Identification of the polyamine induced proteins in Escherichia coli

The polyamine (PA)-induced proteins were identified by SDS-PAGE, and by two dimensional gel analysis in Escherichia coli strains. A large number of the PA-induced proteins were acidic. The molecular weights of the most highly induced proteins were 40 and 82 kDa proteins in the wild type and PA-auxotrophic mutant, respectively. Although a part of the PA-induced proteins were induced both in the wild type and PA auxotrophic mutant, most of them seem to be induced either in the wild type or mutant. These features may provide a foundation for evaluating the role of the PA-induced proteins relative to the physiology and environmental stress of Escherichia coli.