Native gel Western blots of three representative CBS mutants expressed in the absence and presence of chemical chaperones. The crude extracts (soluble fraction, 30 μg) were separated in a 4–15% Tris-HCl native gel, transferred to a polyvinylidene difluoride membrane, and probed with monoclonal anti-CBS antibody (Abnova). For brevity, other studied CBS mutants, which yielded similar results, are not shown.