Model systems, biomineralization

Earlier biochemical studies had reported that the Krebs cycle in mitochondria are closely associated with the intramitochondrial precipitation of electron-dense mineral granules,138 which have been suggested as ACP containing OCP-carboxylate components.139 Previous studies have shown that succinate ions (00CC2H4C002 ) can be incorporated into the lattice of OCP,139-142 leading to the formation of the OCP-succinate (OCPS) compound.139 Consequently, OCPS prepared in vitro could serve as a model system to mimic the biomineralization process in mitochondria. The XRD... 

D, Composite Biominerals Limpet Teeth Model Systems... 

The synthesis of molecular precursors responsible for tailored nucle-ation and growth is a key feature in the chemical control of biomineralization. Here we highlight recent studies using simplified model systems that aim to identify aspects of solution chemistry important in (1) silica polymerization and aggregation and (2) the morphological design of calcite crystals. 

Recent progress in the solid-state NMR studies of biomineralization has been reviewed by Tsai and Chan. The authors have presented some advanced solid-state NMR techniques developed for the study of biominerals and related in vitro model systems. The NMR parameters of a list of model compounds have been compiled, which is expected to be useful for analyzing the NMR spectra of biominerals. ... 

The air/water interface in combination with Langmuir films of lipids or fatty acids is generally considered as a good modeling system for biomineralization processes occurring in cells or vesicles. In nature, of course, the mineralization takes place within the organisms without contact to air. So our approach was to transfer the experiments we first performed at the air/water interface to the oil/water interface. This, again, is a simplification compared to the bilayer membranes of cells that separate... 

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. 

Biomineralization is a slow and complicated in vivo process. Many simple in vitro systems have been developed to model a particular aspect of the biomineralization process. Although in most cases the biological relevance of the in vitro systems may require further justification, the results can provide important insights into the processes being mimicked. In the near future, this divide-and-conquer approach will remain the most effective strategy for the study of biomineralization. 

---