Metalloproteins

Many transition metals have been found serving as prosthetic groups in the active sites of proteins or as the co-factor in metal activated proteins, or metalloproteins. These metalloproteins exploit the redox and electronic properties of the transition metals to perform a variety of complex biological functions, being the metal ions critical to the protein's function, structure, or stability. One third of all proteins are metalloproteins, using metallic ions such as Ca, Mg, Mn, Fe, Co, Ni, Cu, Zn, Mo, W, V. Since we are in an omics science era, and as the number of projects of High/Medium/Small-Scale Throughput is increasing, one of the questions that have been raised is if the proteins expressed/purified and crystallised came with the right co-factor. To overcome this and other problems some Metallomics projects appeared, but the results obtained have not been very satisfactory ,mainly due to the methodology used. Metalloproteins may be studied starting with two different approaches:

i) purification of the proteins directly from the source (often this approach is not easy due to the low amount of protein expression in the natural organism);

ii) heterologous expression of the protein, but in this case it is necessary to have a pre-information on the protein which can be not easy to obtain, especially if it is a protein with an unknown function.

In general in the genomes around 50% of the total genes have an unknown function, and as there are no bioinformatics tools to predict novel metal binding sites, it can be rather difficult to have some preliminary hints on the type of metal center.
I am currently interested on Structural Biology studies of Metalloproteins, which goes from protein production, purification, characterization using different techniques (biochemical and spectroscopic), crystallization and finally analyses of the crystal structure. This subsequently leads to new experiments and design of site specific mutants.