Table 1.

Muropeptide composition of E. coli MC1061(pAK5)a

Muropeptide Trial ITrial II
% in noninduced cells% in induced cells% Change% in noninduced cells% in induced cells% Change
Monomers54.3947.17−13.355.7548.26−13.4
 Tri7.8310.9639.97.6111.1746.8
 Tetra40.3431.71−21.444.2134.15−22.8
 Penta0.040.0400.120.05−58.3
Dimers41.6947.3013.537.6542.5713.1
 Ala-A2pm36.7832.83−10.734.2231.91−6.8
 A2pm-A2pm4.8213.80186.33.3610.48211.9
Trimers3.815.3039.16.918.8227.6
 Ala-A2pm3.414.2223.86.427.5117.0
 A2pm-A2pm0.421.13169.00.521.72230.7
Tetramers0.110.23109.10.180.3594.4
Anhydros3.886.2361.04.257.5477.4
 Monomers0.931.0917.21.381.8733.5
 Dimers2.484.2370.62.074.41113.0
 Trimers0.460.9197.80.811.6198.8
Cross-linked muropeptides23.4727.3516.523.5727.4316.4
 Ala-A2pm20.8919.78−5.321.7021.800.5
 A2pm-A2pm2.557.28185.51.855.81214.1
  • a The abbreviations used for the muropeptides are as follows: Tri, GlcNAc-β-1,4-MurNAc-l-Ala-d-Glu-m-A2pm; Tetra, GlcNAc-β-1,4-MurNAc-l-Ala-d-Glu-m-A2pm-d-Ala; Penta, GlcNAc-β-1,4-MurNAc-l-Ala-d-Glu-m-A2pm-d-Ala-d-Ala; Ala-A2pm, cross-linkage via d-Ala and m-A2pm of two different stem peptides; A2pm-A2pm, cross-linkage via m-A2pm and m-A2pm of two different stem peptides; Anhydros, all muropeptides carrying a 1,6-anhydromuramic acid. The relative amounts of the muropeptides and the degree of cross-linkage were calculated as described by Glauner (17).