Abstract
In order to characterize the several isoenzymes of soybeans, they were examined with respect to the effect of the polar nature of the substrate. In general, lipoxygenase-1 was most active when presented with charged substrates such as the anionic form of linoleic acid or of potassium linoleyl sulfate, whereas lipoxygenase-2 and-3 preferred nonpolar substrates such as unionized linoleic acid, methyl linoleate, linoleyl methane sulfonate, 10,13-nonadecadieneamine, or linoleyl acetate. Linoleyl sulfate, which has been advanced as an excellent readily soluble substrate for lipoxygenase, was indeed the best substrate found for lipoxygenase-1. Lipoxygenase-2 and-3 were, by contrast, totally inactive against this substrate. The favorable response of linnoleic acid to lipoxygenase-2 and-3 at pH 6.8 was ascribed to the anomalously high pKa value of linoleic acid compared to that of short chain carboxylic acids. The pH-activity profile obtained with lipoxygenase acting on linoleyl sulfate (which was charged at all pH values examined) was shifted to lower pH values compared to the linoleic acid activity profile. The effect of changing from the charged to the uncharged substrate, when tested against lipoxygenase-1, was to increase the Km by an order of magnitude.
Article PDF
Similar content being viewed by others
Avoid common mistakes on your manuscript.
References
Holman, R.T., P.O. Egwin, and W.W. Christie, J. Biol. Chem. 244:1149 (1969).
Christopher, J., E. Pistorius, and B. Axelrod, Biochim. Biophys. Acta 198:12 (1970).
Christopher, J.P., E.K. Pistorius, and B. Axelrod, Ibid. 284:54 (1972).
Pistorius, E., “Studies on Isoenzymes of Soybean Lipoxygenase,” Ph.D. Thesis, Purdue University, W. Lafayette, IN, (1974).
Christopher, J., E.K. Pistorius, F.E. Regnier, and B. Axelrod, Biochim. Biophys. Acta 289:82 (1972).
Allen, J.C., Chem. Commun. 16:906 (1969).
Yoon, N.M., and H.C. Brown, J. Am. Chem. Soc. 90:2927 (1968).
Surrey, K., Plant Physiol. 39:65 (1964).
March, J., “Advanced Organic Chemistry: Reactions, Mechanisms, and Structure,” McGraw-Hill, New York, NY, 1968, p. 20
Brown, H.C., D.H. McDaniel, and O. Haflinger, in Braude and Machod, “Determination of Organic Structuresbby Physical Methods,” Academic Press, Inc., New York, NY, 1955, pp. 567–662.
Koch, F.B., B. Stern, and C.G. Ferrari, Arch. Biochem. Biophys. 78:165 (1958).
Theorell, H., R.T. Holman, and Å. Åkeson, Arch. Biochem. 14:250 (1947).
Author information
Authors and Affiliations
About this article
Cite this article
Bild, G.S., Ramadoss, C.S. & Axelrod, B. Effect of substrate polarity on the activity of soybean lipoxygenase isoenzymes. Lipids 12, 732–735 (1977). https://doi.org/10.1007/BF02570904
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF02570904