title: Application of circular dichroism and magnetic circular dichroism for assessing biopharmaceuticals formulations photo-stability and small ligands binding properties.
abstract: Synchrotron radiation circular dichroism (SRCD) is a powerful tool for photo-stability assessment of proteins. Recently our research has been interested in applying SRCD to develop screening methodologies for accelerated photo-stability assessment of monoclonal antibody formulations. Despite it was proven to be reliable and applicable within a wide range of salts and excipients containing solutions, the presence of far-UV (<260nm) strong absorbing species (e.g., sodium chloride, histidine, arginine) in common formulations completely prevent the analysis. Herein, we propose a new method based on CD coupled with magnetic CD (MCD) to address the problem and offer an additional versatile tool for monitoring the photo-stability. This is done by assessing the stability of the samples by looking at the near-UV band, as well as giving insights in the denaturation mechanism. We applied this method to four mAbs formulations and correlated the results with dynamic light scattering data. Finally, we applied MCD in ligand interaction to key proteins such as lysozyme, comparing the human with the hen enzyme in the binding of N,N',N''-triacetylchitotriose.
authors.affiliation: Diamond Light Source Ltd., Diamond House, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0DE, United Kingdom.
authors.forename: Edoardo
authors.initials: E
authors.lastname: Longo
authors.affiliation: Diamond Light Source Ltd., Diamond House, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0DE, United Kingdom. Electronic address: rohanah.hussain@diamond.ac.uk.
authors.forename: Rohanah
authors.initials: R
authors.lastname: Hussain
authors.affiliation: Diamond Light Source Ltd., Diamond House, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0DE, United Kingdom. Electronic address: giuliano.siligardi@diamond.ac.uk.
authors.forename: Giuliano
authors.initials: G
authors.lastname: Siligardi
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000737:chemistry*; D002942:Circular Dichroism / Q000379:methods*; D004355:Drug Stability; D005079:Excipients / Q000737:chemistry; D006801:Humans; D008024:Ligands; D008027:Light; D060328:Magnetic Phenomena; D009113:Muramidase / Q000378:metabolism; D055550:Protein Stability; D011506:Proteins / Q000737:chemistry* / Q000378:metabolism; D015203:Reproducibility of Results; D012492:Salts / Q000737:chemistry; D012542:Scattering, Radiation; D013045:Species Specificity; D017356:Synchrotrons; D014312:Trisaccharides / Q000378:metabolism
chemical_list: D000911:Antibodies, Monoclonal; D005079:Excipients; D008024:Ligands; D011506:Proteins; D012492:Salts; D014312:Trisaccharides; C019117:N,N',N''-triacetylchitotriose; C421864:hen egg lysozyme; D009113:Muramidase
keywords: Biopharmaceuticals; Circular dichroism; Drug development; Ligand binding; Light stability assessment; Magnetic circular dichroism