APLP1 as a cerebrospinal fluid biomarker for γ-secretase modulator treatment

Table 1 APLP1 precursor ion identification in full mass spectrum

Sequence	Theoretical mass (Da)	Observed mass (Da) dogs	ppm dogs	Observed mass (Da) human	ppm human	Annotation
DELAPAGTGVSRE	1300.63	1300.60	−172	1300.63	39	APLP1β13
DELAPAGTGVSREA	1371.66	1371.65	−114	1371.67	20	APLP1β14
DELAPAGTGVSREAVSG	1614.78	1614.78	−8.5	1614.78	−0.058	APLP1β17
DELAPAGTGVSREAVSGL	1727.87	1727.87	13	1727.87	0.12	APLP1β18
DELAPAGTGVSREAVSGLL	1840.95	1840.96	12	1840.95	−8.2	APLP1β19
DELAPAGTGVSREAVSGLLI	1954.04	1954.04	8.5	1954.04	−8.5	APLP1β20
DELAPAGTGVSREAVSGLLIM	2085.08	2085.08	−2.4	2085.08	1.1	APLP1β21
DELAPAGTGVSREAVSGLLIMG	2142.10	2142.10	−7.6	2142.10	−0.46	APLP1β22
DELAPAGTGVSREAVSGLLIMGA	2213.14	–	–	2213.13	−13	APLP1β23
DELAPAGTGVSREAVSGLLIMGAG	2270.16	–	–	2270.16	8.5	APLP1β24
DELAPAGTGVSREAVSGLLIMGAGG	2327.18	2327.18	3.3	2327.18	1.0	APLP1β25
DELAPAGTGVSREAVSGLLIMGAGGG	2384.20	2384.19	−33	2384.19	−65	APLP1β26
DELAPAGTGVSREAVSGLLIMGAGGGS	2471.23	2471.23	−0.53	2471.23	−0.91	APLP1β27
DELAPAGTGVSREAVSGLLIMGAGGGSL	2584.32	2584.32	0.72	2584.32	0.31	APLP1β28

Full mass spectra of amyloid-like protein 1 (APLP1) immunoprecipitated from dog and human cerebrospinal fluid were acquired by MALDI-TOF/TOF. The Table shows the amino acid sequences, the observed masses in Da in dogs and human and their deviation from the theoretical peptide mass in ppm for the peptides identified

ISSN: 1758-9193