Proteomic analysis of rat cartilage: the identification of differentially expressed proteins in the early stages of osteoarthritis

Table 1 Functional classification of differentially expressed proteins in normal articular cartilage and during early OA in rat identified by 2-DE and MALDI-TOF/MS

Spotno.^a)	Proteinname^b)	Description	Accessionno.^b)	Theor M_r//pI^c)	Exp. M_r/pI^d)	% SeqCov.^e)	Match	Score^f)	Proteins expression compared with Normal samples (% increase)^g)
Spotno.^a)	Proteinname^b)	Protein	Accessionno.^b)			% SeqCov.^e)	Pept.
									OA 3 days	OA 5 days	OA 10 days
		Extracellular Matrix
S1	Col2α1	Collagen alpha-1 (II) chain precursor	P05539	38/8.46	30-32/6.6-6.7	12	16	84	22	15	12
		Transcription, protein synthesis
S2	Eef1α1	Elongation factor 1-alpha 1	P62630	50.11/9.1	50.11/9.1	32	13	37	499	407	314
S3	DJ-1	Protein DJ-1	88767	19.9/6.32	19.9/6.3	54	9	85	138	313	271
		Glycolysis and energy production
S4	Nme2	Nucleoside diphosphate kinase	P19804	17.28/6.9	17.3/6.9	87	16	187	127	515	700
S5	Pnp	Purine nucleoside phosphorylase	P85973	32.3/6.46	32.32/6.4-6.5	43	8	49	243	277	384
		Signal transduction
S6	CaM	Calmodulin	P62161	16.7/4.09	16.8/5.47	63	8	101	124	130	185
S7	Pebp1	Phosphatidylethanolamine binding protein 1	P31044	20.6/5.48	17.18/4.9-5.5	52	7	76	54	92	29
		Transport
S8	Alb	Serum albumin (n-terminal fragment)	P02770	65.9/5.8	68.6/6.09	24	12	105	435	853	568
S9	Hba1	Haemoglobin subunit alpha-1/2	P01946	15.1/7.93	19.7/6.32	69	6	88	231	157	284
		Others
S10	Lxn	Latexin	Q64361	25.5/5.77	25/5.8	48	11	118	20	29	54

^a)Spot number as indicated in Figure 2.
^b)Protein name and accession number according UniprotKB/Swiss-prot database of Rattus norvegicus species.
^c)Theoretical M_r and pI according to protein sequence.
^d)Experimental M_r and pI calculated by analysis of the gel image with ImageMaster 2D Platinum 7.0 software.
^e)Sequence coverage for identified protein (peptide confidence ≥95) in relation on the full sequence.
^f)The Score value listed within the Query table is the Ion Score. Ion score is −10*Log (P), where P is the probability that the observed match is random event.
^g)% Relative volume by condition in early OA vs Normal condition (Tukey-Kramer test, p ≤0.001). The percentage of increase of the protein expression is represented by bold numbers.

ISSN: 1477-5956