes which have no known function with eight of these being associated with the membrane. These surface-associated essential genes may provide attractive targets. The essential gene lists presented will help to prioritise targets for the development of novel therapeutic and preventative interventions.
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Affiliation(s)
- Emily Stoakes
- Department of Veterinary Medicine, University of Cambridge, Madingley Road, Cambridge, UK
| | - Keith Turner
- Quadram Institute Bioscience, Norwich Research Park, Norwich, UK
| | - Dave J Baker
- Quadram Institute Bioscience, Norwich Research Park, Norwich, UK
| | - Maria Suau Sans
- Department of Veterinary Medicine, University of Cambridge, Madingley Road, Cambridge, UK
| | - Muhammad Yasir
- Quadram Institute Bioscience, Norwich Research Park, Norwich, UK
| | - Lajos Kalmar
- MRC Toxicology Unit, University of Cambridge, Tennis Court Road, Cambridge, UK
| | - Ruby Costigan
- Department of Veterinary Medicine, University of Cambridge, Madingley Road, Cambridge, UK
| | - Martin Lott
- Quadram Institute Bioscience, Norwich Research Park, Norwich, UK
| | - Andrew J Grant
- Department of Veterinary Medicine, University of Cambridge, Madingley Road, Cambridge, UK.
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Shanbhag C, Saraogi I. Bacterial GTPases as druggable targets to tackle antimicrobial resistance. Bioorg Med Chem Lett 2023; 87:129276. [PMID: 37030567 DOI: 10.1016/j.bmcl.2023.129276] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Revised: 04/03/2023] [Accepted: 04/04/2023] [Indexed: 04/08/2023]
Abstract
Small molecules as antibacterial agents have contributed immensely to the growth of modern medicine over the last several decades. However, the emergence of drug resistance among bacterial pathogens has undermined the effectiveness of the existing antibiotics. Thus, there is an exigency to address the antibiotic crisis by developing new antibacterial agents and identifying novel drug targets in bacteria. In this review, we summarize the importance of guanosine triphosphate hydrolyzing proteins (GTPases) as key agents for bacterial survival. We also discuss representative examples of small molecules that target bacterial GTPases as novel antibacterial agents, and highlight areas that are ripe for exploration. Given their vital roles in cell viability, virulence, and antibiotic resistance, bacterial GTPases are highly attractive antibacterial targets that will likely play a vital role in the fight against antimicrobial resistance.
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Chakraborty A, Halder S, Kishore P, Saha D, Saha S, Sikder K, Basu A. The structure-function analysis of Obg-like GTPase proteins along the evolutionary tree from bacteria to humans. Genes Cells 2022; 27:469-481. [PMID: 35610748 PMCID: PMC9545696 DOI: 10.1111/gtc.12942] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Revised: 04/12/2022] [Accepted: 04/17/2022] [Indexed: 11/28/2022]
Abstract
Obg proteins belong to P-loop guanine triphosphatase (GTPase) that are conserved from bacteria to humans. Like other GTPases, Obg cycles between guanine triphosphate (GTP) bound "on" state and guanine diphosphate (GDP)-bound "off" state, thereby controlling various cellular processes. Different members of this group have unique structural characteristics; a conserved glycine-rich N-terminal domain known as obg fold, a central conserved nucleotide binding domain, and a less conserved C-terminal domain of other functions. Obg is a ribosome dependent GTPase helps in ribosome maturation by interacting with several proteins of the 50S subunit of the ribosome. Obg proteins have been widely considered as a regulator of cellular functions, helping in DNA replication, cell division. Apart from that, this protein also takes part in various stress adaptation pathways like a stringent response, sporulation, and general stress response. In this particular review, the structural features of ObgE have been highlighted and how the structure plays important role in interacting with regulators like GTP, ppGpp that are crucial for executing biological function has been orchestrated. In particular, we believe that Obg-like proteins can provide a link between different global pathways that are necessary for fine-tuning cellular processes to maintain the cellular energy status.
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Affiliation(s)
- Asmita Chakraborty
- JIVAN, Department of Biomedical Science and Technology, School of Biological Sciences, Ramakrishna Mission Vivekananda Educational Research Institute (RKMVERI), Kolkata, India
| | - Sheta Halder
- Department of Biotechnology, Amity University Kolkata, Kolkata, India
| | - Purvi Kishore
- Department of Biotechnology, Amity University Kolkata, Kolkata, India
| | - Disha Saha
- Department of Biotechnology, Amity University Kolkata, Kolkata, India
| | - Sujata Saha
- JIVAN, Department of Biomedical Science and Technology, School of Biological Sciences, Ramakrishna Mission Vivekananda Educational Research Institute (RKMVERI), Kolkata, India
| | - Kunal Sikder
- JIVAN, Department of Biomedical Science and Technology, School of Biological Sciences, Ramakrishna Mission Vivekananda Educational Research Institute (RKMVERI), Kolkata, India
| | - Arnab Basu
- JIVAN, Department of Biomedical Science and Technology, School of Biological Sciences, Ramakrishna Mission Vivekananda Educational Research Institute (RKMVERI), Kolkata, India
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Silvestre I, Nunes A, Borges V, Isidro J, Silva C, Vieira L, Gomes JP, Borrego MJ. Genomic insights on DNase production in Streptococcus agalactiae ST17 and ST19 strains. INFECTION GENETICS AND EVOLUTION 2021; 93:104969. [PMID: 34147652 DOI: 10.1016/j.meegid.2021.104969] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2020] [Revised: 06/08/2021] [Accepted: 06/15/2021] [Indexed: 10/21/2022]
Abstract
Streptococcus agalactiae evasion from the human defense mechanisms has been linked to the production of DNases. These were proposed to contribute to the hypervirulence of S. agalactiae ST17/capsular-type III strains, mostly associated with neonatal meningitis. We performed a comparative genomic analysis between ST17 and ST19 human strains with different cell tropism and distinct DNase production phenotypes. All S. agalactiae ST17 strains, with the exception of 2211-04, were found to display DNase activity, while the opposite scenario was observed for ST19, where 1203-05 was the only DNase(+) strain. The analysis of the genetic variability of the seven genes putatively encoding secreted DNases in S. agalactiae revealed an exclusive amino acid change in the predicted signal peptide of GBS0661 (NucA) of the ST17 DNase(-), and an exclusive amino acid change alteration in GBS0609 of the ST19 DNase(+) strain. Further core-genome analysis identified some specificities (SNVs or indels) differentiating the DNase(-) ST17 2211-04 and the DNase(+) ST19 1203-05 from the remaining strains of each ST. The pan-genomic analysis evidenced an intact phage without homology in S. agalactiae and a transposon homologous to TnGBS2.3 in ST17 DNase(-) 2211-04; the transposon was also found in one ST17 DNase(+) strain, yet with a different site of insertion. A group of nine accessory genes were identified among all ST17 DNase(+) strains, including the Eco47II family restriction endonuclease and the C-5 cytosine-specific DNA methylase. None of these loci was found in any DNase(-) strain, which may suggest that these proteins might contribute to the lack of DNase activity. In summary, we provide novel insights on the genetic diversity between DNase(+) and DNase(-) strains, and identified genetic traits, namely specific mutations affecting predicted DNases (NucA and GBS0609) and differences in the accessory genome, that need further investigation as they may justify distinct DNase-related virulence phenotypes in S. agalactiae.
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Affiliation(s)
- Inês Silvestre
- Department of Life Sciences, UCIBIO, Nova School of Science and Technology, 2829-516 Caparica, Portugal; National Reference Laboratory for Sexually Transmitted Infections, Department of Infectious Diseases, National Institute of Health, Avenida Padre Cruz, 1649-016 Lisbon, Portugal
| | - Alexandra Nunes
- Bioinformatics Unit, Department of Infectious Diseases, National Institute of Health, Avenida Padre Cruz, 1649-016 Lisbon, Portugal; CBIOS - Research Center for Biosciences & Health Technologies, Lusófona University of Humanities and Technologies, Campo Grande 376, 1749-024 Lisbon, Portugal
| | - Vítor Borges
- Bioinformatics Unit, Department of Infectious Diseases, National Institute of Health, Avenida Padre Cruz, 1649-016 Lisbon, Portugal
| | - Joana Isidro
- Bioinformatics Unit, Department of Infectious Diseases, National Institute of Health, Avenida Padre Cruz, 1649-016 Lisbon, Portugal
| | - Catarina Silva
- Innovation and Technology Unit, Department of Human Genetics, National Institute of Health, Avenida Padre Cruz, 1649-016 Lisbon, Portugal; Centre for Toxicogenomics and Human Health (ToxOmics), Nova Medical School
- Faculdade de Ciências Médicas, Universidade Nova de Lisboa, Campo dos Mártires da Pátria, 1169-056 Lisbon, Portugal
| | - Luís Vieira
- Innovation and Technology Unit, Department of Human Genetics, National Institute of Health, Avenida Padre Cruz, 1649-016 Lisbon, Portugal; Centre for Toxicogenomics and Human Health (ToxOmics), Nova Medical School
- Faculdade de Ciências Médicas, Universidade Nova de Lisboa, Campo dos Mártires da Pátria, 1169-056 Lisbon, Portugal
| | - João Paulo Gomes
- Bioinformatics Unit, Department of Infectious Diseases, National Institute of Health, Avenida Padre Cruz, 1649-016 Lisbon, Portugal.
| | - Maria José Borrego
- National Reference Laboratory for Sexually Transmitted Infections, Department of Infectious Diseases, National Institute of Health, Avenida Padre Cruz, 1649-016 Lisbon, Portugal.
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Attenuation of a Pathogenic Mycoplasma Strain by Modification of the obg Gene by Using Synthetic Biology Approaches. mSphere 2019; 4:4/3/e00030-19. [PMID: 31118296 PMCID: PMC6531878 DOI: 10.1128/msphere.00030-19] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
Animal diseases due to mycoplasmas are a major cause of morbidity and mortality associated with economic losses for farmers all over the world. Currently used mycoplasma vaccines exhibit several drawbacks, including low efficacy, short time of protection, adverse reactions, and difficulty in differentiating infected from vaccinated animals. Therefore, there is a need for improved vaccines to control animal mycoplasmoses. Here, we used genome engineering tools derived from synthetic biology approaches to produce targeted mutations in the essential GTPase-encoding obg gene of Mycoplasma mycoides subsp. capri. Some of the resulting mutants exhibited a marked temperature-sensitive phenotype. The virulence of one of the obg mutants was evaluated in a caprine septicemia model and found to be strongly reduced. Although the obg mutant reverted to a virulent phenotype in one infected animal, we believe that these results contribute to a strategy that should help in building new vaccines against animal mycoplasmoses. Mycoplasma species are responsible for several economically significant livestock diseases for which there is a need for new and improved vaccines. Most of the existing mycoplasma vaccines are attenuated strains that have been empirically obtained by serial passages or by chemical mutagenesis. The recent development of synthetic biology approaches has opened the way for the engineering of live mycoplasma vaccines. Using these tools, the essential GTPase-encoding gene obg was modified directly on the Mycoplasma mycoides subsp. capri genome cloned in yeast, reproducing mutations suspected to induce a temperature-sensitive (TS+) phenotype. After transplantation of modified genomes into a recipient cell, the phenotype of the resulting M. mycoides subsp. capri mutants was characterized. Single-point obg mutations did not result in a strong TS+ phenotype in M. mycoides subsp. capri, but a clone presenting three obg mutations was shown to grow with difficulty at temperatures of ≥40°C. This particular mutant was then tested in a caprine septicemia model of M. mycoides subsp. capri infection. Five out of eight goats infected with the parental strain had to be euthanized, in contrast to one out of eight goats infected with the obg mutant, demonstrating an attenuation of virulence in the mutant. Moreover, the strain isolated from the euthanized animal in the group infected with the obg mutant was shown to carry a reversion in the obg gene associated with the loss of the TS+ phenotype. This study demonstrates the feasibility of building attenuated strains of mycoplasma that could contribute to the design of novel vaccines with improved safety. IMPORTANCE Animal diseases due to mycoplasmas are a major cause of morbidity and mortality associated with economic losses for farmers all over the world. Currently used mycoplasma vaccines exhibit several drawbacks, including low efficacy, short time of protection, adverse reactions, and difficulty in differentiating infected from vaccinated animals. Therefore, there is a need for improved vaccines to control animal mycoplasmoses. Here, we used genome engineering tools derived from synthetic biology approaches to produce targeted mutations in the essential GTPase-encoding obg gene of Mycoplasma mycoides subsp. capri. Some of the resulting mutants exhibited a marked temperature-sensitive phenotype. The virulence of one of the obg mutants was evaluated in a caprine septicemia model and found to be strongly reduced. Although the obg mutant reverted to a virulent phenotype in one infected animal, we believe that these results contribute to a strategy that should help in building new vaccines against animal mycoplasmoses.
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Chatterjee A, Acharjee A, Das S, Datta PP. Deletion analyses reveal insights into the domain specific activities of an essential GTPase CgtA in Vibrio cholerae. Arch Biochem Biophys 2019; 665:143-151. [PMID: 30894284 DOI: 10.1016/j.abb.2019.03.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2018] [Revised: 03/08/2019] [Accepted: 03/10/2019] [Indexed: 10/27/2022]
Abstract
CgtA is an essential bacterial GTPase protein involved in multiple cellular activities. In the presence of 50S ribosome, its GTPase activity increases significantly. Through sequential deletions of CgtA protein of Vibrio cholerae (CgtAvc) we found that its N terminal Obg domain is essential for ribosome binding and augmenting the ribosome mediated GTPase activity. Strategic deletions of the three glycine rich loops of Obg domain revealed that loop 1 of Obg domain is involved in anchoring the protein into the 50S, whereas, loop 2 & loop 3 are involved in conveying the effect of interaction of the Obg domain with the 50S to the GTPase domain through an interdomain linker, followed by GTP hydrolysis. On the other hand, the non-conserved C-terminal domain (CTD) is not directly involved in ribosome binding but shows negative impact on GTPase activity.
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Affiliation(s)
- Ananya Chatterjee
- Department of Biological Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur, Nadia, 741246, West Bengal, India; Viral Research and Diagnostic Laboratories, National Institute of Cholera and Enteric Diseases, P-33, C.I.T. Road, Scheme XM, Beliaghata, P.O. Box-177, Kolkata, 700 010, West Bengal, India
| | - Arita Acharjee
- Department of Biological Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur, Nadia, 741246, West Bengal, India
| | - Sagarika Das
- Department of Biological Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur, Nadia, 741246, West Bengal, India
| | - Partha P Datta
- Department of Biological Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur, Nadia, 741246, West Bengal, India.
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Abstract
AbstractRibosome assembly is critical for translation and regulating the response to cellular events and requires a complex interplay of ribosomal RNA and proteins with assembly factors. We investigated putative participants in the biogenesis of the reduced organellar ribosomes of Plasmodium falciparum and identified homologues of two assembly GTPases – EngA and Obg that were found in mitochondria. Both are indispensable in bacteria and P. berghei EngA is among the ‘essential’ parasite blood stage proteins identified recently. PfEngA and PfObg1 interacted with parasite mitoribosomes in vivo. GTP stimulated PfEngA interaction with the 50S subunit of Escherichia coli surrogate ribosomes. Although PfObg1–ribosome interaction was independent of nucleotide binding, GTP hydrolysis by PfObg1 was enhanced upon ribosomal association. An additional function for PfObg1 in mitochondrial DNA transactions was suggested by its specific interaction with the parasite mitochondrial genome in vivo. Deletion analysis revealed that the positively-charged OBG (spoOB-associated GTP-binding protein) domain mediates DNA-binding. A role for PfEngA in mitochondrial genotoxic stress response was indicated by its over-expression upon methyl methanesulfonate-induced DNA damage. PfEngA had lower sensitivity to an E. coli EngA inhibitor suggesting differences with bacterial counterparts. Our results show the involvement of two important GTPases in P. falciparum mitochondrial function, with the first confirmed localization of an EngA homologue in eukaryotic mitochondria.
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Wierzbicki IH, Zielke RA, Korotkov KV, Sikora AE. Functional and structural studies on the Neisseria gonorrhoeae GmhA, the first enzyme in the glycero-manno-heptose biosynthesis pathways, demonstrate a critical role in lipooligosaccharide synthesis and gonococcal viability. Microbiologyopen 2017; 6:e00432. [PMID: 28063198 PMCID: PMC5387315 DOI: 10.1002/mbo3.432] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2016] [Revised: 11/14/2016] [Accepted: 11/17/2016] [Indexed: 12/04/2022] Open
Abstract
Sedoheptulose-7-phosphate isomerase, GmhA, is the first enzyme in the biosynthesis of nucleotide-activated-glycero-manno-heptoses and an attractive, yet underexploited, target for development of broad-spectrum antibiotics. We demonstrated that GmhA homologs in Neisseria gonorrhoeae and N. meningitidis (hereafter called GmhAGC and GmhANM , respectively) were interchangeable proteins essential for lipooligosaccharide (LOS) synthesis, and their depletion had adverse effects on neisserial viability. In contrast, the Escherichia coli ortholog failed to complement GmhAGC depletion. Furthermore, we showed that GmhAGC is a cytoplasmic enzyme with induced expression at mid-logarithmic phase, upon iron deprivation and anaerobiosis, and conserved in contemporary gonococcal clinical isolates including the 2016 WHO reference strains. The untagged GmhAGC crystallized as a tetramer in the closed conformation with four zinc ions in the active site, supporting that this is most likely the catalytically active conformation of the enzyme. Finally, site-directed mutagenesis studies showed that the active site residues E65 and H183 were important for LOS synthesis but not for GmhAGC function in bacterial viability. Our studies bring insights into the importance and mechanism of action of GmhA and may ultimately facilitate targeting the enzyme with small molecule inhibitors.
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Affiliation(s)
- Igor H. Wierzbicki
- Department of Pharmaceutical SciencesCollege of PharmacyOregon State UniversityCorvallisORUSA
| | - Ryszard A. Zielke
- Department of Pharmaceutical SciencesCollege of PharmacyOregon State UniversityCorvallisORUSA
| | - Konstantin V. Korotkov
- Department of Molecular & Cellular BiochemistryCollege of MedicineUniversity of KentuckyLexingtonKYUSA
| | - Aleksandra E. Sikora
- Department of Pharmaceutical SciencesCollege of PharmacyOregon State UniversityCorvallisORUSA
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