. Author manuscript; available in PMC: 2013 Oct 16.

Published in final edited form as: Biochemistry. 2012 Oct 2;51(41):8143–8153. doi: 10.1021/bi3012115

TABLE 2.

Glycine-deficient monomeric muropeptides detected by LC-MS

m/z	Proposed structure^a	Peak area in OD 4 peptidoglycan	Peak area in OD 2 peptidoglycan	Ratio^b
969.5	GlcNAc-MurNAc-AQKAA	471947	23702	20

1040.5	GlcNAc-MurNAc-AQK(A)AA	245256	trace amount
898.5	GlcNAc-MurNAc-AQKA	74923	trace amount

All the Lys (K) in the muropeptides in this study are isotopically enriched as [ε-¹⁵N]Lys;

Ratio of the peak area in the OD 4 and OD 2 peptidoglycan. Both peptidoglycan samples were adjusted to the same concentration by A₆₀₀, and were prepared and injected the same way.