Isolation, characterization, and turnover of glutathionylspermidine from Escherichia coli.

Most of the spermidine in Escherichia coli is converted to glutathionylspermidine at the end of logarithmic growth.Methods are presented for the determination and isolation of glutathionylspermidine and for its characterization as y-glutamylcysteinylglycylspermidine.Isotopic experiments demonstrate that the spermidine of glutathionylspermidine is in equilibrium with free intracellular spermidine.Escher&a COG contains 3 to 4 I.tmol of spermidine per g, wet