Figure 2

Western blot analysis of egg extracts and purified nucleoplasmin proteins. A) SDS-PAGE of heat soluble egg extracts from: Lane1, X.laevis; lane 2, B. marinus; lane 3, R. catesbeiana. Egg extract aliquots were mixed with an equal volume of 2 × SDS sample buffer and loaded in the gel without any previous boiling. Under these conditions the nucleoplasmin protein retains its pentameric conformatiom [25]. Molecular weights are a PageRuler Protein Ladder (Fermentas Life Sciences, Burlington, ON) B) SDS-PAGE of nucleoplasmin proteins purified from the extracts of: Lane1, X. laevis; lane 2, B. marinus; lane 3, R. catesbeiana. Samples were boiled in SDS (0.1%) sample buffer for 10 minutes before loading on the gel to separated nucleoplasmin proteins into their monomeric forms. MW is a prestained broad range molecular weight protein marker (New England Biolabs, Ipswich, MA). Western blot analysis was done using a polyclonal antibody elicited against recombinant X. laevis nucleoplasmin [28] and the results are shown in the lower panels of both A) and B) below the corresponding gels.