TABLE 2

Peptides showing significant decreased responses in LC-MS analysis of endoproteinase Glu-C and thermolysin digests of human type IV MGmin-collagen

ArgMotifUnmodified arginyl peptides
MG-H1–containing peptides
PeptideRt (min)M (Da)(M + H)+PeptideRt (min)M (Da)(M + H)+
a1 390α1 Chain GFOGER395–390RGE (G21390–392) [from GFOGERGE395–392]16.10360.2361.4RMG-H1GE (G21390–392) [from GFOGERMG-H1GE395–392]21.00414.4415.4
a2 889α2 Chain RGD889–891LSGDRGD (T175885–891)20.44718.3719.3LSGDRMG-H1GD (T175885- 891)Not detected
a2 1452α2 Chain RGD1452–1454FRGDEGP (T2891451–1457)27.00776.4777.4FRMG-H1GDEGP (T2891451–1457)Not detected
  • Sequence data are from Swiss-Prot accession nos. PO2462 (α1) and PO8572 (α2). No GLOGER and GLSGER motifs are present. M, theoretical molecular mass of peptide; (M + H)+, mass of protonated peptide molecular ion detected.