Fig 2: Photo-oxidation, and also subsequent glutathionylation, of CRP and B2M decreases the affinity of these proteins towards specific antibodies as measured by ELISA. Panel A: Photo-oxidation of CRP (1.25 µM) for 5, 10 and 15 min without (white bars) or with (black bars) addition of GSH (100-fold molar excess over CRP concentration). Panel B: Photo-oxidation of B2M (10 µM) for 5, 15 and 30 min without (white bars) or with (black bars) further incubation with GSH (100-fold molar excess over B2M concentration). Statistical differences are indicated as follows: *p < 0.05 vs the t = 0 photolysis time sample without GSH; #p < 0.05 vs the t = 0 photolysis time sample with GSH. Data are presented as mean ± SD from three independent experiments.

Fig 3: Comparison of CRP in the 3 groups. *P < 0.05 when compared with the control group. #P < 0.05 when compared with the HF group. No significant differences were observed among other group comparisons.

Fig 4: Correlation between serum levels of YKL-40 and MMP-9 or CRP.

Fig 5: 1O2-induced glutathionylation of CRP can be reversed by the chemical reductant TCEP, or an enzymatic glutaredoxin (Grx) system. Panel A: Representative immunoblotting image of glutathionylated CRP monomer with or without addition of TCEP. Panel B: Representative immunoblotting image of glutathionylated CRP monomer with or without addition of the Grx system (see Materials and methods for details). Panel C: OD ratio (OD lane n/OD lane 4, n = 4, 8) of glutathionylated CRP monomer from immunoblotting data in panel A without (white bar) or with (black bar) addition of TCEP. Panel D: OD ratio (OD lane n/OD lane 4, n = 4, 8) of glutathionylated CRP monomer from immunoblotting data in panel B without (white bar) or with (black bar) addition of the enzymatic Grx system. Statistical differences are indicated as follows: *p < 0.05 vs lane 4 (panel A; monomer); #p < 0.05 vs lane 4 (panel B; monomer). Each blot is a representative image from one of three experiments carried out on independent samples. Data in panels C and D are presented as mean ± SD from three independent experiments.