Details of crystal growth in the calcitostracum of Crassostrea virginica have been studied with the purpose of analyzing the formation of the overlapping rows of oriented tabular crystals characteristic of this part of the shell. Crystal elongation, orientation, and dendritic growth suggest the presence of strong concentration gradients in a thin layer of solution in which crystallization occur...

Past work has shown that it is feasible to mutate surface residues of soluble proteins and to a lesser extent membrane proteins in order to improve their crystallization behavior. Described here is a successful application of this approach to the integral membrane protein Thermus thermophilus cytochrome ba(3) oxidase. Two mutant forms of this enzyme (I-K258R and I-K258R/II-E4Q) were created in ...

Membrane distillation crystallization (MDC) is an emerging technology envisaged to manage challenges affecting the desalination industry. This can sustainably treat concentrated solutions of produced water and industrially discharged saline wastewater. Simultaneous recovery clean minerals achieved through integration membrane (MD). MDC has received vast research interest because its potential h...

In an attempt to better define the parameters governing reconstitution and two-dimensional crystallization of membrane proteins, we have studied Ca2(+)-ATPase from rabbit sarcoplasmic reticulum. This ion pump forms vanadate-induced crystals in its native membrane and has previously been reconstituted at high lipid-to-protein ratios for functional studies. We have characterized the reconstitutio...

Here we report the successful three-dimensional crystallization of GlpT, the glycerol-3-phosphate transporter from Escherichia coli inner membrane. GlpT possesses 12 transmembrane alpha-helices and is a member of the major facilitator superfamily. It mediates the exchange of glycerol-3-phosphate for inorganic phosphate across the membrane. Approximately 20 phospholipid molecules per protein, id...

The in meso method for growing crystals of membrane proteins uses a spontaneously forming lipidic cubic mesophase. The detergent-solubilized protein is dispersed with lipid, typically monoolein, and in so doing the cubic phase self-assembles. A precipitant is added to trigger crystal nucleation and growth. The commercial screen solution series are convenient for use in crystallization trials. T...

Halobacteria are extremely specialized organisms. They live exclusively in saturated solutions of common salt. The cell membrane of these bacteria exhibit insular regions which can be isolated by membrane fractionation. These regions consist of a lipid matrix containing bateriorhodopsin molecules in a hexagonal crystalline arrangement. Bacteriorhodopsin is a deep purple retinal-protein complex ...

The lipidic cubic phase method for crystallizing membrane proteins has posted some high-profile successes recently. This is especially true in the area of G-protein-coupled receptors, with six new crystallographic structures emerging in the last 3½ years. Slowly, it is becoming an accepted method with a proven record and convincing generality. However, it is not a method that is used in every m...

Despite the growing interest in membrane proteins, their crystallization remains a major challenge. In the course of a crystallographic study on the multidrug ATP-binding cassette transporter BmrA, mass spectral analyses on samples purified with six selected detergents revealed unexpected protein contamination visible for the most part on overloaded SDS-PAGE. A major contamination from the oute...

Despite the marked increase in the number of membrane-protein structures solved using crystals grown by the lipid cubic phase or in meso method, only ten have been determined by SAD/MAD. This is likely to be a consequence of the technical difficulties associated with handling proteins and crystals in the sticky and viscous hosting mesophase that is usually incubated in glass sandwich plates for...