Glutathionylspermidine metabolism in Escherichia coli.
Intracellular levels of glutathione and glutathionylspermidine conjugates have been measured throughout the growth phases of Escherichia coli. Glutathionylspermidine was present in mid-log-phase cells, and under stationary and anaerobic growth conditions accounted for 80% of the total glutathione content. N1,N8-bis(glutathionyl)spermidine (trypanothione) was undetectable under all growth conditions. The catalytic constant kcat/Km of recombinant E. coli glutathione reductase for glutathionylspermidine disulphide was approx. 11,000-fold lower than that for glutathione disulphide. The much higher catalytic constant for the mixed disulphide of glutathione and glutathionylspermidine (11% that of GSSG), suggests a possible explanation for the low turnover of trypanothione disulphide by E. coli glutathione reductase, given the apparent lack of a specific glutathionylspermidine disulphide reductase in E. coli.
Department of Medical Parasitology, London School of Hygiene and Tropical Medicine, U.K.
K
K
Smith
A
A
Borges
M R
MR
Ariyanayagam
A H
AH
Fairlamb
D000595:Amino Acid Sequence; D001483:Base Sequence; D017931:DNA Primers; D004220:Disulfides / Q000378:metabolism; D004926:Escherichia coli / Q000254:growth & development / Q000378:metabolism*; D005978:Glutathione / Q000031:analogs & derivatives* / Q000378:metabolism*; D019803:Glutathione Disulfide; D005980:Glutathione Reductase / Q000096:biosynthesis / Q000302:isolation & purification / Q000378:metabolism*; D007700:Kinetics; D008954:Models, Biological; D008969:Molecular Sequence Data; D010084:Oxidation-Reduction; D016133:Polymerase Chain Reaction; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000302:isolation & purification / Q000378:metabolism; D015183:Restriction Mapping; D013095:Spermidine / Q000031:analogs & derivatives* / Q000378:metabolism
D017931:DNA Primers; D004220:Disulfides; D011994:Recombinant Proteins; C012333:glutathionylspermidine; C044809:trypanothione; D005980:Glutathione Reductase; D005978:Glutathione; D013095:Spermidine; D019803:Glutathione Disulfide