TABLE 1.

Mass spectrometry identification of endosomal VPS peptides isolated with PTHR

Gene symbol, peptide sequence, observed theoretical m/z, charge state, cross-correction, accession number, and sequence coverage are listed. The downward arrows following the first residue and preceding the last indicate the sites of trypsin cleavage. Differences in protein coverage for VPS proteins may be due to 1) variable retention during isolation, 2) dissimilar trypsinization properties of the three VPS subunits, and 3) distinct ionization properties of VPS tryptic peptides during MS analysis with fragments outside the detection range (90). Obs m/z, observed theoretical m/z; z, charge state; Xcorr, cross-correction.

Gene symbol	Peptide	Obs m/z	z	ppm	XCorr	Accession no.	Sequence coverage
							%
VPS26A	R↓YFLNLVLVDEEDRR↓Y	594.31249	3	0.03	2.863	O75436	4.3
VPS29	K↓IGLIHGHQVIPWGDMASLALLQR↓Q	842.46618	3	1.24	4.115	Q9UBQ0-1	32.4
	R↓GDFDENLNYPEQK↓V	784.84689	2	0.07	3.329
	R↓QFDVDILISGHTHKFEAFEHENK↓F	686.08939	4	1.44	3.077
VPS35	K↓HFHPLFEYFDYESR↓K	629.62145	3	0.1	3.942	Q96QK1	12.7
	R↓KVADLYELVQYAGNIIPR↓L	688.04981	3	0.88	3.756
	K↓VADLYELVQYAGNIIPR↓L	645.35091	3	−0.02	3.233
	R↓ACAELHQNVNVK↓N	461.56638	3	0.11	3.083
	K↓AQLAAITLIIGTFER↓M	539.65083	3	0.58	2.972
	R↓LSQLEGVNVER↓Y	622.33586	2	0.31	2.969
	R↓FTLPPLVFAAYQLAFR↓Y	618.68235	3	0.67	2.829
	K↓LFDIFSQQVATVIQSR↓Q	618.00391	3	0.45	2.335