The polyamine (PA)-induced proteins were identified by SDS-PAGE, and by two
dimensional gel analysis in Escherichia coli strains. A large number of th
e 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-auxot
rophic mutant, respectively. Although a part of the PA-induced proteins wer
e induced both in the wild type and PA auxotrophic mutant, most of them see
m to be induced either in the wild type or mutant. These features may provi
de a foundation for evaluating the role of the PA-induced proteins relative
to the physiology and environmental stress of Escherichia coli.