Time-resolved fluorescence spectroscopy and molecular dynamics simulations point out the effects of pressure on the stability and dynamics of the porcine odorant-binding protein.

The effects of hydrostatic pressure on the structure and stability of porcine odorant-binding protein (pOBP) in the presence and absence of the odorant molecule 2-isobutyl-3-methoxypyrazine (IBMP) were studied by steady-state and time-resolved fluorescence spectroscopy as well as by molecular dynamics simulation. We found that the application of moderate values of hydrostatic pressure to pOBP solutions perturbed the microenvironment of Trp(16) and disrupted its highly quenched complex with Met(39). In addition, compared to the protein in the absence of IBMP, the MD simulations experiments carried out at different pressures highlighted the role of this ligand in stabilizing the Trp16/Met39 interaction even at 2000 bar.The obtained results will assist for the tailoring of this protein as specific sensing element in a new class of fluorescence-based biosensors for the detection of explosives.