Biologics and Biosimilars Characterization

生物制剂和生物仿制药，也称为生物治疗药物，是由细菌，酵母和哺乳动物细胞等活生物体产生的：这与化学合成的小分子药物相反。这意味着，在非常大的分子（肽，小蛋白质，抗体，多糖等）上，它们表现出翻译后修饰和某些结构的变化程度。

通过结构表征确认治疗药物的身份，从初级氨基酸序列到高阶结构，以及杂质控制是确保功效和患者安全的关键因素。

力量的质谱分析解决方案超越交易ditional peptide mapping and intact mass analysis. These solutions combine ultimate performance, speed and versatility with powerful workflow-enabled software to provide biologics developers with ready access to orthogonal characterization approaches: from monoclonal antibody (mAb) subunit analysis using middle up and middle down approaches for the unambiguous detection and characterization of sequence variants and modifications including deamidation, oxidation and N-terminal clipping to higher order structure studies for the detailed characterization of disulfide bridges, conformational epitopes, structural changes upon perturbation to calculating accurate drug antibody ratios (DAR) in antibody drug conjugate (ADC) studies.

二硫键（DSB）分析和Hydrogendeuterium Exchange（HDX）已成为可以采用的技术，可用于洞悉蛋白质结构。这些见解对于确定生物仿制药的结构相似性至关重要，或者对于监测药物开发过程中的蛋白质稳定性至关重要。治疗蛋白的三级结构是其活性和稳定性的关键。 

Research and development labs require technology capable of automated DSB analysis in biopharmaceuticals, based on a single digest of the unreduced protein and without prior knowledge of enzyme specificity or native DSBs. Due to the complexity of these proteins and the fact that they will contain multiple disulfide bonds, analysis is a challenge, often requiring several LC-MS runs with the tryptic digests from reduced and non-reduced protein and a manual comparison of these two analyses.

NMR is especially sensitive to changes to higher order structure at atomic resolution, making it ideally suited for similarity assessment of biologics and biosimilars (high order structure). NMR allows for intact protein analysis, enabling evaluation of the structure of therapeutic drugs without modification, in conditions that are physiologically relevant. Due to the quantitative nature of magnetic resonance and its selectivity, potency determination, impurity profiling and degradation studies (e.g. polysorbates）直接进行快速简便的测试，而无需响应因素计算或传统LC方法所需的方法重建活动，从而节省了时间和降低成本。此外，台式时间域NMR（TD-NMR）正在成为分析的重要技术protein aggregates和100％填充检查of vials and syringes.

傅立叶变换红外（FT-IR）光谱法可用于分析水溶性和膜蛋白（例如核受体），这些核受体目前是药物研究和开发中非常重要的靶标，与阿尔茨海默氏症，帕金森氏症，糖尿病，糖尿病，糖尿病等疾病有关和肥胖。FT-IR通常应用于蛋白质二级结构阐明，构象变化的检测以及蛋白质动力学等诸如聚集，沉淀和结晶等蛋白质动力学的监测。红外蛋白质分析是一种快速且相对廉价的技术，用于配方优化，药物开发过程中的稳定性研究以及蛋白质药物的QC。

Surface Plasmon Resonance (SPR) is the gold standard methodology to characterize an interaction from a kinetic point of view. Whilst solution-based approaches offer an equilibrium-based perspective on an interaction, the label-free and real-time analysis of SPR gives insights into the kinetics and thus adds a key characteristic to understand an interaction more precisely. Biologics with similar affinities in equilibrium-based methods like ELISA may have vastly different off-rates with subsequently different biological outcomes. SPR thus enables to identify the biologics with the optimal half-life at your target protein.

SPR further allows to identify antibodies targeting different epitopes on a protein. Equally, conditional binding based on factors like pH, e.g. as in cancer tissue, or the effect of different buffers on the binding interaction can be investigate with ease. These approaches help to understand an interaction in a physiologically more translatable context.