Investigation of wool protein heterogeneity using two-dimensional electrophoresis with immobilised pH gradients

The heterogeneity of intermediate filament proteins (IFP) from wool has been investigated using two-dimensional polyacrylamide gel electrophoresis with immobilised pH gradients in the first dimension. The charge heterogeneity has been confirmed with some of the IFP separated as a string of spots with similar molecular weight, but markedly different in isoelectric point (pI). The molecular weight and pI distribution of the string of IFP changed after treatment with alkaline phosphatase, indicating that some of the heterogeneity is caused by phosphorylation.