MRC Centre for Drug Safety Science, Department of Pharmacology and Therapeutics, University of Liverpool, UK.
Proteomics Clin Appl. 2009 Jun;3(6):720-9. doi: 10.1002/prca.200800222.
Flucloxacillin is a synthetic penicillin used in the treatment of Staphylococcal infections. Adverse reactions to the drug are believed to arise through covalent modification of proteins, with tissue damage occurring secondary to an immune reaction. Serum proteins have been shown by adduct-specific antibodies to be modified by flucloxacillin, but the nature and sites of modification have not been characterised. Here, in vitro studies on HSA have shown by MS that the modification of protein lysine residues occurs in a dose-, time- and site-dependent manner. Affinity, cation exchange and reversed phase chromatography prior to MS revealed in vivo modification of HSA with flucloxacillin in tolerant patients, with up to nine modified lysine residues being detected in each patient, and with modification of Lys190 and Lys212 being detected in 8/8 patients. It was also revealed for the first time that plasma proteins could be modified with the 5-hydroxymethyl metabolite of flucloxacillin, and that essentially the same Lys residues were targeted by both the parent drug and its metabolite. This study provides a detailed characterisation of sites of chemical modification of an endogenous target and reveals candidate peptides for T-cell and antibody assays of flucloxacillin hypersensitivity.
氟氯西林是一种用于治疗葡萄球菌感染的合成青霉素。据认为，药物的不良反应是通过蛋白质的共价修饰引起的，组织损伤继发于免疫反应。通过结合特异性抗体，已经表明血清蛋白被氟氯西林修饰，但修饰的性质和部位尚未确定。在这里，通过 MS 对 HSA 的体外研究表明，蛋白质赖氨酸残基的修饰以剂量、时间和部位依赖的方式发生。在 MS 之前进行的亲和、阳离子交换和反相色谱揭示了在耐受患者中 HSA 与氟氯西林的体内修饰，每个患者中检测到多达 9 个修饰的赖氨酸残基，并且在 8/8 名患者中检测到 Lys190 和 Lys212 的修饰。这也是首次揭示了血浆蛋白可以被氟氯西林的 5-羟甲基代谢物修饰，并且基本上相同的 Lys 残基是母体药物及其代谢物的靶点。这项研究详细描述了内源性靶标的化学修饰部位，并揭示了用于氟氯西林过敏的 T 细胞和抗体检测的候选肽。
