title: Application of matrix-assisted laser desorption and ionization time of flight mass spectrometry to the study of the proteinaceous binders in paint: blue paint composition in the series "The Life of Virgin" by Alonso Cano (17th century) as a case study.
abstract: The identification of proteinaceous materials in paint constituents provides very valuable information regarding the techniques used by the painter and the most suitable procedures for conserving and restoring their works. Although the analysis of proteinaceous materials is nowadays a common task when dealing with works of art, the reliable detection and identification of protein traces is still complicated, particularly when very small samples can be taken that may contain a mixture of different organic materials (oils, waxes, resins, gums etc.). We therefore proposed a proteomic approach to investigate protein materials in paintings at trace levels in order to obtain a better understanding of the painter's technique. After trypsin digestion of the paint samples, mass spectra were obtained by matrix-assisted laser desorption and ionization time of flight mass spectrometry (MALDI-TOF-MS) and they were compared with the Mascot database and with theoretical digested proteins. This study contributes to the knowledge about the technique used by Alonso Cano (Granada, Spain, 1601-1667), one of the most original and brilliant artists from the Spanish Golden Age (17th century), in the series called the Life of the Virgin (six paintings), part of the iconographic program about the life of the Virgin Mary, nowadays seen in the main chapel of Granada Cathedral. The objective of the present study was to test the use of proteinaceous material, mainly egg yolk, in the paint used by Cano, as suggested in previous research, although this would have been unusual at that time when most artists used oil paints. Based on the results of the analysis here presented, the use of protein in the binding media can most likely be excluded.
authors.affiliation: Department of Mineralogy and Petrology, Faculty of Science, University de Granada, Campus Fuentenueva s/n, 18071 Granada, Spain. Instituto del Patrimonio Cultural de España, Madrid 28040, Spain. juliaromero@ugr.es.
authors.forename: Julia
authors.initials: J
authors.lastname: Romero-Pastor
authors.affiliation: Department of Analytical Chemistry, Faculty of Science, Biomedical Research Institute ibis,Granada University de Granada, Campus Fuentenueva s/n, 18071 Granada, Spain. natalia@ugr.es.
authors.forename: Natalia Navas
authors.initials: NN
authors.lastname: Natalia Navas
authors.affiliation: Department of Painting, University of Granada, Av. Andalucía s/n, 18071, Granada, Spain. lrsimon@ugr.es.
authors.forename: Luís
authors.initials: L
authors.lastname: Rodríguez-Simón
authors.affiliation: Proteomic Unit, Institute of Parasitology and Biomedicine "López-Neyra", Avda. Del Conocimiento, s/n.18100 Armilla, Granada, Spain.. alario@ipb.csic.es.
authors.forename: Antonio
authors.initials: A
authors.lastname: Lario-Simón
authors.affiliation: Department of Chemistry and Chemical Education, Charles University, M.D. Rettigové 4, 116 39 Prague 1, Czech Republic. kuckovas@vscht.cz.
authors.forename: Stepanka
authors.initials: S
authors.lastname: Kuckova
authors.affiliation: Department of Analytical Chemistry, Faculty of Science, Biomedical Research Institute ibis,Granada University de Granada, Campus Fuentenueva s/n, 18071 Granada, Spain. emanzano@ugr.es.
authors.forename: Eloísa
authors.initials: E
authors.lastname: Manzano
mesh_terms: D010150:Paint / Q000032:analysis*; D010151:Paintings; D011506:Proteins / Q000032:analysis* / Q000737:chemistry*; D013030:Spain; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*
chemical_list: D011506:Proteins