1
|
Myers C, Cornwall GA. Host defense amyloids: Biosensors of the immune system? Andrology 2024; 12:973-980. [PMID: 37963844 DOI: 10.1111/andr.13555] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2023] [Revised: 11/01/2023] [Accepted: 11/03/2023] [Indexed: 11/16/2023]
Abstract
There is considerable evidence showing that highly ordered aggregate structures known as amyloids carry out essential biological roles in species ranging from bacteria to humans. Indeed, many antimicrobial peptides/proteins form amyloids to carry out their host defense functions and many amyloids are antimicrobial. The similarity of host defense amyloids from bacterial biofilms to the mammalian epididymal amyloid matrix implies highly conserved host defense structures/functions. With an emphasis on the epididymal amyloid matrix, here we review the common properties of host defense amyloids including unique traits that would allow them to function as powerful biosensors of the immune system.
Collapse
Affiliation(s)
- Caitlyn Myers
- Department of Microbiology and Immunology, Institute of Biomedicine, University of Gothenburg, Gothenburg, Sweden
| | - Gail A Cornwall
- Department of Cell Biology and Biochemistry, Texas Tech University Health Sciences Center, Lubbock, Texas, USA
| |
Collapse
|
2
|
Nutini A. Amyloid oligomers and their membrane toxicity - A perspective study. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2024; 187:9-20. [PMID: 38211711 DOI: 10.1016/j.pbiomolbio.2024.01.002] [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: 10/25/2023] [Revised: 12/21/2023] [Accepted: 01/07/2024] [Indexed: 01/13/2024]
Abstract
Amyloidosis is a condition involving a disparate group of pathologies characterized by the extracellular deposition of insoluble fibrils composed of broken-down proteins. These proteins can accumulate locally, causing peculiar symptoms, or in a widespread way, involving many organs and. causing severe systemic failure. The damage that is created is related not only to the accumulation of. amyloid fibrils but above all to the precursor oligomers of the fibrils that manage to enter the cell in a very particular way. This article analyzes the current state of research related to the entry of these oligomers into the cell membrane and the theories related to their toxicity. The paper proposed here not only aims to review the contents in the literature but also proposes a new vision of amyloid toxicity. that could occur in a multiphase process catalyzed by the cell membrane itself. In this process, the denaturation of the lipid bilayer is followed by the stabilization of a pore through energetically favorable self-assembly processes which are achieved through particular oligomeric structures.
Collapse
Affiliation(s)
- Alessandro Nutini
- Biology and Biomechanics Dept - Centro Studi Attività Motorie, Italy.
| |
Collapse
|
3
|
Jang C, Portugal Barron D, Duo L, Ma C, Seabaugh H, Guo Z. EPR Studies of Aβ42 Oligomers Indicate a Parallel In-Register β-Sheet Structure. ACS Chem Neurosci 2024; 15:86-97. [PMID: 38109787 PMCID: PMC10767747 DOI: 10.1021/acschemneuro.3c00364] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2023] [Revised: 10/31/2023] [Accepted: 11/30/2023] [Indexed: 12/20/2023] Open
Abstract
Aβ aggregation leads to the formation of both insoluble amyloid fibrils and soluble oligomers. Understanding the structures of Aβ oligomers is important for delineating the mechanism of Aβ aggregation and developing effective therapeutics. Here, we use site-directed spin labeling and electron paramagnetic resonance (EPR) spectroscopy to study Aβ42 oligomers prepared by using the protocol of Aβ-derived diffusible ligands. We obtained the EPR spectra of 37 Aβ42 oligomer samples, each spin-labeled at a unique residue position of the Aβ42 sequence. Analysis of the disordered EPR components shows that the N-terminal region has a lower local structural stability. Spin label mobility analysis reveals three structured segments at residues 9-11, 15-22, and 30-40. Intermolecular spin-spin interactions indicate a parallel in-register β-sheet structure, with residues 34-38 forming the structural core. Residues 16-21 also adopt the parallel in-register β-structure, albeit with weaker intermolecular packing. Our results suggest that there is a structural class of Aβ oligomers that adopt fibril-like conformations.
Collapse
Affiliation(s)
- Chelsea Jang
- Department of Neurology,
Brain Research Institute, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California 90095, United States
| | - Diana Portugal Barron
- Department of Neurology,
Brain Research Institute, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California 90095, United States
| | - Lan Duo
- Department of Neurology,
Brain Research Institute, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California 90095, United States
| | - Christine Ma
- Department of Neurology,
Brain Research Institute, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California 90095, United States
| | - Hanna Seabaugh
- Department of Neurology,
Brain Research Institute, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California 90095, United States
| | - Zhefeng Guo
- Department of Neurology,
Brain Research Institute, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California 90095, United States
| |
Collapse
|
4
|
Alvarez AB, Rodríguez PEA, Fidelio GD, Caruso B. Aβ Amyloid Fibers Drastically Alter the Topography and Mechanical Properties of Lipid Membranes. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2023; 39:18923-18934. [PMID: 38079396 DOI: 10.1021/acs.langmuir.3c02831] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2023]
Abstract
Alzheimer's disease (AD) is related to the fibrillation of the Aβ peptides at neuronal membranes, a process that depends on the lipid composition and may impart different physical states to the membrane. In the present work, we study the properties of the Aβ peptide when mixed with a zwitterionic lipid (DMPC), using the Langmuir monolayer technique as an approach to control membrane physical conditions. First, we build on previous characterizations of pure Aβ monolayers and observe that, in addition to high shear, these films present a pronounced compressional hysteresis. When Aβ is assembled with DMPC in a binary film, the resulting membranes become heterogeneous, with a peptide-enriched phase distributed in a network-like pattern, and they exhibit a lateral transition that depends on the Aβ content. At lower peptide proportions, the films segregate into two well-defined phases: one consisting of lipids and another enriched with peptides. The reflectivity of these phases differs from that obtained for pure Aβ films. Thus, the formed fibers effectively cover most of the interface area and remain stable at higher pressures (from 20 to 30 mN m-1 depending on Aβ content) compared to pure peptide films (17 mN m-1). Furthermore, such structures induce a compressional hysteresis in the film, similar to that of pure peptide films (which is nonexistent in the pure lipid monolayer), even at low peptide proportions. We claim that the mechanical properties at the interface are governed by the size of the fibril-like structures. Based on the low molar fractions and surface packing at which these phenomena were observed, we postulate that as a consequence of peptide intermolecular interactions, Aβ may have drastic effects on the molecular arrangement and mechanical properties of a lipid membrane.
Collapse
Affiliation(s)
- Alain Bolaño Alvarez
- Departamento de Química Biológica Ranwel Caputto, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba CP5000, Argentina
- Centro de Investigaciones en Química Biológica de Córdoba, CIQUIBIC, CONICET-Universidad Nacional de Córdoba, Córdoba CP5000, Argentina
- Department of Dermatology and Venerology, Aalborg University Hospital, Aalborg, DK-9000 Denmark
| | | | - Gerardo D Fidelio
- Departamento de Química Biológica Ranwel Caputto, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba CP5000, Argentina
- Centro de Investigaciones en Química Biológica de Córdoba, CIQUIBIC, CONICET-Universidad Nacional de Córdoba, Córdoba CP5000, Argentina
| | - Benjamín Caruso
- Cátedra de Química Biológica, Departamento de Química, Facultad de Ciencias Exactas, Físicas y Naturales, Universidad Nacional de Córdoba, Córdoba CP5000, Argentina
- Instituto de Investigaciones Biológicas y Tecnológicas (IIBYT), CONICET, Universidad Nacional de Córdoba, Córdoba CP5000, Argentina
| |
Collapse
|
5
|
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
|
6
|
Ivankov O, Kondela T, Dushanov EB, Ermakova EV, Murugova TN, Soloviov D, Kuklin AI, Kučerka N. Cholesterol and melatonin regulated membrane fluidity does not affect the membrane breakage triggered by amyloid-beta peptide. Biophys Chem 2023; 298:107023. [PMID: 37148823 DOI: 10.1016/j.bpc.2023.107023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2023] [Revised: 04/12/2023] [Accepted: 04/12/2023] [Indexed: 05/08/2023]
Abstract
We have studied by means of small angle neutron scattering and diffraction, and molecular dynamics simulations the effect of lipid membrane fluidity on the amyloid-beta peptide interactions with the membrane. These interactions have been discovered previously to trigger the reorganization of model membranes between unilamellar vesicles and planar membranes (bicelle-like structures) during the lipid phase transition. The morphology changes were taking place in rigid membranes prepared of fully saturated lipids and were proposed to play a role in the onset of amyloid related disorders. We show in this study that the replacement of fully saturated lipids by more fluid mono-unsaturated lipids eliminates the mentioned morphology changes, most likely due to the absence of phase transition within the temperature range investigated. We have therefore controlled the membrane rigidity also while ensuring the presence of membrane phase transition within the biologically relevant temperatures. It was done by the addition of melatonin and/or cholesterol to the initial membranes made of saturated lipids. Small angle neutron scattering experiments performed over a range of cholesterol and melatonin concentrations show their distinctive effects on the local membrane structure only. The cholesterol for example affects the membrane curvature such that spontaneously formed unilamellar vesicles are of much larger sizes than those formed by the neat lipid membranes or membranes with melatonin added. The temperature dependent experiments, however, reveal no influence on the previously discovered membrane breakage whether cholesterol or melatonin have been added.
Collapse
Affiliation(s)
- O Ivankov
- Frank Laboratory of Neutron Physics, Joint Institute for Nuclear Research, Dubna 141980, Russia.
| | - T Kondela
- Department of Nuclear Physics and Biophysics, Faculty of Mathematics, Physics and Informatics, Comenius University Bratislava, Bratislava 842 48, Slovakia
| | - E B Dushanov
- Laboratory of Radiation Biology, Joint Institute for Nuclear Research, Dubna 141980, Russia
| | - E V Ermakova
- Frank Laboratory of Neutron Physics, Joint Institute for Nuclear Research, Dubna 141980, Russia
| | - T N Murugova
- Frank Laboratory of Neutron Physics, Joint Institute for Nuclear Research, Dubna 141980, Russia
| | - D Soloviov
- European Molecular Biology Laboratory (EMBL), Hamburg Outstation c/o DESY, Notkestrasse 85, 22607 Hamburg, Germany
| | - A I Kuklin
- Frank Laboratory of Neutron Physics, Joint Institute for Nuclear Research, Dubna 141980, Russia; Research Center for Molecular Mechanisms of Aging and Age-related Diseases, Moscow Institute of Physics and Technology, Dolgoprudny 141701, Russia
| | - N Kučerka
- Frank Laboratory of Neutron Physics, Joint Institute for Nuclear Research, Dubna 141980, Russia; Department of Physical Chemistry of Drugs, Faculty of Pharmacy, Comenius University Bratislava, Bratislava SK-832 32, Slovakia.
| |
Collapse
|
7
|
Myers C, Hastert MC, Cornwall GA. Host defense functions of the epididymal amyloid matrix. Mol Hum Reprod 2022; 28:6823549. [PMID: 36367296 PMCID: PMC9709822 DOI: 10.1093/molehr/gaac038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Revised: 10/17/2022] [Indexed: 11/13/2022] Open
Abstract
The epididymal lumen is an immunologically distinct environment. It maintains tolerance for the naturally antigenic spermatozoa to allow their maturation into functional cells while simultaneously defending against pathogens that can ascend the male tract and cause infertility. We previously demonstrated that a nonpathological amyloid matrix that includes several cystatin-related epididymal spermatogenic (CRES) subgroup family members is distributed throughout the mouse epididymal lumen but its function was unknown. Here, we reveal a role for the epididymal amyloid matrix in host defense and demonstrate that the CRES amyloids and CD-1 mouse epididymal amyloid matrix exhibit potent antimicrobial activity against bacterial strains that commonly cause epididymal infections in men. We show the CRES and epididymal amyloids use several defense mechanisms including bacterial trapping, disruption of bacterial membranes and promotion of unique bacterial ghost-like structures. Remarkably, these antimicrobial actions varied depending on the bacterial strain indicating CRES amyloids and the epididymal amyloids elicit strain-specific host defense responses. We also demonstrate that the CRES monomer and immature assemblies of the epididymal amyloid transitioned into advanced structures in the presence of bacteria, suggesting their amyloid-forming/shape-shifting properties allows for a rapid reaction to a pathogen and provides an inherent plasticity in their host defense response. Together, our studies reveal new mechanistic insight into how the male reproductive tract defends against pathogens. Future studies using a mouse model for human epididymitis are needed to establish the epididymal amyloid responses to pathogens in vivo. Broadly, our studies provide an example of why nature has maintained the amyloid fold throughout evolution.
Collapse
Affiliation(s)
- Caitlyn Myers
- Department of Cell Biology and Biochemistry, Texas Tech University Health Sciences Center, Lubbock, TX, USA
| | | | - Gail A Cornwall
- Correspondence address. Department of Cell Biology and Biochemistry, Texas Tech University Health Sciences Center, Lubbock, TX 79430, USA; E-mail:
| |
Collapse
|
8
|
Quiñones-Ruiz T, Rosario-Alomar MF, Shanmugasundaram M, Ali MM, Lednev IK. Spontaneous Refolding of Amyloid Fibrils from One Polymorph to Another Caused by Changes in Environmental Hydrophobicity. Biochemistry 2022; 61:1456-1464. [PMID: 35786852 DOI: 10.1021/acs.biochem.2c00143] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Here, we report a new phenomenon in which lysozyme fibrils formed in a solution of acetic acid spontaneously refold to a different polymorph through a disassembled intermediate upon the removal of acetic acid. The structural changes were revealed and characterized by deep-UV resonance Raman spectroscopy, nonresonance Raman spectroscopy, intrinsic tryptophan fluorescence spectroscopy, and atomic force microscopy. A PPII-like structure with highly solvent-exposed tryptophan residues predominates the intermediate aggregates before refolding to polymorph II fibrils. Furthermore, the disulfide (SS) bonds undergo significant rearrangements upon the removal of acetic acid from the lysozyme fibril environment. The main SS bond conformation changes from gauche-gauche-trans in polymorph I to gauche-gauche-gauche in polymorph II. Changing the hydrophobicity of the fibril environment was concluded to be the decisive factor causing the spontaneous refolding of lysozyme fibrils from one polymorph to another upon the removal of acetic acid. Potential biological implications of the discovered phenomenon are discussed.
Collapse
Affiliation(s)
- Tatiana Quiñones-Ruiz
- Department of Chemistry, University at Albany, SUNY, Albany, New York 12222, United States
| | | | | | - Muhammad M Ali
- Department of Chemistry, University at Albany, SUNY, Albany, New York 12222, United States
| | - Igor K Lednev
- Department of Chemistry, University at Albany, SUNY, Albany, New York 12222, United States
| |
Collapse
|