Rotenberg S A, Grandizio A M, Selzer A T, Clapp C H
Department of Chemistry, Bucknell University, Lewisburg, Pennsylvania 17837.
Biochemistry. 1988 Nov 29;27(24):8813-8. doi: 10.1021/bi00424a019.
12-Iodo-cis-9-octadecenoic acid (12-IODE) is a time-dependent, irreversible inactivator of soybean lipoxygenase 1. The rate of inactivation is independent of 12-IODE concentration above 20 microM and is half-maximal at about 4 microM. Inactivation by 12-IODE requires lipid hydroperoxide, which must be present even after the initial oxidation of the iron in the enzyme from ferrous to ferric. Inactivation by 12-IODE is also dependent on O2. These findings suggest that 12-IODE is converted by the enzyme into a more reactive species, which is responsible for inactivation. No inactivation has been detected with 12-iodooctadecanoic acid, 12-bromo-cis-9-octadecenoic acid, 12-iodo-trans-9-octadecenoic acid, or a mixture of stereoisomers of 9,11-octadecadienoic acid.
12-碘-顺-9-十八碳烯酸（12-碘代油酸，12-IODE）是大豆脂氧合酶1的一种时间依赖性、不可逆失活剂。失活速率在12-IODE浓度高于20微摩尔时与浓度无关，在约4微摩尔时达到最大失活速率的一半。12-IODE失活需要脂质氢过氧化物，即使在酶中铁从亚铁氧化为铁离子的初始氧化之后，脂质氢过氧化物也必须存在。12-IODE失活也依赖于氧气。这些发现表明，12-IODE被该酶转化为一种更具反应活性的物质，这种物质导致了失活。用12-碘代十八烷酸、12-溴-顺-9-十八碳烯酸、12-碘-反-9-十八碳烯酸或9,11-十八碳二烯酸的立体异构体混合物未检测到失活现象。
