Kato Yoji
School of Human Science and Environment, University of Hyogo, Himeji, Hyogo, Japan,
Subcell Biochem. 2014;77:21-39. doi: 10.1007/978-94-007-7920-4_2.
Lipid peroxidation is an important biological reaction. In particular, polyunsaturated fatty acid (PUFA) can be oxidized easily. Peroxidized lipids often react with other amines accompanied by the formation of various covalent adducts. Novel amide-type lipid-lysine adducts have been identified from an in vitro reaction mixture of lipid hydroperoxide with a protein, biological tissues exposed to conditions of oxidative stress and human urine from a healthy person. In this chapter, the current knowledge of amide type adducts is reviewed with a focus on the evaluation of functional foods and diseases with a history of discovery of hexanoyl-lysine (HEL). Although there is extensive research on HEL and other amide-type adducts, the mechanism of generation of the amide bond remains unclear. We have found that the decomposed aldehyde plus peroxide combined with a lysine moiety does not fully explain the formation of the amide-type lipid-lysine adduct that is generated by lipid hydroperoxide. Singlet oxygen or an excited state of the ketone generated from the lipid hydroperoxide may also contribute to the formation of the amide linkage. The amide-adducts may prove useful not only for the detection of oxidative stress induced by disease but also for the estimation of damage caused by an excess intake of PUFA.
脂质过氧化是一种重要的生物反应。特别是，多不饱和脂肪酸（PUFA）很容易被氧化。过氧化脂质常常与其他胺类发生反应，并伴有各种共价加合物的形成。新型酰胺型脂质 - 赖氨酸加合物已在脂质氢过氧化物与蛋白质的体外反应混合物、暴露于氧化应激条件下的生物组织以及健康人的尿液中被鉴定出来。在本章中，将对酰胺型加合物的现有知识进行综述，重点是对功能性食品的评估以及以己酰赖氨酸（HEL）的发现历史为背景的疾病研究。尽管对HEL和其他酰胺型加合物有广泛的研究，但酰胺键的生成机制仍不清楚。我们发现，脂质氢过氧化物分解产生的醛与过氧化物与赖氨酸部分结合，并不完全能解释脂质氢过氧化物产生的酰胺型脂质 - 赖氨酸加合物的形成。单线态氧或脂质氢过氧化物产生的酮的激发态也可能有助于酰胺键的形成。酰胺加合物不仅可能对检测疾病诱导的氧化应激有用，而且对评估多不饱和脂肪酸过量摄入所造成的损害也可能有用。
