Fig. (6) BN-PAGE analysis of purified fumarase variants (5 µg loaded). (A) Analysis of recombinant human fumarase variants: lane 1) protein molecular mass standards, 2) HsFH, 3) A308T, and 4) H318Y. (B) Analysis of E. coli fumarase variants: lane 1) protein molecular mass standards, 2) FumC, and 3) E315Q (which is equivalent to E362Q in HsFH).