抄録
Crude ammonium sulfate fraction of a cell free extract from Bacillus natto contained an enzyme (or enzymes) which catalyzed the transamidation reaction specific for glutamine. Both L- and D-isomers of glutamine were active as substrate. On incubation of L- Or D-glutamine with the enzyme preparation, two peptides consisting of glutamic acid and glutamine were formed. The main component of the peptides was readily isolated by ion-exchange chromatography and identified as γ-glutamylglutamine by paper chromatography and by paper electrophoresis using authentic peptides. The optical configuration of the amino acid residues in the dipeptide was determined by digestion of the acid hydrolyzate with L-glutamic acid decarboxylase, and the result showed that the dipeptide obtained from L-glutamine was a L-L isomer, while the dipeptide from D-glutamine was a D-D isomer.
