Effects of rotational speed on the hydrodynamic properties of pharmaceutical antibodies measured by analytical ultracentrifugation sedimentation velocity (original) (raw)

Assessing sedimentation equilibrium profiles in analytical ultracentrifugation experiments on macromolecules: from simple average molecular weight analysis to molecular weight distribution and interaction analysis

Biophysical reviews, 2016

Molecular weights (molar masses), molecular weight distributions, dissociation constants and other interaction parameters are fundamental characteristics of proteins, nucleic acids, polysaccharides and glycoconjugates in solution. Sedimentation equilibrium analytical ultracentrifugation provides a powerful method with no supplementary immobilization, columns or membranes required. It is a particularly powerful tool when used in conjunction with its sister technique, namely sedimentation velocity. Here, we describe key approaches now available and their application to the characterization of antibodies, polysaccharides and glycoconjugates. We indicate how major complications, such as thermodynamic non-ideality, can now be routinely dealt with, thanks to a great extent to the extensive contribution of Professor Don Winzor over several decades of research.

Detection of protein aggregates by sedimentation velocity analytical ultracentrifugation (SV-AUC): Sources of variability and their relative importance

Journal of Pharmaceutical Sciences, 2009

Sedimentation velocity analytical ultracentrifugation (SV-AUC) has found application in the biopharmaceutical industry as a method of detecting and quantifying protein aggregates. While the technique offers several advantages (i.e., matrix-free separation and minimal sample handling), its results exhibit a high degree of variability relative to orthogonal size-sensitive separation techniques such as size exclusion chromatography (SEC). The goal of this work is to characterize and quantify the sources of variability that affect SV-AUC results, particularly size distributions for a monoclonal antibody monomer/dimer system. Contributions of individual factors to the overall variability are examined. Results demonstrate that alignment of sample cells to the center of rotation is the most significant contributing factor to overall variability. The relative importance of other factors (e.g., temperature equilibration, time-invariant noise, meniscus misplacement, etc.) are quantified and discussed. © 2008 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 98:3522–3539, 2009