scholarly journals Decoding Conformational Imprint of Convoluted Molecular Interactions Between Prenylflavonoids and Aggregated Amyloid-Beta42 Peptide Causing Alzheimer’s Disease

2021 ◽  
Vol 9 ◽  
Author(s):  
E. Srinivasan ◽  
G. Chandrasekhar ◽  
P. Chandrasekar ◽  
K. Anbarasu ◽  
AS Vickram ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Amyloid Beta ◽  
Protein Misfolding ◽  
Amyloid Fibrils ◽  
Senile Plaques ◽  
Docking Studies ◽  
Dynamics Simulation ◽  
Fibril Structure ◽  
Potential Inhibitors

Protein misfolding occurs due to the loss of native protein structure and adopts an abnormal structure, wherein the misfolded proteins accumulate and form aggregates, which result in the formation of amyloid fibrils that are associated with neurodegenerative diseases. Amyloid beta (Aβ42) aggregation or amyloidosis is contemplated as a unique hallmark characteristic of Alzheimer’s disease (AD). Due to aberrant accrual and aggregation of Aβ42 in extracellular space, the formation of senile plaques is found in AD patients. These senile plaques occur usually in the cognitive and memory region of the brain, enfeebles neurodegeneration, hinders the signaling between synapse, and disrupts neuronal functioning. In recent years, herbal compounds are identified and characterized for their potential as Aβ42 inhibitors. Thus, understanding their structure and molecular mechanics can provide an incredible finding in AD therapeutics. To describe the structure-based molecular studies in the rational designing of drugs against amyloid fibrils, we examined various herbal compounds that belong to prenylflavonoids. The present study characterizes the trends we identified at molecular docking studies and dynamics simulation where we observed stronger binding orientation of bavachalcone, bavachin, and neobavaisoflavone with the amyloid-beta (Aβ42) fibril structure. Hence, we could postulate that these herbal compounds could be potential inhibitors of Aβ42 fibrils; these anti-aggregation agents need to be considered in treating AD.

Emerging Proof of Protein Misfolding and Interactions in Multifactorial Alzheimer's Disease

2020 ◽  
Vol 20 (26) ◽  
pp. 2380-2390 ◽  
Author(s):  
Md. Sahab Uddin ◽  
Abdullah Al Mamun ◽  
Md. Ataur Rahman ◽  
Tapan Behl ◽  
Asma Perveen ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Protein Misfolding ◽  
Neurodegenerative Disorder ◽  
Senile Plaques ◽  
Neuronal Cell Death ◽  
Neuronal Cell ◽  
Misfolded Proteins ◽  
Cell Organelles ◽  
The Impact

Objective: Alzheimer's disease (AD) is a devastating neurodegenerative disorder, characterized by the extracellular accumulations of amyloid beta (Aβ) as senile plaques and intracellular aggregations of tau in the form of neurofibrillary tangles (NFTs) in specific brain regions. In this review, we focus on the interaction of Aβ and tau with cytosolic proteins and several cell organelles as well as associated neurotoxicity in AD. Summary: Misfolded proteins present in cells accompanied by correctly folded, intermediately folded, as well as unfolded species. Misfolded proteins can be degraded or refolded properly with the aid of chaperone proteins, which are playing a pivotal role in protein folding, trafficking as well as intermediate stabilization in healthy cells. The continuous aggregation of misfolded proteins in the absence of their proper clearance could result in amyloid disease including AD. The neuropathological changes of AD brain include the atypical cellular accumulation of misfolded proteins as well as the loss of neurons and synapses in the cerebral cortex and certain subcortical regions. The mechanism of neurodegeneration in AD that leads to severe neuronal cell death and memory dysfunctions is not completely understood until now. Conclusion: Examining the impact, as well as the consequences of protein misfolding, could help to uncover the molecular etiologies behind the complicated AD pathogenesis.

Modulation of ϐ-amyloid production and fibrillization

2001 ◽  
Vol 67 ◽  
pp. 1-14 ◽  
Author(s):  
David Allsop ◽  
Lance J. Twyman ◽  
Yvonne Davies ◽  
Susan Moore ◽  
Amber York ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Amyloid Fibrils ◽  
Senile Plaques ◽  
Neurofibrillary Tangle ◽  
Neuronal Loss ◽  
Brain Parenchyma ◽  
Amino Acid Peptide ◽  
Close Relatives ◽  
The Brain

Alzheimer's disease (AD) is the most common cause of dementia in old age and presently affects an estimated 4 million people in the U.S.A. and 0.75 million people in the U.K. It is a relentless, degenerative brain disease, characterized by progressive cognitive impairment. In the final stages of the disease, patients are often bedridden, doubly incontinent and unable to speak or to recognize close relatives. Pathological changes of Alzheimer's disease include extensive neuronal loss and the presence of numerous neurofibrillary tangles and senile plaques in the brain. The senile plaques contain amyloid fibrils derived from a 39-43-amino-acid peptide referred to as ϐ-amyloid or Aϐ. The basic theory of the so-called 'amyloid hypothesis' is that the deposition of aggregated forms of Aϐ in the brain parenchyma triggers a pathological cascade of events that leads to neurofibrillary tangle formation, neuronal loss and the associated dementia [1]. Here we discuss progress towards the identification of inhibitors of Aϐ production and fibrillization.

Ajmalicine and its Analogues Against AChE and BuChE for the Management of Alzheimer’s Disease: An In-silico Study

2020 ◽  
Vol 26 (37) ◽  
pp. 4808-4814
Author(s):  
Shu Liu ◽  
Minyan Dang ◽  
Yan Lei ◽  
Syed S. Ahmad ◽  
Mohammad Khalid ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Binding Energy ◽  
3D Structure ◽  
Docking Studies ◽  
Kcal Mole ◽  
In Silico Study ◽  
Phytochemical Compounds ◽  
Inhibitory Potential ◽  
Potential Inhibitors

Background: Alzheimer's disease (AD) is the most well-known reason for disability in persons aged greater than 65 years worldwide. AD influences the part of the brain that controls cognitive and non-cognitive functions. Objective: The study focuses on the screening of natural compounds for the inhibition of AChE and BuChE using a computational methodology. Methods: We performed a docking-based virtual screening utilizing the 3D structure of AChE and BuChE to search for potential inhibitors for AD. In this work, a screened inhibitor Ajmalicine similarity search was carried out against a natural products database (Super Natural II). Lipinski rule of five was carried out and docking studies were performed between ligands and enzyme using ‘Autodock4.2’. Results: wo phytochemical compounds SN00288228 and SN00226692 were predicted for the inhibition of AChE and BuChE, respectively. The docking results revealed Ajmalicine, a prominent natural alkaloid, showing promising inhibitory potential against AChE and BuChE with the binding energy of -9.02 and -8.89 kcal/mole, respectively. However, SN00288228- AChE, and SN00226692-BuChE were found to have binding energy -9.88 and -9.54 kcal/mole, respectively. These selected phytochemical compounds showed better interactions in comparison to Ajmalicine with the target molecule. Conclusion: The current study verifies that SN00288228 and SN00226692 are more capable inhibitors of human AChE and BuChE as compared to Ajmalicine with reference to ΔG values.

Therapeutic Strategies Targeting Amyloid-β in Alzheimer’s Disease

2019 ◽  
Vol 16 (5) ◽  
pp. 418-452 ◽  
Author(s):  
Lídia Pinheiro ◽  
Célia Faustino
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Protein Misfolding ◽  
Neurodegenerative Disorder ◽  
Neuronal Degeneration ◽  
Senile Plaques ◽  
Symptomatic Relief ◽  
Amyloid Β ◽  
Therapeutic Strategies ◽  
App Processing

Alzheimer’s disease (AD) is a neurodegenerative disorder linked to protein misfolding and aggregation. AD is pathologically characterized by senile plaques formed by extracellular Amyloid-β (Aβ) peptide and Intracellular Neurofibrillary Tangles (NFT) formed by hyperphosphorylated tau protein. Extensive synaptic loss and neuronal degeneration are responsible for memory impairment, cognitive decline and behavioral dysfunctions typical of AD. Amyloidosis has been implicated in the depression of acetylcholine synthesis and release, overactivation of N-methyl-D-aspartate (NMDA) receptors and increased intracellular calcium levels that result in excitotoxic neuronal degeneration. Current drugs used in AD treatment are either cholinesterase inhibitors or NMDA receptor antagonists; however, they provide only symptomatic relief and do not alter the progression of the disease. Aβ is the product of Amyloid Precursor Protein (APP) processing after successive cleavage by β- and γ-secretases while APP proteolysis by α-secretase results in non-amyloidogenic products. According to the amyloid cascade hypothesis, Aβ dyshomeostasis results in the accumulation and aggregation of Aβ into soluble oligomers and insoluble fibrils. The former are synaptotoxic and can induce tau hyperphosphorylation while the latter deposit in senile plaques and elicit proinflammatory responses, contributing to oxidative stress, neuronal degeneration and neuroinflammation. Aβ-protein-targeted therapeutic strategies are thus a promising disease-modifying approach for the treatment and prevention of AD. This review summarizes recent findings on Aβ-protein targeted AD drugs, including β-secretase inhibitors, γ-secretase inhibitors and modulators, α-secretase activators, direct inhibitors of Aβ aggregation and immunotherapy targeting Aβ, focusing mainly on those currently under clinical trials.

Molecular modeling and docking calculations of 4-acyloxy-biphenyl-4′-N-butylcarbamates as potential inhibitors of human butyrylcholinesterase

2016 ◽  
Vol 94 (1) ◽  
pp. 72-77 ◽  
Author(s):  
Yu-Fang Shen ◽  
Gan-Hong Chen ◽  
Shu-Hsien Lin ◽  
Gialih Lin
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Binding Energy ◽  
Linear Correlation ◽  
Kinetic Studies ◽  
Docking Studies ◽  
Binding Energies ◽  
Binding Modes ◽  
Docking Calculations ◽  
Potential Inhibitors

The kinetic studies and drug designs of butyrylcholinesterase play an important role in the development of Alzheimer’s disease therapeutics. In this research, automated docking studies were performed to provide useful insights into butyrylcholinesterase inhibition binding modes with designed 4-acyloxy-biphenyl-4′-N-butylcarbamates (compounds 1–8). Moreover, several significant linear correlations between experimental and calculated docking results are observed. Among compounds 1–7, compound 3, which exhibits the strongest hydrophobicity and has four carbonyl hydrogen bindings, shows the highest binding affinity (Ki = 1.4 μmol/L) with a binding energy of −7.99 kcal/mol. The observed linear correlation of experimental and calculated inhibition constants (Ki) indicates that the molecular docking results are reliable. Moreover, a good linear correlation is observed between calculated binding energies and experimental pKi. The experimental Hansch hydrophobicity constants (π values) are also correlated with the docked binding energy. This study reveals important correlations between butyrylcholinesterase experimental and docking results that contribute to the kinetic based identification of antagonists for the treatment of Alzheimer’s disease. Furthermore, these docked models provide important insights into a potential series of 4,4′-biphenol-based inhibitors of butyrylcholinesterase.

scholarly journals The genetic landscape for amyloid beta fibril nucleation accurately discriminates familial Alzheimer’s disease mutations

2020 ◽  
Author(s):  
Mireia Seuma ◽  
Andre Faure ◽  
Marta Badia ◽  
Ben Lehner ◽  
Benedetta Bolognesi
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Amyloid Beta ◽  
Amyloid Fibrils ◽  
List Type ◽  
Familial Alzheimer’S Disease ◽  
Disease Mutations ◽  
Genetic Landscape ◽  
Familial Alzheimer's Disease

AbstractAmyloid fibrils are associated with many human diseases but how mutations alter the propensity of proteins to form fibrils has not been comprehensively investigated and is not well understood. Alzheimer’s Disease (AD) is the most common form of dementia with amyloid plaques of the amyloid beta (Aß) peptide a pathological hallmark of the disease. Mutations in Aß also cause familial forms of AD (fAD). Here we use deep mutational scanning to quantify the effects of >14,000 mutations on the aggregation of Aß. The resulting genetic landscape reveals fundamental mechanistic insights into fibril nucleation, including the importance of charge and gatekeeper residues in the disordered region outside of the amyloid core in preventing nucleation. Strikingly, unlike computational predictors and previous measurements, the in vivo nucleation scores accurately identify all known dominant fAD mutations, validating this simple cell-based assay as highly relevant to the human genetic disease and suggesting accelerated fibril nucleation is the ultimate cause of fAD. Our results provide the first comprehensive map of how mutations alter the formation of any amyloid fibril and a validated resource for the interpretation of genetic variation in Aß.HighlightsFirst comprehensive map of how mutations alter the propensity of a protein to form amyloid fibrils.Charge and gatekeeper residues in the disordered N-terminus of amyloid beta prevent fibril nucleation.Rates of nucleation in a cell-based assay accurately identify the mutations that cause dominant familial Alzheimer’s disease.The combination of deep mutational scanning and human genetics provides a general strategy to quantify the disease-relevance of in vitro and in vivo assays.

Exploiting amyloid: how and why bacteria use cross-β fibrils

2012 ◽  
Vol 40 (4) ◽  
pp. 728-734 ◽  
Author(s):  
Elizabeth B. Sawyer ◽  
Dennis Claessen ◽  
Sally L. Gras ◽  
Sarah Perrett
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Protein Misfolding ◽  
Amyloid Fibrils ◽  
Streptomyces Coelicolor ◽  
Present Review ◽  
Protein Fibrils ◽  
Recent Developments ◽  
Misfolding Diseases

Many bacteria produce protein fibrils that are structurally analogous to those associated with protein misfolding diseases such as Alzheimer's disease. However, unlike fibrils associated with disease, bacterial amyloids have beneficial functions including conferring stability to biofilms, regulating development or imparting virulence. In the present review, we consider what makes amyloid fibrils so suitable for these roles and discuss recent developments in the study of bacterial amyloids, in particular the chaplins from Streptomyces coelicolor. We also consider the broader impact of the study of bacterial amyloids on our understanding of infection and disease and on developments in nanotechnology.

scholarly journals Atomistic investigation of an Iowa Amyloid-β trimer in aqueous solution

RSC Advances ◽  
2018 ◽  
Vol 8 (73) ◽  
pp. 41705-41712 ◽  
Author(s):  
Son Tung Ngo ◽  
Huong Thi Thu Phung ◽  
Khanh B. Vu ◽  
Van V. Vu
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Aqueous Solution ◽  
Amyloid Beta ◽  
Amyloid Β ◽  
Amyloid Beta Peptide ◽  
Disease Pathogenesis ◽  
Beta Peptide ◽  
Potential Inhibitors

Amyloid beta peptide oligomers are believed to play key roles in Alzheimer's disease pathogenesis. D23N mutation significantly changes their structure and how they bind potential inhibitors.

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