Fig. 5. Protein analysis of MMP-2 and MT1-MMP in HUVECs in 2D and 3D cultures. HUVECs were grown either within fibrin gels or in 2D cultures in standard serum-containing EC medium and stimulated with VEGF (25 ng/ml) and FGF-2 (25 ng/ml). The cells were incubated at 37°C and 5% (v/v) CO₂ for the indicated time period, after which total cell lysates were collected. Equal amounts of cell lysates as determined by a BCA protein quantification assay were analysed by gelatin zymography (A) or western analysis for MT1-MMP (B). Duplicate samples from separate cultures were analysed for each treatment. Pro-MMP-2 has a molecular mass of 72 kDa, whereas the intermediate and fully active forms run at 64 kDa and 62 kDa, respectively. Active MT1-MMP has a molecular mass of 60 kDa.