Open AccessNanoscale Structural Analysis of a Lipid-Driven Aggregation of Insulin
Author(s) -
Stanislav Rizevsky,
Mikhail Matveyenka,
Dmitry Kurouski
Publication year - 2022
Publication title -
the journal of physical chemistry letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.563
H-Index - 203
ISSN - 1948-7185
DOI - 10.1021/acs.jpclett.1c04012
Subject(s) - oligomer , fibril , protein aggregation , chemistry , biophysics , infrared spectroscopy , amyloid (mycology) , atomic force microscopy , spectroscopy , crystallography , nanoscopic scale , materials science , biochemistry , nanotechnology , biology , organic chemistry , inorganic chemistry , physics , quantum mechanics
Abrupt aggregation of misfolded proteins is a hallmark of a large number of severe pathologies, including diabetes types 1 and 2, Alzheimer, and Parkinson diseases. A growing body of evidence suggests that lipids can uniquely change rates of amyloid-associated proteins as well as modify the structure of formed oligomers and fibrils. In this study, we utilize atomic force microscopy infrared (AFM-IR) spectroscopy, also known as nano-IR spectroscopy, to examine the structure of individual insulin oligomers, protofilaments, and fibrils grown in the presence of phospholipids. Our findings show that AFM-IR spectra of insulin oligomers have strong signals of C-H and PO 2 - vibrations, which points on the presence of lipids in the oligomer structure. Furthermore, substantial shifts in lipid vibrations in AFM-IR spectra of the oligomers relative to the corresponding bands of pure lipids have been observed. This points on strong interactions between a lipid and a protein that are developed at the stage of the oligomer formation.