Figure 2.

Western blot analysis of fibroblast extracts (native PAGE). The normally assembled tetramer is present only in control fibroblasts (10 μg of protein per lane) and is not detectable in any of the mutant cell lines (100 μg of protein per lane). Lane numbers correspond to patient numbers in table 2. Lanes 1, 2, 3, 4, 6 7, 9, 10, and 11 show results in patients who were not responsive to pyridoxine. Lane N shows results in a negative sample, mutant cell line 599 devoid of any CBS antigen (Skovby et al. 1984); lanes 13, 17, 19, and 20 show results in patients who were fully or partially responsive to pyridoxine. Lane C1 shows results in control fibroblasts 2047 with the sample frozen and thawed twice; lane C2 shows results in control fibroblasts 2047 analyzed in a separate experiment. The extract for lane C2 was prepared immediately before loading, with addition of β-mercaptoethanol and protease inhibitors.