TABLE 1.

NGR and iso-DGR/DGR sequences detected by LTQ-MS/MS analysis of tryptic fragments of reduced and alkylated proteolytic N-terminal FN fragments

p, plasma; r, recombinant. *, alkylation of cysteine; ND, peptide not detected. Asn²⁶³ and Asn⁵⁰¹ are underlined.

Attribute of peptide	Tryptic peptide
	253GNLLQC*IC*TGNGR		494C*TC*VGNGRGEWTC*IAYSQLR
	Unmodified	Modified	Unmodified	Modified
Expected mass	1462.69	1463.67	2388.69	2389.68
Found in p70K	1462.08a	1463.10a	2388.06	ND
Found in p40K	ND	ND	2388.06	ND
Found in r70K	1462.64	ND	2388.90	ND

^a MS/MS shown in Fig. 1.