Campus Units

Biochemistry, Biophysics and Molecular Biology, Chemical and Biological Engineering, Physics and Astronomy, Ames Laboratory

Document Type

Article

Publication Version

Published Version

Publication Date

2012

Journal or Book Title

Biomacromolecules

Volume

13

Issue

1

First Page

98

Last Page

105

DOI

10.1021/bm201278u

Abstract

Highly ordered mineralized structures created by living organisms are often hierarchical in structure with fundamental structural elements at nanometer scales. Proteins have been found responsible for forming many of these structures, but the mechanisms by which these biomineralization proteins function are generally poorly understood. To better understand its role in biomineralization, the magnetotactic bacterial protein, Mms6, which promotes the formation in vitro of superparamagnetic magnetite nanoparticles of uniform size and shape, was studied for its structure and function. Mms6 is shown to have two phases of iron binding: one high affinity and stoichiometric and the other low affinity, high capacity, and cooperative with respect to iron. The protein is amphipathic with a hydrophobic N-terminal domain and hydrophilic C-terminal domain. It self-assembles to form a micelle, with most particles consisting of 20–40 monomers, with the hydrophilic C-termini exposed on the outside. Studies of proteins with mutated C-terminal domains show that the C-terminal domain contributes to the stability of this multisubunit particle and binds iron by a mechanism that is sensitive to the arrangement of carboxyl/hydroxyl groups in this domain.

Comments

Reprinted (adapted) with permission from Biomacromolecules, 2012, 13 (1), pp 98-105, doi:10.1021/bm201278u. Copyright 2011 American Chemical Society.

Copyright Owner

American Chemical Society

Language

en

File Format

application/pdf

2011_Nilsen_SelfAssemblyBiphasic_Data.pdf (315 kB)
Supporting Information and data