Development of native two-dimensional electrophoresis methods for the separation and detection of platinum carrying serum proteins: initial steps

The initial development steps of a native and powerful two-dimensional elec trophoretic (2-D) method for the separation of platinum-proteins is describ ed. Mild conditions were selected, particularly for the second dimension, e .g., avoiding buffer systems with platinophile N- or S-donor groups. Theref ore, the separation reagents were checked if and at which concentration the y can be used for this purpose. In the first dimension isoelectric focusing (IEF) was performed using immobilised pH gradients (IPGs). Native polyacry lamide gel electrophoresis (PAGE) was done in the second dimension. Detecti on of proteins was achieved via silverstaining. For the determination of pl atinum in the ultra-trace range, double focusing inductively coupled plasma mass spectrometry (HR-ICP-MS) was used. Autoradiography (Pt-191 tracer) wi ll be done additionally in the future as a fast, powerful and elegant way o f detecting the platinum carrying proteins after the second dimension.