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The intrinsically disordered C-RING biomineralization protein, AP7, creates protein phases that introduce nanopatterning and nanoporosities into mineral crystals.

Chang EP, Russ JA, Verch A, Kröger R, Estroff LA, Evans JS - Biochemistry (2014)

Bottom Line: Under mineralization conditions, AP7 forms protein phases that direct the nucleation of ordered calcite nanoparticles via a repetitive protein phase deposition process onto calcite crystals.These organized nanoparticles are separated by gaps or spaces that become incorporated into the forming bulk crystal as nanoporosities.This is an unusual example of organized nanoparticle biosynthesis and mineral modification directed by a C-RING protein phase.

View Article: PubMed Central - PubMed

Affiliation: Laboratory for Chemical Physics, Department of Skeletal Biology, New York University , New York, New York 10012, United States.

ABSTRACT
We report an interesting process whereby the formation of nanoparticle assemblies on and nanoporosities within calcite crystals is directed by an intrinsically disordered C-RING mollusk shell nacre protein, AP7. Under mineralization conditions, AP7 forms protein phases that direct the nucleation of ordered calcite nanoparticles via a repetitive protein phase deposition process onto calcite crystals. These organized nanoparticles are separated by gaps or spaces that become incorporated into the forming bulk crystal as nanoporosities. This is an unusual example of organized nanoparticle biosynthesis and mineral modification directed by a C-RING protein phase.

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Scanning electron microscopyimages of mineral deposits and AP7phases that form in time-resolved mineralization assays. Images inthe bottom row represent higher magnifications of important featuresfor each time point. At 1 min, note the resemblance between the crystal-boundproteinphases and those deposited on SI wafers (Figure S5 of the Supporting Information). White arrows denotethe location of AP7 protein phases captured on crystal surfaces.
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fig3: Scanning electron microscopyimages of mineral deposits and AP7phases that form in time-resolved mineralization assays. Images inthe bottom row represent higher magnifications of important featuresfor each time point. At 1 min, note the resemblance between the crystal-boundproteinphases and those deposited on SI wafers (Figure S5 of the Supporting Information). White arrows denotethe location of AP7 protein phases captured on crystal surfaces.

Mentions: A further confirmationof the deposition of the AP7 protein ontocalcite crystals was obtained using time-resolved assays (Figure 3). At 1 min, typical rhombohedral calcite crystalsare observed along with AP7 protein phases that were deposited ontothe surfaces of the Si wafers and calcite crystals. Nanoparticle formationis initiated on surface regions where the protein phase has coatedor migrated over the calcite crystal. After 5 min, we observe orderednanoparticles coating the exposed surfaces of calcite (Figure 3) and the continued deposition of AP7 protein phaseson the Si wafer background and on exposed calcite surfaces. By 15min, these crystal assemblies are largely complete and exhibit thefamiliar three-dimensional surface topographies, gaps, and crystalorientations that we observed at 1 h (Figure 1). Thus, these mineral assembliesresult from the repetitive deposition of AP7 phases onto a calcite“core”, with each wave of AP7 deposition directing additionalnucleation of single-crystal calcite nanoparticles on exposed surfaces.


The intrinsically disordered C-RING biomineralization protein, AP7, creates protein phases that introduce nanopatterning and nanoporosities into mineral crystals.

Chang EP, Russ JA, Verch A, Kröger R, Estroff LA, Evans JS - Biochemistry (2014)

Scanning electron microscopyimages of mineral deposits and AP7phases that form in time-resolved mineralization assays. Images inthe bottom row represent higher magnifications of important featuresfor each time point. At 1 min, note the resemblance between the crystal-boundproteinphases and those deposited on SI wafers (Figure S5 of the Supporting Information). White arrows denotethe location of AP7 protein phases captured on crystal surfaces.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4215888&req=5

fig3: Scanning electron microscopyimages of mineral deposits and AP7phases that form in time-resolved mineralization assays. Images inthe bottom row represent higher magnifications of important featuresfor each time point. At 1 min, note the resemblance between the crystal-boundproteinphases and those deposited on SI wafers (Figure S5 of the Supporting Information). White arrows denotethe location of AP7 protein phases captured on crystal surfaces.
Mentions: A further confirmationof the deposition of the AP7 protein ontocalcite crystals was obtained using time-resolved assays (Figure 3). At 1 min, typical rhombohedral calcite crystalsare observed along with AP7 protein phases that were deposited ontothe surfaces of the Si wafers and calcite crystals. Nanoparticle formationis initiated on surface regions where the protein phase has coatedor migrated over the calcite crystal. After 5 min, we observe orderednanoparticles coating the exposed surfaces of calcite (Figure 3) and the continued deposition of AP7 protein phaseson the Si wafer background and on exposed calcite surfaces. By 15min, these crystal assemblies are largely complete and exhibit thefamiliar three-dimensional surface topographies, gaps, and crystalorientations that we observed at 1 h (Figure 1). Thus, these mineral assembliesresult from the repetitive deposition of AP7 phases onto a calcite“core”, with each wave of AP7 deposition directing additionalnucleation of single-crystal calcite nanoparticles on exposed surfaces.

Bottom Line: Under mineralization conditions, AP7 forms protein phases that direct the nucleation of ordered calcite nanoparticles via a repetitive protein phase deposition process onto calcite crystals.These organized nanoparticles are separated by gaps or spaces that become incorporated into the forming bulk crystal as nanoporosities.This is an unusual example of organized nanoparticle biosynthesis and mineral modification directed by a C-RING protein phase.

View Article: PubMed Central - PubMed

Affiliation: Laboratory for Chemical Physics, Department of Skeletal Biology, New York University , New York, New York 10012, United States.

ABSTRACT
We report an interesting process whereby the formation of nanoparticle assemblies on and nanoporosities within calcite crystals is directed by an intrinsically disordered C-RING mollusk shell nacre protein, AP7. Under mineralization conditions, AP7 forms protein phases that direct the nucleation of ordered calcite nanoparticles via a repetitive protein phase deposition process onto calcite crystals. These organized nanoparticles are separated by gaps or spaces that become incorporated into the forming bulk crystal as nanoporosities. This is an unusual example of organized nanoparticle biosynthesis and mineral modification directed by a C-RING protein phase.

Show MeSH