Lawrence R M, Sweetman G M, Tavares R, Farmer P B
MRC Toxicology Unit, University of Leicester, United Kingdom.
Teratog Carcinog Mutagen. 1996;16(3):139-48. doi: 10.1002/(SICI)1520-6866(1996)16:3<139::AID-TCM1>3.0.CO;2-J.
Human exposure to ethylene oxide and acrylonitrile may be monitored by determination of the products that these electrophilic compounds form with the amino terminal of hemoglobin. The procedure involves a modified Edman degradation, using the reagent pentafluorophenyl isothiocyanate, which cleaves the adducted N-terminal amino acid from the protein chain as a substituted pentafluorophenyl thiohydantoin. This may then be quantitated using selected ion monitoring gas chromatography-mass spectrometry (GC-MS). To overcome problems arising from the lack of an ideal internal standard for this analysis, we have now synthesized adducts of ethylene oxide and acrylonitrile with the N-terminal tripeptide of the alpha-chain of human globin (Val-Leu-Ser). These adducts should behave analogously to the protein adduct in the Edman degradation. The adducts were characterized by nuclear magnetic resonance and fast atom bombardment and electrospray MS and tandem MS. Additionally, an analogous stable isotope-labeled standard was synthesized for the acrylonitrile adduct using a d8-labeled tripeptide. Quantitative calibration lines for analysis of the adducts have been established and the validity of the assays established by the detection of acrylonitrile adducts in the globin of acrylonitrile-exposed workers and of cigarette smokers.
人体接触环氧乙烷和丙烯腈的情况可通过测定这些亲电化合物与血红蛋白氨基末端形成的产物来监测。该程序涉及一种改良的埃德曼降解法，使用试剂异硫氰酸五氟苯酯，它将加合的N端氨基酸从蛋白质链上裂解下来，形成取代的五氟苯硫代乙内酰脲。然后可使用选择离子监测气相色谱 - 质谱联用仪（GC - MS）对其进行定量。为克服该分析缺乏理想内标所产生的问题，我们现已合成了环氧乙烷和丙烯腈与人珠蛋白α链N端三肽（缬氨酸 - 亮氨酸 - 丝氨酸）的加合物。这些加合物在埃德曼降解中应与蛋白质加合物表现类似。通过核磁共振、快原子轰击、电喷雾质谱和串联质谱对加合物进行了表征。此外，使用d8标记的三肽为丙烯腈加合物合成了类似的稳定同位素标记标准品。已建立了用于分析加合物的定量校准曲线，并通过检测接触丙烯腈工人和吸烟者珠蛋白中的丙烯腈加合物确定了测定方法的有效性。
