Use of the sodium borohydride reduction technique to identify a gamma-glutamyl phosphate intermediary in the Escherichia coli glutamine synthetase reaction.
Incubation of unadenylylated Escherichia coli glutamine synthetase with ATP, L-[14C]glutamate and metal ion results in the formation of gamma-glutamyl-P which can under appropriate conditions be reduced by sodium borohydride. The acyl-P compound is formed catalytically as judged by the quantity of radioactive alpha-amino-delta-hydroxyvalerate produced compared to the concentration of enzyme subunits. Formation of the glutamyl-P compound occurs in the presence of magnesium or manganous ions, and the relation of this apparent lack of metal ion specificity with regard to the highly specific Mg2+-supported biosynthetic activity of the unadenylylated form is discussed.
D000255:Adenosine Triphosphate / Q000378:metabolism; D001894:Borohydrides; D004926:Escherichia coli / Q000201:enzymology*; D005974:Glutamate-Ammonia Ligase / Q000378:metabolism*; D005971:Glutamates / Q000378:metabolism; D006714:Homoserine / Q000031:analogs & derivatives / Q000378:metabolism; D008345:Manganese / Q000494:pharmacology; D009943:Organophosphorus Compounds / Q000378:metabolism; D014631:Valerates / Q000378:metabolism
D001894:Borohydrides; D005971:Glutamates; D009943:Organophosphorus Compounds; D014631:Valerates; D008345:Manganese; D006714:Homoserine; D000255:Adenosine Triphosphate; D005974:Glutamate-Ammonia Ligase