Identification of squamous cell carcinoma associated proteins by proteomics and loss of beta tropomyosin expression in esophageal cancer

Table 1 Mass spectrometric identification and characteristics of the 14 proteins whose expression were subjected to change in SCCE

Polypeptide	Tissue specification	Protein name	Accession numberbased on NCBI	Chromosome	PI/MW	Expression profilingor level
A	Normal	Beta tropomyosin	NM-003289	9p13.2-p13.1	5.5/40.3	Disappearance
B	Normal	Myosin regulatory light chain 2	XM-027060	18p11.31	5.45/17.6	Down Regulation
C	Normal	Myosin light chain 2	NM-000432	16p11.2	5.6/17.6	Down Regulation
D	Normal	Unknown	NC-000963	Map No	5.8/17.6	Down Regulation
E	Normal	Myosin light chain 2	NM-000432	16p11.2	6/17.6	Down Regulation
F	Normal	Peroxiredoxin 2	NM-005809	19p13/2	6.6/26	Down Regulation
G	Normal	Annexin 1	NM-000700	9	7.3/35.5	Down Regulation
1	Tumor	Heat shock protein 70 kD	XM-044201	Unpublish	6/64	Up Regulation
2	Tumor	TPM4-ALK fusion oncoprotein 2	A186109	19p13/1	5.5/32.5	Up Regulation
3	Tumor	Myosin light polypeptide 6	NM-0211019	12p13/3	5.4/20.1	Up Regulation
4	Tumor	Keratin 1	AF304164	12q13	6.9/42.5	Up Regulation
5	Tumor	DNA directed RNA polymerase B (ropB)	NC-000915		6.1/27.2	Up Regulation
6	Tumor	GH16431P	Ay051511		6.6/30.1	Up Regulation
7	Tumor	Calreticulin	NM-004343	19p13/3	5.2/50	Up Regulation

Table 2 An example of MALDI/TOF/TOF mass spectrometry. The identified protein was β tropomyosin, one of the fourteen identified proteins as designated by letter A in Figure 1A

Calculated mass	Observed mass	Start Seq.	End Seq.	Sequence	Modification
846.4679	846.433	232	238	LKEAETR
894.4679	894.4463	162	168	YEEVARK
916.4734	916.4508	192	198	QLEEELR
1107.5792	1107.5211	239	248	AEFAERSVAK
1143.6116	1143.5856	190	198	ARQLEEELR
1170.6727	1170.6464	169	178	LVILEGELER
1243.6528	1243.6317	92	101	IQLVEEELDR
1262.597	1262.5764	179	189	SEERAEVAESR
1298.7677	1298.7423	168	178	KLVILEGELER
1332.6389	1332.6127	78	90	ATDAEADVASLNR
1343.6801	1343.6615	38	48	QLEEEQQALQK
1399.7539	1399.7324	91	101	RIQLVEEELDR
1443.8053	1443.7762	106	118	LATALQKLEEAEK
1460.7339	1460.7119	77	90	KATDAEADVASLNR
1471.775	1471.7477	38	49	QLEEEQQALQKK
1488.74	1488.715	78	91	ATDAEADVASLNRR
1493.7338	1493.7158	141	152	MELQEMQLKEAK	Oxidation (M)
1616.835	1616.8109	77	91	KATDAEADVASLNRR
1671.8911	1671.8682	169	182	LVILEGELERSEER
1702.8792	1702.8088	36	49	CKQLEEEQQALQKK
1719.8582	1719.834	192	205	QLEEELRTMDQAL	Oxidation (M)
1727.8922	1727.8687	92	105	IQLVEEELDRAQER
1799.9861	1799.9597	168	182	KLVILEGELERSEER
1817.8776	1817.8594	153	167	HIAEDSDRKYEEVAR
1883.9933	1883.9731	91	105	RIQLVEEELDRAQER
1946.9963	1946.9734	190	205	ARQLEEELRTMDQALK	Oxidation (M)
2202.1248	2202.1091	106	125	LATALQKLEEAEKAADESER
2414.252	2414.2375	169	189	LVILEGELERSEERAEVAESR
2534.1636	2534.271	199	220	TMDQALKSLMASEEEYSTKEDK
3751.876	3751.9631	252	284	TIDDLEETLASAKEENVEIHQTLDQTLLELNNL