Variation of the lateral mobility of transmembrane peptides with hydrophobic mismatch.

摘要: A hydrophobic mismatch between protein length and membrane thickness can lead to a modification of conformation, function, oligomerization. To study the role mismatch, we have measured change in mobility transmembrane peptides possessing helix various d(pi) lipid membranes giant vesicles. We also used model system where bilayers, h, be tuned at will. precisely diffusion coefficient embedded gained access apparent size diffusing objects. For bilayers thinner than d(pi), decreases, derived characteristic sizes are larger peptide radii. Previous studies suggest that accommodate by tilting. This scenario was confirmed ATR-FTIR spectroscopy. As increases, value increases reach maximum h approximately = d(pi). show this variation is consistent with decrease tilt. do so, relation tilt angle, derive from our measurements. raise (i.e., their reduced) an upright position maximal for Using accessibility measurements, when becomes too thick, polar heads sink into interfacial region. Surprisingly, "pinching" behavior does not hinder lateral peptides. Ultimately, break anchorage observed revealed "jump" D values.