TABLE 2.

Structural data for novel muropeptides^a

Peak	Amt (nmol)						Predicted structure	(M-H)− calculated m/zb	(M-H)− observed m/zb
	N-acetylglucosamine	N-acetylmuramic acid	Ala	Glu	Dpm	Gly
3A	1 (1)	1.0 (1)	2.1 (2)	1.2 (1)	1.2 (1)	1.0 (1)	DS-TP-Gly	999.0	998.7
3B	1 (1)	1.2 (1)	2.9 (3)	1.3 (1)	1.2 (1)	0.1 (0)	DS-TP-Ala	1,036.0c	1,034.5c
8A	1 (2)	1.1 (2)	2.0 (4)	1.3 (2)	1.1 (2)	0.6 (1)	DS-TP-Gly-DS-TP	1,921.9	1,921.5
9A	1 (2)	1.3 (2)	3.2 (5)	1.7 (2)	1.6 (2)	0.05 (0)	DS-TP-Ala-DS-TP	1,936.0	1,935.0
13B	1 (3)	1.1 (3)	2.1 (7)	1.1 (3)	1.3 (3)	0.1 (0)	DS-TP-DS-TP-DS-TP-(Ala)	2,859.9	2,859.1
13C	1 (4)	1.0 (4)	2.0 (8)	1.2 (4)	1.2 (4)	0.04 (0)	DS-TP-DS-TP-DS-TP-DS-TP	3,712.7	3,712.5

^aPeaks are numbered as shown in Fig. 1. All nanomole amounts determined using amino acid and amino sugar analyses (14) are normalized to the amount of N-acetylglucosamine taken as 1. Values in parentheses are predicted numbers of moles of the residues within the molecule. The placement of an Ala residue in parentheses in muropeptide 13B indicates that this residue could be on either the first or second acceptor peptide. 

^b(M-H)⁻ is the deprotonated molecular ion observed in the negative-ion mode. Calculated m/z values are the mass-to-charge ratios predicted from the amino acid and amino sugar analyses. Average mass values are given. Observed m/z values are the values measured by MALDI time-of-flight mass spectrometry. 

^cThese are calculated and observed values for the (M+Na)⁺ ion.