Determination of the number and relative molecular mass of subunits in an oligomeric protein by two-dimensional electrophoresis: Application to the subunit structure analysis of rat liver amidophosphoribosyltransferase

Abstract

To determine simultaneously the relative molecular mass ( M r) of a native oligomeric protein, and the number and M r of its subunits, a method using two-dimensional electrophoresis was developed. To determine the M r of a native oligomeric protein, pore gradient gel electrophoresis was performed for the first dimension. Native proteins were dissociated into their subunits by sodium dodecyl sulphate (SDS) in a gel slice, then applied to SDS polyacrylamide gel electrophoresis for the second dimension to determine the M r of subunits. The advantage, accuracy, limitations and application of the method are discussed.