Magnesium-aspartate-based crystallization switch inspired from shell molt of crustacean

Abstract

Many animals such as crustacean periodically undergo cyclic molt of the exoskeleton. During this process, amorphous calcium mineral phases are biologically stabilized by magnesium and are reserved for the subsequent rapid formation of new shell tissue. However, it is a mystery how living organisms can regulate the transition of the precursor phases precisely. We reveal that the shell mineralization from the magnesium stabilized precursors is associated with the presence of Asp-rich proteins. It is suggested that a cooperative effect of magnesium and Asp-rich compound can result into a crystallization switch in biomineralization. Our in vitro experiments confirm that magnesium increases the lifetime of amorphous calcium carbonate and calcium phosphate in solution so that the crystallization can be temporarily switched off. Although Asp monomer alone inhibits the crystallization of pure amorphous calcium minerals, it actually reduces the stability of the magnesium-stabilized precursors to switch on the transformation from the amorphous to crystallized phases. These modification effects on crystallization kinetics can be understood by an Asp-enhanced magnesium desolvation model. The interesting magnesium-Asp-based switch is a biologically inspired lesson from nature, which can be developed into an advanced strategy to control material fabrications.biomineralization ͉ calcium biominerals ͉ phase transformation

Simultaneous mechanical property and biodegradation improvement of wollastonite bioceramic through magnesium dilute doping

“…It has been proven that traces of Mg ion can reduce the overall rate of seeded CaP crystallization and markedly delay the transformation of amorphous CaP to more stable apatite phase (Tao et al, 2009). This effect is also in agreement with the CaO-MgO-SiO 2 system, in which the crystallization shifts to higher temperature with increasing MgO content (Diba et al, 2012).…”

The Skeletal Organic Matrix from Mediterranean Coral Balanophyllia europaea Influences Calcium Carbonate Precipitation

“…The ACC stabilizing role of magnesium ions is switched off by Asp-rich proteins. Thus, these proteins favour the polymorphic transition from ACC to a crystalline phase [11]. Although the OM macromolecules from coral skeleton have a high content of aspartate, this destabilization of the ACC has not been observed and the experimental data suggest an opposite effect.…”

“…Indeed, it is reported that the precipitation of aragonite from solutions containing magnesium ions is due to an inhibition of the precipitation of calcite; magnesium ions poison crystal nuclei of calcite and stop their growth [28]. This mechanism of preferential interaction of acidic macromolecules with magnesium ions was also proposed to explain the switch off of ACC stabilization done by some specific aspartate rich macromolecules [11]. Another possibility is that the SOM inhibits the precipitation of aragonite, interacting with some specific crystalline planes and stopping the growth of the crystals in a process mediated by magnesium ions, as observed to occur in calcite as a consequence of mineral-macromolecules interaction [50].…”

Rational design of thermostable vaccines by engineered peptide-induced virus self-biomineralization under physiological conditions

“…That EV71-W6 displayed better self-biomineralization capacity than EV71-NW may due to the higher density of anionic Glu and Asp amino acids in W6p. It has been documented that Glu and Asp are the most active residues for inducing biomineralization in nature (40,41). In comparison to W6p, NWp cannot initiate CaP mineralization efficiently because the Ser residues in NWp are replaced by Asp and Glu in W6p.…”