to electrophoresis in 15% PAA for 16 h at 100 V and then stained with Coomassie Brilliant Blue R 250 (0.1% in 10% acetic acid and 20% methanol). Gels were destained in 10% acetic acid and 20% methanol.Poro-PAGE (5-25% PAA in Tris-borate buffer, pH 8.9) was carried out according to the method of Margolis and Kenrick (1968). Staining and destaining were carried out as described for SDS-PAGE.Electrophoresis was carried out on POOMA-PHOR apparatus (Labor Muller-3510 Hann-Mvinden).