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Title: Morphological transformations in the magnetite biomineralizing protein Mms6 in iron solutions: A small-angle x-ray scattering study

Abstract

In this study, magnetotactic bacteria that produce magnetic nanocrystals of uniform size and well-defined morphologies have inspired the use of biomineralization protein Mms6 to promote formation of uniform magnetic nanocrystals in vitro. Small angle X-ray scattering (SAXS) studies in physiological solutions reveal that Mms6 forms compact globular three-dimensional (3D) micelles (approximately 10 nm in diameter) that are, to a large extent, independent of concentration. In the presence of iron ions in the solutions, the general micellar morphology is preserved, however, with associations among micelles that are induced by iron ions. Compared with Mms6, the m2Mms6 mutant (with the sequence of hydroxyl/carboxyl containing residues in the C-terminal domain shuffled) exhibits subtle morphological changes in the presence of iron ions in solutions. The analysis of the SAXS data is consistent with a hierarchical core–corona micellar structure similar to that found in amphiphilic polymers. The addition of ferric and ferrous iron ions to the protein solution induces morphological changes in the micellar structure by transforming the 3D micelles into objects of reduced dimensionality of 2, with fractal-like characteristics (including Gaussian-chain-like) or, alternatively, platelet-like structures.

Authors:
 [1];  [1];  [1];  [2];  [1];  [1];  [1];  [1];  [1]
  1. Ames Lab., Ames, IA (United States); Iowa State Univ., Ames, IA (United States)
  2. Ames Lab., Ames, IA (United States)
Publication Date:
Research Org.:
Ames Laboratory (AMES), Ames, IA (United States)
Sponsoring Org.:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
OSTI Identifier:
1227436
Report Number(s):
IS-J-8577
Journal ID: ISSN 0743-7463
Grant/Contract Number:  
AC02-07CH11358
Resource Type:
Journal Article: Accepted Manuscript
Journal Name:
Langmuir
Additional Journal Information:
Journal Volume: 31; Journal Issue: 9; Journal ID: ISSN 0743-7463
Publisher:
American Chemical Society
Country of Publication:
United States
Language:
English
Subject:
77 NANOSCIENCE AND NANOTECHNOLOGY

Citation Formats

Zhang, Honghu, Liu, Xunpei, Feng, Shuren, Wang, Wenjie, Schmidt-Rohr, Klaus, Akinc, Mufit, Nilsen-Hamilton, Marit, Vaknin, David, and Mallapragada, Surya. Morphological transformations in the magnetite biomineralizing protein Mms6 in iron solutions: A small-angle x-ray scattering study. United States: N. p., 2015. Web. doi:10.1021/la5044377.
Zhang, Honghu, Liu, Xunpei, Feng, Shuren, Wang, Wenjie, Schmidt-Rohr, Klaus, Akinc, Mufit, Nilsen-Hamilton, Marit, Vaknin, David, & Mallapragada, Surya. Morphological transformations in the magnetite biomineralizing protein Mms6 in iron solutions: A small-angle x-ray scattering study. United States. doi:10.1021/la5044377.
Zhang, Honghu, Liu, Xunpei, Feng, Shuren, Wang, Wenjie, Schmidt-Rohr, Klaus, Akinc, Mufit, Nilsen-Hamilton, Marit, Vaknin, David, and Mallapragada, Surya. Tue . "Morphological transformations in the magnetite biomineralizing protein Mms6 in iron solutions: A small-angle x-ray scattering study". United States. doi:10.1021/la5044377. https://www.osti.gov/servlets/purl/1227436.
@article{osti_1227436,
title = {Morphological transformations in the magnetite biomineralizing protein Mms6 in iron solutions: A small-angle x-ray scattering study},
author = {Zhang, Honghu and Liu, Xunpei and Feng, Shuren and Wang, Wenjie and Schmidt-Rohr, Klaus and Akinc, Mufit and Nilsen-Hamilton, Marit and Vaknin, David and Mallapragada, Surya},
abstractNote = {In this study, magnetotactic bacteria that produce magnetic nanocrystals of uniform size and well-defined morphologies have inspired the use of biomineralization protein Mms6 to promote formation of uniform magnetic nanocrystals in vitro. Small angle X-ray scattering (SAXS) studies in physiological solutions reveal that Mms6 forms compact globular three-dimensional (3D) micelles (approximately 10 nm in diameter) that are, to a large extent, independent of concentration. In the presence of iron ions in the solutions, the general micellar morphology is preserved, however, with associations among micelles that are induced by iron ions. Compared with Mms6, the m2Mms6 mutant (with the sequence of hydroxyl/carboxyl containing residues in the C-terminal domain shuffled) exhibits subtle morphological changes in the presence of iron ions in solutions. The analysis of the SAXS data is consistent with a hierarchical core–corona micellar structure similar to that found in amphiphilic polymers. The addition of ferric and ferrous iron ions to the protein solution induces morphological changes in the micellar structure by transforming the 3D micelles into objects of reduced dimensionality of 2, with fractal-like characteristics (including Gaussian-chain-like) or, alternatively, platelet-like structures.},
doi = {10.1021/la5044377},
journal = {Langmuir},
number = 9,
volume = 31,
place = {United States},
year = {Tue Feb 10 00:00:00 EST 2015},
month = {Tue Feb 10 00:00:00 EST 2015}
}

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Cited by: 16 works
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