Table 2. SAP proteins secreted into the extracellular medium by epimastigotes and metacyclic trypomastigotes (clone Dm28c) identified by mass spectrometry.

Peptide sequence	Accession number(1)	Sample	Xcorr(2)	DCn (3)
IEDGAEHGVFTINVSTFTQNQVK	-	Epi-V2(4)	2.53	0.187
INVTSPTPNILEIWWK	Tc00.1047053508219.90	Epi-V2	2.71	0.179
AVTVAIVPAKPPEVPRSPPDDK	Tc00.1047053507953.70	Epi-V2	2.79	0.114
SLWYDCTAEAGGLGSVICGMGVGNCEPEDVERR	Tc00.1047053510373.30	Epi-V16(5)	2.74	0.222
INVTSPTPNILEIWWK	Tc00.1047053508219.90	Epi-V16	2.72	0.194
DGAKDGVFTINVTSPNPSAVKSWWQR	Tc00.1047053506499.90	Epi-VF(6)	2.25	0.181
DSRDTSTPDSESPADAANSAGARSLAETPPGGAGESVPATR	Tc00.1047053510373.30	Meta-V2	2.38	0.148
GFGQMICGMGVGNCASEDFKK	Tc00.1047053504081.440	Meta-V2	2.08	0.244
KNSVSPTAGAEVAAGAPSPA	-	Meta-VF	2.02	0.197
GKPLWYNCTDAASDAGKMICDMGVGNCAPEDVEK	-	Meta-VF	2.67	0.261

(1) Accession number according to the TriTrypDB database.

(2 and 3) To validate the quality of protein identification, the following parameters were used: (2) Xcorr (CrossCorr/avg [AutoCorr offset = -75 to 75]) ≥1.5, 2.0, and 2.5, for singly, doubly and triply charged peptides, respectively. (3) DCn (Xcorr₁ – Xcorr₂/Xcorr₁) ≥0.1.

(4) Sample enriched in plasma membrane-derived vesicles/ectosomes.

(5) Sample enriched in exosomes.

(6) Sample enriched in soluble proteins (vesicle-free, VF).