Curriculum in Applied and Materials Sciences, UNC-CH, Chapel Hill, NC, USA.
Proteomics Clin Appl. 2007 Dec;1(12):1651-9. doi: 10.1002/prca.200700009.
The epidermal growth factor receptor (EGFR) is highly expressed in a variety of tumors, and is therefore an important biomarker for cancer diagnosis and a target for cancer therapy. We have developed a novel peptide-based immuno tandem mass spectrometry (iMALDI) diagnostic assay for highly sensitive, highly specific, and quantitative analysis of EGFR, which we have applied to the detection of the EGFR peptide in three cell lines and in a tumor biopsy sample. This assay is capable of detecting the EGFR target peptide bound to the antibody beads at attomole levels. The ability to directly obtain amino acid sequence data by MS/MS on any affinity-captured peptides provides specificity to this diagnostic technique. This avoids the problem of "false positives" which can result from the nonspecific binding that can occur with any affinity-based technique. The addition of stable-labeled versions of the target peptide (synthesized from stable-isotope coded amino acids) as internal standards allows absolute quantitation of the target protein.
表皮生长因子受体 (EGFR) 在多种肿瘤中高度表达，因此是癌症诊断的重要生物标志物和癌症治疗的靶点。我们开发了一种新型基于肽的免疫串联质谱 (iMALDI) 诊断检测方法，用于 EGFR 的高灵敏度、高特异性和定量分析，我们将其应用于三种细胞系和肿瘤活检样本中的 EGFR 肽检测。该检测方法能够检测到与抗体珠结合的 EGFR 靶肽在飞摩尔水平。通过 MS/MS 直接在任何亲和捕获的肽上获得氨基酸序列数据的能力为该诊断技术提供了特异性。这避免了任何基于亲和力的技术都可能发生的非特异性结合导致的“假阳性”问题。添加作为内部标准的目标肽的稳定标记版本（由稳定同位素编码的氨基酸合成）允许对目标蛋白进行绝对定量。
