Molecular Insights into the Recognition of Cellular Membrane Geometry

Abstract

present in the membrane. We have performed contrast-matching small-angle neutron scattering (SANS) experiments to study the conformational changes of the glycosylated form of A1AT for different concentrations of the osmolyte poly(ethelene glycol) (PEG) and in the presence of two different lipid membranes: POPC and POPS. We also monitor the structural changes of the lipid vesicles in the presence of A1AT by SANS. Guinier fits were used as a first approximation to obtain the radius of gyration (Rg) of A1AT. Bragg peaks were used to study structural changes of lipid vesicles. We observed that the Rg of A1AT changes as a function of PEG concentration in solution and when in the presence of lipid vesicles. The deformations monitored through changed in A1AT Rg in the presence of lipid vesicles are compared to the deformations of the glycoprotein observed under osmotic pressure and to the structural changes observed in the lipid vesicles. [1] Petrusca, et al., JBC 2010.