Biopolymers and cell. 2001; 17 (2): 147 - 151

The role of 4-hydroxy-TEMPO in the reaction of the linoleyl alcohol oxidation by potato tuber 5-lipoxygenase

0. V. Kharchenko, M. G. Kazachkov, T. D. Skaternaya, I. A. Butovich

It has been previously shown that the potato tuber 5-lipoxygenase (ptLOX) catalyzes aerobic oxidation of linoleyl alcohol (LAL). In the absence of 4-hydroxy-TEMPO, a major part of the oxidation products is formed in the free radical chain reaction initiated by free radicals dissociated from the enzyme-substrate complex. In the presence of 4-hydroxy-TEMPO, 9(S)-hydroperoxy-10E, 12Z-octa-decadien-1-ol and 13(S)-hydroperoxy-9Z, HE- octadecadien-1-ol are formed. The scavenger does not affect the functional groups of the enzyme, and does not compete with LAL for the active center of ptLOX. The results of the kinetic experiments point toward trie reaction mechanism in which, the scavenger intercepts free radicals of LAL leaked from the enzyme active center more effectively than the radicals tightly bound to the enzyme, thus changing the product profile of the overall reaction.