Methods for structural studies of an antibody, screening metabolites in rat urine and analysis of spent cell cultivation media using LC/ESI-MS and chemometrics

Sammanfattning: This thesis describes bioanalytical methods for generating fingerprints of biological systems for extracting relevant information with (protein) drugs in focus. Similarities and differences between samples can reveal the hidden relevant information, which can be used to optimize the production and facilitate the quality control of such protein drugs during their development and manufacture. Metabolic fingerprinting and multivariate data analysis (MVDA) can also facilitate early diagnosis of diseases and the effects and toxicity of drugs.Currently, several protein drugs are available on the global market. Nevertheless, despite, the success of such biotherapeutics significant challenges remain to be overcome in maintaining their stability and efficacity throughout their production cycle and long-term storage. The native structure and functional activity of therapeutic proteins is affected by many variables from production to delivery, incl. variables assoc. with conditions in bioreactors, purification, storage and delivery. Thus, part of the work underlying this thesis focused on structural analysis of a protein drug using chemical labeling, peptide mapping, and evaluation of the charge state distributions of the whole protein generated by ESI. The other part focuses on non-targeted metabolomics with a view to optimizing the cell cultivation process and assessment of the drug’s toxicity. A combination of appropriate analytical methods and MVDA is needed to find markers that can facilitate optimization of the cultivation system and expression of the target proteins in early stages of process development. Rapid methods for characterizing the protein drugs in different stages of the process are also required for quality control.In order to obtain high quality fingerprints analytical separation techniques with high resolution (such as HPLC or UHPLC) and sensitive analytical detection techniques (such as ESI, quadrupole or TOF MS) have been used, singly or in combination.