title: Further characterization of the human fumarase variant, FH 2--1.
abstract: 1. Further investigation of fumarase using lymphoblastoid cells derived from an individual of the FH 2--1 phenotype has confirmed that the mitochondrial (FHM) and soluble (FHS) forms of fumarase are determined at the same structural locus. 2. The FH 2--1 variant is associated with enzyme deficiency: c. 70% of normal in lymphoblastoid cells and c. 20% of normal in red cells. 3. The pH optimum and apparent Michaelis constant of the variant fumarase were normal but heat-inactivation studies suggest that the isozymes containing polypeptides determined by the variant allele are unstable.
mesh_terms: D002460:Cell Line; D004592:Electrophoresis, Starch Gel; D005649:Fumarate Hydratase / Q000097:blood / Q000235:genetics*; D014644:Genetic Variation; D006358:Hot Temperature; D006801:Humans; D007527:Isoenzymes / Q000097:blood / Q000235:genetics*; D008214:Lymphocytes / Q000201:enzymology; D008928:Mitochondria / Q000201:enzymology
chemical_list: D007527:Isoenzymes; D005649:Fumarate Hydratase