Table 2.

Molecular mass and composition of the muropeptides of S. pneumoniae R6 and transformant R6T3-CCP after separation by HPLC

Peak no.aStructurebMrSize of peak/ total size of all peaks (%)
ObservedCalculatedR6R6T3CCP
1DS-tri825.4825.319.0120.81
2DS-tri(OH)826.4826.33.183.28
3DS-tri(−42)783.4783.312.4415.11
4DS-tri(OH)(−42)784.4784.33.154.40
5DS-tetra897.2896.42.671.18
6DS-S-tri912.2912.40.811.03
7DS-penta967.4967.34.753.52
8DS-A-S-tri983.6983.57.707.12
9DS-penta(−42)925.7925.50.920.60
10DS-A-A-tri967.6967.51.381.63
11DS-A-S-tri(−42)941.6941.25.166.21
12DS-A-S-tri(OH)(−42)942.5942.21.621.73
12*DS-A-A-tri(−42)925.8925.501.96
13BisDS-tetra-tri1704.41703.86.652.46
14BisDS-tetra-A-S-tri1862.718626.14.13
15BisDS-A-S-tetra-tri1862.818621.661.15
16BisDS-tetra-tri(−42)1662.61662.93.053.16
17BisDS-A-S-tetra-A-S-tri2020.42020.12.582.15
BisDS-A-A-tetra-A-S-tri2004.32004.1
18BisDS-tetra-A-S-tri(−42)182018202.212.72
19BisDS-A-S-tetra-tri(−42)1820.81820.12.713.46
20BisDS-A-A-tetra-A-S-tri(OH)2005.22005.11.801.26
21BisDS-tetra-tri(−42x2)1620.51619.74.542.89
22BisDS-tetra-A-A-tri(−42)1804.81804.81.622.47
23BisDS-A-S-tetra-A-S-tri(−42)1978.61978.12.312.50
24BisDS-tetra-A-S-tri(−42x2)1778.21777.91.983.07
  • a Peaks are shown in Fig. 6.

  • b DS, disaccharide (GlcNAc-MurNAc); bis, dimeric form; tri, tripeptide (l-Ala-d-Gln-l-Lys); tetra, tetrapeptide (l-Ala-d-Gln-l-Lys-d-Ala); penta, pentapeptide (l-Ala-d-Gln-l-Lys-d-Ala-d-Ala). OH indicates the presence of Glu instead of Gln. S, serine; A-A, Ala-Ala; A-S, Ala-Ser; these amino acids are branched to the ɛ amino group of the Lys residue and are also present in the interpeptide bridge. Peak 17 contained two compounds as described which could not be separated. −42, the mass that was obtained after cleavage of an acetyl radical from the GlcNAc moiety of the DS during preparation of the peptidoglycan; −42x2, two acetyl radicals were missing, one on each DS of the dimer.