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Kellogg GE, Marabotti A, Spyrakis F, Mozzarelli A. HINT, a code for understanding the interaction between biomolecules: a tribute to Donald J. Abraham. Front Mol Biosci 2023; 10:1194962. [PMID: 37351551 PMCID: PMC10282649 DOI: 10.3389/fmolb.2023.1194962] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Accepted: 05/24/2023] [Indexed: 06/24/2023] Open
Abstract
A long-lasting goal of computational biochemists, medicinal chemists, and structural biologists has been the development of tools capable of deciphering the molecule-molecule interaction code that produces a rich variety of complex biomolecular assemblies comprised of the many different simple and biological molecules of life: water, small metabolites, cofactors, substrates, proteins, DNAs, and RNAs. Software applications that can mimic the interactions amongst all of these species, taking account of the laws of thermodynamics, would help gain information for understanding qualitatively and quantitatively key determinants contributing to the energetics of the bimolecular recognition process. This, in turn, would allow the design of novel compounds that might bind at the intermolecular interface by either preventing or reinforcing the recognition. HINT, hydropathic interaction, was a model and software code developed from a deceptively simple idea of Donald Abraham with the close collaboration with Glen Kellogg at Virginia Commonwealth University. HINT is based on a function that scores atom-atom interaction using LogP, the partition coefficient of any molecule between two phases; here, the solvents are water that mimics the cytoplasm milieu and octanol that mimics the protein internal hydropathic environment. This review summarizes the results of the extensive and successful collaboration between Abraham and Kellogg at VCU and the group at the University of Parma for testing HINT in a variety of different biomolecular interactions, from proteins with ligands to proteins with DNA.
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Affiliation(s)
- Glen E. Kellogg
- Department of Medicinal Chemistry and Institute for Structural Biology, Drug Discovery and Development, Virginia Commonwealth University, Richmond, VA, United States
| | - Anna Marabotti
- Department of Chemistry and Biology “A Zambelli”, University of Salerno, Fisciano (SA), Italy
| | - Francesca Spyrakis
- Department of Drug Science and Technology, University of Turin, Turin, Italy
| | - Andrea Mozzarelli
- Department of Food and Drug, University of Parma and Institute of Biophysics, Parma, Italy
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Brunson DN, Colomer-Winter C, Lam LN, Lemos JA. Identification of Multiple Iron Uptake Mechanisms in Enterococcus faecalis and Their Relationship to Virulence. Infect Immun 2023; 91:e0049622. [PMID: 36912636 PMCID: PMC10112239 DOI: 10.1128/iai.00496-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2022] [Accepted: 02/17/2023] [Indexed: 03/14/2023] Open
Abstract
Among the unfavorable conditions bacteria encounter within the host is restricted access to essential trace metals such as iron. To overcome iron deficiency, bacteria deploy multiple strategies to scavenge iron from host tissues, with abundant examples of iron acquisition systems being implicated in bacterial pathogenesis. Yet the mechanisms utilized by the major nosocomial pathogen Enterococcus faecalis to maintain intracellular iron balance are poorly understood. In this study, we conducted a systematic investigation to identify and characterize the iron acquisition mechanisms of E. faecalis and to determine their contribution to virulence. Bioinformatic analysis and literature surveys revealed that E. faecalis possesses three conserved iron uptake systems. Through transcriptomics, we discovered two novel ABC-type transporters that mediate iron uptake. While inactivation of a single transporter had minimal impact on the ability of E. faecalis to maintain iron homeostasis, inactivation of all five systems (Δ5Fe strain) disrupted intracellular iron homeostasis and considerably impaired cell growth under iron deficiency. Virulence of the Δ5Fe strain was generally impaired in different animal models but showed niche-specific variations in mouse models, leading us to suspect that heme can serve as an iron source to E. faecalis during mammalian infections. Indeed, heme supplementation restored growth of Δ5Fe under iron depletion and virulence in an invertebrate infection model. This study revealed that the collective contribution of five iron transporters promotes E. faecalis virulence and that the ability to acquire and utilize heme as an iron source is critical to the systemic dissemination of E. faecalis.
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Affiliation(s)
- Debra N. Brunson
- Department of Oral Biology, University of Florida College of Dentistry, Gainesville, Florida, USA
| | - Cristina Colomer-Winter
- Department of Oral Biology, University of Florida College of Dentistry, Gainesville, Florida, USA
| | - Ling Ning Lam
- Department of Oral Biology, University of Florida College of Dentistry, Gainesville, Florida, USA
| | - José A. Lemos
- Department of Oral Biology, University of Florida College of Dentistry, Gainesville, Florida, USA
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Kayastha F, Herrington NB, Kapadia B, Roychowdhury A, Nanaji N, Kellogg GE, Gartenhaus RB. Novel eIF4A1 inhibitors with anti-tumor activity in lymphoma. Mol Med 2022; 28:101. [PMID: 36058921 PMCID: PMC9441068 DOI: 10.1186/s10020-022-00534-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2022] [Accepted: 08/25/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Deregulated translation initiation is implicated extensively in cancer initiation and progression. It is actively pursued as a viable target that circumvents the dependency on oncogenic signaling, a significant factor in current strategies. Eukaryotic translation initiation factor (eIF) 4A plays an essential role in translation initiation by unwinding the secondary structure of messenger RNA (mRNA) upstream of the start codon, enabling active ribosomal recruitment on the downstream genes. Several natural product molecules with similar scaffolds, such as Rocaglamide A (RocA), targeting eIF4A have been reported in the last decade. However, their clinical utilization is still elusive due to several pharmacological limitations. In this study we identified new eIF4A1 inhibitors and their possible mechanisms. METHODS In this report, we conducted a pharmacophore-based virtual screen of RocA complexed with eIF4A and a polypurine RNA strand for novel eIF4A inhibitors from commercially available compounds in the MolPort Database. We performed target-based screening and optimization of active pharmacophores. We assessed the effects of novel compounds on biochemical and cell-based assays for efficacy and mechanistic evaluation. RESULTS We validated three new potent eIF4A inhibitors, RBF197, RBF 203, and RBF 208, which decreased diffuse large B-cell lymphoma (DLBCL) cell viability. Biochemical and cellular studies, molecular docking, and functional assays revealed that thosenovel compounds clamp eIF4A into mRNA in an ATP-independent manner. Moreover, we found that RBF197 and RBF208 significantly depressed eIF4A-dependent oncogene expression as well as the colony formation capacity of DLBCL. Interestingly, exposure of these compounds to non-malignant cells had only minimal impact on their growth and viability. CONCLUSIONS Identified compounds suggest a new strategy for designing novel eIF4A inhibitors.
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Affiliation(s)
- Forum Kayastha
- McGuire Cancer Center, Hunter Holmes McGuire VA Medical Center, Richmond, VA, USA
- Division of Hematology, Oncology, and Palliative care, Department of Internal Medicine, Massey Cancer Center, Virginia Commonwealth University School of Medicine, Richmond, VA, USA
| | - Noah B Herrington
- Department of Medicinal Chemistry, Institute for Structural Biology, Drug Discovery and Development, Virginia Commonwealth University School of Pharmacy, Richmond, VA, USA
| | - Bandish Kapadia
- McGuire Cancer Center, Hunter Holmes McGuire VA Medical Center, Richmond, VA, USA
- Division of Hematology, Oncology, and Palliative care, Department of Internal Medicine, Massey Cancer Center, Virginia Commonwealth University School of Medicine, Richmond, VA, USA
| | - Anirban Roychowdhury
- McGuire Cancer Center, Hunter Holmes McGuire VA Medical Center, Richmond, VA, USA
- Division of Hematology, Oncology, and Palliative care, Department of Internal Medicine, Massey Cancer Center, Virginia Commonwealth University School of Medicine, Richmond, VA, USA
| | - Nahid Nanaji
- Department of Veteran Affairs, Maryland Healthcare System, Baltimore, MD, USA
| | - Glen E Kellogg
- Department of Medicinal Chemistry, Institute for Structural Biology, Drug Discovery and Development, Virginia Commonwealth University School of Pharmacy, Richmond, VA, USA
| | - Ronald B Gartenhaus
- McGuire Cancer Center, Hunter Holmes McGuire VA Medical Center, Richmond, VA, USA.
- Division of Hematology, Oncology, and Palliative care, Department of Internal Medicine, Massey Cancer Center, Virginia Commonwealth University School of Medicine, Richmond, VA, USA.
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Puccio T, Kunka KS, An SS, Kitten T. Contribution of a ZIP-family protein to manganese uptake and infective endocarditis virulence in Streptococcus sanguinis. Mol Microbiol 2021; 117:353-374. [PMID: 34855265 PMCID: PMC8844249 DOI: 10.1111/mmi.14853] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Revised: 11/24/2021] [Accepted: 11/30/2021] [Indexed: 01/18/2023]
Abstract
Streptococcus sanguinis is an important cause of infective endocarditis. In strain SK36, the ABC‐family manganese transporter, SsaACB, is essential for virulence. We have now identified a ZIP‐family protein, TmpA, as a secondary manganese transporter. A tmpA mutant had no phenotype, but a ΔssaACB ΔtmpA mutant was more attenuated for serum growth and for virulence in a rabbit model than its ΔssaACB parent. The growth of both mutants was restored by supplemental manganese, but the ΔssaACB ΔtmpA mutant required twenty‐fold more and accumulated less. Although ZIP‐family proteins are known for zinc and iron transport, TmpA‐mediated transport of either metal was minimal. While ssaACB appears ubiquitous in St. sanguinis, tmpA was present in a majority of strains and a mntH gene encoding an NRAMP‐family transporter was identified in relatively few, including VMC66. As in SK36, deletion of ssaACB greatly diminished VMC66 endocarditis virulence and serum growth, and deletion of tmpA from this mutant diminished virulence further. Virulence was not significantly altered by deletion of mntH from either VMC66 or its ΔssaACB mutant. This and the accompanying paper together suggest that SsaACB is of primary importance for endocarditis virulence while secondary transporters TmpA and MntH contribute to growth under differing conditions.
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Affiliation(s)
- Tanya Puccio
- Philips Institute for Oral Health Research, Virginia Commonwealth University School of Dentistry, Richmond, Virginia, USA
| | - Karina S Kunka
- Philips Institute for Oral Health Research, Virginia Commonwealth University School of Dentistry, Richmond, Virginia, USA
| | - Seon-Sook An
- Philips Institute for Oral Health Research, Virginia Commonwealth University School of Dentistry, Richmond, Virginia, USA
| | - Todd Kitten
- Philips Institute for Oral Health Research, Virginia Commonwealth University School of Dentistry, Richmond, Virginia, USA
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Cools F, Delputte P, Cos P. The search for novel treatment strategies for Streptococcus pneumoniae infections. FEMS Microbiol Rev 2021; 45:6064299. [PMID: 33399826 PMCID: PMC8371276 DOI: 10.1093/femsre/fuaa072] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Accepted: 01/01/2021] [Indexed: 12/13/2022] Open
Abstract
This review provides an overview of the most important novel treatment strategies against Streptococcus pneumoniae infections published over the past 10 years. The pneumococcus causes the majority of community-acquired bacterial pneumonia cases, and it is one of the prime pathogens in bacterial meningitis. Over the last 10 years, extensive research has been conducted to prevent severe pneumococcal infections, with a major focus on (i) boosting the host immune system and (ii) discovering novel antibacterials. Boosting the immune system can be done in two ways, either by actively modulating host immunity, mostly through administration of selective antibodies, or by interfering with pneumococcal virulence factors, thereby supporting the host immune system to effectively overcome an infection. While several of such experimental therapies are promising, few have evolved to clinical trials. The discovery of novel antibacterials is hampered by the high research and development costs versus the relatively low revenues for the pharmaceutical industry. Nevertheless, novel enzymatic assays and target-based drug design, allow the identification of targets and the development of novel molecules to effectively treat this life-threatening pathogen.
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Affiliation(s)
- F Cools
- Laboratory for Microbiology, Parasitology and Hygiene (LMPH), University of Antwerp, Universiteitsplein 1, 2610 Wilrijk, Belgium
| | - P Delputte
- Laboratory for Microbiology, Parasitology and Hygiene (LMPH), University of Antwerp, Universiteitsplein 1, 2610 Wilrijk, Belgium
| | - P Cos
- Laboratory for Microbiology, Parasitology and Hygiene (LMPH), University of Antwerp, Universiteitsplein 1, 2610 Wilrijk, Belgium
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Microscale communication between bacterial pathogens and the host epithelium. Genes Immun 2021; 22:247-254. [PMID: 34588625 PMCID: PMC8497271 DOI: 10.1038/s41435-021-00149-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2021] [Revised: 08/18/2021] [Accepted: 08/23/2021] [Indexed: 02/01/2023]
Abstract
Pathogenic bacteria have evolved a variety of highly selective adhesins allowing these microbes to engage specific surface determinants of their eukaryotic host cells. Receptor clustering induced by the multivalent microorganisms will not only anchor the bacteria to the tissue, but will inevitably trigger host cell signaling. It has become clear, that these bacteria-initiated signaling events can be seen as a form of localized communication with host epithelial cells. Such a microscale communication can have immediate consequences in the form of changes in host cell membrane morphology or cytoskeletal organization, but can also lead to transcriptional responses and medium- and long-term alterations in cellular physiology. In this review, we will discuss several examples of this form of microscale communication between bacterial pathogens and mammalian host cells and try to delineate their downstream ramifications in the infection process. Furthermore, we will highlight recent findings that specialized pathogenic bacteria utilize the adhesin-based interaction to diffuse the short-range messenger molecule nitric oxide into the host tissue. While anti-adhesive strategies to disrupt the initial bacterial attachment have not yet translated into medical applications, the ability to interfere with the microscale communication emanating on the host side provides an unconventional approach for preventing infectious diseases.
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