Blue native polyacrylamide gel electrophoresis - a functional approach to plant plasma membrane proteome studies

In this thesis, I have shown that a method called BN-PAGE (a kind of native gel electrophoresis) can be used for studying the protein composition in the plasma membrane of plants. The method enables the study of native (in the functional units) hydrophobic protein complexes, i.e., the membrane proteins and membrane associated proteins that form complexes in the cell. In the method, the protein complexes are first separated in a native dimension, then the componens of the complexes are separated.

The most abundant plasma membrane protein complexes could be mapped using BN-PAGE. These complexes are water channels, proton pumps, proteins that build cell wall resembling sugar polymers and proteins that probably contribute to maintaining the cell structure upon environmental stress. In the thesis, it is also shown how a change in the outer environment such as cold stress affect these protein complexes, as well as how salt treatment can affect the complexes. Yet another approach to the separation method is presented.

The method is one of few that enables the study of membrane proteins in functional units. Hopefully, the method can be more extensively used in the future, as it appears to be highly promising and at the same time not widely used today.