Structural Insight of Amyloidogenic Intermediates of Human Insulin.

ABSTRACT: Engaging Raman spectroscopy as a primary tool, we investigated the early events of insulin fibrilization and determined the structural content present in oligomer and protofibrils that are formed as intermediates in the fibril formation pathway. Insulin oligomer, as obtained upon incubation of zinc-free insulin at 60 °C, was mostly spherical in shape, with a diameter of 3-5 nm. Longer incubation produced "necklace"-like beaded protofibrillar assembly species. These intermediates eventually transformed into 5-8 nm thick fibers with smooth surface texture. A broad amide I band in the Raman spectrum of insulin monomer appeared at 1659 cm^-1, with a shoulder band at 1676 cm^-1. This signature suggested the presence of major helical and extended secondary structure of the pr

SUBMITTER: Dolui S 

PROVIDER: S-EPMC6045404 | biostudies-literature | 2018 Feb

REPOSITORIES: biostudies-literature