Conformational changes of lipoxygenase (LOX) in modified environments. Contribution to the variation in specificity of soybean LOX type 1.
The addition of water-soluble cosolvents in the reaction medium of type 1 soybean lipoxygenase can modify the selectivity of the enzyme in the hydroperoxide synthesis reaction. This also results in changes in secondary reactions such as carbonyl compound formation. The possibility of a conformational change of the enzyme due to variations in its microenvironment was considered. Using enzyme immobilization and laser visible Raman spectroscopy, both indirect and direct observations of such a protein conformational rearrangement are described. Subtle modifications in the secondary and/or tertiary structures, for example in microenvironments of Tyr and Trp residues, in orientations of lateral side chains were evidenced, and their importance to enzyme specificity is discussed.
Pourplanche
C
C
Laboratoire de Technologie Enzymatique, URA 1442 CNRS, Compiègne University, France.
Lambert
C
C
Berjot
M
M
Marx
J
J
Chopard
C
C
Alix
A J
AJ
Larreta-Garde
V
V
D019787:Linoleic Acid; D008041:Linoleic Acids / Q000378:metabolism; D008084:Lipoxygenase / Q000737:chemistry*; D010084:Oxidation-Reduction; D010940:Plant Proteins / Q000737:chemistry; D011048:Polarography; D011487:Protein Conformation; D017433:Protein Structure, Secondary; D012997:Solvents; D013025:Glycine max; D013059:Spectrum Analysis, Raman; D014867:Water
D008041:Linoleic Acids; D010940:Plant Proteins; D012997:Solvents; D014867:Water; D019787:Linoleic Acid; D008084:Lipoxygenase