Table 1.

Observed LC-MS/MS peaks of trypsin-digested PE peptides

Strain	α-82 (m/z)1+	α-139 (m/z)1+	β-80 (m/z)1+	β-165 (m/z)1+	β-48/59 (m/z)1+
WT	936	1361	1251	2105	4797
ΔcpeF	936	1361	1251a	2105	4210b

^a Peptide mixtures contained peptides with PEB, PCB, or PUB bound at that specific Cys residue.

^b Only the peptide without bound PEB (m/z 4210; PEB molecular mass, 587 Da) was observed.