Glutamylsulfamoyladenosine and pyroglutamylsulfamoyladenosine are competitive inhibitors of E-coli glutamyl-tRNA synthetase

5'-O-[N-(L-glutamyl)-sulfamoyl]adenosine is a potent competitive inhibitor of E. coli glutamyl-tRNA synthetase with respect to glutamic acid (K-i = 2.8 nM) and is the best inhibitor of this enzyme. It is a weaker inhibitor of mammalian glutamyl-tRNA synthetase (K-i = 70 nM). The corresponding 5'-O-[N-(L-pyroglutamyl)-sulfamoyl] adenosine is a weak inhibitor (K-i = 15 muM) of the E. coli enzyme.