Lipoxygenase catalysis

J. F.G. 1993. Kinetic analysis of the induction period in lipoxygenase catalysis. Biochemistry 32 7686-7691. 

Lewis, E.R., Johansen, E. and Holman, T.R. (1999). Large competitive kinetic isotope effects in human 15-lipoxygenase catalysis measured by a novel HPLC method. J. Am. Chem. Soc. 121, 1395-1396... 

Therefore, the nature of the oxygenated cholesterol products in atherosclerotic human aorta does not exclude the fact, that they have been formed during lipoxygenase catalysis. Really, our results demonstrated that the activity of C-15 animal lipoxygenase may be greatly stimulated by addition of the atherogenic LDL to the incubation media [21,22] (Figure 6). 

Moiseyev, N., Rucker, J., Glickman, M. H. (1997) Reduction of ferric iron could drive hydrogen tunneling in lipoxygenase catalysis Implications for enzymatic and chemical mechanisms, J. Am. Chem. Soc. 119, 3853-3860. 

Autoxidation should be distinguished from lipoxygenase catalysis in the process denoted as lipid peroxidation. Both oxidations provide hydroperoxides, but the latter occurs only in the presence of the enzyme. 

Fruits and vegetables (e. g., pineapple, apple, pear, peach, passion fruit, kiwi, celery, parsley) contain unsaturated Cn hydrocarbons which play a role as aroma substances. Of special interest are (E,Z)-l,3,5-undecatriene and (E,Z,Z)-1,3,5,8-undecatetraene, which with very low threshold concentrations have a balsamic, spicy, pinelike odor. It is assumed that the hydrocarbons are formed from unsaturated fatty acids by P-oxidation, lipoxygenase catalysis, oxidation of the radical to the carbonium ion and decarboxylation. The hypothetical reaction pathway from linoleic acid to (E,Z)-l,3,5-undecatrieneis shown in Formula 5.25. 

Furthermore, in the system with coupled lipase and lipoxygenase, the production rate of HP is governed by the first enzymatic reaction and mass transfer. When TL,- is small (0 to 1 mM equiv. 3 mM LA), the kinetic curve has a sigmoid shape due to surface active properties of LA and HP [25]. Hydrolysis of TL and the increase of LA favor the transfer of LA. Such a transfer allows the lipoxygenase reaction to progress. Since lipox-ygenation consumes LA and produces HP, catalysis and transfer demonstrates a reciprocal influence. 

Liavonchanka A and Feussner, I. 2006. Lipoxygenases occurrence, functions and catalysis. J Plant Physiol 163 348-357. 

Olsson, M. H. M., Mavri, J., Warshel, A., Transition State Theory can be Used in Studies of Enzyme Catalysis Lessons from Simulations of Tunneling and Dynamical Effects in Lipoxygenase and Other Systems, Phil. Trans. R. Soc. B. 2006, 361,1417-1432. 

S. J., Klinman, J. P. (1996) Experimental evidence for extensive tunneling of hydrogen in the lipoxygenase reaction - implications for enzyme catalysis, J. Am. Chem. 

Brash, A.R. (1999). Lipoxygenases Occurrence, function, catalysis, and acquisition substrate. J. Biol. Chem. 274, 23679-23680, and cited references. 

Brash, A.R. Lipoxygenases occurrence, functions, catalysis, and acquisition of substrate. /. Biol Chem. 1999,274, 23679-23682. 

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