Molecular Dynamics Study of Membrane Binding Mechanism of a Peripheral Membrane Protein OSH4

Oxysterol-binding protein-related proteins play major role in sterol and lipid transport via a non-vesicular pathway between cellular organelles. Osh4 is the most abundantly expressed member among seven homologue oxysterol binding proteins (OSH) in yeast. It is a peripheral membrane protein and its biological function is still not well understood. The binding mechanism of Osh4 towards various cellular membranes is crucial for its efficient biological function. Previous studies indicated six different membrane binding regions of Osh4 and identified non-specific electrostatic attractions between the membrane and the protein as the guiding factor for its membrane attachment. In this study, using a modified protein force field (CHARMM36m) and more accurate description for lipid-protein electrostatic interactions (CUFIX), we have investigated how the binding mechanism of Osh4 is affected by these new force field