1
|
Singh K, Kaur A, Goyal B, Goyal D. Harnessing the Therapeutic Potential of Peptides for Synergistic Treatment of Alzheimer's Disease by Targeting Aβ Aggregation, Metal-Mediated Aβ Aggregation, Cholinesterase, Tau Degradation, and Oxidative Stress. ACS Chem Neurosci 2024; 15:2545-2564. [PMID: 38979773 DOI: 10.1021/acschemneuro.4c00246] [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] [Indexed: 07/10/2024] Open
Abstract
Alzheimer's disease (AD) is a progressive multifaceted neurodegenerative disease and remains a formidable global health challenge. The current medication for AD gives symptomatic relief and, thus, urges us to look for alternative disease-modifying therapies based on a multitarget directed approach. Looking at the remarkable progress made in peptide drug development in the last decade and the benefits associated with peptides, they offer valuable chemotypes [multitarget directed ligands (MTDLs)] as AD therapeutics. This review recapitulates the current developments made in harnessing peptides as MTDLs in combating AD by targeting multiple key pathways involved in the disease's progression. The peptides hold immense potential and represent a convincing avenue in the pursuit of novel AD therapeutics. While hurdles remain, ongoing research offers hope that peptides may eventually provide a multifaceted approach to combat AD.
Collapse
Affiliation(s)
- Kamaljot Singh
- 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
| | - Bhupesh Goyal
- Department of Chemistry and Biochemistry, Thapar Institute of Engineering & Technology, Patiala, 147004 Punjab, India
| | - Deepti Goyal
- Department of Chemistry, DAV College, Sector 10, Chandigarh 160011, India
| |
Collapse
|
2
|
Dudure R, Ganorkar K, Beldar V, Ghosh SK, Panda AK, Jadhao M. Effect of artificial sweetener saccharin on lysozyme aggregation: A combined spectroscopic and in silico approach. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2023; 290:122269. [PMID: 36566534 DOI: 10.1016/j.saa.2022.122269] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2022] [Revised: 12/11/2022] [Accepted: 12/18/2022] [Indexed: 06/17/2023]
Abstract
The use of saccharin in food products attracts much attention as it involves the risk of lethal allergies and many protein aggregation diseases. However, its role in protein aggregation has not been explored to date. This study embodies the effect of artificial sweeteners on HEWL in the absence and presence of commonly available natural products such as curcumin and EGCG. Various techniques have been used to characterize the protein interaction, such as steady-state emission and time-resolved fluorescence, FTIR, gel electrophoresis, TEM, and molecular docking. Steady-state and time-resolved studies revealed the binding strength and concomitant effect of saccharin on HEWL protein. Kinetic measurements revealed that saccharin causes significant enhancement of HEWL aggregation with a considerable reduction in lag phase time i.e. from 37 hr to 08 hr. Whereas in the presence of natural products, the effect of saccharin on HEWL aggregation was significantly reduced specifically in the case of curcumin. The result obtained in the fluorescence experiment were also supported by the gel electrophoresis technique and morphological images taken by TEM. The rapid change in the secondary structure of the protein in the presence of saccharin was confirmed by the FTIR spectroscopy technique. This study is instrumental in understanding the effect of saccharin on protein aggregation and the role of commonly available natural products in curbing its effect.
Collapse
Affiliation(s)
- Rushali Dudure
- Institute of Chemical Technology Mumbai-Marathwada Campus, Jalna, Maharashtra 431203, India
| | - Kapil Ganorkar
- Department of Chemistry, Visvesvaraya National Institute of Technology, Nagpur, Maharashtra 440010, India
| | - Vishal Beldar
- Institute of Chemical Technology Mumbai-Marathwada Campus, Jalna, Maharashtra 431203, India
| | - Sujit Kumar Ghosh
- Department of Chemistry, Visvesvaraya National Institute of Technology, Nagpur, Maharashtra 440010, India
| | - Alok Kumar Panda
- Environmental Science Laboratory, School of Applied Sciences, KIIT Deemed to be University, Bhubaneswar, Odisha 751 024, India
| | - Manojkumar Jadhao
- Institute of Chemical Technology Mumbai-Marathwada Campus, Jalna, Maharashtra 431203, India.
| |
Collapse
|
3
|
Bassan GA, Marchesan S. Peptide-Based Materials That Exploit Metal Coordination. Int J Mol Sci 2022; 24:ijms24010456. [PMID: 36613898 PMCID: PMC9820281 DOI: 10.3390/ijms24010456] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2022] [Revised: 12/12/2022] [Accepted: 12/22/2022] [Indexed: 12/29/2022] Open
Abstract
Metal-ion coordination has been widely exploited to control the supramolecular behavior of a variety of building blocks into functional materials. In particular, peptides offer great chemical diversity for metal-binding modes, combined with inherent biocompatibility and biodegradability that make them attractive especially for medicine, sensing, and environmental remediation. The focus of this review is the last 5 years' progress in this exciting field to conclude with an overview of the future directions that this research area is currently undertaking.
Collapse
|
4
|
Aβ and Tau Interact with Metal Ions, Lipid Membranes and Peptide-Based Amyloid Inhibitors: Are These Common Features Relevant in Alzheimer’s Disease? Molecules 2022; 27:molecules27165066. [PMID: 36014310 PMCID: PMC9414153 DOI: 10.3390/molecules27165066] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Revised: 08/04/2022] [Accepted: 08/05/2022] [Indexed: 12/13/2022] Open
Abstract
In the last two decades, the amyloid hypothesis, i.e., the abnormal accumulation of toxic Aβ assemblies in the brain, has been considered the mainstream concept sustaining research in Alzheimer’s Disease (AD). However, the course of cognitive decline and AD development better correlates with tau accumulation rather than amyloid peptide deposition. Moreover, all clinical trials of amyloid-targeting drug candidates have been unsuccessful, implicitly suggesting that the amyloid hypothesis needs significant amendments. Accumulating evidence supports the existence of a series of potentially dangerous relationships between Aβ oligomeric species and tau protein in AD. However, the molecular determinants underlying pathogenic Aβ/tau cross interactions are not fully understood. Here, we discuss the common features of Aβ and tau molecules, with special emphasis on: (i) the critical role played by metal dyshomeostasis in promoting both Aβ and tau aggregation and oxidative stress, in AD; (ii) the effects of lipid membranes on Aβ and tau (co)-aggregation at the membrane interface; (iii) the potential of small peptide-based inhibitors of Aβ and tau misfolding as therapeutic tools in AD. Although the molecular mechanism underlying the direct Aβ/tau interaction remains largely unknown, the arguments discussed in this review may help reinforcing the current view of a synergistic Aβ/tau molecular crosstalk in AD and stimulate further research to mechanism elucidation and next-generation AD therapeutics.
Collapse
|
5
|
Asadbegi M, Shamloo A. Evaluating the Multifunctionality of a New Modulator of Zinc-Induced Aβ Aggregation Using a Novel Computational Approach. J Chem Inf Model 2021; 61:1383-1401. [PMID: 33617717 DOI: 10.1021/acs.jcim.0c01264] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The high concentration of zinc metal ions in Aβ aggregations is one of the most cited hallmarks of Alzheimer's disease (AD), and several substantial pieces of evidence emphasize the key role of zinc metal ions in the pathogenesis of AD. In this study, while designing a multifunctional peptide for simultaneous targeting Aβ aggregation and chelating the zinc metal ion, a novel and comprehensive approach is introduced for evaluating the multifunctionality of a multifunctional drugs based on computational methods. The multifunctional peptide consists of inhibitor and chelator domains, which are included in the C-terminal hydrophobic region of Aβ, and the first four amino acids of human albumin. The ability of the multifunctional peptide in zinc ion chelation has been investigated using molecular dynamics (MD) simulations of the peptide-zinc interaction for 300 ns, and Bennett's acceptance ratio (BAR) method has been used to accurately calculate the chelation free energy. Data analysis demonstrates that the peptide chelating domain can be stably linked to the zinc ion. Besides, the introduced method used for evaluating chelation and calculating the free energy of peptide binding to zinc ions was successfully validated by comparison with previous experimental and theoretical published data. The results indicate that the multifunctional peptide, coordinating with the zinc metal ion, can be effective in Aβ inhibition by preserving the native helical structure of the Aβ42 monomer as well as disrupting the β-sheet structure of Aβ42 aggregates. Detailed assessments of the Aβ42-peptide interactions elucidate that the inhibition of Aβ is achieved by considerable hydrophobic interactions and hydrogen bonding between the multifunctional peptide and the hydrophobic Aβ regions, along with interfering in stable bridges formed inside the Aβ aggregate.
Collapse
Affiliation(s)
- Mohsen Asadbegi
- School of Mechanical Engineering, Sharif University of Technology, Tehran 1458889694, Iran
| | - Amir Shamloo
- School of Mechanical Engineering, Sharif University of Technology, Tehran 1458889694, Iran
| |
Collapse
|
6
|
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: 4] [Impact Index Per Article: 1.0] [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
|
7
|
Yang T, Sui X, Yu B, Shen Y, Cong H. Recent Advances in the Rational Drug Design Based on Multi-target Ligands. Curr Med Chem 2020; 27:4720-4740. [DOI: 10.2174/0929867327666200102120652] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2019] [Revised: 09/02/2019] [Accepted: 09/07/2019] [Indexed: 12/31/2022]
Abstract
Multi-target drugs have gained considerable attention in the last decade owing to their
advantages in the treatment of complex diseases and health conditions linked to drug resistance.
Single-target drugs, although highly selective, may not necessarily have better efficacy or fewer
side effects. Therefore, more attention is being paid to developing drugs that work on multiple
targets at the same time, but developing such drugs is a huge challenge for medicinal chemists.
Each target must have sufficient activity and have sufficiently characterized pharmacokinetic parameters.
Multi-target drugs, which have long been known and effectively used in clinical practice,
are briefly discussed in the present article. In addition, in this review, we will discuss the
possible applications of multi-target ligands to guide the repositioning of prospective drugs.
Collapse
Affiliation(s)
- Ting Yang
- Institute of Biomedical Materials and Engineering, College of Materials Science and Engineering, Qingdao University, Qingdao 266071, China
| | - Xin Sui
- Institute of Biomedical Materials and Engineering, College of Materials Science and Engineering, Qingdao University, Qingdao 266071, China
| | - Bing Yu
- Institute of Biomedical Materials and Engineering, College of Materials Science and Engineering, Qingdao University, Qingdao 266071, China
| | - Youqing Shen
- Institute of Biomedical Materials and Engineering, College of Materials Science and Engineering, Qingdao University, Qingdao 266071, China
| | - Hailin Cong
- Institute of Biomedical Materials and Engineering, College of Materials Science and Engineering, Qingdao University, Qingdao 266071, China
| |
Collapse
|
8
|
Kumar R, Pavlov PF, Winblad B. Metal Binding by GMP-1 and Its Pyrimido [1, 2]benzimidazole Analogs Confirms Protection Against Amyloid-β Associated Neurotoxicity. J Alzheimers Dis 2020; 73:695-705. [DOI: 10.3233/jad-190695] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Affiliation(s)
- Rajnish Kumar
- Department of Neurobiology, Care sciences and Societ, Centre for Alzheimer Research, Division of Neurogeriatrics, Karolinska Institutet, Solna, Sweden
| | - Pavel F. Pavlov
- Department of Neurobiology, Care sciences and Societ, Centre for Alzheimer Research, Division of Neurogeriatrics, Karolinska Institutet, Solna, Sweden
- Memory Clinic, Theme Aging, Karolinska University Hospital, Huddinge, Sweden
| | - Bengt Winblad
- Department of Neurobiology, Care sciences and Societ, Centre for Alzheimer Research, Division of Neurogeriatrics, Karolinska Institutet, Solna, Sweden
- Memory Clinic, Theme Aging, Karolinska University Hospital, Huddinge, Sweden
| |
Collapse
|
9
|
Asadbegi M, Shamloo A. Identification of a Novel Multifunctional Ligand for Simultaneous Inhibition of Amyloid-Beta (Aβ 42) and Chelation of Zinc Metal Ion. ACS Chem Neurosci 2019; 10:4619-4632. [PMID: 31566950 DOI: 10.1021/acschemneuro.9b00468] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Zinc binding to β-amyloid structure could promote amyloid-β aggregation, as well as reactive oxygen species (ROS) production, as suggested in many experimental and theoretical studies. Therefore, the introduction of multifunctional drugs capable of chelating zinc metal ion and inhibiting Aβ aggregation is a promising strategy in the development of AD treatment. The present study has evaluated the efficacy of a new bifunctional peptide drug using molecular docking and molecular dynamics (MD) simulations. This drug comprises two different domains, an inhibitor domain, obtained from the C-terminal hydrophobic region of Aβ, and a Zn2+ chelating domain, derived from rapeseed meal, merge with a linker. The multifunctionality of the ligand was evaluated using a comprehensive set of MD simulations spanning up to 3.2 μs including Aβ relaxation, ligand-Zn2+ bilateral interaction, and, more importantly, ligand-Zn2+-Aβ42 trilateral interactions. Analysis of the results strongly indicated that the bifunctional ligand can chelate zinc metal ion and avoid Aβ aggregation simultaneously. The present study illustrated that the proposed ligand has considerable hydrophobic interactions and hydrogen bonding with monomeric Aβ in the presence of zinc metal ion. Therefore, in light of these considerable interactions and contacts, the α-helical structure of Aβ has been enhanced, while the β-sheet formation is prevented and the α-helix native structure is protected. Furthermore, the analysis of interactions between Aβ and ligand-zinc complex revealed that the zinc metal ion is coordinated to Met13, the ending residue of the ligand and merely one residue in Aβ. The results have proven the previous experimental and theoretical findings in the literature about Aβ interactions with zinc metal ion and also Aβ interactions with the first domain of the proposed ligand. Moreover, the current research has evaluated the chelation using MD simulation and linear interaction energy (LIE) methods, and the result has been satisfactorily verified with previous experimental and theoretical (DFT) studies.
Collapse
Affiliation(s)
- Mohsen Asadbegi
- Sharif University of Technology, School of Mechanical Engineering, Tehran 94305, Iran
| | - Amir Shamloo
- Sharif University of Technology, School of Mechanical Engineering, Tehran 94305, Iran
| |
Collapse
|
10
|
Jokar S, Khazaei S, Behnammanesh H, Shamloo A, Erfani M, Beiki D, Bavi O. Recent advances in the design and applications of amyloid-β peptide aggregation inhibitors for Alzheimer's disease therapy. Biophys Rev 2019; 11:10.1007/s12551-019-00606-2. [PMID: 31713720 DOI: 10.1007/s12551-019-00606-2] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2019] [Accepted: 10/31/2019] [Indexed: 01/05/2023] Open
Abstract
Alzheimer's disease (AD) is an irreversible neurological disorder that progresses gradually and can cause severe cognitive and behavioral impairments. This disease is currently considered a social and economic incurable issue due to its complicated and multifactorial characteristics. Despite decades of extensive research, we still lack definitive AD diagnostic and effective therapeutic tools. Consequently, one of the most challenging subjects in modern medicine is the need for the development of new strategies for the treatment of AD. A large body of evidence indicates that amyloid-β (Aβ) peptide fibrillation plays a key role in the onset and progression of AD. Recent studies have reported that amyloid hypothesis-based treatments can be developed as a new approach to overcome the limitations and challenges associated with conventional AD therapeutics. In this review, we will provide a comprehensive view of the challenges in AD therapy and pathophysiology. We also discuss currently known compounds that can inhibit amyloid-β (Aβ) aggregation and their potential role in advancing current AD treatments. We have specifically focused on Aβ aggregation inhibitors including metal chelators, nanostructures, organic molecules, peptides (or peptide mimics), and antibodies. To date, these molecules have been the subject of numerous in vitro and in vivo assays as well as molecular dynamics simulations to explore their mechanism of action and the fundamental structural groups involved in Aβ aggregation. Ultimately, the aim of these studies (and current review) is to achieve a rational design for effective therapeutic agents for AD treatment and diagnostics.
Collapse
Affiliation(s)
- Safura Jokar
- Department of Nuclear Pharmacy, Faculty of Pharmacy, Tehran University of Medical Sciences, P.O. BOX: 14155-6559, Tehran, Iran
| | - Saeedeh Khazaei
- Department of Pharmaceutical Biomaterials , Faculty of Pharmacy, Tehran University of Medical Sciences, P.O. BOX: 14155-6559, Tehran, Iran
| | - Hossein Behnammanesh
- Department of Nuclear Pharmacy, Faculty of Pharmacy, Tehran University of Medical Sciences, P.O. BOX: 14155-6559, Tehran, Iran
| | - Amir Shamloo
- Department of Mechanical Engineering, Sharif University of Technology, P.O. Box: 11365-11155, Tehran, Iran
| | - Mostafa Erfani
- Radiation Application Research School, Nuclear Science and Technology Research Institute (NSTRI), P.O. Box: 14155-1339, Tehran, Iran
| | - Davood Beiki
- Research Center for Nuclear Medicine, Tehran University of Medical Sciences, P.O. BOX: 14155-6559, Tehran, Iran
| | - Omid Bavi
- Department of Mechanical and Aerospace Engineering, Shiraz University of Technology, P.O. Box: 71555-313, Shiraz, Iran.
| |
Collapse
|
11
|
Karimi H, Heydari Dokoohaki M, Zolghadr AR, Ghatee MH. The interactions of an Aβ protofibril with a cholesterol-enriched membrane and involvement of neuroprotective carbazolium-based substances. Phys Chem Chem Phys 2019; 21:11066-11078. [PMID: 31090756 DOI: 10.1039/c9cp00859d] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Recent studies have shown that the aggregation of the amyloid-beta peptide (Aβ) in the brain cell membrane is responsible for the emergence of Alzheimer's disease (AD); the exploration of effective factors involved in the extension of the aggregation process and alternatively the examination of an effective inhibitor via theoretical and experimental tools are among the main research topics in the field of AD treatment. Therefore, in this study, we used all-atom molecular dynamics (MD) simulations to clarify the impact of cell membrane cholesterol on the interaction of Aβ with 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) as a membrane model. Moreover, the effect of the P7C3-S243 molecule on the abovementioned process was investigated. The simulation results disclosed the neuroprotective property of the P7C3-S243 molecule. The MD simulation results indicate that the interaction of cholesterol molecules with the Aβ oligomer is negligible and cannot enhance membrane rupture. However, strong hydrogen bonding between the POPC molecules and the oligomers led to membrane perturbation. According to our modellings, the P7C3-S243 molecular layer can protect the cell membrane by inhibiting the direct interaction between the bilayer and Aβ. In addition, free-energy calculations were conducted to determine the possible penetration of Aβ fibrils into the cholesterol-enriched membrane.
Collapse
Affiliation(s)
- Hedayat Karimi
- Department of Chemistry, Shiraz University, Shiraz, 71946-84795, Iran.
| | | | | | | |
Collapse
|