Comparison of polarographic and chemical measurements of oxygen uptake in complex media: the example of lipoxygenase reaction.
A polarographic method using a Clark oxygen electrode was used to assess oxygen concentrations in model and complex media before and during the lipoxygenase-catalyzed oxidation of linoleic acid to hydroperoxides. The results were in good agreement with those obtained with the chemical determination of dissolved oxygen. The electrode correctly responded when the dissolved oxygen concentration was decreased by the addition of water activity depressors (sorbitol, sucrose, glucose). The influence of the medium components on the gas solubility was discussed. The linear relationship between partial pressure of oxygen (determined by polarographic method) and the oxygen concentration (determined by chemical method) indicated that the Clark oxygen electrode can be used to study enzyme reactions consuming or evolving oxygen in non-Newtonian media.
Pourplanche
C
C
Laboratoire de Technologie Enzymatique, URA D-1442 du CNRS, University of Compiègne, France.
Larreta-Garde
V
V
Thomas
D
D
D005947:Glucose; D019787:Linoleic Acid; D008041:Linoleic Acids / Q000378:metabolism; D008084:Lipoxygenase / Q000378:metabolism; D010100:Oxygen / Q000032:analysis* / Q000378:metabolism; D011048:Polarography; D012996:Solutions / Q000737:chemistry; D013012:Sorbitol; D013395:Sucrose
D008041:Linoleic Acids; D012996:Solutions; D013012:Sorbitol; D013395:Sucrose; D019787:Linoleic Acid; D008084:Lipoxygenase; D005947:Glucose; D010100:Oxygen