1
|
Johannsen S, Gierse RM, Krüger A, Edwards RL, Nanna V, Fontana A, Zhu D, Masini T, de Carvalho LP, Poizat M, Kieftenbelt B, Hodge DM, Alvarez S, Bunt D, Lacour A, Shams A, Meissner KA, de Souza EE, Dröge M, van Vliet B, den Hartog J, Hutter MC, Held J, Odom John AR, Wrenger C, Hirsch AKH. High Target Homology Does Not Guarantee Inhibition: Aminothiazoles Emerge as Inhibitors of Plasmodium falciparum. ACS Infect Dis 2024; 10:1000-1022. [PMID: 38367280 PMCID: PMC10928712 DOI: 10.1021/acsinfecdis.3c00670] [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: 12/06/2023] [Revised: 01/24/2024] [Accepted: 01/24/2024] [Indexed: 02/19/2024]
Abstract
In this study, we identified three novel compound classes with potent activity against Plasmodium falciparum, the most dangerous human malarial parasite. Resistance of this pathogen to known drugs is increasing, and compounds with different modes of action are urgently needed. One promising drug target is the enzyme 1-deoxy-d-xylulose-5-phosphate synthase (DXPS) of the methylerythritol 4-phosphate (MEP) pathway for which we have previously identified three active compound classes against Mycobacterium tuberculosis. The close structural similarities of the active sites of the DXPS enzymes of P. falciparum and M. tuberculosis prompted investigation of their antiparasitic action, all classes display good cell-based activity. Through structure-activity relationship studies, we increased their antimalarial potency and two classes also show good metabolic stability and low toxicity against human liver cells. The most active compound 1 inhibits the growth of blood-stage P. falciparum with an IC50 of 600 nM. The results from three different methods for target validation of compound 1 suggest no engagement of DXPS. All inhibitor classes are active against chloroquine-resistant strains, confirming a new mode of action that has to be further investigated.
Collapse
Affiliation(s)
- Sandra Johannsen
- Helmholtz
Institute for Pharmaceutical Research Saarland (HIPS) − Helmholtz
Centre for Infection Research (HZI), Campus Building E8.1, Saarbrücken 66123, Germany
- Department
of Pharmacy, Saarland University, Campus Building E8.1, Saarbrücken 66123, Germany
| | - Robin M. Gierse
- Helmholtz
Institute for Pharmaceutical Research Saarland (HIPS) − Helmholtz
Centre for Infection Research (HZI), Campus Building E8.1, Saarbrücken 66123, Germany
- Department
of Pharmacy, Saarland University, Campus Building E8.1, Saarbrücken 66123, Germany
- Stratingh
Institute for Chemistry, University of Groningen, Nijenborgh 7, Groningen 9747 AG, The Netherlands
| | - Arne Krüger
- Unit
for Drug Discovery, Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, Av. Prof. Lineu Prestes 1374, São Paulo-SP 05508-000, Brazil
| | - Rachel L. Edwards
- Department
of Pediatrics, Washington University School
of Medicine, Saint
Louis, Missouri 63110, United States
| | - Vittoria Nanna
- Helmholtz
Institute for Pharmaceutical Research Saarland (HIPS) − Helmholtz
Centre for Infection Research (HZI), Campus Building E8.1, Saarbrücken 66123, Germany
| | - Anna Fontana
- Helmholtz
Institute for Pharmaceutical Research Saarland (HIPS) − Helmholtz
Centre for Infection Research (HZI), Campus Building E8.1, Saarbrücken 66123, Germany
| | - Di Zhu
- Helmholtz
Institute for Pharmaceutical Research Saarland (HIPS) − Helmholtz
Centre for Infection Research (HZI), Campus Building E8.1, Saarbrücken 66123, Germany
- Stratingh
Institute for Chemistry, University of Groningen, Nijenborgh 7, Groningen 9747 AG, The Netherlands
| | - Tiziana Masini
- Stratingh
Institute for Chemistry, University of Groningen, Nijenborgh 7, Groningen 9747 AG, The Netherlands
| | | | - Mael Poizat
- Symeres, Kadijk 3, Groningen 9747
AT, The Netherlands
| | | | - Dana M. Hodge
- Department
of Pediatrics, Children’s Hospital
of Philadelphia, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Sophie Alvarez
- Proteomics
& Metabolomics Facility, Center for Biotechnology, Department
of Agronomy and Horticulture, University
of Nebraska-Lincoln, Lincoln, Nebraska 68588, United States
| | - Daan Bunt
- Stratingh
Institute for Chemistry, University of Groningen, Nijenborgh 7, Groningen 9747 AG, The Netherlands
| | - Antoine Lacour
- Helmholtz
Institute for Pharmaceutical Research Saarland (HIPS) − Helmholtz
Centre for Infection Research (HZI), Campus Building E8.1, Saarbrücken 66123, Germany
- Department
of Pharmacy, Saarland University, Campus Building E8.1, Saarbrücken 66123, Germany
| | - Atanaz Shams
- Helmholtz
Institute for Pharmaceutical Research Saarland (HIPS) − Helmholtz
Centre for Infection Research (HZI), Campus Building E8.1, Saarbrücken 66123, Germany
- Department
of Pharmacy, Saarland University, Campus Building E8.1, Saarbrücken 66123, Germany
| | - Kamila Anna Meissner
- Unit
for Drug Discovery, Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, Av. Prof. Lineu Prestes 1374, São Paulo-SP 05508-000, Brazil
| | - Edmarcia Elisa de Souza
- Unit
for Drug Discovery, Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, Av. Prof. Lineu Prestes 1374, São Paulo-SP 05508-000, Brazil
| | | | | | | | - Michael C. Hutter
- Center
for Bioinformatics, Saarland University, Campus Building E2.1, Saarbrücken 66123, Germany
| | - Jana Held
- Institute
of Tropical Medicine, University of Tübingen, Wilhelmstraße 27, Tübingen 72074, Germany
- German
Center for Infection Research (DZIF), Partner Site Tübingen, Tübingen 72074, Germany
- Centre
de Recherches Médicales de Lambaréné (CERMEL), B.P. 242 Lambaréné, Gabon
| | - Audrey R. Odom John
- Department
of Pediatrics, Children’s Hospital
of Philadelphia, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Carsten Wrenger
- Unit
for Drug Discovery, Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, Av. Prof. Lineu Prestes 1374, São Paulo-SP 05508-000, Brazil
| | - Anna K. H. Hirsch
- Helmholtz
Institute for Pharmaceutical Research Saarland (HIPS) − Helmholtz
Centre for Infection Research (HZI), Campus Building E8.1, Saarbrücken 66123, Germany
- Department
of Pharmacy, Saarland University, Campus Building E8.1, Saarbrücken 66123, Germany
- Stratingh
Institute for Chemistry, University of Groningen, Nijenborgh 7, Groningen 9747 AG, The Netherlands
| |
Collapse
|
2
|
Liao J, Wang Q, Wu F, Huang Z. In Silico Methods for Identification of Potential Active Sites of Therapeutic Targets. Molecules 2022; 27:7103. [PMID: 36296697 PMCID: PMC9609013 DOI: 10.3390/molecules27207103] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Revised: 08/12/2022] [Accepted: 08/25/2022] [Indexed: 07/30/2023] Open
Abstract
Target identification is an important step in drug discovery, and computer-aided drug target identification methods are attracting more attention compared with traditional drug target identification methods, which are time-consuming and costly. Computer-aided drug target identification methods can greatly reduce the searching scope of experimental targets and associated costs by identifying the diseases-related targets and their binding sites and evaluating the druggability of the predicted active sites for clinical trials. In this review, we introduce the principles of computer-based active site identification methods, including the identification of binding sites and assessment of druggability. We provide some guidelines for selecting methods for the identification of binding sites and assessment of druggability. In addition, we list the databases and tools commonly used with these methods, present examples of individual and combined applications, and compare the methods and tools. Finally, we discuss the challenges and limitations of binding site identification and druggability assessment at the current stage and provide some recommendations and future perspectives.
Collapse
Affiliation(s)
- Jianbo Liao
- Key Laboratory of Big Data Mining and Precision Drug Design of Guangdong Medical University, Key Laboratory of Computer-Aided Drug Design of Dongguan City, Key Laboratory for Research and Development of Natural Drugs of Guangdong Province, School of Pharmacy, Guangdong Medical University, Dongguan 523808, China
- The Second School of Clinical Medicine, Guangdong Medical University, Dongguan 523808, China
| | - Qinyu Wang
- Key Laboratory of Big Data Mining and Precision Drug Design of Guangdong Medical University, Key Laboratory of Computer-Aided Drug Design of Dongguan City, Key Laboratory for Research and Development of Natural Drugs of Guangdong Province, School of Pharmacy, Guangdong Medical University, Dongguan 523808, China
| | - Fengxu Wu
- Hubei Key Laboratory of Wudang Local Chinese Medicine Research, School of Pharmaceutical Sciences, Hubei University of Medicine, Shiyan 442000, China
| | - Zunnan Huang
- Key Laboratory of Big Data Mining and Precision Drug Design of Guangdong Medical University, Key Laboratory of Computer-Aided Drug Design of Dongguan City, Key Laboratory for Research and Development of Natural Drugs of Guangdong Province, School of Pharmacy, Guangdong Medical University, Dongguan 523808, China
- Marine Biomedical Research Institute of Guangdong Zhanjiang, Zhanjiang 524023, China
| |
Collapse
|
3
|
Mondal A, Paul D, Dastidar SG, Saha T, Goswami AM. In silico analyses of Wnt1 nsSNPs reveal structurally destabilizing variants, altered interactions with Frizzled receptors and its deregulation in tumorigenesis. Sci Rep 2022; 12:14934. [PMID: 36056132 PMCID: PMC9440047 DOI: 10.1038/s41598-022-19299-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Accepted: 08/26/2022] [Indexed: 11/26/2022] Open
Abstract
Wnt1 is the first mammalian Wnt gene, which is discovered as proto-oncogene and in human the gene is located on the chromosome 12q13. Mutations in Wnt1 are reported to be associated with various cancers and other human diseases. The structural and functional consequences of most of the non-synonymous SNPs (nsSNPs), present in the human Wnt1 gene, are not known. In the present work, extensive bioinformatics analyses are used to screen 292 nsSNPs of Wnt1 for predicting pathogenic and harmless polymorphisms. We have identified 10 highly deleterious nsSNPs among which 7 are located within the highly conserved areas. These 10 nsSNPs are also predicted to affect the post-translational modifications of Wnt1. Further, structure based stability analyses of these 10 highly deleterious nsSNPs revealed 8 variants as highly destabilizing. These 8 highly destabilizing variants were shown to have high BC score and high RMSIP score from normal mode analyses. Based on the deformation energies, obtained from the normal mode analyses, variants like G169A, G169S, G331R and G331S were found to be unstable. Molecular Dynamics (MD) simulations revealed structural stability and fluctuation of WT Wnt1 and its prioritized variants. RMSD remained fluctuating mostly between 4 and 5 Å and occasionally between 3.5 and 5.5 Å ranges. RMSF in the CTD region (residues 330–360) of the binding pocket were lower compared to that of WT. Studying the impacts of nsSNPs on the binding interface of Wnt1 and seven Frizzled receptors have predicted substitutions which can stabilize or destabilize the binding interface. We have found that Wnt1 and FZD8-CRD is the best docked complex in our study. MD simulation based analyses of wild type Wnt1-FZD8-CRD complex and the 8 prioritized variants revealed that RMSF was higher in the unstructured regions and RMSD remained fluctuating in the region of 5 Å ± 1 Å. We have also observed differential Wnt1 gene expression pattern in normal, tumor and metastatic conditions across different tissues. Wnt1 gene expression was significantly higher in metastatic tissues of lungs, colon and skin; and was significantly lower in metastatic tissues of breast, esophagus and kidney. We have also found that Wnt1 deregulation is associated with survival outcome in patients with gastric and breast cancer. Furthermore, these computationally screened highly deleterious nsSNPs of Wnt1 can be analyzed in population based genetic studies and may help understand the Wnt1 associated diseases.
Collapse
Affiliation(s)
- Amalesh Mondal
- Department of Physiology, Katwa College, Purba Bardhaman, Katwa, West Bengal, 713130, India.,Department of Molecular Biology and Biotechnology, University of Kalyani, Nadia, Kalyani, India
| | - Debarati Paul
- Division of Bioinformatics, Bose Institute, P-1/12 CIT Scheme VII M, Kolkata, 700054, India
| | - Shubhra Ghosh Dastidar
- Division of Bioinformatics, Bose Institute, P-1/12 CIT Scheme VII M, Kolkata, 700054, India
| | - Tanima Saha
- Department of Molecular Biology and Biotechnology, University of Kalyani, Nadia, Kalyani, India.
| | - Achintya Mohan Goswami
- Department of Physiology, Krishnagar Govt. College, Nadia, Krishnagar, West Bengal, 741101, India.
| |
Collapse
|
4
|
Gierse RM, Reddem ER, Alhayek A, Baitinger D, Hamid Z, Jakobi H, Laber B, Lange G, Hirsch AKH, Groves MR. Identification of a 1-deoxy-D-xylulose-5-phosphate synthase (DXS) mutant with improved crystallographic properties. Biochem Biophys Res Commun 2021; 539:42-47. [PMID: 33421767 DOI: 10.1016/j.bbrc.2020.12.069] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Revised: 12/16/2020] [Accepted: 12/18/2020] [Indexed: 10/22/2022]
Abstract
In this report, we describe a truncated Deinococcus radiodurans 1-deoxy-D-xylulose-5-phosphate synthase (DXS) protein that retains enzymatic activity, while slowing protein degradation and showing improved crystallization properties. With modern drug-design approaches relying heavily on the elucidation of atomic interactions of potential new drugs with their targets, the need for co-crystal structures with the compounds of interest is high. DXS itself is a promising drug target, as it catalyzes the first reaction in the 2-C-methyl-D-erythritol 4-phosphate (MEP)-pathway for the biosynthesis of the universal precursors of terpenes, which are essential secondary metabolites. In contrast to many bacteria and pathogens, which employ the MEP pathway, mammals use the distinct mevalonate-pathway for the biosynthesis of these precursors, which makes all enzymes of the MEP-pathway potential new targets for the development of anti-infectives. However, crystallization of DXS has proven to be challenging: while the first X-ray structures from Escherichia coli and D. radiodurans were solved in 2004, since then only two additions have been made in 2019 that were obtained under anoxic conditions. The presented site of truncation can potentially also be transferred to other homologues, opening up the possibility for the determination of crystal structures from pathogenic species, which until now could not be crystallized. This manuscript also provides a further example that truncation of a variable region of a protein can lead to improved structural data.
Collapse
Affiliation(s)
- Robin M Gierse
- Department for Drug Design and Optimization, Helmholtz Institute for Pharmaceutical Research (HIPS) - Helmholtz Centre for Infection Research (HZI), Campus Building E 8.1, 66123, Saarbrücken, Germany; Department of Pharmacy, Saarland University, Campus Building E8.1, 66123, Saarbrücken, Germany; Stratingh Institute for Chemistry, University of Groningen, Nijenborgh 7, 9747, AG Groningen, Netherlands
| | - Eswar R Reddem
- Stratingh Institute for Chemistry, University of Groningen, Nijenborgh 7, 9747, AG Groningen, Netherlands; Pharmacy Department, Drug Design Group, University of Groningen, Antonius Deusinglaan 1, 9700, AV Groningen, Netherlands
| | - Alaa Alhayek
- Department for Drug Design and Optimization, Helmholtz Institute for Pharmaceutical Research (HIPS) - Helmholtz Centre for Infection Research (HZI), Campus Building E 8.1, 66123, Saarbrücken, Germany; Department of Pharmacy, Saarland University, Campus Building E8.1, 66123, Saarbrücken, Germany
| | - Dominik Baitinger
- Department for Drug Design and Optimization, Helmholtz Institute for Pharmaceutical Research (HIPS) - Helmholtz Centre for Infection Research (HZI), Campus Building E 8.1, 66123, Saarbrücken, Germany
| | - Zhoor Hamid
- Department for Drug Design and Optimization, Helmholtz Institute for Pharmaceutical Research (HIPS) - Helmholtz Centre for Infection Research (HZI), Campus Building E 8.1, 66123, Saarbrücken, Germany; Department of Pharmacy, Saarland University, Campus Building E8.1, 66123, Saarbrücken, Germany
| | - Harald Jakobi
- Research & Development Crop Science, Bayer AG, Industriepark Höchst, 65926, Frankfurt, Germany
| | - Bernd Laber
- Research & Development Crop Science, Bayer AG, Industriepark Höchst, 65926, Frankfurt, Germany
| | - Gudrun Lange
- Research & Development Crop Science, Bayer AG, Industriepark Höchst, 65926, Frankfurt, Germany
| | - Anna K H Hirsch
- Department for Drug Design and Optimization, Helmholtz Institute for Pharmaceutical Research (HIPS) - Helmholtz Centre for Infection Research (HZI), Campus Building E 8.1, 66123, Saarbrücken, Germany; Department of Pharmacy, Saarland University, Campus Building E8.1, 66123, Saarbrücken, Germany; Stratingh Institute for Chemistry, University of Groningen, Nijenborgh 7, 9747, AG Groningen, Netherlands.
| | - Matthew R Groves
- Pharmacy Department, Drug Design Group, University of Groningen, Antonius Deusinglaan 1, 9700, AV Groningen, Netherlands.
| |
Collapse
|
5
|
Goswami AM. Computational analyses prioritize and reveal the deleterious nsSNPs in human angiotensinogen gene. Comput Biol Chem 2020; 84:107199. [PMID: 31931433 DOI: 10.1016/j.compbiolchem.2019.107199] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2019] [Revised: 12/26/2019] [Accepted: 12/30/2019] [Indexed: 12/27/2022]
Abstract
Angiotensinogen (AGT) is a key component of renin-angiotensin-aldosterone system (RAAS), which plays central role in blood pressure homeostasis. Association of AGT polymorphisms have been investigated in different ethnic populations in variety of cardiovascular and non-cardiovascular conditions. In this study, 354 non-synonymous SNPs (nsSNPs) of AGT were evaluated to predict damaging and structurally important variants. Majority of the deleterious nsSNPs occurred in the evolutionary conserved regions. Several of these nsSNPs were found to affect post-translational modifications like methylation, glycosylation, phosphorylation, ubiquitination etc. Structural evaluations predicted 19 variants as destabilizing and some of them were also predicted to destabilize the renin-AGT interaction. Therefore, the present computational investigation predicted pathogenic and functionally important variants of human AGT gene. The study has also shown that AGT deregulation is associated with survival outcome in patients with gastric and breast cancer, using microarray gene expression profile. Furthermore, the computationally screened nsSNPs can be analyzed in population based genotyping studies and may help futuristic drug development in the area of AGT pharmacogenomics.
Collapse
Affiliation(s)
- Achintya Mohan Goswami
- Department of Physiology, Krishnagar Govt. College, Krishnagar, Nadia, West Bengal, 741101, India.
| |
Collapse
|
6
|
Untaroiu AM, Carey MA, Guler JL, Papin JA. Leveraging the effects of chloroquine on resistant malaria parasites for combination therapies. BMC Bioinformatics 2019; 20:186. [PMID: 30987583 PMCID: PMC6466727 DOI: 10.1186/s12859-019-2756-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2019] [Accepted: 03/19/2019] [Indexed: 11/10/2022] Open
Abstract
Background Malaria is a major global health problem, with the Plasmodium falciparum protozoan parasite causing the most severe form of the disease. Prevalence of drug-resistant P. falciparum highlights the need to understand the biology of resistance and to identify novel combination therapies that are effective against resistant parasites. Resistance has compromised the therapeutic use of many antimalarial drugs, including chloroquine, and limited our ability to treat malaria across the world. Fortunately, chloroquine resistance comes at a fitness cost to the parasite; this can be leveraged in developing combination therapies or to reinstate use of chloroquine. Results To understand biological changes induced by chloroquine treatment, we compared transcriptomics data from chloroquine-resistant parasites in the presence or absence of the drug. Using both linear models and a genome-scale metabolic network reconstruction of the parasite to interpret the expression data, we identified targetable pathways in resistant parasites. This study identified an increased importance of lipid synthesis, glutathione production/cycling, isoprenoids biosynthesis, and folate metabolism in response to chloroquine. Conclusions We identified potential drug targets for chloroquine combination therapies. Significantly, our analysis predicts that the combination of chloroquine and sulfadoxine-pyrimethamine or fosmidomycin may be more effective against chloroquine-resistant parasites than either drug alone; further studies will explore the use of these drugs as chloroquine resistance blockers. Additional metabolic weaknesses were found in glutathione generation and lipid synthesis during chloroquine treatment. These processes could be targeted with novel inhibitors to reduce parasite growth and reduce the burden of malaria infections. Thus, we identified metabolic weaknesses of chloroquine-resistant parasites and propose targeted chloroquine combination therapies. Electronic supplementary material The online version of this article (10.1186/s12859-019-2756-y) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Ana M Untaroiu
- Department of Biomedical Engineering, University of Virginia, Charlottesville, VA, USA.,Present address: Department of Radiology and Medical Imaging, University of Virginia, Charlottesville, VA, USA
| | - Maureen A Carey
- Department of Microbiology, Immunology, and Cancer Biology, University of Virginia, Charlottesville, VA, USA.,Present address: Division of Infectious Diseases and International Health, Department of Medicine, University of Virginia, Charlottesville, VA, USA
| | - Jennifer L Guler
- Department of Biology, University of Virginia, Charlottesville, VA, USA.
| | - Jason A Papin
- Department of Biomedical Engineering, University of Virginia, Charlottesville, VA, USA.
| |
Collapse
|
7
|
Nedjoua D, Krallafa AM. Temperature effect on the structure and conformational fluctuations in two zinc knuckles from the mouse mammary tumor virus. Comput Biol Chem 2018; 74:86-93. [PMID: 29567490 DOI: 10.1016/j.compbiolchem.2018.03.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2017] [Revised: 10/28/2017] [Accepted: 03/07/2018] [Indexed: 11/18/2022]
Abstract
Zinc fingers are small protein domains in which zinc plays a structural role, contributing to the stability of the zinc-peptide complex. Zinc fingers are structurally diverse and are present in proteins that perform a broad range of functions in various cellular processes, such as replication and repair, transcription and translation, metabolism and signaling, cell proliferation, and apoptosis. Zinc fingers typically function as interaction modules and bind to a wide variety of compounds, such as nucleic acids, proteins, and small molecules. In this study, we investigated the structural properties, in solution, of the proximal and distal zinc knuckles of the nucleocapsid (NC) protein from the mouse mammary tumor virus (MMTV) (MMTV NC). For this purpose, we performed a series of molecular dynamics simulations in aqueous solution at 300 K, 333 K, and 348 K. The temperature effect was evaluated in terms of root mean square deviation of the backbone atoms and root mean square fluctuation of the coordinating residue atoms. The stability of the zinc coordination sphere was analyzed based upon the time profile of the interatomic distances between the zinc ions and the chelator atoms. The results indicate that the hydrophobic character of the proximal zinc finger is dominant at 333 K. The low mobility of the coordinating residues suggests that the strong electrostatic effect exerted by the zinc ion on its coordinating residues is not influenced by the increase in temperature. The evolution of the structural parameters of the coordination sphere of the distal zinc finger at 300 K gives us a reasonable picture of the unfolding pathway, as proposed by Bombarda and coworkers (Bombarda et al., 2005), which can predict the binding order of the four conserved ligand-binding residues. Our results support the conclusion that the structural features can vary significantly between the two zinc knuckles of MMTV NC.
Collapse
Affiliation(s)
- Drici Nedjoua
- LCPM, Department of Chemistry, University of Oran 1 Ahmed Benbella, PO Box 1524, El m'naouer, Oran, 31000, Algeria.
| | - Abdelghani Mohamed Krallafa
- LCPM, Department of Chemistry, University of Oran 1 Ahmed Benbella, PO Box 1524, El m'naouer, Oran, 31000, Algeria.
| |
Collapse
|