Excess substrate inhibition of soybean lipoxygenase‐1 is mainly oxygen‐dependent

FEBS Letters

Debat, Hélène¹  Berry, Hugues¹  Larreta-Garde, Véronique² 

[1] Laboratoire de Technologie Enzymatique, UPRES A 6022 CNRS, Université de Technologie de Compiègne, B.P. 20.529, 60205 Compiègne Cedex, France;Laboratoire d'Etude des Protéines, Département Biologie, Université de Cergy-Pontoise, 2, avenue Adolphe Chauvin, 95304 Cergy-Pontoise Cedex, France

关键词: Soybean lipoxygenase-1;    Oxygen;    Excess substrate inhibition;    Linoleic acid;   

DOI  :  10.1016/S0014-5793(97)00453-5

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

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.

【 授权许可】

Unknown