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Iodine staining as a useful probe for distinguishing insulin amyloid polymorphs
- Source :
- Scientific Reports, Vol 10, Iss 1, Pp 1-13 (2020), Scientific Reports
- Publication Year :
- 2020
- Publisher :
- Nature Research, 2020.
-
Abstract
- It is recently suggested that amyloid polymorphism, i.e., structural diversity of amyloid fibrils, has a deep relationship with pathology. However, its prompt recognition is almost halted due to insufficiency of analytical methods for detecting polymorphism of amyloid fibrils sensitively and quickly. Here, we propose that iodine staining, a historically known reaction that was firstly found by Virchow, can be used as a method for distinguishing amyloid polymorphs. When insulin fibrils were prepared and iodine-stained, they exhibited different colors depending on polymorphs. Each of the colors was inherited to daughter fibrils by seeding reactions. The colors were fundamentally represented as a sum of three absorption bands in visible region between 400 and 750 nm, and the bands showed different titration curves against iodine, suggesting that there are three specific iodine binding sites. The analysis of resonance Raman spectra and polarization microscope suggested that several polyiodide ions composed of I3− and/or I5− were formed on the grooves or the edges of β-sheets. It was concluded that the polyiodide species and conformations formed are sensitive to surface structure of amyloid fibrils, and the resultant differences in color will be useful for detecting polymorphism in a wide range of diagnostic samples.
- Subjects :
- 0301 basic medicine
Amyloid
Titration curve
Biophysics
chemistry.chemical_element
lcsh:Medicine
Fibril
Iodine
Biochemistry
Iodine staining
Article
03 medical and health sciences
Polyiodide
chemistry.chemical_compound
symbols.namesake
0302 clinical medicine
Humans
Insulin
Surface structure
lcsh:Science
Multidisciplinary
Staining and Labeling
lcsh:R
Crystallography
030104 developmental biology
chemistry
Polymorphism (materials science)
symbols
lcsh:Q
Protein aggregation
Raman spectroscopy
030217 neurology & neurosurgery
Subjects
Details
- Language :
- English
- ISSN :
- 20452322
- Volume :
- 10
- Issue :
- 1
- Database :
- OpenAIRE
- Journal :
- Scientific Reports
- Accession number :
- edsair.doi.dedup.....fadd711ca9558ead981182db0a45a835