Fig 4.

Detection of sialylated MMP-9 isoforms by 2-DZ and desialylation with neuraminidase. (A) 2-D zymography (2-DZ) of 20 μl of a pool of sera obtained from four active RR-MS patients, after enrichment (10 × ) by gelatin-Sepharose affinity chromatography. (B) Analysis by 2-DZ of the different MMP-9 isoforms after desialylation of 20 μl of the enriched (10 × ) pool of MS sera with neuraminidase (0.5 U/μl) for 16 hrs at 37°C. Sialylated forms of MMP-9 were detected for the acidic forms and the multimeric forms of MMP-9, but not for NGAL-pro-MMP-9. The oval box on the top shows a magnification of the multimeric forms of MMP-9.