Skip to main content
. 2016 Mar 16;291(20):10916–10933. doi: 10.1074/jbc.M116.715573

FIGURE 6.

FIGURE 6.

AmiC is capable of cleaving a synthetic PG substrate. A, structure of synthetic PG substrate and four possible products of reaction with AmiC (P1–P4). Partial amidase reaction would give a tetrasaccharide-pentapeptide P1 and/or P2 (predicted mass of 1502.62) along with pentapeptide P4 (predicted mass of 532.25). The complete amidase reaction would give tetrasaccharide P3 and pentapeptide P4. B, collision-induced spectrum of AmiC tetrasaccharide-peptide product and fragmentation. The m/z values in bold (682, 822, and 1025) are unique fragment ions and can only be formed in P1, not P2. C, reverse-phase HPLC analysis of digestions of PG dimer using His-AmiC, His-NlpD, His-AmiCQ316K, or a combination of enzymes. S, synthetic dimer substrate; P1, tetrasaccharide-pentapeptide; P4, pentapeptide. Products were confirmed by mass spectrometry. HPLC analysis is representative of two independent experiments on a synthetic dimer under identical conditions used for independent LC-MS analysis of reactions (Table 2).