MEMBER INFORMATION
Caroline Tokarski is an analytical chemist specialized in high resolution mass spectrometry. Her research is focused on methodological developments for analysis of organic material from native or transformed biological samples. She adapted omics techniques to cultural heritage samples for accurate identification of proteins/lipids/polysaccharides, their modifications and their biological origins. Her current work is focused on organic networking and degradation mechanisms in Cultural Heritage samples.
ABM CONFERENCES
Poster Presenter
Minimally invasive proteomics analysis: Application to museum objects made of ivory and bone
Co-authored with Julie Arslanoglu. Read the Abstract.
Team Presenter
Chemistry and Cultural Heritage: Deciphering Natural Polymers by Bottom up and Top down Mass Spectrometry Analysis
ABM MEMBER EVENTS
PUBLICATIONS + PROJECTS
Francesca Galluzzi, Stéphane Chaignepain, Julie Arslanoglu, Caroline Tokarski
Hydrogen deuterium exchange mass spectrometry to elucidate reticulations, interactions and conformational changes of proteins in tempera paintings
Little is known about structural alterations of proteins within the polymeric films of paints. For the first time, hydrogen‑deuterium exchange mass spectrometry (HDX-MS) was implemented to explore the conformational alterations of proteins resulting from their interaction with inorganic pigments within the early stages of the paint film formation. Intact protein analysis and bottom-up electrospray-ionisation mass spectrometry strategies combined with progressively increasing deuterium incubation times were used to compare the protein structures of the model protein hen egg-white lysozyme (HEWL) extracted from newly dried non-pigmented films and newly dried films made from a freshly made mixture of HEWL with lead white pigment (2PbCO3 Pb(OH)2). The action of other pigments was also investigated, expanding the HDX study with a global approach to paint models of HEWL mixed with zinc white (ZnO), cinnabar (HgS) and red lead (Pb3O4) pigments. The results show structural modifications of HEWL induced by the interaction with the pigment metal ions during the paint formulation after drying and prior to ageing. Both the charge distribution of HEWL proteoforms, its oxidation rate and its deuterium absorption rate, were influenced by the pigment type, providing the first insights into the correlation of pigment type/metal cation to specific chemistries related to protein stability.