title: Deviation from Michaelis-Menten kinetics for fumarase.
abstract: A study of the steady-state kinetics of fumarase over an extended concentration range, using novel methods of analysis, reveals an initial-rate equation of at least fourth degree for malate as substrate at pH 7.0, with no kinetically significant dead-end complex formation even up to concentrations of 100 mM. In the absence of demonstrable enzyme-aggregation phenomena, this is interpreted as indicating co-operative effects overlooked previously, although a mixture of isoenzymes, each individually of high degree and giving a complex curve, may be a contributing factor.
mesh_terms: D000818:Animals; D005649:Fumarate Hydratase / Q000378:metabolism*; D006836:Hydro-Lyases / Q000378:metabolism*; D007700:Kinetics; D009206:Myocardium / Q000201:enzymology
chemical_list: D006836:Hydro-Lyases; D005649:Fumarate Hydratase