Poly(ethylene glycol)methacrylate-acrylamide copolymer media for hydrophobic protein and low temperature...

The properties of poly(ethylene glycol)methacrylate-acrylamide copolymer media (PEGMACs) were exploited in two ways: (i) in the first-dimensional gel of two-dimensional electrophoresis (2-DE) of hydrophobic proteins and (ii) for high speed, high-resolution electrophoresis at low temperatures. In the first application, improved resolution and yield of isoelectric focusing (IEF) separations for the hydrophobic protein zein was achieved compared to IEF in standard polyacrylamide gels. This appears promising as a candidate approach for higher resolution 2-DE mapping of uncharacterized hydrophobic proteins. In the second application, PEGMACs compatible with hydroorganic antifreeze buffer systems below cooling of the gels to low temperatures (-20 degrees C), which allowed greater current to be tolerated during electrophoresis. PEGMAC gels enabled us to perform sixfold faster electrophoretic separations and achieve threefold improved resolution of six standard proteins at the lower temperatures in a direct comparison with the normal sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) system. If this approach is coupled with more precise instrumentation to control low temperatures during electrophoresis, greater separation speeds and resolution may be anticipated.