Crystallisation - A Biological Perspective: Faraday Discussions No 159(Volume 159 Faraday Discussions)

The last ten years have seen a revolution in our understanding of the mechanisms of biological crystal growth. While it had long been assumed that crystallisation would occur by the same classical mechanisms which form the basis for most descriptions of crystallisation processes, it is now becoming apparent that this is not the case. There are a number of key observations which have changed our view of crystallisation mechanisms. While it had long been assumed that crystalline biominerals typically form by ion-by-ion growth, it is now recognised that they often precipitate via amorphous precursor phases. This is well established for calcium carbonate and there is growing evidence that biogenic crystalline calcium phosphate phases may form via an analogous route. Recent re-examination of the structure of many calcium carbonate biominerals is also suggesting that "non-classical" crystallisation pathways, where crystals grow from the assembly of precursor particles, may also be widespread. Significantly, these mechanisms are not unique to the biological world. Possibly partly inspired by the identification of these biogenic mineralisation strategies, there is currently great interest from the general crystal growth community in these new and controversial ideas. A number of studies on crystal nucleation have recently re-examined classical nucleation theory, and the observation of pre-nucleation clusters is a recurrent theme of great interest. This controversial result apparently contradicts classical nucleation theory which leads the subject of crystal nucleation and growth via assembly to demand attention. The Scientific Committee warmly invites you to take part in this thought-provoking Discussion and looks forward to welcoming you to Leeds.

Table of Contents:
Introductory Lecture: Spiers Memorial Lecture: Effect of interaction specificity on the phase behaviour of patchy particles; Amino acids form prenucleation clusters: ESI-MS as a fast detection method in comparison to analytical ultracentrifugation; Probing the structure and stability of calcium carbonate pre-nucleation clusters; Exploring the influence of organic species on pre- and post-nucleation calcium carbonate; Control of the nucleation of sickle cell hemoglobin polymers by free hematin; Structural evolution, formation pathways and energetic controls during template-directed nucleation of CaCO3; A two-step mechanism for crystal nucleation without supersaturation; General discussion; Phase behavior of colloidal silica rods; Inorganic salts direct the assembly of charged nanoparticles into composite nanoscopic spheres, plates, or needles; Real-space studies of the structure and dynamics of self-assembled colloidal clusters; Aggregation of ferrihydrite nanoparticles in aqueous systems; Biomimetic type morphologies of calcium carbonate grown in absence of additives; Computer simulation of soft matter at the growth front of a hard-matter phase: incorporation of polymers, formation of transient pits and growth arrest; General discussion; A metastable liquid precursor phase of calcium carbonate and its interactions with polyaspartate; The role of cluster formation and metastable liquid—liquid phase separation in protein crystallization; Polymer-induced liquid precursor (PILP) phases of calcium carbonate formed in the presence of synthetic acidic polypeptides—relevance to biomineralization; Precipitation of ACC in liposomes—a model for biomineralization in confined volumes; The role of the amorphous phase on the biomimetic mineralization of collagen; Revisiting geochemical controls on patterns of carbonate deposition through the lens of multiple pathways to mineralization; General discussion; Aragonite crystal orientation in mollusk shell nacre may depend on temperature. The angle spread of crystalline aragonite tablets records the water temperature at which nacre was deposited by Pinctada margaritifera; 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?; Oligomer formation, metalation, and the existence of aggregation-prone and mobile sequences within the intracrystalline protein family, Asprich; GSP-37, a novel goldfish scale matrix protein: identification, localization and functional analysis; CaCO3/Chitin hybrids: recombinant acidic peptides based on a peptide extracted from the exoskeleton of a crayfish controls the structures of the hybrids; General discussion; Concluding remarks; The thermodynamics of calcite nucleation at organic interfaces: Classical vs. non-classical pathways; Poster titles; list of participants; index of contributors

About the Author :
Faraday Discussions documents a long-established series of Faraday Discussion meetings which provide a unique international forum for the exchange of views and newly acquired results in developing areas of physical chemistry, biophysical chemistry and chemical physics. The papers presented are published in the Faraday Discussion volume together with a record of the discussion contributions made at the meeting. Faraday Discussions therefore provide an important record of current international knowledge and views in the field concerned. The latest (2012) impact factor of Faraday Discussions is 3.82.