Characterization of amyloidogenic intermediate states is of central importance in understanding the molecular mechanism of amyloid formation. In this study, we utilized CD and NMR spectroscopy to investigate secondary structure of the monomeric amyloidogenic intermediate of a beta-structured SH3 domain, which was induced by trifluoroethanol (TFE). The combined biophysical studies showed that the native state SH3 domain is gradually converted to the amyloidogenic intermediate state at TFE concentrations of 20-26% (v/v) and the aggregation-prone state contains substantial amount of the beta-sheet conformation ( approximately 30%) with disordered (54%) and some helical characters (16%). Under weaker amyloidogenic conditions of higher TFE concentrations (>40%), the beta-sheet structures were gradually changed to helical conformations and the relative content of the helical and beta-sheet conformations was highly correlated with the aggregation propensity of the SH3 domain. This indicates that the beta-sheet characters of the amyloidogenic states may be critical to the effective amyloid formation.
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http://dx.doi.org/10.1016/j.bpc.2010.06.007 | DOI Listing |
J Phys Chem B
December 2024
Physical and Materials Chemistry Division, CSIR-National Chemical Laboratory, Dr. Homi Bhabha Road, Pune 411008, India.
Changes in water-protein interactions are crucial for proteins to achieve functional and nonfunctional conformations during structural transitions by modulating local stability. Amyloid-like protein aggregates in deteriorating neurons are hallmarks of neurodegenerative disorders. These aggregates form through significant structural changes, transitioning from functional native conformations to supramolecular cross-β-sheet structures via misfolded and oligomeric intermediates in a multistep process.
View Article and Find Full Text PDFJAMA Cardiol
December 2024
Department of Clinical Biochemistry, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark.
Importance: Transthyretin tetramer destabilization is the rate-limiting step in the development of transthyretin cardiac amyloidosis, an underrecognized contributor to mortality in older adults.
Objective: To test the hypothesis that transthyretin tetramer destabilization is associated with all-cause and cardiovascular mortality in the general population.
Design, Setting, And Participants: In this cohort study including individuals aged 20 to 80 years, genetic data were analyzed from 2 similar prospective studies of the Danish general population, the Copenhagen City Heart Study (CCHS) and the Copenhagen General Population Study (CGPS).
Int J Biol Macromol
December 2024
Laboratory of Structural Dynamics, Stability and Folding of Proteins, Institute of Cytology of the Russian Academy of Sciences, 4 Tikhoretsky ave., 194064 St. Petersburg, Russia. Electronic address:
The transition of β-barrel proteins from a soluble to an amyloid form is biologically significant in some cases but may lead to functional activity loss. In particular, odorant-binding proteins' (OBPs) fibrils are unable to bind odorant molecules potentially contributing to olfactory dysfunction. As shown previously, OBPs' fibrillogenesis is initiated by uncoupling of protein C-terminal fragment from the β-barrel and exposing amyloidogenic sites.
View Article and Find Full Text PDFJACC Basic Transl Sci
September 2024
National Amyloidosis Centre, University College London, London, United Kingdom.
Mol Divers
October 2024
Department of Chemical Engineering, Indian Institute of Technology Guwahati, Guwahati, 781039, Assam, India.
Alzheimer's disease (AD) is the most common form of dementia and the fifth leading cause of death globally. Aggregation and deposition of neurotoxic Aβ fibrils in the neural tissues of the brain is a key hallmark in AD pathogenesis. Destabilisation studies of the amyloid-peptide by various natural molecules are highly relevant due to their neuroprotective and therapeutic potential for AD.
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