Supramolecular structures regulate β-Gal functionality

FLORES SS; NOLAN MV; SANCHEZ JM; CLOP PD; CLOP EM; PERILLO MA

Castellon

Congreso; 6th International Iberian Biophysics Congress and X Iberoamerican Congress of Biophysics; 2018

Spanish Biophysical Society (SBE), the Portuguese Biophysical Society (SPBf) and the Latin American Federation of Biophysical Societies (LAFeBS)

In our laboratory we studied the structure-function relationship of proteins in complex environment. We applied -galactosidase from E. coli (b-Gal) as a model protein. Previously we proved that the soluble enzyme interacts with lipid/water interfaces and demonstrated that in this condition b-Gal activity increased and acquired a structure more hydrated and more resistant to thermal unfolding with respect to b-Gal in solution. We also prepared mixed b-Gal/phospholipid Langmuir films (LF) at the air/water interface. At high surface pressures the AFM analysis of LF suggested that b-Gal was in a state of higher order of oligomerization than the typical tetramer.Currently, we overexpress a recombinant -Gal in E.coli. In some conditions we obtain b-Gal inclusion bodies (IBsb-Gal). Interestingly, the IBs-Gal exhibits not only higher activity but also higher resistance to temperature and pH inactivation with respect to the soluble b-Gal. We conclude that the protein-protein contact at the lipid/water and at the protein/water interfaces confers b-Gal an activating environment allowing a non-native but active and stablestructure