Ion Mobility Mass Spectrometry Studies of the Inhibition of Alpha Synuclein Amyloid Fibril Formation by ( - )-Epigallocatechin-3-Gallate

2011 ◽  
Vol 64 (1) ◽  
pp. 36 ◽  
Author(s):  
Yanqin Liu ◽  
Lam H. Ho ◽  
John. A. Carver ◽  
Tara L. Pukala
Keyword(s):  
Mass Spectrometry ◽  
Conformational Change ◽  
Ion Mobility ◽  
Amyloid Fibril ◽  
Heterogeneous Systems ◽  
Alpha Synuclein ◽  
Fibril Formation ◽  
Ion Mobility Mass Spectrometry ◽  
Compact Structure ◽  
Amyloid Fibril Formation

Ion mobility-mass spectrometry (IM-MS) is emerging as an important biophysical technique for the structural analysis of proteins and their assemblies, in particular for structurally heterogeneous systems such as those on the protein misfolding and aggregation pathway. Using IM-MS we have monitored amyloid fibril formation of A53T α-synuclein, a mutant synuclein protein associated with Parkinson’s disease, and identified that a conformational change towards a more compact structure occurs during the initial stages of aggregation. Binding of A53T α-synuclein to a flavenoid based amyloid fibril inhibitor, (–)-epigallocatechin-3-gallate, has been observed with a 1:1 stoichiometry. By analysis of ion collision cross-sections, we show epigallocatechin gallate binding prevents protein conformational change, and in turn decreases the formation of fibrillar aggregates.

scholarly journals Acceleration of amyloid fibril formation by multichannel sonochemical reactor

2021 ◽  
Author(s):  
Kentaro Noi ◽  
Kichitaro Nakajima ◽  
Keiichi Yamaguchi ◽  
Masatomo So ◽  
Kensuke Ikenaka ◽  
...  
Keyword(s):  
Amyloid Fibrils ◽  
Amyloid Fibril ◽  
Ultrasonic Transducer ◽  
Reaction System ◽  
Ultrasound Irradiation ◽  
Alpha Synuclein ◽  
Fibril Formation ◽  
Driving Voltage ◽  
Amyloid Fibril Formation ◽  
Beta 2 Microglobulin

Abstract Formation of amyloid fibrils of various amyloidogenic proteins is dramatically enhanced by ultrasound irradiation. For applying this phenomenon to the study of protein aggregation science and diagnosis of neurodegenerative diseases, a multichannel ultrasound irradiation system with individually adjustable ultrasound-irradiation conditions is necessary. Here, we develop a sonochemical reaction system, where an ultrasonic transducer is placed in each well of a 96-well microplate to perform ultrasonic irradiation of sample solutions under various conditions with high reproducibility, and applied it for studying amyloid-fibril formation of amyloid $\beta$, $\alpha$-synuclein, $\beta$2-microglobulin, and lysozyme. The results clearly show that our instrument is superior to conventional shaking method in terms of degree of acceleration and reproducibility of fibril formation reaction. The acceleration degree is controllable by controlling the driving voltage applied to each transducer. We have thus succeeded in developing a useful tool for the study of amyloid fibril formation in various proteins.

scholarly journals Conformational distortion in a fibril-forming oligomer arrests alpha-Synuclein fibrillation and minimizes its toxic effects

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Ritobrita Chakraborty ◽  
Sandip Dey ◽  
Pallabi Sil ◽  
Simanta Sarani Paul ◽  
Dipita Bhattacharyya ◽  
...  
Keyword(s):  
Small Molecule ◽  
Solid State Nmr ◽  
Amyloid Fibril ◽  
Alpha Synuclein ◽  
Fibril Formation ◽  
Stoichiometric Ratio ◽  
Oligomeric State ◽  
C Terminus ◽  
Amyloid Fibril Formation ◽  
Oligomeric Forms

AbstractThe fibrillation pathway of alpha-Synuclein, the causative protein of Parkinson’s disease, encompasses transient, heterogeneous oligomeric forms whose structural understanding and link to toxicity are not yet understood. We report that the addition of the physiologically-available small molecule heme at a sub-stoichiometric ratio to either monomeric or aggregated α-Syn, targets a His50 residue critical for fibril-formation and stabilizes the structurally-heterogeneous populations of aggregates into a minimally-toxic oligomeric state. Cryo-EM 3D reconstruction revealed a ‘mace’-shaped structure of this monodisperse population of oligomers, which is comparable to a solid-state NMR Greek key-like motif (where the core residues are arranged in parallel in-register sheets with a Greek key topology at the C terminus) that forms the fundamental unit/kernel of protofilaments. Further structural analyses suggest that heme binding induces a distortion in the Greek key-like architecture of the mace oligomers, which impairs their further appending into protofilaments and fibrils. Additionally, our study reports a novel mechanism of prevention as well as reclamation of amyloid fibril formation by blocking an inter-protofilament His50 residue using a small molecule.

Sign in / Sign up

Export Citation Format

Share Document