Date of Graduation

Summer 2017

Degree

Master of Science in Materials Science

Department

Physics, Astronomy, and Materials Science

Committee Chair

Maria Stepanova

Keywords

ferritin, iron ion transit, molecular dynamics, Raman spectroscopy, nano-biological conjugation

Subject Categories

Biology and Biomimetic Materials | Biomaterials | Materials Science and Engineering

Abstract

Ferritin is an iron-storage globular protein with an ability to uptake, mineralize and release iron ions in a controllable manner. The globular hollow shell allows storage of mineralized iron, with several channels responsible for the transit of ions into the shell and out of it. Understanding of the detailed molecular functioning of ferritin is required for rational design of biomimetic conjugate nano-biosystems containing ferritin-like constituents. In this work, ferritin was investigated both numerically by all-atom molecular dynamics (MD) simulations, and experimentally by Raman spectroscopy. Molecular dynamic simulations of a model system comprising iron ions (Fe2+) and a ferritin trimer expressing a three-fold channel responsible for the ion transport, have revealed a quick entering of ions in the channel. The transit of iron ions through the channel was thoroughly investigated. The transit was found to be driven by both electrostatic charge of ferritin, and interaction between the ions. Exit (expulsion) of an iron ion from the channel was observed at a condition that at least one more ion is present in the channel. Raman characterization of an iron-loaded ferritin solution revealed pronounced bands attributable to iron, as expected. However, Raman spectra of apo-ferritin, which does not contain an iron mineral, also exhibited similar bands. Based on the results of MD simulations, it was hypothesized that apo-ferritin retains iron ions in its three-fold channels, and these ions may produce the observed Raman bands. The study of molecular mechanisms involved in the iron ion transit elucidates the pathways of iron uptake and release in ferritin.

Copyright

© Shah Alam Limon

Available for download on Saturday, August 31, 2019

Open Access

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