A MONOCLONAL-ANTIBODY REACTS WITH MALTOSE-BINDING PROTEIN OF ESCHERICHIA-COLI AND RELATED ENTERIC BACTERIA

Maltose-binding protein (MBP) encoded by malE is essential for the ene rgy-dependent translocation of maltose through the cytoplasmic membran e of bacteria. Its property of specific binding to maltose has been us ed in constructing fusion proteins for easy affinity purification. A m onoclonal antibody named MAb SC1D7 was produced against Escherichia co li MBP. This MAb also bound to MBP-containing recombinant proteins in both Western blotting and immunoprecipitation analysis. As a result, t his MAb can be a useful probe for tracing MBP-fusion proteins in vario us applications. Furthermore, intrinsic MBPs from E. coli, Shigella dy senteriae, Salmonella typhimurium, Enterobacter cloacae, and Klebsiell a pneumoniae were also detected by this MAb. No reaction was observed with the total proteins from Serratia marcescens, Aeromonas hydrophila and Plesiomonas shigelloides. These observations suggest that the MAb SC1D7-defined epitope is conserved among some enteric bacteria, but n ot the others. The results strengthen the phylogenetic positions of th ese closely related bacteria previously placed by other means.