A protein band around 25 kDa could be also the chloramphenicolacetyltransferase which is expressed in E.coli RIL/RP cells for the coselection of the rare codon plasmids. MS woud give the soution and it may help to identify the potential cleavage site between GST and fused protein.
-- Christian Roth Institut für Bioanalytische Chemie Biotechnologisch-Biomedizinisches Zentrum Fakultät für Chemie und Mineralogie Universität Leipzig Deutscher Platz 5 04103 Leipzig Telefon: +49 (0)341 97 31316 Fax: +49 (0)341 97 31319
