Functional property of a material is determined by the spacial configuration of its constituents and their physical interactions in accordance with laws of exact sciences.Hence an understanding by a clear resolution is vital for any physical particulate matter to functional association.Several different techniques have been developed so far to accomplish it and crystallography is one among powerful tools to determine the geometry of biomolecules in particular, the proteins which have been characterized by it since the middle of twentieth century.
Swedish researchers have chosen to characterize an enzyme catalyst of castor delta 9 stearoyl acyl carrier protein desaturase by crystallography which is accelerating the synthesis of ricinoleic acid from stearic acid by unsaturation.Enzyme crystal generated was targeted by high energy radiations to produce a fingerprint for analysis of constituents and their orientation.They identified multiple alpha helical folding pattern with two iron atoms in a co-ordinate covalent bonding with charged amino acids of the protein moiety.An holistic structural analysis of the enzyme revealed it as a hollow cylinder to accommodate the substrate fatty acid with its 9th carbon atom exactly interacts with iron atoms for electron transfers to make the unsaturated carbon-carbon bonding by metal ion catalysis.
Scientists have prepared an elegant picture for the key regulatory desaturase enzyme in castor.Protein purification and crystallization are painstaking processes to resolve it from solution as the influence of temperature,pressure,concentration of solute protein etc are significant.However the quality of information by crystallography is definitely superior to other in silico structural studies.