Biomineralization models

Elderfield H., Bertram C., and Erez J. (1996) Biomineralization model for the incorporation of trace elements into... 

The binding properties of the synthetic polycarboxylate hgand have been demonstrated for Ca(II) complexes and biomineral model composites in terms of the intramolecular NH 0 hydrogen bond. This hydrogen bond contributes not only to the increase of the formation constant by the lower shift of pXa but also to the increase of Ca-0 covalency upon neutral complexation. Both factors are supported in hydrophobic environments and even in the solid state, as analytical data have demonstrated for the CaCOa/polymer composite in a low dielectric constant solvent. In nature, the dislodgement of a polymer ligand from the surface of biominerals often occurs with the coexistence of water. Therefore, both factors are crucial for preventing the Ca-0 bond from hydrolysis with water. 

Since some structural and dynamic features of w/o microemulsions are similar to those of cellular membranes, such as dominance of interfacial effects and coexistence of spatially separated hydrophilic and hydrophobic nanoscopic domains, the formation of nanoparticles of some inorganic salts in microemulsions could be a very simple and realistic way to model or to mimic some aspects of biomineralization processes [216,217]. 

Fricke M, Volkmer D (2007) Crystallization of Calcium Carbonate Beneath Insoluble Mono-layers Suitable Models of Mineral-Matrix Interactions in Biomineralization 270 1-41 Fujimoto D, see Tamura R (2007) 269 53-82... 

There are many bi- and polynuclear iron(III) complexes where bridging oxide is supported by carboxylates. Combinations of Fe—O—Fe plus carboxylate bridges occur in model compounds for proteins and in biomineralization. Electronic spectra of [Fe(/u-0)(//-02CR)2Fe] complexes have been reviewed briefly. [Fe2(//-0)(M-02CMe)2(bipy)2Cl2] is both an alkane activation catalyst and a bio-model. ... 

The membrane-mimetic approach has the potential of providing superior size, morphology, and monodispersity control for ceramic particles. The relatively meager amount of published work in this area [826-834] (see Table 11) is rather surprising. Vigorous and sustained activities, inspired by biomineralization [15-18] and modeled on the incorporation of metallic, catalytic, and semiconducting particles into membrane-mimetic compartments, are fully expected. 

Solid-State Bioinorganic Chemistry Mechanisms and Models of Biomineralization Stephen Mann and Carole C. Perry... 

In almost all instances of biological mineralization fibrous proteins represent the bulk of the organic matrix. In the past, this phenomenon has been interpreted to mean that proteins such as collagen, keratin or elastin are the key elements in mineralization by providing nucleation sites and at the same time offering structure and space for oriented crystal growth. However, with the advance in the field of biomineralization this model came under severe attack. At present, there is no universal concept which could explain all the intriguing facets of phosphate deposition in cellular systems. 

In conclusions, many schemes have been developed for metal ion — phosphate — organic matter interactions in biomineralization. A variety of organic compounds of the kind present in mineralized tissues were found to coordinate calcium ions at neutral or functional sites and in many instances metal ion coordination was accompanied by the binding of phosphate. Although a wealth of information exists on the organic-inorganic interplay, data could not be reduced to a point where a simple model on biological mineralization could be formulated. 

In 1962 it was said that the nature of the local mechanism of calcification is one of the most important unsolved problems in biochemistry 484. This statement still holds true in spite of all the significant work that has been done in the years in between. There is no easy way out for a reviewer who tries to coordinate the various findings, hypotheses, and ideas that have been made in this direction but no universally acceptable model on the mechanisms of biomineralization has yet emerged. There is no need to duplicate the efforts of other reviewers. Instead, the present work will only concentrate on one key aspect of biomineralization where some new insight has recently been gained binding and transfer of calcium ions, and subsequent formation of mineral phases. 

Model compounds with well-defined chemical compositions and structures are indispensable for any study of biominerals or biomineralization processes. The solid-state NMR parameters of selected model compounds... 

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