Alzheimer's Disease (AD) is a neurodegenerative disorder proven to be caused by the aggregation of protein tau into fibrils, resulting in neuronal death. The irreparable neuronal damage leads to irreversible symptoms with no cure; therefore, disaggregation of these tau fibrils could be targeted as a therapeutic approach to AD. Here we have developed a fungal natural product library to screen for secondary metabolites that have bioactive potential towards AD tau.
View Article and Find Full Text PDFFibril-type aggregates of tau occur in Alzheimer's disease (AD) and dozens of tauopathies. Fibrils catalyze aggregation by prion-like seeding, which in part underlies disease progression. Seeding by recombinant and brain-derived tau fibrils is measured using biosensor cells that express aggregation-prone tau mutants fused with fluorescent reporter proteins.
View Article and Find Full Text PDFGrp94 is the endoplasmic reticulum paralog of the hsp90 family of chaperones, which have been targeted for therapeutic intervention via their highly conserved ATP binding sites. The design of paralog-selective inhibitors relies on understanding the protein structural elements that drive higher affinity in selective inhibitors. Here, we determined the structures of Grp94 and Hsp90 in complex with the Grp94-selective inhibitor PU-H36, and of Grp94 with the non-selective inhibitor PU-H71.
View Article and Find Full Text PDFAmyloid fibrils of tau are increasingly accepted as a cause of neuronal death and brain atrophy in Alzheimer's disease (AD). Diminishing tau aggregation is a promising strategy in the search for efficacious AD therapeutics. Previously, our laboratory designed a six-residue, nonnatural amino acid inhibitor D-TLKIVW peptide (6-DP), which can prevent tau aggregation in vitro.
View Article and Find Full Text PDFAlzheimer's disease (AD) is a common debilitating neurodegenerative disease with limited treatment options. Amyloid-β (Aβ) and tau fibrils are well-established hallmarks of AD, which can induce oxidative stress, neuronal cell death, and are linked to disease pathology. Here, we describe the effects of Oolonghomobisflavan A (OFA) and Oolonghomobisflavan B (OFB) on tau fibril disaggregation and prionogenic seeding.
View Article and Find Full Text PDFis a serious human pathogen causing life-threatening Aspergillosis in immunocompromised patients. Secondary metabolites (SMs) play an important role in pathogenesis, but the products of many SM biosynthetic gene clusters (BGCs) remain unknown. In this study, we have developed a heterologous expression platform in , using a newly created genetic dereplication strain, to express a previously unknown BGC from and determine its products.
View Article and Find Full Text PDFDespite much effort, antibody therapies for Alzheimer's disease (AD) have shown limited efficacy. Challenges to the rational design of effective antibodies include the difficulty of achieving specific affinity to critical targets, poor expression, and antibody aggregation caused by buried charges and unstructured loops. To overcome these challenges, we grafted previously determined sequences of fibril-capping amyloid inhibitors onto a camel heavy chain antibody scaffold.
View Article and Find Full Text PDFGrp94 is the endoplasmic reticulum paralog of the hsp90 family of chaperones, which have been targeted for therapeutic intervention via their highly conserved ATP binding sites. The design of paralog-selective inhibitors relies on understanding the protein structural elements that drive higher affinity in selective inhibitors. Here, we determined the structures of Grp94 and Hsp90 in complex with the Grp94-selective inhibitor PU-H36, and of Grp94 with the non-selective inhibitor PU-H71.
View Article and Find Full Text PDFThe availability of thin-film lithium niobate on insulator (LNOI) and advances in processing have led to the emergence of fully integrated LiNbO electro-optic devices. Yet to date, LiNbO photonic integrated circuits have mostly been fabricated using non-standard etching techniques and partially etched waveguides, that lack the reproducibility achieved in silicon photonics. Widespread application of thin-film LiNbO requires a reliable solution with precise lithographic control.
View Article and Find Full Text PDFEarly works and recent advances in thin-film lithium niobate (LiNbO) on insulator have enabled low-loss photonic integrated circuits, modulators with improved half-wave voltage, electro-optic frequency combs and on-chip electro-optic devices, with applications ranging from microwave photonics to microwave-to-optical quantum interfaces. Although recent advances have demonstrated tunable integrated lasers based on LiNbO (refs. ), the full potential of this platform to demonstrate frequency-agile, narrow-linewidth integrated lasers has not been achieved.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
February 2023
Alzheimer's disease (AD) is the consequence of neuronal death and brain atrophy associated with the aggregation of protein tau into fibrils. Thus disaggregation of tau fibrils could be a therapeutic approach to AD. The small molecule EGCG, abundant in green tea, has long been known to disaggregate tau and other amyloid fibrils, but EGCG has poor drug-like properties, failing to fully penetrate the brain.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
August 2022
Neurodegenerative diseases are characterized by the pathologic accumulation of aggregated proteins. Known as amyloid, these fibrillar aggregates include proteins such as tau and amyloid-β (Aβ) in Alzheimer's disease (AD) and alpha-synuclein (αSyn) in Parkinson's disease (PD). The development and spread of amyloid fibrils within the brain correlates with disease onset and progression, and inhibiting amyloid formation is a possible route toward therapeutic development.
View Article and Find Full Text PDFProteins including FUS, hnRNPA2, and TDP-43 reversibly aggregate into amyloid-like fibrils through interactions of their low-complexity domains (LCDs). Mutations in LCDs can promote irreversible amyloid aggregation and disease. We introduce a computational approach to identify mutations in LCDs of disease-associated proteins predicted to increase propensity for amyloid aggregation.
View Article and Find Full Text PDFElectrically actuated optomechanical resonators provide a route to quantum-coherent, bidirectional conversion of microwave and optical photons. Such devices could enable optical interconnection of quantum computers based on qubits operating at microwave frequencies. Here we present a platform for microwave-to-optical conversion comprising a photonic crystal cavity made of single-crystal, piezoelectric gallium phosphide integrated on pre-fabricated niobium circuits on an intrinsic silicon substrate.
View Article and Find Full Text PDFDifferent tauopathies are characterized by the isoform-specific composition of the aggregates found in the brain and by structurally distinct tau strains. Although tau oligomers have been implicated as important neurotoxic species, little is known about how the primary structures of the six human tau isoforms affect tau oligomerization because the oligomers are metastable and difficult to analyze. To address this knowledge gap, here, we analyzed the initial oligomers formed by the six tau isoforms in the absence of posttranslational modifications or other manipulations using dot blots probed by an oligomer-specific antibody, native-PAGE/western blots, photo-induced cross-linking of unmodified proteins, mass-spectrometry, and ion-mobility spectroscopy.
View Article and Find Full Text PDFVaccines (Basel)
October 2021
Two of the three COVID-19 vaccines approved in the United States require two doses to reach full efficacy, as do others available elsewhere in the world. The complete series of multidose COVID-19 vaccines offers stronger protection against infection by SARS-CoV-2 compared to single-dose injections with the same vaccines. Achieving perfect community-level adherence is a challenge in any public health campaign, even in non-pandemic times.
View Article and Find Full Text PDFWe present efficient evanescent coupling of single organic molecules to a gallium phosphide (GaP) subwavelength waveguide (nanoguide) decorated with microelectrodes. By monitoring their Stark shifts, we reveal that the coupled molecules experience fluctuating electric fields. We analyze the spectral dynamics of different molecules over a large range of optical powers in the nanoguide to show that these fluctuations are light-induced and local.
View Article and Find Full Text PDFUnlabelled: The SARS-CoV-2 Nucleoprotein (NCAP) functions in RNA packaging during viral replication and assembly. Computational analysis of its amino acid sequence reveals a central low-complexity domain (LCD) having sequence features akin to LCDs in other proteins known to function in liquid-liquid phase separation. Here we show that in the presence of viral RNA, NCAP, and also its LCD segment alone, form amyloid-like fibrils when undergoing liquid-liquid phase separation.
View Article and Find Full Text PDFSoluble oligomers of aggregated tau accompany the accumulation of insoluble amyloid fibrils, a histological hallmark of Alzheimer disease (AD) and two dozen related neurodegenerative diseases. Both oligomers and fibrils seed the spread of Tau pathology, and by virtue of their low molecular weight and relative solubility, oligomers may be particularly pernicious seeds. Here, we report the formation of tau oligomers formed by an ionic liquid (IL15).
View Article and Find Full Text PDFOptomechanical systems in the well-resolved-sideband regime are ideal for studying a myriad of quantum phenomena with mechanical systems, including backaction-evading measurements, mechanical squeezing, and nonclassical states generation. For these experiments, the mechanical oscillator should be prepared in its ground state, i.e.
View Article and Find Full Text PDFBackground: Repeated failure of drug candidates targeting Alzheimer's disease (AD) in clinical trials likely stems from a lack of understanding of the molecular mechanisms underlying AD pathogenesis. Recent research has highlighted synergistic interactions between aggregated amyloid-β (Aβ) and tau proteins in AD, but the molecular details of how these interactions drive AD pathology remain elusive and speculative.
Methods: Here, we test the hypothesis that Aβ potentiates intracellular tau aggregation, and show that oligomeric Aβ specifically exacerbates proteopathic seeding by tau.
Alzheimer's disease (AD) pathology is characterized by plaques of amyloid beta (Aβ) and neurofibrillary tangles of tau. Aβ aggregation is thought to occur at early stages of the disease, and ultimately gives way to the formation of tau tangles which track with cognitive decline in humans. Here, we report the crystal structure of an Aβ core segment determined by MicroED and in it, note characteristics of both fibrillar and oligomeric structure.
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