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. The authors found that the application of moderate values of hydrostatic pressure to pOBP solutions perturbed the microenvironment of Trp¹⁶ and disrupted its highly quenched complex with Met.³⁹ In addition, compared with 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.