The Complexity of Protein Structure and the Challenges it Poses in Developing Biopharmaceuticals

Comparative biosimilar quality studies between a rituximab product and MabThera

“…These higher-order structures are maintained through a set of weaker interactions than the covalent bonds holding the primary structure together such as hydrogen bonds, ionic bonds, and Van der Waals forces. Thus, proteins are considered as delicate molecules compared to small molecules and need special conditions in production and handling [4]. Biological medicinal products including biosimilars are also produced in living cells such as mammalian cells, yeast, and bacteria.…”

Automated, High-Throughput Infrared Spectroscopy for Secondary Structure Analysis of Protein Biopharmaceuticals

“…It is an important product quality attribute (PQA) that governs the structure-function characteristics, safety and efficacy of therapeutic proteins. 1 Throughout the biotherapeutic development life cycle, characterization of the protein HOS is critical for establishing product understanding, obtaining robust manufacturing processes, and developing stable formulations, as well as successfully making process improvements, manufacturing site changes, and biosimilars with fingerprint-like similarity to the originator product. Loss or alterations of HOS may potentially contribute to increased aggregation, decreased stability, higher immunogenicity, and loss of biological function.…”

“…There are a number of mainstream biophysical techniques that can be used to monitor HOS during biotherapeutics development such as X-ray crystallography, nuclear magnetic resonance (NMR) spectroscopy, far-UV and near-UV circular dichroism (CD), Fourier transform infrared (FTIR) spectroscopy, fluorescence spectroscopy, differential scanning calorimetry (DSC), and hydrogen/deuterium exchange mass spectrometry (HDX/MS). [1][2][3] Among these methods, far-UV CD and FTIR spectroscopy methods provide rapid determination of protein secondary structure in solutions and thus have been commonly used as protein secondary structure characterization tools to study the effect of manufacturing, formulation, storage conditions and delivery systems on therapeutic protein conformation and stability. [4][5][6][7] FTIR spectroscopy has long been recognized as an equally powerful tool as far-UV CD in the study of protein secondary structure, especially for analysis of high concentration samples, which achieves more representative information about mAb bulk drug substance and the formulated drug product.…”