The metabolic fate of 14C-labeled peptidoglycan monomer in mice. I. Identification of the monomer and the corresponding pentapeptide in urine.

Abstract The distribution of radioactive products in mouse urine following intravenous administration of the 14 C-labeled peptidoglycan monomer, GlcNAc-MurNaC- L -Ala- D -isoglutamine- meso -diaminopimelic acid- D -Ala- D -Ala, has been studied. 60–80% of radioactivity was recovered within first 3 h, 4–8% in the next 3 h and 2–7% in the following 18 h. The majority of the label was associated with the unchanged peptidoglycan monomer (42–56% of the dose). 14–21% of the label was incorporated into a compound which was isolated and tentatively identified as L -Ala- D -isoglutamine- meso -diaminopimelic acid- D -Ala- D -Ala. The kinetics of excretion and the distribution of radioactivity did not differ in immunized, when compared to non-immunized, mice.