Structural analysis of monoclonal antibodies by trapped ion mobility-mass spectrometry

Monoclonal antibodies (mAbs) constitute the largest group of biotechnology-based drugs, holding a significant position in the pharmaceutical industry. Due to the complex chemical structures of these drugs and the diverse composition of their samples, the production processes and analyses of mAb-based drugs are quite challenging. Hence, a thorough analysis and evaluation of the structural properties of mAb-based drugs are critically important during the drug development stages. To meet this analytical requirement, complementary analytical techniques that combine chromatographic, spectroscopic, and spectrometric methods are being developed for the characterization of mAbs. In these analyses, mass spectrometry (MS) techniques are predominantly used. Additionally, systems that combine ion mobility (IM), based on the separation of ions in the gas phase according to their collision cross section (CCS) values, with mass spectrometry (IM-MS), are also used effectively for the conformational analysis of mAb species. In this thesis, analytical methods based on trapped ion mobility spectrometry (TIMS) technology were developed to perform the conformational analyses of monoclonal antibody drugs. In these studies, TIMS technology was combined with liquid chromatography (LC) and capillary electrophoresis (CE) pre-separation techniques; in addition, mAb analysis methods were developed using TIMS technology to provide gas-phase separation via direct infusion without any pre-separation or purification using a column or capillary. As a result of this thesis, lot-to-lot bevacizumab analysis data obtained from IM-MS analysis methods were compared with the data from surface plasmon resonance (SPR) analyses, circular dichroism (CD), charge variants, and glycan analyses. This comparison provided valuable insights into the effects of these variants and modifications on the conformational structure of mAbs.