Division of Pharmaceutical Research, Office of Testing and Research, Center for Drug Evaluation and Research, U.S. Food and Drug Administration, St. Louis, Missouri 63101, United States.
Anal Chem. 2012 Sep 18;84(18):8045-51. doi: 10.1021/ac301949j. Epub 2012 Sep 4.
Implementation of modern analytical techniques, such as intact mass spectrometry, may allow for more detailed quality assessments of protein therapeutics. The complexity of the protein therapeutic manufacturing process as well as the sensitivity of these drugs to different storage conditions can lead to the presence of several undesired products, including truncations, degradation products, byproducts, and differentially modified protein variants that are difficult to detect by peptide mapping. Intact mass spectrometry can be used to identify the intact protein composition, inclusive of post-translational modifications (PTMs) but can also generate a chemical fingerprint of the different protein species present in a given sample. In this work, we systematically evaluated the influence of multiple charge states, multiple isotopes per charge state, and operating resolution on the suitability of intact mass spectrometry for quantitative analysis using insulin and somatotropin as model systems. Standard curves could be generated using absolute intensity data or using the relative ratio between the analyte and internal standard. These methods demonstrate the validity of quantitative intact mass spectrometry for the analysis of protein therapeutic drugs, thus providing a foundation for future comparative methods.
采用现代分析技术，如完整质谱分析，可以更详细地评估蛋白质治疗药物的质量。蛋白质治疗药物的生产工艺非常复杂，而且这些药物对不同储存条件非常敏感，容易产生多种不理想的产物，包括截短产物、降解产物、副产物和差异修饰的蛋白变体，而肽图法难以检测到这些产物。完整质谱分析可用于鉴定完整的蛋白质组成，包括翻译后修饰（PTMs），也可以生成给定样品中不同蛋白质种类的化学特征指纹。在这项工作中，我们系统地评估了多个电荷态、每个电荷态的多个同位素以及操作分辨率对使用胰岛素和生长激素作为模型系统进行完整质量质谱定量分析的适用性的影响。可以使用绝对强度数据或分析物与内标之间的相对比值来生成标准曲线。这些方法证明了定量完整质量质谱分析蛋白质治疗药物的有效性，为未来的比较方法提供了基础。
