Table I.

Changed proteins identified by MALDI-TOF/TOF MS/MS from 2-D gels

The spectrum for each peptide is illustrated in supplemental Fig. S1.

No.a	Swiss-Prot ID	Protein name	Molecular weight/pI	Scoreb	Pep.c	Ratio		Loc.f	Function
						1md	6me
1	OAT_MOUSE	Ornithine aminotransferase	48,723/6.19	336	4	1.56	2.72	MC	Transaminase
2	HACL1_MOUSE	2-Hydroxyacyl-CoA lyase 1	64,588/5.89	532	4	1.23	0.68	Pero	Lipid metabolism
3	HMCS2_MOUSE	HMG-CoA synthase	57,300/8.65	115	1	1.1	0.63	MC	Ketone body biosynthesis
4	ODO2_MOUSE	Dihydrolipoamide succinyltransferase	49,306/9.11	194	2	0.96	0.45	MC	Tricarboxylic acid cycle
5	NDUBA_MOUSE	NADH-ubiquinone oxidoreductase PDSW subunit	21,296/8.19	342	3	1.06	0.62	MC	Respiratory chain
6	NDUAA_MOUSE	NADH-ubiquinone oxidoreductase 42-kDa subunit	40,863/7.63	338	4	0.93	0.48	MC	Respiratory chain
7	NDUS3_MOUSE	NADH-ubiquinone oxidoreductase 30-kDa subunit	30,302/6.67	530	6	0.89	0.5	MC	Respiratory chain
8	UCRI_MOUSE	Ubiquinol-cytochrome c reductase iron-sulfur subunit	29,634/8.91	196	2	0.9	0.67	MC	Respiratory chain
9	ETFA_MOUSE	Electron transfer flavoprotein subunit α	35,330/8.62	404	3	1.05	0.61	MC	Respiratory chain
10	PRDX3_MOUSE	Thioredoxin-dependent peroxide reductase	28,337/7.15	155	2	1.43	1.85	MC	Oxidative damage protection

^aProtein numbers on the 2-D gel (see Fig. 2).

^bMolecular weight search (MOWSE) scores obtained by the combined search (peptide mass fingerprint and LIFT data) using Mascot engine.

^cNumbers of peptides identified by MALDI-TOF/TOF MS/MS using the Ultraflex instrument in LIFT mode.

^dProtein expression ratios of SAMP8/SAMR1 at 1 month old.

^eProtein expression ratios of SAMP8/SAMR1 at 6 months old.

^fProtein subcellular locations. MC represents mitochondria, and Pero represents peroxisome.