Analysis of the Rana catesbeiana tadpole tail fin proteome and phosphoproteome during T3-induced apoptosis: identification of a novel type I keratin

Table 1 MS analysis of protein spot identified to be a type I keratin fragment

Observed peptide mass (Da, [M+H]⁺)¹	Peptide sequence from MS/MS²	Identified by MALDI-TOF-TOF³	% confidence⁴(MS/MS/MALDI)	Matched database sequence⁵
807.4	LAADDFR	Yes	84/89	LAADDFR
809.4	LASYLDK	Yes	100/na	LASYLEK
991.5	FENELALR	Yes	100/98	FENELALR
1041.6	LVLQIDNAR	Yes	100/100	VVLQIDNAK
1073.6	ILAATIDNSR	Yes	100/100	ILSATIDNSR
1079.5	VLDELTMSR	Yes	100/74	VLDELTLAR
1184.6	YYDIINDLR	-	96/-	YFEIISDLR
1202.6	QSVEADINGLR	-	43/-	QSVETDINGLR
1224.6	NHEEELQVAR	-	73/-	NHEEEMSIAK
1232.7	-	Yes	-/100	LKFENELALR
1301.6	ALEAANTELELK	-	93/-	ALEAANADLELK

¹Observed peptide masses resulting from the tryptic digestion of the protein spot, reported as singly charged. ²Peptide sequence information deduced from MS/MS spectra of the corresponding peptides from ESI-QqTOF analysis. The masses of isoleucine are indistinguishable from leucine in MS and therefore L can be I and vice versa. ³Indicates which peptides were additionally observed with MALDI-TOF-TOF analysis. ⁴Percent confidence for the peptide sequences as reported by PEAKS software for the ESI-QqTOF spectra and by MASCOT for MALDI-TOF-TOF data. ⁵Highest homology match from protein database searching with the observed peptide sequences to X. laevis type I keratin 47 kD using SPIDER software. Bold lettering indicates differences between the observed and database sequences.

ISSN: 1471-213X