TY - JOUR A1 - Wolf, S. E. A1 - Leiterer, Jork A1 - Pipich, V. A1 - Barrea, R. A1 - Emmerling, Franziska A1 - Tremel, W. T1 - Strong stabilization of amorphous calcium carbonate emulsion by ovalbumin: gaining insight into the mechanism of "polymer-induced liquid precursor" processes N2 - The impact of the ovo proteins ovalbumin and lysozyme—present in the first stage of egg shell formation—on the homogeneous formation of the liquid amorphous calcium carbonate (LACC) precursor, was studied by a combination of complementing methods: in situ WAXS, SANS, XANES, TEM, and immunogold labeling. Lysozyme (pI = 9.3) destabilizes the LACC emulsion whereas the glycoprotein ovalbumin (pI = 4.7) extends the lifespan of the emulsified state remarkably. In the light of the presented data: (a) Ovalbumin is shown to behave commensurable to the 'polymer-induced liquid precursor' (PILP) process proposed by Gower et al. Ovalbumin can be assumed to take a key role during eggshell formation where it serves as an effective stabilization agent for transient precursors and prevents undirected mineralization of the eggshell. (b) It is further shown that the emulsified LACC carries a negative surface charge and is electrostatically stabilized. (c) We propose that the liquid amorphous calcium carbonate is affected by polymers by depletion stabilization and de-emulsification rather than 'induced' by acidic proteins and polymers during a so-called polymer-induced liquid-precursor process. The original PILP coating effect, first reported by Gower et al., appears to be a result of a de-emulsification process of a stabilized LACC phase. The behavior of the liquid amorphous carbonate phase and the polymer-induced liquid-precursor phase itself can be well described by colloid chemical terms: electrostatic and depletion stabilization and de-emulsification by depletion destabilization. KW - Biomineralisation KW - Calcium carbonate KW - PILP KW - LACC PY - 2011 DO - https://doi.org/10.1021/ja202622g SN - 0002-7863 SN - 1520-5126 VL - 133 IS - 32 SP - 12642 EP - 12649 PB - American Chemical Society CY - Washington, DC AN - OPUS4-24628 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wolf, S. E. A1 - Lieberwirth, I. A1 - Natalio, F. A1 - Bardeau, J.-F. A1 - Delorme, N. A1 - Emmerling, Franziska A1 - Barrea, R. A1 - Kappl, M. A1 - Marin, F. T1 - Merging models of biomineralisation with concepts of nonclassical crystallisation: is a liquid amorphous precursor involved in the formation of the prismatic layer of the Mediterranean Fan Mussel Pinna nobilis? N2 - The calcitic prisms of Pinna nobilis (Pinnidae, Linnaeus 1758) are shown to be perfect examples of a mesocrystalline material. Based on their ultrastructure and on the occurrence of an amorphous transient precursor during the early stages of prism formation, we provide evidence for the pathway of mesocrystallisation proposed by Seto et al. (2012), which proceeds not by self-organized oriented attachment of crystalline nano-bricks but by aggregation of initially amorphous nanogranules which later transform by epitaxial nucleation to a three-dimensional array of well aligned nanocrystals. We further fathom the role of a liquid amorphous calcium carbonate in biomineralisation processes and provide strong evidence for the occurrence of PILP-like intermediates during prism formation. We develop a new scenario of prism formation based on the presented findings presented findings and discuss the implications of a speculative liquid amorphous calcium carbonate (LACC) intermediate in vivo. PY - 2012 DO - https://doi.org/10.1039/c2fd20045g SN - 1359-6640 SN - 1364-5498 VL - 159 IS - 0 SP - 433 EP - 448 PB - Soc. CY - Cambridge [u.a.] AN - OPUS4-27122 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wolf, S. E. A1 - Müller, L. A1 - Barrea, R. A1 - Kampf, C.J. A1 - Leiterer, Jork A1 - Panne, Ulrich A1 - Hoffmann, T. A1 - Emmerling, Franziska A1 - Tremel, W. T1 - Carbonate-coordinated metal complexes precede the formation of liquid amorphous mineral emulsions of divalent metal carbonates N2 - During the mineralisation of metal carbonates MCO3 (M = Ca, Sr, Ba, Mn, Cd, Pb) liquid-like amorphous intermediates emerge. These intermediates that form via a liquid/liquid phase separation behave like a classical emulsion and are stabilized electrostatically. The occurrence of these intermediates is attributed to the formation of highly hydrated networks whose stability is mainly based on weak interactions and the variability of the metal-containing pre-critical clusters. Their existence and compositional freedom are evidenced by electrospray ionization mass spectrometry (ESI-MS). Liquid intermediates in non-classical crystallisation pathways seem to be more common than assumed. PY - 2011 DO - https://doi.org/10.1039/c0nr00761g SN - 2040-3364 SN - 2040-3372 IS - 3 SP - 1158 EP - 1165 PB - RSC Publ. CY - Cambridge AN - OPUS4-23355 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -