Tyrosyl radical generation is one of the major factors for hemin/peroxide-induced oxidative stress. A method for trapping tyrosyl radical directly was developed using N-methyl luminol derivative, a tyrosine labeling reagent. N-Methyl luminol derivative selectively forms a covalent bond with a tyrosine residue under the single-electron oxidation condition. This reaction labels oxidative stress hotspots not only at the protein level but also at the level of tyrosine residues undergoing oxidation. Human serum albumin complexed with hemin was labeled at Tyr138, the tyrosine residue closest to the hemin binding site and most strongly subjected to oxidative stress caused by hemin/H₂O₂. Oxidatively damaged proteins were visualized in protein mixtures.

酪氨酰自由基的产生是血红素/过氧化物诱导的氧化应激的主要因素之一。利用酪氨酸标记试剂N-甲基鲁米诺衍生物，开发了一种直接捕获酪氨酸自由基的方法。N-甲基鲁米诺衍生物在单电子氧化条件下与酪氨酸残基选择性地形成共价键。该反应不仅在蛋白质水平上而且在经历氧化的酪氨酸残基的水平上标记氧化应激热点。与人血红素复合的人血清白蛋白在Tyr138处标记，酪氨酸残基最靠近人血红素结合位点，最受人血红素/ H ₂ O ₂引起的氧化应激。氧化破坏的蛋白质在蛋白质混合物中可见。