Shtarkman I N, Gudkov S V, Chernikov A V, Bruskov V I
Biofizika. 2008 Jan-Feb;53(1):5-13.
The action of 1 mM solutions of L-amino acids in 5 mM phosphate buffer, pH 7.4, on the production of hydrogen peroxide and hydroxyl radicals under the action of X-rays and heating has been studied. Hydrogen peroxide was estimated by the method of enhanced luminescence in a system luminol-paraiodophenol-peroxidase and hydroxyl radicals were determined by using the fluorescence probe coumarin-3-carboxylic acid. It was shown that amino acids can be divided by their influence on H202 formation into three groups: those that reduce the yield of H202, that do not influence it, and that increase it. A similar action of amino acids was observed upon heating, but the composition of the groups was different. All amino acids lowered the formation of hydroxyl radicals under the action of X-rays, and the most effective among them were Cys > His > Phe = Met = Trp > Tyr. Met, His and Phe lowered the amount of hydroxyl radicals by heating, Ser raised it, whereas Tyr and Pro did not change it. Thus, amino acids differently influence the formation of reactive oxygen species by the action of X-rays and heat, and some of amino acids reveal themselves as effective natural antioxidants.
研究了在pH 7.4的5 mM磷酸盐缓冲液中1 mM L-氨基酸溶液在X射线和加热作用下对过氧化氢和羟基自由基产生的影响。通过鲁米诺-对碘苯酚-过氧化物酶体系中的增强发光法估算过氧化氢，使用荧光探针香豆素-3-羧酸测定羟基自由基。结果表明，氨基酸可根据其对H2O2形成的影响分为三组：降低H2O2产量的、不影响H2O2产量的和增加H2O2产量的。加热时观察到氨基酸有类似作用，但分组组成不同。所有氨基酸在X射线作用下均降低羟基自由基的形成，其中最有效的是Cys > His > Phe = Met = Trp > Tyr。Met、His和Phe加热时降低羟基自由基的量，Ser增加其含量，而Tyr和Pro则不改变其含量。因此，氨基酸在X射线和加热作用下对活性氧的形成有不同影响，一些氨基酸表现为有效的天然抗氧化剂。
