Steady-state kinetics of the anaerobic reaction of soybean lipoxygenase-1 with linoleic acid and 13-L-hydroperoxylinoleic acid.
The steady-state kinetics of the anaerobic reaction of soybean lipoxygenase-1 with linoleic acid and 13-L-hydroperoxylinoleic acid were studied. Initial rates of the formation of oxodienoic acids**, absorbing at 285 nm, were measured at pH 10. About 50% of the consumed 13-L-hydroperoxylinoleic acid was converted into oxodienoic acids regardless of the initial ratio of the two substrates. A linear inhibition by both linoleic acid and 13-L-hydroperoxylinoleic acid was observed in the concentration range studied, which is on the upper side limited by the concentrations at which micelle- or acid-soap formation starts. A kinetic scheme is proposed based on one active site in lipoxygenase-1 which alternately binds the two substrates. Values for the kinetic constants were calculated by fitting simultaneously the complete set of data to the appropriate rate equation.
D007651:Keto Acids / Q000378:metabolism; D007700:Kinetics; D008041:Linoleic Acids / Q000378:metabolism*; D008084:Lipoxygenase / Q000378:metabolism*; D008956:Models, Chemical; D010100:Oxygen; D010545:Peroxides / Q000378:metabolism; D013025:Glycine max
D007651:Keto Acids; D008041:Linoleic Acids; D010545:Peroxides; D008084:Lipoxygenase; D010100:Oxygen