Institute of Chemistry, Food Chemistry, Martin-Luther-University Halle-Wittenberg, Kurt-Mothes-Str. 2, 06120 Halle, Saale, Germany.
J Agric Food Chem. 2022 Aug 24;70(33):10271-10283. doi: 10.1021/acs.jafc.2c04052. Epub 2022 Aug 14.
In the present work, the contribution of lipid peroxidation on modifications of lysine and arginine residues of proteins was investigated. Lipid peroxidation had a major impact on malondialdehyde-derived protein modifications; however, the influence on glyoxal and methylglyoxal-derived modifications in flat wafers was negligible. Therefore, vegetable oils (either linseed oil, sunflower oil, or coconut oil) were added to respective batters, and flat wafers were baked (150 °C, 3-10 min). Analysis of malondialdehyde indicated oxidation in linseed wafers, which was supported by the direct quantitation of three malondialdehyde protein adducts in the range of 0.09-23.5 mg/kg after enzymatic hydrolysis. In contrast, levels of free glyoxal and methylglyoxal were independent of the type of oil added, which was in line with the analysis of 13 advanced glycation end products. Comprehensive incubations of 40 mM --Boc-lysine (100 mM phosphate buffer, pH 7.4) with either 10% oil or an equimolar concentration of carbohydrates led to magnitudes higher (10-10) amounts of -carboxymethyl lysine, -glycolyl lysine, and -carboxyethyl lysine in the latter. Furthermore, malondialdehyde exceeded glyoxal and methylglyoxal in incubations of pure oils at 150 °C by factors of 30 and 100, respectively.
在本工作中，研究了脂质过氧化作用对赖氨酸和精氨酸残基修饰的贡献。脂质过氧化对丙二醛衍生的蛋白质修饰有重大影响；然而，对糖醛和甲基乙二醛衍生的修饰在薄片中的影响可以忽略不计。因此，将植物油（亚麻籽油、葵花籽油或椰子油）添加到各自的面糊中，并烘焙薄片（150°C，3-10 分钟）。丙二醛的分析表明亚麻籽油发生了氧化，这得到了在酶解后范围内为 0.09-23.5mg/kg 的三种丙二醛蛋白质加合物的直接定量的支持。相比之下，游离的糖醛和甲基乙二醛的水平与添加的油的类型无关，这与 13 种晚期糖基化终产物的分析一致。在 100mM 磷酸缓冲液（pH7.4）中，40mM--Boc-赖氨酸（100mM 磷酸缓冲液，pH7.4）与 10%油或等摩尔浓度的碳水化合物的综合孵育导致 -羧甲基赖氨酸、-乙二醛赖氨酸和 -羧乙基赖氨酸的数量分别增加了 10-10 倍。此外，在 150°C 下，纯油的孵育中，丙二醛超过了糖醛和甲基乙二醛，分别为 30 倍和 100 倍。
