Doorn Jonathan A, Petersen Dennis R
Department of Pharmaceutical Sciences, School of Pharmacy, The University of Colorado Health Sciences Center, Denver 80262, USA.
Chem Res Toxicol. 2002 Nov;15(11):1445-50. doi: 10.1021/tx025590o.
Lipid peroxidation yields the aldehydes 4-hydroxynonenal (4HNE) and 4-oxononenal (4ONE). Protein adduction by 4HNE is thought to be involved in the pathogenesis of several diseases. Currently, the reactivity of 4ONE toward proteins is unknown. The purpose of this study was to identify amino acids that react with 4HNE and 4ONE, characterize the chemical structure of the adduct, and determine the preference for amino acid modification. Model peptides containing one or more nucleophilic residues (i.e., Arg, Cys, His, Met, and Lys) were reacted with 4HNE and 4ONE and analyzed using matrix-assisted laser desorption/ionization mass spectrometry. Post-source decay analysis was used to confirm peptide modification. The bimolecular rate constant for adduction of amino acids and peptides by 4HNE and 4ONE was measured. Results of this work indicate that Cys, His, and Lys are modified by 4HNE and 4ONE. In addition, Arg was adducted by 4ONE. The predominant adduct resulting from modification of peptides by 4HNE or 4ONE had a mass of 156 or 154 Da (respectively), indicating that adduction occurs via Michael addition. Reactivity of amino acids toward 4HNE and 4ONE was found to have the following order: Cys >> His > Lys (> Arg for 4ONE). The presence of an Arg on a Cys-containing peptide increased the reaction rate with 4HNE and 4ONE by a factor of approximately 5-6 compared to the Cys nucleophile alone. Rate constants determined for the modification of Cys by the lipid aldehydes demonstrated a >100-fold difference in reactivity between 4HNE and 4ONE toward Cys. Results of the present study indicate that both 4HNE and 4ONE modify amino acid nucleophiles; however, the reactivity between these two lipid aldehydes differs both qualitatively and quantitatively.
脂质过氧化产生醛类物质4-羟基壬烯醛（4HNE）和4-氧代壬烯醛（4ONE）。4HNE与蛋白质的加合作用被认为与多种疾病的发病机制有关。目前，4ONE与蛋白质的反应活性尚不清楚。本研究的目的是确定与4HNE和4ONE反应的氨基酸，表征加合物的化学结构，并确定氨基酸修饰的偏好性。含有一个或多个亲核残基（即精氨酸、半胱氨酸、组氨酸、甲硫氨酸和赖氨酸）的模型肽与4HNE和4ONE反应，并使用基质辅助激光解吸/电离质谱进行分析。源后衰变分析用于确认肽的修饰。测定了4HNE和4ONE与氨基酸和肽加合的双分子速率常数。这项工作的结果表明，半胱氨酸、组氨酸和赖氨酸会被4HNE和4ONE修饰。此外，精氨酸会被4ONE加合。4HNE或4ONE修饰肽产生的主要加合物质量分别为156或154 Da，表明加合是通过迈克尔加成反应发生的。发现氨基酸对4HNE和4ONE的反应活性顺序如下：半胱氨酸>>组氨酸>赖氨酸（对于4ONE，精氨酸>赖氨酸）。与单独的半胱氨酸亲核试剂相比，含半胱氨酸的肽上存在精氨酸会使与4HNE和4ONE的反应速率提高约5-6倍。脂质醛对半胱氨酸修饰的速率常数表明，4HNE和4ONE对半胱氨酸的反应活性相差100倍以上。本研究结果表明，4HNE和4ONE都会修饰氨基酸亲核试剂；然而，这两种脂质醛之间的反应活性在定性和定量上都有所不同。
