Zamani Leila, Lindholm Jessica, Ilag Leopold L, Jacobsson Sven P
Department of Analytical Chemistry, Stockholm University, Stockholm, Sweden.
J Am Soc Mass Spectrom. 2009 Jun;20(6):1030-6. doi: 10.1016/j.jasms.2009.01.008. Epub 2009 Feb 27.
Charge state distributions (CSDs) of proteins in nanoESI mass spectra are affected by the instrumental settings and experimental conditions, in addition to the conformations of the proteins in the analyzed solutions. In the presented study, instrumental and experimental parameters--the desolvation gas flow rate, temperature, pH, buffer (ammonium acetate), and organic modifier (methanol) concentrations--were optimized according to a reduced central composite face experimental design to maximize the separation of CSDs of monoclonal IgG1-kappa antibodies produced by two production systems (CHO and GS-NS0 cell lines). Principal component analysis and Fisher linear discriminant analysis were then used to reduce the dimensions of the acquired dataset and quantify the separation of the protein classes, respectively. The results show that the IgG1-kappa molecules produced by the two production systems can be clearly distinguished using the described approach, which could be readily applied to other proteins and production systems.
除了分析溶液中蛋白质的构象外，纳喷雾电离质谱中蛋白质的电荷态分布（CSD）还受仪器设置和实验条件的影响。在本研究中，根据简化的中心复合表面实验设计对仪器和实验参数（去溶剂化气体流速、温度、pH值、缓冲液（醋酸铵）和有机改性剂（甲醇）浓度）进行了优化，以最大限度地分离由两种生产系统（CHO和GS-NS0细胞系）产生的单克隆IgG1-κ抗体的CSD。然后分别使用主成分分析和Fisher线性判别分析来降低所采集数据集的维度并量化蛋白质类别的分离情况。结果表明，使用所述方法可以清晰区分由两种生产系统产生的IgG1-κ分子，该方法可轻松应用于其他蛋白质和生产系统。
