Table 1.

Summary of identified peptides from Cat L proteolytic processing of PGRN

	Peptide	Sequence location	QS	SEQUEST XCorr	Mascot Ion Score	Δ mass (ppm)
(i) DKWPTT (Linker P – G)
CL-1	DKWPTT	47–52	2	1.46	20	−0.39
(ii) ITPTGTHPLAKKLPAQR (Linker F – B)
CL-2	ITPTGTHPLA	179–188	2	1.33	23	0.65
CL-3	KKLPAQR	189–195	2	1.78	31	−0.43
CL-4	KLPAQR	190–195	2	1.49	31	−0.29
(iii) EQGPHQVPWM (Linker A – C)
CL-5	EQGPHQVPWM(ox)	336–345	2	1.54	23	0.23
(iv) LPDPQALK (Linker A – C)
CL-6	LPDPQALK	354–361	2	1.73	36	0.20
CL-7	LPDPQAL	354–360	2	1.86	30	−0.64
CL-8	LPDPQA	354–359	1	1.57	30	−0.26
(v) AQPATF (Linker D – E)
CL-9	AQPATF	502–507	1	1.47	22	0.53
(vi) EAPRWDAPLR (Linker C-terminus end)
CL-10	EAPRWDAPLR	576–585	3	1.83	25	0.13

QS: Charge state, (ox) methionine oxidation, Δ mass (ppm), difference between experimental and theoretical masses in parts-per-million. Annotated MS/MS spectra of the identified granulin peptides generated by Cat L activity were included in Additional file 1: Figure S2, numbered from CL-1 to CL-10