Table 3.

Comparison of different resins in the ability to enrich phosphopeptides from a tryptic digest of a moderately complex protein mixture, an in vitro kinase assay containing the purified kinase Fus3 and and its protein substrate Dig1.

Dig1 Phosphopeptides Identified	RP-only	TiO2	TiO2-Sac	ZrO2	IMAC
K.DGNLAS*SNSAHFPPVANQNVK.S		+		+
K.RVNDSYDS*PLSGTASTGK.T		+	+	+
R.LRT*TAEDTSIAK.S		+		+
R.NSSVGS*SANAGPTQQR.A		+	+
R.NSSVGSS*ANAGPTQQR.A	+	+	+	+
R.RSEEGSRNS*SVGSSANAGPTQQR.A		+		+
R.SEEGSRNS*SVGSSANAGPTQQR.A		+
R.SSWHEAEPNKDEEEGTDLAIEDGAVPT*PTFTTFQR.T	+	+	+	+	+
R.SSWHEAEPNKDEEEGTDLAIEDGAVPTPT*FTTFQR.T		+
R.TS*QPQQQSPSLLQGEIR.L		+	+	+
R.TSQPQQQS*PSLLQGEIR.L		+	+	+
R.TTAEDTSIAKST*QDPIGDTEISVANAK.G		+	+	+
R.VNDSYDS*PLS*GTASTGK.T		+
R.VNDSYDS*PLSGTASTGK.T	+	+	+	+
R.VNDSYDSPLS*GTASTGK.T		+	+	+
Dig1 phosphopeptides	3	15	9	11	1
Total phosphopeptides	4	29	13	17	3
Total unmodified peptides	493	297	457	401	84
Ratio phos. / unmod. peptides (norm.)	1	12.1	3.5	5.2	4.4