Sebastian Ardanaz

Promiscuous activities have been related to the capacity to catalyze reactions different from those a protein has evolved to sustain. From this evolutionary perspective, we rethought the serum albumins promiscuous behavior. We found that the cross aldol condensation of acetone and p-formylbenzonitrile is a promiscuous reaction conserved in humans and other mammals. Structural and evolutionary analysis indicates that the involved residues could have evolved for a still unknown biological function. Our results could contribute to better characterize the serum albumin family and raise questions about the evolution of protein promiscuity and function.

Biocatalysis in organic solvents is nowadays a common practice with a large potential in Biotechnology. Several studies report that proteins which are co-crystallized or soaked in organic solvents preserve their fold integrity showing almost identical arrangements when compared to their aqueous forms. However, it is well established that the catalytic activity of proteins in organic solvents is much lower than in water. In order to explain this diminished activity and to further characterize the behaviour of proteins in non-aqueous environments, we performed a large-scale analysis (1737 proteins) of the conformational diversity of proteins crystallized in aqueous and co-crystallized or soaked in non-aqueous media. Using proteins' experimentally determined conformational diversity taken from CoDNaS database, we found that proteins in non-aqueous media display much lower conformational diversity when compared to the corresponding conformers obtained in water. When conformational d...