Abstract: Compositions and methods for reconstituting a protein of interest in the plasma membrane of a Xenopus oocyte are disclosed. The method generally includes combining a preassembled membrane protein or proteins with a liposome to prepare a proteo-liposome. The proteo-liposome can have a specific composition of lipids. The proteo-liposome is incubated for sufficient time and under conditions suitable for the protein of interest to fold, associate with, or insert into the liposome's lipid bilayer. In some embodiments, the protein or proteins assemble into a protein channel or complex on or in the proteo-liposome's membrane. The treated oocytes can be used to determine the structure, function, or activity of the membrane protein of interest, the effect of a lipid microenvironment on a membrane protein of interest, or to identify compounds that modulate the function or activity of the membrane protein of interest.