Premium
Excess substrate inhibition of soybean lipoxygenase‐1 is mainly oxygen‐dependent
Author(s) -
Berry Hugues,
Debat Hélène,
Larreta-Garde Véronique
Publication year - 1997
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/s0014-5793(97)00453-5
Subject(s) - substrate (aquarium) , chemistry , linoleic acid , oxygen , product inhibition , kinetics , lipoxygenase , enzyme , michaelis–menten kinetics , biochemistry , saturation (graph theory) , enzyme assay , non competitive inhibition , organic chemistry , biology , fatty acid , mathematics , quantum mechanics , combinatorics , ecology , physics
Soybean lipoxygenase‐1 kinetics are known to show product and substrate inhibition. With linoleic acid as the substrate and using a simple Michaelis‐Menten formulation, we have shown that K ss , the substrate inhibition constant was increased by more than five‐fold when initial oxygen concentration was increased from 228 to 1140 μM. Excess substrate inhibition is in fact almost avoided at high initial oxygen concentration. This modification seems correlated with enzyme saturation with oxygen relative to linoleic acid, as reflected by alterations of the substrate conversion rate. Possible implications for the enzyme kinetics are discussed.