Kasai Hiroshi, Kawai Kazuaki, Fujisawa Koichi
Department of Environmental Oncology, Institute of Industrial Ecological Sciences, University of Occupational and Environmental Health, 1-1 Iseigaoka, Yahatanishi-Ku, Kitakyushu, Fukuoka, 807-8555, Japan.
Genes Environ. 2025 Apr 8;47(1):8. doi: 10.1186/s41021-025-00330-2.
The mechanism of protein modification by 2,4-alkadienals (ADE), lipid peroxidation products prevalent in fried foods, was investigated through model reactions.
A mixture of 2,4-heptadienal (HDE) and hemin was initially incubated at pH 3.0-7.4, followed by treatment with acetyl-cysteine (AcCys) and acetyl-lysine (AcLys) at pH 7.4. Analysis via HPLC revealed a product with a characteristic UV spectrum as the primary peak. This product was identified as an AcCys-pyrrole-AcLys (CPL) crosslink derived from AcCys, 2-butene-1,4-dial (BDA), and AcLys. Increasing the HDE concentration in the initial reaction led to maximum CPL formation at pH 3.5 in the presence of hemin. Lowering the HDE concentration with a higher Cys/HDE ratio resulted in CPL formation, which was observed at pH 7.4 and 3.5 in the presence of hemin. Upon incubation of ADE and hemin at pH 3.0-3.5, BDA was directly identified as 2,4-dinitrophenylhydrazone. BDA was also detected in the 2,4-decadienal reaction mixture. Additionally, a notable propensity for high BDA-dC adduct formation with hemin under acidic conditions was observed, consistent with the results of CPL assay and BDA-2,4-dinitrophenylhydrazone analysis.
通过模型反应研究了油炸食品中普遍存在的脂质过氧化产物2,4-链二烯醛（ADE）对蛋白质的修饰机制。
将2,4-庚二烯醛（HDE）和血红素的混合物最初在pH 3.0 - 7.4下孵育，然后在pH 7.4下用乙酰半胱氨酸（AcCys）和乙酰赖氨酸（AcLys）处理。通过高效液相色谱分析显示，具有特征紫外光谱的一种产物作为主要峰。该产物被鉴定为源自AcCys、2-丁烯-1,4-二醛（BDA）和AcLys的AcCys-吡咯-AcLys（CPL）交联物。在初始反应中增加HDE浓度会在pH 3.5且存在血红素的情况下导致CPL形成最大化。在较高的半胱氨酸/HDE比率下降低HDE浓度会导致CPL形成，在存在血红素的情况下于pH 7.4和3.5时观察到这种情况。在pH 3.0 - 3.5下将ADE和血红素孵育后，BDA被直接鉴定为2,4-二硝基苯腙。在2,4-癸二烯醛反应混合物中也检测到了BDA。此外，在酸性条件下观察到BDA与血红素形成高BDA-dC加合物的显著倾向，这与CPL测定和BDA-2,4-二硝基苯腙分析的结果一致。
1）在胃部条件下，在血红素存在时，ADE可有效生成BDA；2）通过ADE、血红素、半胱氨酸和赖氨酸的相互作用，源自BDA的CPL在生理条件（pH 7.4）下也可形成。BDA被认为是疑似致癌物呋喃（国际癌症研究机构，2B类）的主要反应性代谢产物。鉴于人类对ADE的摄入量比呋喃和丙烯酰胺（国际癌症研究机构2A类）高出几个数量级，并且餐后胃中血红素的估计浓度与本研究相当，食用油炸食品和肉类后胃中可能会形成大量BDA。基于BDA的毒性机制，对ADE的风险评估值得进行全面重新评估。
