Control of the morphology and size of magnetite particles with peptides mimicking the Mms6 protein from magnetotactic bacteria

Arakaki, Atsushi; Masuda, Fukashi; Amemiya, Yosuke; Tanaka, Tsuyoshi; Matsunaga, Tadashi

doi:10.1016/j.jcis.2009.11.043

Cited by 124 publications

(142 citation statements)

References 31 publications

(42 reference statements)

Supporting

Mentioning

131

Contrasting

Unclassified

Order By: Relevance

“…Magnetite crystals consisting of (1 0 0) and (1 1 1) faces were obtained in the presence of Mms6 protein, while the crystals consisting of mainly the (1 1 1) face were formed in the absence of this protein (17). A similar observation was reported in an investigation using synthetic peptides mimicking the characteristic amino acids of Mms6 protein (18).…”

supporting

confidence: 81%

“…These proteins include Mms5, Mms6, Mms7/MamD, and Mms13/MamC (16). Among these proteins, Mms6 possesses a hydrophobic Leucine-Glycine repeat motif at the N terminus and the hydrophilic region of the C terminus, which is thought to interact with magnetite crystal and iron ions (17)(18). The recombinant Mms6 protein has been shown to mediate the formation of uniform magnetite crystals during in vitro chemical synthesis (16).…”

mentioning

confidence: 99%

See 1 more Smart Citation

MMS6 Protein Regulates Crystal Morphology during Nano-sized Magnetite Biomineralization in Vivo

Tanaka

Mazuyama

Arakaki

et al. 2011

Journal of Biological Chemistry

Self Cite

161

189

View full text Add to dashboard Cite

Biomineralization, the process by which minerals are deposited by organisms, has attracted considerable attention because this mechanism has shown great potential to inspire bottom-up material syntheses. To understand the mechanism for morphological regulation that occurs during biomineralization, many regulatory proteins have been isolated from various biominerals. However, the molecular mechanisms that regulate the morphology of biominerals remain unclear because there is a lack of in vivo evidence. Magnetotactic bacteria synthesize intracellular magnetosomes that comprise membraneenveloped single crystalline magnetite (Fe 3 O 4 ). These nanosized magnetite crystals (<100 nm) are bacterial species dependent in shape and size. Mms6 is a protein that is tightly associated with magnetite crystals. Based on in vitro experiments, this protein was first implicated in morphological regulation during nano-sized magnetite biomineralization. In this study, we analyzed the mms6 gene deletion mutant (⌬mms6) of Magnetospirillum magneticum (M. magneticum) AMB-1. Surprisingly, the ⌬mms6 strain was found to synthesize the smaller magnetite crystals with uncommon crystal faces, while the wild-type and complementation strains synthesized highly ordered cubo-octahedral crystals. Furthermore, deletion of mms6 gene led to drastic changes in the profiles of the proteins tightly bound to magnetite crystals. It was found that Mms6 plays a role in the in vivo regulation of the crystal structure to impart the cubo-octahedral morphology to the crystals during biomineralization in magnetotactic bacteria. Magnetotactic bacteria synthesize magnetite crystals under ambient conditions via a highly controlled morphological regulation system that uses biological molecules.

show abstract

supporting

confidence: 81%

mentioning

confidence: 99%

MMS6 Protein Regulates Crystal Morphology during Nano-sized Magnetite Biomineralization in Vivo

Tanaka

Mazuyama

Arakaki

et al. 2011

Journal of Biological Chemistry

Self Cite

161

189

View full text Add to dashboard Cite

show abstract

“…RS-1 (RS-1) is an ideal system to investigate the range of magnetite biomineralization mechanisms used by MB, because it is the only axenically cultured magnetotactic bacterium outside of the α-Proteobacteria and forms crystals that are irregular or bullet-shaped (11)(12)(13). Recently, the genome of RS-1 was sequenced and found to contain a region resembling a highly edited version of the MAI (14,15). Many of the genes in the RS-1 MAI are highly divergent from their homologs in the magnetotactic α-Proteobacteria, and a number of the genes thought to be important for crystal growth and morphology are absent, raising the question of whether RS-1 has evolved a divergent mechanism of magnetite biomineralization.…”

mentioning

confidence: 99%

Desulfovibrio magneticus RS-1 contains an iron- and phosphorus-rich organelle distinct from its bullet-shaped magnetosomes

Byrne

Ball²,

Guerquin‐Kern³

et al. 2010

Proc. Natl. Acad. Sci. U.S.A.

107

View full text Add to dashboard Cite

Intracellular magnetite crystal formation by magnetotactic bacteria has emerged as a powerful model for investigating the cellular and molecular mechanisms of biomineralization, a process common to all branches of life. Although magnetotactic bacteria are phylogenetically diverse and their crystals morphologically diverse, studies to date have focused on a few, closely related species with similar crystal habits. Here, we investigate the process of magnetite biomineralization in Desulfovibrio magneticus sp. RS-1, the only reported species of cultured magnetotactic bacteria that is outside of the α-Proteobacteria and that forms bulletshaped crystals. Using a variety of high-resolution imaging and analytical tools, we show that RS-1 cells form amorphous, noncrystalline granules containing iron and phosphorus before forming magnetite crystals. Using NanoSIMS (dynamic secondary ion mass spectroscopy), we show that the iron-phosphorus granules and the magnetite crystals are likely formed through separate cellular processes. Analysis of the cellular ultrastructure of RS-1 using cryo-ultramicrotomy, cryo-electron tomography, and tomography of ultrathin sections reveals that the magnetite crystals are not surrounded by membranes but that the iron-phosphorus granules are surrounded by membranous compartments. The varied cellular paths for the formation of these two minerals lead us to suggest that the iron-phosphorus granules constitute a distinct bacterial organelle.bacterial organelle | biomineralization | magnetotactic bacteria | dynamic secondary ion mass spectroscopy | magnetite B iomineralization, the biologically controlled transformation of inorganic compounds into highly-ordered structures, is performed by organisms in all branches of life, from bacteria to humans. Because biogenic minerals often have superior properties to their chemically synthesized counterparts, understanding biomineralization is important to fields as diverse as inorganic materials synthesis and medicine (1, 2). Among the numerous organisms capable of biomineralization, magnetotactic bacteria (MB), a group of microbes that form intracellular chains of magnetic minerals including magnetite and greigite, have become powerful models for studying biomineralization because of their relatively fast growth rate and genetic tractability (3).Investigation of the cellular ultrastructure of MB has shown that the magnetite crystals are formed within membranous intracellular compartments called magnetosomes, which are present before the formation of magnetite (4, 5). Other studies have shown that when magnetite formation is induced by decreasing oxygen levels or adding iron to iron-deprived cells, multiple crystals in the chain nucleate simultaneously (5, 6). These insights into the kinetics of magnetite biomineralization have been complemented by molecular studies. A genomic island called the magnetosome island (MAI) has been found in all MB studied to date. Loss of the MAI results in an absence of magnetosome membranes and magnetite crystals, and gene...

show abstract

“…[288] Mms6 is an amphiphilic protein which mainly consists of an N-terminal hydrophobic region responsible for the self-aggregation of the protein, [289] and C-terminal hydrophilic region containing multiples of acidic amino acids which is suggested to act as an iron-binding site. [290] It was suggested by Arakaki that Mms6 protein is a dominant protein and regulates the biomineralization and controls the morphology of uniform magnetosomes by acting as a template to guide the shape and size of the magnetite crystals formed. [291] Surprisingly, the combination of these biomineral-associating proteins and their mimic peptides has enabled the biomimicking of inorganic materials, especially magnetite nanoparticles.…”

Section: Protein Mediated Synthesis Of Magnetite Nanoparticlesmentioning

confidence: 99%

“…[288] Two main synthetic methods have been used to elucidate the function of the Mms6 protein for preparing magnetite crystals and use the function for an effective biomimicry. [290,293] In the first case, the function of Mms6 during the biomineralization of magnetosomes in BTM was elucidated through the analysis of the Mms6 deletion during the coprecipitation of ferrous and ferric ions. It was concluded that highly ordered cuboidal magnetite crystals consisting of (1 0 0) and (1 1 1) crystal faces with sizes ranging from 20 to 30 nm were formed in the presence of Mms6, while smaller and irregular-shaped magnetite crystals consisting of mainly (1 1 1) faces were formed in the absence of the protein.…”

Section: Protein Mediated Synthesis Of Magnetite Nanoparticlesmentioning

confidence: 99%

Synthesis, Functionalization, and Design of Magnetic Nanoparticles for Theranostic Applications

Mosayebi

Kiyasatfar

Laurent

2017

Adv Healthcare Materials

192

171

View full text Add to dashboard Cite

In order to translate nanotechnology into medical practice, magnetic nanoparticles (MNPs) have been presented as a class of non‐invasive nanomaterials for numerous biomedical applications. In particular, MNPs have opened a door for simultaneous diagnosis and brisk treatment of diseases in the form of theranostic agents. This review highlights the recent advances in preparation and utilization of MNPs from the synthesis and functionalization steps to the final design consideration in evading the body immune system for therapeutic and diagnostic applications with addressing the most recent examples of the literature in each section. This study provides a conceptual framework of a wide range of synthetic routes classified mainly as wet chemistry, state‐of‐the‐art microfluidic reactors, and biogenic routes, along with the most popular coating materials to stabilize resultant MNPs. Additionally, key aspects of prolonging the half‐life of MNPs via overcoming the sequential biological barriers are covered through unraveling the biophysical interactions at the bio–nano interface and giving a set of criteria to efficiently modulate MNPs' physicochemical properties. Furthermore, concepts of passive and active targeting for successful cell internalization, by respectively exploiting the unique properties of cancers and novel targeting ligands are described in detail. Finally, this study extensively covers the recent developments in magnetic drug targeting and hyperthermia as therapeutic applications of MNPs. In addition, multi‐modal imaging via fusion of magnetic resonance imaging, and also innovative magnetic particle imaging with other imaging techniques for early diagnosis of diseases are extensively provided.

show abstract

Control of the morphology and size of magnetite particles with peptides mimicking the Mms6 protein from magnetotactic bacteria

Cited by 124 publications

References 31 publications

MMS6 Protein Regulates Crystal Morphology during Nano-sized Magnetite Biomineralization in Vivo

MMS6 Protein Regulates Crystal Morphology during Nano-sized Magnetite Biomineralization in Vivo

Desulfovibrio magneticus RS-1 contains an iron- and phosphorus-rich organelle distinct from its bullet-shaped magnetosomes

Synthesis, Functionalization, and Design of Magnetic Nanoparticles for Theranostic Applications

Contact Info

Product

Resources

About