1
|
Abdollahi S, Raissi H, Farzad F. Examine stability polyvinyl alcohol-stabilized nanosuspensions to overcome the challenge of poor drug solubility utilizing molecular dynamic simulation. Sci Rep 2024; 14:17386. [PMID: 39075104 PMCID: PMC11286956 DOI: 10.1038/s41598-024-68362-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2024] [Accepted: 07/23/2024] [Indexed: 07/31/2024] Open
Abstract
The pharmaceutical industry faces a significant challenge from the low water solubility of nearly 90% of newly developed Active Pharmaceutical Ingredients (APIs). Despite extensive efforts to improve solubility, approximately 40% of these APIs encounter commercialization hurdles, impacting drug efficacy. In this context, a promising strategy will be introduced in which nanosuspensions, particularly polyvinyl alcohol (PVA) as a stabilizer, are applied to increase drug solubility. In this work using molecular dynamics simulations, the nanosuspension of four poorly water-soluble drugs (flurbiprofen, bezafibrate, miconazole, and phenytoin) stabilized with PVA is investigated. The simulation data showed van der Waals energies between polyvinyl alcohol with flurbiprofen and bezafibrate are - 101.12 and - 58.42 kJ/mol, respectively. The results indicate that PVA is an effective stabilizer for these drugs, and superior interactions are obtained with flurbiprofen and bezafibrate. The study also explores the impact of PVA on water molecule diffusion, providing insights into the stability of nanosuspensions. Obtained results also provide valuable insights into hydrogen bond formation, diffusion coefficients, and nanosuspension stability, contributing to the rational design and optimization of pharmaceutical formulations.
Collapse
Affiliation(s)
| | - Heidar Raissi
- Department of Chemistry, University of Birjand, Birjand, Iran.
| | - Farzaneh Farzad
- Department of Chemistry, University of Birjand, Birjand, Iran
| |
Collapse
|
2
|
Afzal M, Mehmood R, Mughal EU, Naeem N, Ashraf Z, Nazir Y, Shalaby FM, El-Sayed Abd El Hady A, Sadiq A. Elucidating bis-pyrimidines as new and efficient mushroom tyrosinase inhibitors: synthesis, SAR, kinetics and computational studies. RSC Adv 2024; 14:22769-22780. [PMID: 39035128 PMCID: PMC11258615 DOI: 10.1039/d4ra04652h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2024] [Accepted: 07/14/2024] [Indexed: 07/23/2024] Open
Abstract
In this study, a series of novel bis-pyrimidine derivatives (1P-8P) were designed, synthesized, characterized, and investigated for their in vitro inhibitory activity against mushroom tyrosinase, an enzyme critical in melanin biosynthesis and implicated in various hyperpigmentation disorders. To the best of our knowledge, the bispyrimidine scaffold has been evaluated for the first time for its tyrosinase inhibitory activity. Their inhibitory activities were assessed, revealing inhibition with IC50 values in the micromolar range. Additionally, this series of compounds were found to inhibit tyrosinase activity in a mixed-type manner, with IC50 values ranging from 12.36 ± 1.24 to 86.67 ± 3.08 μM. To further elucidate the binding interactions, molecular docking simulations were performed, identifying key residues in the active site responsible for binding affinity. Furthermore, molecular dynamics (MD) simulations were conducted to assess the dynamic behavior, stability, and binding affinity of the most potent inhibitor, compound 6P. Quantitative Structure-Activity Relationship (QSAR) models were developed to correlate the structural features of the bis-pyrimidines with their inhibitory activity, providing insights into the structure-activity relationships (SAR) that govern their potency. The experimental and theoretical findings demonstrated excellent agreement. These findings pave the way for the development of novel bis-pyrimidine-based therapeutic agents for treating hyperpigmentation and related conditions.
Collapse
Affiliation(s)
- Manazza Afzal
- Department of Chemistry, Govt College Women University Sialkot-51300 Pakistan
| | - Rabia Mehmood
- Department of Chemistry, Govt College Women University Sialkot-51300 Pakistan
| | | | - Nafeesa Naeem
- Department of Chemistry, University of Gujrat Gujrat-50700 Pakistan
| | - Zaman Ashraf
- Department of Chemistry, Rawalpindi Women University Rawalpindi-46300 Pakistan
| | - Yasir Nazir
- Department of Chemistry, University of Sialkot Sialkot-51300 Pakistan
| | - Fatma Mohsen Shalaby
- King Khalid University, Faculty of Sciences, Biology Department Abha Kingdom of Saudi Arabia
| | - Amal El-Sayed Abd El Hady
- Department of Biology, Faculty of Science, Majmaah University Al Majma'ah 15341 Kingdom of Saudi Arabia
| | - Amina Sadiq
- Department of Chemistry, Govt College Women University Sialkot-51300 Pakistan
| |
Collapse
|
3
|
Agrawal N, Parisini E. Investigating the Effects of the POPC-POPG Lipid Bilayer Composition on PAP248-286 Binding Using CG Molecular Dynamics Simulations. J Phys Chem B 2023; 127:9095-9101. [PMID: 37843472 PMCID: PMC10614185 DOI: 10.1021/acs.jpcb.3c05385] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2023] [Revised: 09/21/2023] [Indexed: 10/17/2023]
Abstract
PAP248-286 is a fusogenic peptide derived from prostatic acid phosphatase, commonly found in human semen, and is known to mediate HIV fusion with cell membranes. In this study, we performed 120 independent coarse-grained molecular dynamics simulations to investigate the spontaneous binding of PAP248-286 monomers, considering both charged and neutral histidine (His) residues, to membrane bilayers composed of different lipid compositions: 100% POPC, 70% POPC-30% POPG, and 50% POPC-50% POPG. Our simulations revealed that PAP248-286 displayed spontaneous binding to the membrane, with increased binding observed in the presence of anionic lipid POPG. Specifically, in systems containing 30% and 50% POPG lipids, monomer residues, particularly in the systems containing charged histidine (His) residues, exhibited prolonged binding with the membrane. Furthermore, our simulations indicated that PAP248-286 adopted a parallel orientation with the membrane, exposing its positively charged residues to the lipid bilayer. Interestingly, systems containing charged His residues showed a higher lipid occupancy around the peptide. These findings are consistent with previous experimental data, suggesting that PAP248-286 binding is enhanced in membranes with charged His residues, resembling the conditions found in the acidic vaginal pH environment. The results of our study provide further insights into the molecular mechanisms underlying the membrane binding of PAP248-286, contributing to our understanding of its potential role in HIV fusion and infection.
Collapse
Affiliation(s)
- Nikhil Agrawal
- Latvian
Institute of Organic Synthesis, Aizkraukles 21, LV, Riga 1006, Latvia
- College
of Health Sciences, University of KwaZulu-Natal, Private Bag, X54001, Durban 4000, South Africa
| | - Emilio Parisini
- Latvian
Institute of Organic Synthesis, Aizkraukles 21, LV, Riga 1006, Latvia
- Department
of Chemistry “G. Ciamician”, University of Bologna, Via Selmi 2, Bologna 40126, Italy
| |
Collapse
|
4
|
Obstarczyk P, Pniakowska A, Nonappa, Grzelczak MP, Olesiak-Bańska J. Crown Ether-Capped Gold Nanoclusters as a Multimodal Platform for Bioimaging. ACS OMEGA 2023; 8:11503-11511. [PMID: 37008092 PMCID: PMC10061685 DOI: 10.1021/acsomega.3c00426] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Accepted: 03/02/2023] [Indexed: 12/01/2023]
Abstract
The distinct polarity of biomolecule surfaces plays a pivotal role in their biochemistry and functions as it is involved in numerous processes, such as folding, aggregation, or denaturation. Therefore, there is a need to image both hydrophilic and hydrophobic bio-interfaces with markers of distinct responses to hydrophobic and hydrophilic environments. In this work, we present a synthesis, characterization, and application of ultrasmall gold nanoclusters capped with a 12-crown-4 ligand. The nanoclusters present an amphiphilic character and can be successfully transferred between aqueous and organic solvents and have their physicochemical integrity retained. They can serve as probes for multimodal bioimaging with light (as they emit near-infrared luminescence) and electron microscopy (due to the high electron density of gold). In this work, we used protein superstructures, namely, amyloid spherulites, as a hydrophobic surface model and individual amyloid fibrils with a mixed hydrophobicity profile. Our nanoclusters spontaneously stained densely packed amyloid spherulites as observed under fluorescence microscopy, which is limited for hydrophilic markers. Moreover, our clusters revealed structural features of individual amyloid fibrils at a nanoscale as observed under a transmission electron microscope. We show the potential of crown ether-capped gold nanoclusters in multimodal structural characterization of bio-interfaces where the amphiphilic character of the supramolecular ligand is required.
Collapse
Affiliation(s)
- Patryk Obstarczyk
- Institute
of Advanced Materials, Wroclaw University
of Science and Technology, 50-370 Wrocław, Poland
| | - Anna Pniakowska
- Institute
of Advanced Materials, Wroclaw University
of Science and Technology, 50-370 Wrocław, Poland
| | - Nonappa
- Faculty
of Engineering and Natural Sciences, Tampere
University, FI-33720 Tampere, Finland
| | - Marcin P. Grzelczak
- Institute
of Advanced Materials, Wroclaw University
of Science and Technology, 50-370 Wrocław, Poland
| | - Joanna Olesiak-Bańska
- Institute
of Advanced Materials, Wroclaw University
of Science and Technology, 50-370 Wrocław, Poland
| |
Collapse
|
5
|
Agrawal N, Skelton AA, Parisini E. A coarse-grained molecular dynamics investigation on spontaneous binding of Aβ 1-40 fibrils with cholesterol-mixed DPPC bilayers. Comput Struct Biotechnol J 2023; 21:2688-2695. [PMID: 37143763 PMCID: PMC10151222 DOI: 10.1016/j.csbj.2023.04.013] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2022] [Revised: 04/14/2023] [Accepted: 04/14/2023] [Indexed: 05/06/2023] Open
Abstract
Alzheimer's disease is the most common form of dementia. Its aetiology is characterized by the misfolding and aggregation of amyloid-β (Aβ) peptides into β-sheet-rich Aβ oligomers/fibrils. Although multiple experimental studies have suggested that Aβ oligomers/fibrils interact with the cell membranes and perturb their structures and dynamics, the molecular mechanism of this interaction is still not fully understood. In the present work, we have performed a total of 120 μs-long simulations to investigate the interaction between trimeric or hexameric Aβ1-40 fibrils with either a 100% DPPC bilayer, a 70% DPPC-30% cholesterol bilayer or a 50% DPPC-50% cholesterol bilayer. Our simulation data capture the spontaneous binding of the aqueous Aβ1-40 fibrils with the membranes and show that the central hydrophobic amino acid cluster, the lysine residue adjacent to it and the C-terminal hydrophobic residues are all involved in the process. Moreover, our data show that while the Aβ1-40 fibril does not bind to the 100% DPPC bilayer, its binding affinity for the membrane increases with the amount of cholesterol. Overall, our data suggest that two clusters of hydrophobic residues and one lysine help Aβ1-40 fibrils establish stable interactions with a cholesterol-rich DPPC bilayer. These residues are likely to represent potential target regions for the design of inhibitors, thus opening new avenues in structure-based drug design against Aβ oligomer/fibril-membrane interaction.
Collapse
Affiliation(s)
- Nikhil Agrawal
- Latvian Institute of Organic Synthesis, Aizkraukles 21, LV, Riga 1006, Latvia
- College of Health Sciences, University of KwaZulu-Natal, Durban, South Africa
- Corresponding authors at: Latvian Institute of Organic Synthesis, Aizkraukles 21, LV, Riga 1006, Latvia.
| | - Adam A. Skelton
- College of Health Sciences, University of KwaZulu-Natal, Durban, South Africa
| | - Emilio Parisini
- Latvian Institute of Organic Synthesis, Aizkraukles 21, LV, Riga 1006, Latvia
- Department of Chemistry “G. Ciamician”, University of Bologna, Via Selmi 2, 40126 Bologna, Italy
- Corresponding authors at: Latvian Institute of Organic Synthesis, Aizkraukles 21, LV, Riga 1006, Latvia.
| |
Collapse
|
6
|
Agrawal N, Parisini E. Early Stages of Misfolding of PAP248-286 at two different pH values: An Insight from Molecular Dynamics Simulations. Comput Struct Biotechnol J 2022; 20:4892-4901. [PMID: 36147683 PMCID: PMC9474323 DOI: 10.1016/j.csbj.2022.08.060] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Revised: 08/26/2022] [Accepted: 08/26/2022] [Indexed: 01/01/2023] Open
Abstract
PAP248-286 peptides, which are highly abundant in human semen, aggregate and form amyloid fibrils that enhance HIV infection. Previous experimental studies have shown that the infection-promoting activity of PAP248-286 begins to increase well before amyloid formation takes place and that pH plays a key role in the enhancement of PAP248-286-related infection. Hence, understanding the early stages of misfolding of the PAP2482-86 peptide is crucial. To this end, we have performed 60 independent MD simulations for a total of 24 µs at two different pH values (4.2 and 7.2). Our data shows that early stages of misfolding of the PAP248-286 peptide is a multistage process and that the first step of the process is a transition from an “I-shaped” structure to a “U-shaped” structure. We further observed that the structure of PAP248-286 at the two different pH values shows significantly different features. At pH 4.2, the peptide has less intra-molecular H-bonds and a reduced α-helical content than at pH 7.2. Moreover, differences in intra-peptide residues contacts are also observed at the two pH values. Finally, free energy landscape analysis shows that there are more local minima in the energy surface of the peptide at pH 7.2 than at pH 4.2. Overall, the present study elucidates the early stages of misfolding of the PAP248-286 peptide at the atomic level, thus possibly opening new avenues in structure-based drug discovery against HIV infection.
Collapse
Affiliation(s)
- Nikhil Agrawal
- Latvian Institute of Organic Synthesis, Aizkraukles 21, LV, Riga 1006, Latvia
- College of Health Sciences, University of KwaZulu-Natal, Durban, South Africa
- Corresponding authors at: Latvian Institute of Organic Synthesis, Aizkraukles 21, LV, Riga 1006, Latvia.
| | - Emilio Parisini
- Latvian Institute of Organic Synthesis, Aizkraukles 21, LV, Riga 1006, Latvia
- Department of Chemistry “G. Ciamician”, University of Bologna, Bologna, Italy
- Corresponding authors at: Latvian Institute of Organic Synthesis, Aizkraukles 21, LV, Riga 1006, Latvia.
| |
Collapse
|
7
|
Jiang L, Sun Q, Li L, Lu F, Liu F. Molecular Insights into the Inhibitory Effect of GV971 Components Derived from Marine Acidic Oligosaccharides against the Conformational Transition of Aβ42 Monomers. ACS Chem Neurosci 2021; 12:3772-3784. [PMID: 34565139 DOI: 10.1021/acschemneuro.1c00555] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
GV971 derived from marine acidic oligosaccharides has been used to cure Alzheimer's disease (AD). However, the molecular mechanism of its inhibition of the conformational transition of amyloid β-proteins (Aβ) is still unclear. Herein, molecular dynamics simulations were used to explore the molecular mechanism of the main GV971 components including DiM, TetraM, HexaM, and OctaM to inhibit the conformational conversion of the Aβ42 monomer. It is found that the GV971 components inhibit the conformational transition from α-helix to β-sheet and the hydrophobic collapse of the Aβ42 monomer. In addition, the binding energy analysis implies that both electrostatic and van der Waals interactions are beneficial to the binding of GV971 components to the Aβ42 monomer. Among them, electrostatic interactions occupy the dominant position. Moreover, the GV971 components mainly interact directly with the charged residues D1, R5, K16, and K28 by forming salt bridges and hydrogen bonds, which specifically bind to the N-terminal region of Aβ42.
Collapse
Affiliation(s)
- Luying Jiang
- Key Laboratory of Industrial Fermentation Microbiology of Ministry of Education, Tianjin Key Laboratory of Industrial Microbiology, College of Biotechnology, Tianjin University of Science & Technology, Tianjin 300457, P. R. China
| | - Quancheng Sun
- Key Laboratory of Industrial Fermentation Microbiology of Ministry of Education, Tianjin Key Laboratory of Industrial Microbiology, College of Biotechnology, Tianjin University of Science & Technology, Tianjin 300457, P. R. China
| | - Li Li
- College of Marine and Environmental Science, Tianjin University of Science & Technology, Tianjin 300457, P. R. China
| | - Fuping Lu
- Key Laboratory of Industrial Fermentation Microbiology of Ministry of Education, Tianjin Key Laboratory of Industrial Microbiology, College of Biotechnology, Tianjin University of Science & Technology, Tianjin 300457, P. R. China
| | - Fufeng Liu
- Key Laboratory of Industrial Fermentation Microbiology of Ministry of Education, Tianjin Key Laboratory of Industrial Microbiology, College of Biotechnology, Tianjin University of Science & Technology, Tianjin 300457, P. R. China
| |
Collapse
|
8
|
Kaur A, Goyal D, Goyal B. An α-helix mimetic oligopyridylamide, ADH-31, modulates Aβ 42 monomer aggregation and destabilizes protofibril structures: insights from molecular dynamics simulations. Phys Chem Chem Phys 2020; 22:28055-28073. [PMID: 33289734 DOI: 10.1039/d0cp04672h] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Alzheimer's disease (AD), an epidemic growing worldwide due to no effective medical aid available in the market, is a neurological disorder. AD is known to be directly associated with the toxicity of amyloid-β (Aβ) aggregates. In search of potent inhibitors of Aβ aggregation, Hamilton and co-workers reported an α-helix mimetic, ADH-31, which acts as a powerful antagonist of Aβ42 aggregation. To identify the key interactions between protein-ligand complexes and to gain insights into the inhibitory mechanism of ADH-31 against Aβ42 aggregation, molecular dynamics (MD) simulations were performed in the present study. The MD simulations highlighted that ADH-31 showed distinct binding capabilities with residues spanning from the N-terminal to the central hydrophobic core (CHC) region of Aβ42 and restricted the conformational transition of the helix-rich structure of Aβ42 into another form of secondary structures (coil/turn/β-sheet). Hydrophobic contacts, hydrogen bonding and π-π interaction contribute to the strong binding between ADH-31 and Aβ42 monomer. The Dictionary of Secondary Structure of Proteins (DSSP) analysis highlighted that the probability of helical content increases from 38.5% to 50.2% and the turn content reduces from 14.7% to 6.2% with almost complete loss of the β-sheet structure (4.5% to 0%) in the Aβ42 monomer + ADH-31 complex. The per-residue binding free energy analysis demonstrated that Arg5, Tyr10, His14, Gln15, Lys16, Val18, Phe19 and Lys28 residues of Aβ42 are responsible for the favourable binding free energy in Aβ42 monomer + ADH-31 complex, which is consistent with the 2D HSQC NMR of the Aβ42 monomer that depicted a change in the chemical shift of residues spanning from Glu11 to Phe20 in the presence of ADH-31. The MD simulations highlighted the prevention of sampling of amyloidogenic β-strand conformations in Aβ42 trimer in the presence of ADH-31 as well as the ability of ADH-31 to destabilize Aβ42 trimer and protofibril structures. The lower binding affinity between Aβ42 trimer chains in the presence of ADH-31 highlights the destabilization of the Aβ42 trimer structure. Overall, MD results highlighted that ADH-31 inhibited Aβ42 aggregation by constraining Aβ peptides into helical conformation and destabilized Aβ42 trimer as well as protofibril structures. The present study provides a theoretical insight into the atomic level details of the inhibitory mechanism of ADH-31 against Aβ42 aggregation as well as protofibril destabilization and could be implemented in the structure-based drug design of potent therapeutic agents for AD.
Collapse
Affiliation(s)
- Anupamjeet Kaur
- Department of Chemistry, Faculty of Basic and Applied Sciences, Sri Guru Granth Sahib World University, Fatehgarh Sahib-140406, Punjab, India.
| | | | | |
Collapse
|
9
|
Kaur A, Kaur A, Goyal D, Goyal B. How Does the Mono-Triazole Derivative Modulate Aβ 42 Aggregation and Disrupt a Protofibril Structure: Insights from Molecular Dynamics Simulations. ACS OMEGA 2020; 5:15606-15619. [PMID: 32637837 PMCID: PMC7331201 DOI: 10.1021/acsomega.0c01825] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Accepted: 06/08/2020] [Indexed: 05/31/2023]
Abstract
Clinical studies have identified that abnormal self-assembly of amyloid-β (Aβ) peptide into toxic fibrillar aggregates is associated with the pathology of Alzheimer's disease (AD). The most acceptable therapeutic approach to stop the progression of AD is to inhibit the formation of β-sheet-rich structures. Recently, we designed and evaluated a series of novel mono-triazole derivatives 4(a-x), where compound 4v was identified as the most potent inhibitor of Aβ42 aggregation and disaggregates preformed Aβ42 fibrils significantly. Moreover, 4v strongly averts the Cu2+-induced Aβ42 aggregation and disaggregates the preformed Cu2+-induced Aβ42 fibrils, halts the generation of reactive oxygen species, and shows neuroprotective effects in SH-SY5Y cells. However, the underlying molecular mechanism of inhibition of Aβ42 aggregation by 4v and disaggregation of preformed Aβ42 fibrils remains obscure. In this work, molecular dynamics (MD) simulations have been performed to explore the conformational ensemble of the Aβ42 monomer and a pentameric protofibril structure of Aβ42 in the presence of 4v. The MD simulations highlighted that 4v binds preferentially at the central hydrophobic core region of the Aβ42 monomer and chains D and E of the Aβ42 protofibril. The dictionary of secondary structure of proteins analysis indicated that 4v retards the conformational conversion of the helix-rich structure of the Aβ42 monomer into the aggregation-prone β-sheet conformation. The binding free energy calculated by the molecular mechanics Poisson-Boltzmann surface area method revealed an energetically favorable process with ΔG binding = -44.9 ± 3.3 kcal/mol for the Aβ42 monomer-4v complex. The free energy landscape analysis highlighted that the Aβ42 monomer-4v complex sampled conformations with significantly higher helical contents (35 and 49%) as compared to the Aβ42 monomer alone (17%). Compound 4v displayed hydrogen bonding with Gly37 (chain E) and π-π interactions with Phe19 (chain D) of the Aβ42 protofibril. Further, the per-residue binding free energy analysis also highlighted that Phe19 (chain D) and Gly37 (chain E) of the Aβ42 protofibril showed the maximum contribution in the binding free energy. The decreased binding affinity and residue-residue contacts between chains D and E of the Aβ42 protofibril in the presence of 4v indicate destabilization of the Aβ42 protofibril structure. Overall, the structural information obtained through MD simulations indicated that 4v stabilizes the native helical conformation of the Aβ42 monomer and persuades a destabilization in the protofibril structure of Aβ42. The results of the study will be useful in the rational design of potent inhibitors against amyloid aggregation.
Collapse
Affiliation(s)
- Amandeep Kaur
- Department
of Chemistry, Faculty of Basic and Applied Sciences, Sri Guru Granth Sahib World University, Fatehgarh Sahib 140406, Punjab, India
| | - Anupamjeet Kaur
- Department
of Chemistry, Faculty of Basic and Applied Sciences, Sri Guru Granth Sahib World University, Fatehgarh Sahib 140406, Punjab, India
| | - Deepti Goyal
- Department
of Chemistry, Faculty of Basic and Applied Sciences, Sri Guru Granth Sahib World University, Fatehgarh Sahib 140406, Punjab, India
| | - Bhupesh Goyal
- School
of Chemistry & Biochemistry, Thapar
Institute of Engineering & Technology, Patiala 147004, Punjab, India
| |
Collapse
|
10
|
Saini RK, Thakur H, Goyal B. Effect of Piedmont mutation (L34V) on the structure, dynamics, and aggregation of Alzheimer's Aβ 40 peptide. J Mol Graph Model 2020; 97:107571. [PMID: 32143150 DOI: 10.1016/j.jmgm.2020.107571] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2019] [Revised: 01/26/2020] [Accepted: 02/19/2020] [Indexed: 12/22/2022]
Abstract
The amyloid-β (Aβ) aggregation in the brain has been associated with the development of Alzheimer's disease (AD). The previous studies have reported that Piedmont mutation (L34V) increases the rate of Aβ40 aggregation. However, the underlying molecular mechanism of the effect of L34V mutation on Aβ40 structure, dynamics, and aggregation remains largely unclear. In the present study, molecular dynamics (MD) simulations were performed to elucidate the effect of L34V mutation on the structural changes and conformational dynamics of Aβ40. The secondary structure analysis highlight that L34V mutation enhances Aβ40 self-assembly due to the formation of aggregation-prone β-sheet structure at the C-terminus of Aβ40 monomeric structure. The higher probability of Asp23-Lys28 salt bridge interaction in Aβ40(L34V) leads to aggregation prone β-sheet conformations, which has the potential to increase the fibril formation rate. The free energy landscape (FEL) analysis depict a sampling of coil conformation in the free energy minima of Aβ40, whereas the aggregation-prone β-sheet conformation was observed at the C-terminal region of Aβ40(L34V) in the minimum energy conformations extracted from FEL of Aβ40(L34V). MD simulations, in agreement with experiment, highlight that L34V mutation increases Aβ40 aggregation as the sampling of the aggregation-prone β-sheet conformation substantially increased. Overall, MD simulations provided atomic level details into the increased fibril formation tendency upon L34V mutation and physical insights into the L34V-mediated conformational as well as structural changes in Aβ40.
Collapse
Affiliation(s)
- Rajneet Kaur Saini
- Department of Chemistry, Faculty of Basic and Applied Sciences, Sri Guru Granth Sahib World University, Fatehgarh Sahib, 140406, Punjab, India
| | - Hema Thakur
- School of Chemistry & Biochemistry, Thapar Institute of Engineering & Technology, Patiala, 147004, Punjab, India
| | - Bhupesh Goyal
- School of Chemistry & Biochemistry, Thapar Institute of Engineering & Technology, Patiala, 147004, Punjab, India.
| |
Collapse
|
11
|
Kaur A, Shuaib S, Goyal D, Goyal B. Interactions of a multifunctional di-triazole derivative with Alzheimer's Aβ42monomer and Aβ42protofibril: a systematic molecular dynamics study. Phys Chem Chem Phys 2020; 22:1543-1556. [DOI: 10.1039/c9cp04775a] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The molecular dynamics simulations results highlighted that the multi-target-directed ligand6nstabilizes the native α-helix conformation of the Aβ42monomer and induces a sizable destabilization in the Aβ42protofibril structure.
Collapse
Affiliation(s)
- Anupamjeet Kaur
- Department of Chemistry
- Faculty of Basic and Applied Sciences
- Sri Guru Granth Sahib World University
- Fatehgarh Sahib-140406
- India
| | - Suniba Shuaib
- Department of Chemistry
- Faculty of Basic and Applied Sciences
- Sri Guru Granth Sahib World University
- Fatehgarh Sahib-140406
- India
| | - Deepti Goyal
- Department of Chemistry
- Faculty of Basic and Applied Sciences
- Sri Guru Granth Sahib World University
- Fatehgarh Sahib-140406
- India
| | - Bhupesh Goyal
- School of Chemistry & Biochemistry
- Thapar Institute of Engineering & Technology
- Patiala-147004
- India
| |
Collapse
|
12
|
Maji R, Omolo CA, Agrawal N, Maduray K, Hassan D, Mokhtar C, Mackhraj I, Govender T. pH-Responsive Lipid–Dendrimer Hybrid Nanoparticles: An Approach To Target and Eliminate Intracellular Pathogens. Mol Pharm 2019; 16:4594-4609. [DOI: 10.1021/acs.molpharmaceut.9b00713] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Affiliation(s)
- Ruma Maji
- Discipline of Pharmaceutical Sciences, College of Health Sciences, University of KwaZulu-Natal, Durban, South Africa
| | - Calvin A. Omolo
- Discipline of Pharmaceutical Sciences, College of Health Sciences, University of KwaZulu-Natal, Durban, South Africa
- School of Pharmacy and Health Sciences, United States International University of Africa, Nairobi, Kenya
| | - Nikhil Agrawal
- Discipline of Pharmaceutical Sciences, College of Health Sciences, University of KwaZulu-Natal, Durban, South Africa
| | - Kaminee Maduray
- Department of Physiology, College of Health Sciences, University of KwaZulu-Natal, Durban, South Africa
| | - Daniel Hassan
- Discipline of Pharmaceutical Sciences, College of Health Sciences, University of KwaZulu-Natal, Durban, South Africa
| | - Chunderika Mokhtar
- Discipline of Pharmaceutical Sciences, College of Health Sciences, University of KwaZulu-Natal, Durban, South Africa
| | - Irene Mackhraj
- Department of Physiology, College of Health Sciences, University of KwaZulu-Natal, Durban, South Africa
| | - Thirumala Govender
- Discipline of Pharmaceutical Sciences, College of Health Sciences, University of KwaZulu-Natal, Durban, South Africa
| |
Collapse
|
13
|
Ghorbani M, Soleymani H, Allahverdi A, Shojaeilangari S, Naderi-Manesh H. Effects of natural compounds on conformational properties and hairpin formation of amyloid-β 42 monomer: docking and molecular dynamics simulation study. J Biomol Struct Dyn 2019; 38:3371-3383. [PMID: 31496378 DOI: 10.1080/07391102.2019.1664934] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The β42 amyloid peptides (Aβ) are identified as a candidate target for Alzheimer's drugs. Phenolic compounds can bind to the Aβ and inhibit amyloid formation. However, the inhibitory mechanism of phenolic compounds remains unclear. In this study, the molecular dynamic simulation and docking program were used to characterize the molecular details of inhibitory mechanism of the phenolic compounds. Our Results show that the phenolic compounds can bind to hydrophobic region in Aβ42 monomer and alter hydrophobic interactions network at Aβ42 which play a key role in β-sheet formation. The cluster analysis and interactions network analysis were used to probe conformational changes in Aβ42. In most populated clusters of Aβ42-phenolic compounds complexes, the sheet structures were not observed or reduced. It seems that the binding of phenolic compounds can induce larger conformational diversity for amyloid peptide and changes conformational properties of amyloid peptide. The phenolic compounds can deform β-Hairpin structure of Aβ by destabilizing salt bridges E22-K28 and D23-K28 which can alter the conformation of Aβ42 in aqueous solution. These findings are in accordance with experimental results, to some extent give a molecular level interpretation for the inhibitory mechanism of phenolic compounds .In addition, this study may add important new details to the inhibitory mechanism of Alzheimer's drug.Communicated by Ramaswamy H. Sarma.
Collapse
Affiliation(s)
- Mohammad Ghorbani
- Faculty of Biological Sciences, Biophysics Department, Tarbiat Modares University, Tehran, Iran
| | - Hossein Soleymani
- Faculty of Biological Sciences, Biophysics Department, Tarbiat Modares University, Tehran, Iran
| | - Abdollah Allahverdi
- Faculty of Biological Sciences, Biophysics Department, Tarbiat Modares University, Tehran, Iran
| | | | - Hossein Naderi-Manesh
- Faculty of Biological Sciences, Biophysics Department, Tarbiat Modares University, Tehran, Iran.,School of Biological Science, Institute for Research in Fundamental Sciences (IPM), Tehran, Iran
| |
Collapse
|
14
|
Shaikh MS, Kanhed AM, Chandrasekaran B, Palkar MB, Agrawal N, Lherbet C, Hampannavar GA, Karpoormath R. Discovery of novel N-methyl carbazole tethered rhodanine derivatives as direct inhibitors of Mycobacterium tuberculosis InhA. Bioorg Med Chem Lett 2019; 29:2338-2344. [DOI: 10.1016/j.bmcl.2019.06.015] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2019] [Revised: 05/31/2019] [Accepted: 06/12/2019] [Indexed: 01/06/2023]
|
15
|
Agrawal N, Skelton AA. Structure and Function of Alzheimer’s Amyloid βeta Proteins from Monomer to Fibrils: A Mini Review. Protein J 2019; 38:425-434. [DOI: 10.1007/s10930-019-09854-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
|
16
|
Bhattacharya S, Xu L, Thompson D. Molecular Simulations Reveal Terminal Group Mediated Stabilization of Helical Conformers in Both Amyloid-β42 and α-Synuclein. ACS Chem Neurosci 2019; 10:2830-2842. [PMID: 30917651 DOI: 10.1021/acschemneuro.9b00053] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
The presence of partially structured helices in natively unfolded amyloid-β42 (Aβ42) and α-synuclein (αS) has been shown to accelerate fibrillation in the onset of Alzheimer's and Parkinson's disease, respectively. At the other extreme, folded stable helical conformers have also been reported to resist amyloid formation. Recent studies indicate that amyloidogenic aggregation can be impeded using small molecules that stabilize the α-helical monomers and switch off the neurotoxic pathway. We predict a common intrapeptide route to stabilization based on the plasticity of helical conformations of Aβ42 and αS as assessed through extensive atomistic molecular dynamics (MD) computer simulations (∼36 μs) across ten distinct protein force field and water model combinations. Computed free energies and interaction maps (not obtainable from experiments alone) show that flexible terminal groups (N-terminus of Aβ42 and C-terminus of αS) show a tendency to stabilize folded helical conformations in both peptides via primary hydrophobic interactions with central hydrophobic domains, and secondary salt bridges with other domains. These interactions confer aggregation resistance by decreasing the population of partially structured helices and are absent in control simulations of complete unfolding. Computed helical stability is also significantly reduced in terminal-deleted variants. The models suggest new strategies to tackle neurodegeneration by rationally re-engineering terminal groups to optimize their predicted ability to deactivate helical monomers.
Collapse
Affiliation(s)
- Shayon Bhattacharya
- Department of Physics, Bernal Institute, University of Limerick, Limerick V94 T9PX, Ireland
| | - Liang Xu
- Department of Physics, Bernal Institute, University of Limerick, Limerick V94 T9PX, Ireland
| | - Damien Thompson
- Department of Physics, Bernal Institute, University of Limerick, Limerick V94 T9PX, Ireland
| |
Collapse
|
17
|
Agrawal N, Chandrasekaran B, Al-Aboudi A. Recent Advances in the In-silico Structure-based and Ligand-based Approaches for the Design and Discovery of Agonists and Antagonists of A2A Adenosine Receptor. Curr Pharm Des 2019; 25:774-782. [DOI: 10.2174/1381612825666190306162006] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2019] [Accepted: 02/26/2019] [Indexed: 01/20/2023]
Abstract
A2A receptor belongs to the family of GPCRs, which are the most abundant membrane protein family.
Studies in the last few decades have shown the therapeutic applications of A2A receptor in various diseases. In the
present mini-review, we have discussed the recent progress in the in-silico studies of the A2A receptor. Herein, we
described the different structures of A2A receptor, the discovery of new agonists and antagonists using virtualscreening/
docking, pharmacophore modeling, and QSAR based pharmacophore modeling. We have also discussed
various molecular dynamics (MD) simulations studies of A2A receptor in complex with ligands.
Collapse
Affiliation(s)
- Nikhil Agrawal
- College of Health Sciences, University of KwaZulu-Natal, P. O. Box: 4000, Westville, Durban, South Africa
| | - Balakumar Chandrasekaran
- College of Health Sciences, University of KwaZulu-Natal, P. O. Box: 4000, Westville, Durban, South Africa
| | - Amal Al-Aboudi
- Faculty of Science, The University of Jordan, Amman, 11942, Jordan
| |
Collapse
|
18
|
Adamovich SN. New atranes and similar ionic complexes. Synthesis, structure, properties. Appl Organomet Chem 2019. [DOI: 10.1002/aoc.4940] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Sergey N. Adamovich
- A. E. Favorsky Irkutsk Institute of ChemistrySB RAS 1 Favorsky Street 664033 Irkutsk Russian Federation
| |
Collapse
|
19
|
Faya M, Kalhapure RS, Dhumal D, Agrawal N, Omolo C, Akamanchi KG, Govender T. Antimicrobial cell penetrating peptides with bacterial cell specificity: pharmacophore modelling, quantitative structure activity relationship and molecular dynamics simulation. J Biomol Struct Dyn 2018; 37:2370-2380. [PMID: 30047310 DOI: 10.1080/07391102.2018.1484814] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
Current research has shown cell-penetrating peptides and antimicrobial peptides (AMPs) as probable vectors for use in drug delivery and as novel antibiotics. It has been reported that the higher the therapeutic index (TI) the higher would be the bacterial cell penetrating ability. To the best of our knowledge, no in-silico study has been performed to determine bacterial cell specificity of the antimicrobial cell penetrating peptides (aCPP's) based on their TI. The aim of this study was to develop a quantitative structure activity relationship (QSAR) model, which can estimate antimicrobial potential and cell-penetrating ability of aCPPs against S. aureus, to confirm the relationship between the TI and aCPPs and to identify specific descriptors responsible for aCPPs penetrating ability. Molecular dynamics (MD) simulation was also performed to confirm the membrane insertion of the most active aCPPs obtained from the QSAR study. The most appropriate pharmacophore was identified to predict the aCPP's activity. The statistical results confirmed the validity of the model. The QSAR model was successful in identifying the optimal aCPP with high activity prediction and provided insights into the structural requirements to correlate their TI to cell penetrating ability. MD simulation of the best aCPP with 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) bilayer confirmed its interaction with the membrane and the C-terminal residues of the aCPP played a key role in membrane penetration. The strategy of combining QSAR and molecular dynamics, allowed for optimal estimation of ligand-target interaction and confirmed the importance of Trp and Lys in interacting with the POPC bilayer. Communicated by Ramaswamy H. Sarma.
Collapse
Affiliation(s)
- Mbuso Faya
- a Department of Pharmaceutical Sciences , University of KwaZulu-Natal , Private Bag , Durban , South Africa
| | - Rahul S Kalhapure
- a Department of Pharmaceutical Sciences , University of KwaZulu-Natal , Private Bag , Durban , South Africa
| | - Dinesh Dhumal
- b Department of Pharmaceutical Sciences and Technology , Institute of Chemical Technology , Mumbai , India
| | - Nikhil Agrawal
- a Department of Pharmaceutical Sciences , University of KwaZulu-Natal , Private Bag , Durban , South Africa
| | - Calvin Omolo
- a Department of Pharmaceutical Sciences , University of KwaZulu-Natal , Private Bag , Durban , South Africa
| | - Krishnacharya G Akamanchi
- b Department of Pharmaceutical Sciences and Technology , Institute of Chemical Technology , Mumbai , India
| | - Thirumala Govender
- a Department of Pharmaceutical Sciences , University of KwaZulu-Natal , Private Bag , Durban , South Africa
| |
Collapse
|
20
|
Omolo CA, Kalhapure RS, Agrawal N, Jadhav M, Rambharose S, Mocktar C, Govender T. A hybrid of mPEG-b-PCL and G1-PEA dendrimer for enhancing delivery of antibiotics. J Control Release 2018; 290:112-128. [DOI: 10.1016/j.jconrel.2018.10.005] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Revised: 09/17/2018] [Accepted: 10/06/2018] [Indexed: 01/02/2023]
|
21
|
Agrawal N, Hossain MS, Skelton AA, Muralidhar K, Kaushik S. Unraveling the mechanism of l-gulonate-3-dehydrogenase inhibition by ascorbic acid: Insights from molecular modeling. Comput Biol Chem 2018; 77:146-153. [PMID: 30316191 DOI: 10.1016/j.compbiolchem.2018.09.015] [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: 06/05/2018] [Revised: 09/06/2018] [Accepted: 09/23/2018] [Indexed: 10/28/2022]
Abstract
l-Gulonate dehydrogenase (GuDH) is a crucial enzyme in the non-phosphorylated sugar metabolism or glucuronate-xylulose (GX) pathway. Some naturally occurring compounds inhibit GuDH. Ascorbic acid is one of such inhibitors for GuDH. However, the exact mechanism by which ascorbic acid inhibits GuDH is still unknown. In this study, we try to investigate GuDH inhibition using computational approaches by generating a model for buffalo GuDH. We used this model to perform blind dockings of ascorbic acid to GuDH. Some docked conformations of ascorbic acid bind near Asp39 and have steric clashes with crystal structure conformation of NADH. To assess the dynamic stability of the GuDH-ascorbic acid complex, we performed six molecular dynamics simulations for GuDH, three each in its free form and in complex with ascorbic acid for 50 ns, to obtain 300 ns of trajectories in total. During the simulations, ascorbic acid interacted with several residues nearby Asp39. As Asp39 is an important residue for NADH binding and specificity, the interaction of ascorbic acid near Asp39 hinders further NADH binding and ultimately affects the enzymatic functioning of GuDH. In this study, we analyze these interactions between ascorbic acid and GuDH. Our analysis reveals novel details on the mechanism of GuDH inhibition by ascorbic acid.
Collapse
Affiliation(s)
- Nikhil Agrawal
- School of Pharmacy and Pharmacology, University of KwaZulu-Natal, Durban, South Africa
| | | | - Adam A Skelton
- School of Pharmacy and Pharmacology, University of KwaZulu-Natal, Durban, South Africa
| | | | - Sandeep Kaushik
- 3B's Research Group, Head Quarters of European Institute of Excellence on Tissue Engineering and Regenerative Medicine, AvePark - Parque de Ciência e Tecnologia, Zona Industrial da Gandra, Barco, 4805-017, Guimarães, Portugal.
| |
Collapse
|
22
|
Omolo CA, Kalhapure RS, Agrawal N, Rambharose S, Mocktar C, Govender T. Formulation and Molecular Dynamics Simulations of a Fusidic Acid Nanosuspension for Simultaneously Enhancing Solubility and Antibacterial Activity. Mol Pharm 2018; 15:3512-3526. [PMID: 29953816 DOI: 10.1021/acs.molpharmaceut.8b00505] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The aim of the present study was to formulate a nanosuspension (FA-NS) of fusidic acid (FA) to enhance its aqueous solubility and antibacterial activity. The nanosuspension was characterized using various in vitro, in silico, and in vivo techniques. The size, polydispersity index, and zeta potential of the optimized FA-NS were 265 ± 2.25 nm, 0.158 ± 0.026, and -16.9 ± 0.794 mV, respectively. The molecular dynamics simulation of FA and Poloxamer-188 showed an interaction and binding energy of -74.42 kJ/mol and -49.764 ± 1.298 kJ/mol, respectively, with van der Waals interactions playing a major role in the spontaneous binding. There was an 8-fold increase in the solubility of FA in a nanosuspension compared to the bare drug. The MTT assays showed a cell viability of 75-100% confirming the nontoxic nature of FA-NS. In vitro antibacterial activity revealed a 16- and 18-fold enhanced activity against Staphylococcus aureus (SA) and methicillin-resistant SA (MRSA), respectively, when compared to bare FA. Flowcytometry showed that MRSA cells treated with FA-NS had almost twice the percentage of dead bacteria in the population, despite having an 8-fold lower MIC in comparison to the bare drug. The in vivo skin-infected mice showed a 76-fold reduction in the MRSA load for the FA-NS treated group compared to that of the bare FA. These results show that the nanosuspension of antibiotics can enhance their solubility and antibacterial activity simultaneously.
Collapse
Affiliation(s)
- Calvin A Omolo
- Discipline of Pharmaceutical Sciences , College of Health Sciences, University of KwaZulu-Natal , Private Bag , X54001 Durban , South Africa
| | - Rahul S Kalhapure
- Discipline of Pharmaceutical Sciences , College of Health Sciences, University of KwaZulu-Natal , Private Bag , X54001 Durban , South Africa.,School of Pharmacy , The University of Texas at El Paso , 500 W. University Avenue , El Paso , Texas 79968 , United States
| | - Nikhil Agrawal
- Discipline of Pharmaceutical Sciences , College of Health Sciences, University of KwaZulu-Natal , Private Bag , X54001 Durban , South Africa
| | - Sanjeev Rambharose
- Discipline of Pharmaceutical Sciences , College of Health Sciences, University of KwaZulu-Natal , Private Bag , X54001 Durban , South Africa.,Division of Emergency Medicine, Department of Surgery , University of Cape Town , Cape Town 7700 , South Africa
| | - Chunderika Mocktar
- Discipline of Pharmaceutical Sciences , College of Health Sciences, University of KwaZulu-Natal , Private Bag , X54001 Durban , South Africa
| | - Thirumala Govender
- Discipline of Pharmaceutical Sciences , College of Health Sciences, University of KwaZulu-Natal , Private Bag , X54001 Durban , South Africa
| |
Collapse
|