TABLE 2.

Analysis of L. lactis F44-murF PG by LC-MS

Additive	Structurea	Mol wt	Retention time (min)	Area (%)
D-Met	PentaMet	1,140.6	2.03	0.72
D-Phe	PentaPhe	1,156.6	5.6/10.4	10.48
D-Phe	TetraPhe	1,074.5	24.5/24.7/29.4	9.35
D-Phe	PentaPhe(X)	1,139.5	21.7	1.18

^aPenta^Met, G–M–l-Ala–d-Gln–l-Lys (d-Asn)–d-Ala–d-Met; Penta^Phe, G–M–l-Ala–d-Gln–l-Lys (d-Asn)–d-Ala–d-Phe; Tetra^Phe, G–M–l-Ala–d-Gln–l-Lys (d-Asp)–d-Phe; Penta^Phe(X), G–M–l-Ala–d-Gln–l-Lys (d-Asp)–d-Ala–d-Phe (d-Asn) or d-Asp is the peptide bridge bound to l-Lys, G is N-acetylglucosamine [GlcNAc], M is N-acetylmuramic acid [MurNAc], and X is the loss of an H₂O molecule (18 Da).