In enzymology, a glutathionylspermidine synthase () is an enzyme that catalyzes the chemical reaction
glutathione + spermidine + ATP glutathionylspermidine + ADP + phosphate
The 3 substrates of this enzyme are glutathione, spermidine, and ATP, whereas its 3 products are glutathionylspermidine, ADP, and phosphate.
This enzyme belongs to the family of ligases, specifically those forming carbon-nitrogen bonds as acid-D-ammonia (or amine) ligases (amide synthases). The systematic name of this enzyme class is gamma-L-glutamyl-L-cysteinyl-glycine:spermidine ligase (ADP-forming) [spermidine is numbered so that atom N-1 is in the amino group of the aminopropyl part of the molecule]. This enzyme is also called glutathione:spermidine ligase (ADP-forming). This enzyme participates in glutathione metabolism. It employs one cofactor, magnesium.
Structural studies
As of late 2007, 5 structures have been solved for this class of enzymes, with PDB accession codes , , , , and .