MALDI-TOF-MS Analysis And Characterization Of Painted Protein Cementitious Materials

Polychrome artworks is a carrier to the. progress of human civilization. Human can realize the history on them which are of great significance on archaeology, art and science. It is of great significance for china, world, even the all Mankind to protect and restore polychrome artworks. Some chemical reactions including oxidation, degradation and so on are the main causes of damage of them. In this thesis, MALDI-TOF-MS (matrix-assisted laser desorption/ionization-time of flight-mass spectrometry) was used to analysis and characterization of the binding media from ancient polychrome artworks based on proteomics techniques. The extraction process of proteins in the binding media of polychrome artworks was studied which was the first to compare the extracting efficiency of proteins with five different extractant(NaOH, TFA, HCOOH, HC1 and NH3·H2O). Response surface methodology (RSM) with Box-Behnken design (BBD) was used to optimize the ultrasound-assisted extraction process of proteins in the binding media of polychrome artworks. Proteomic Study of free-range and barn-raised chicken egg white was conducted. MALDI-TOF-MS was used to analysis and characterization of egg white, egg yolk, animal glue and their model samples of the proteinaceous binding media. The peptide mass fingerprints of the binding media of egg white and animal glue were set up. It turned out that trifluoroacetic acid is suitable for proteins extraction and analysis and characterization of the binding media by MALDI-TOF-MS. The optimum extraction parameters for proteins from egg white were trifluoroacetic acid concentration,0.53%(v/v); ultrasonic power,50%; ultrasonic time,40 min. The optimum extraction parameters for proteins from animal glue were trifluoroacetic acid concentration,0.81%(v/v); ultrasonic power,70%; ultrasonic time, 38.5 min.6 collagen peptides were first detected in free-range chicken egg white and 8 collagen peptides were first detected in barn-raised chicken egg white. EDTA can bind with metallic ions of pigments so as to release proteins. The impact of CuCO3·Cu(OH)2 is more dramatic than HgS because of the strong complex reagent between the amino acid of proteins and copper ion of CuCO3·Cu(OH)2.The dissertation consists of five parts as follows:Chapter 1:ReviewThe research methods for the binding media of ancient artworks were summarized and the theory of mass spectrometry and its application to binding media were introduced. Then Proteomic research strategies were reviewed. Based on the review, the topic of the thesis was proposed.Chapter 2:Extraction process of proteins in the chicken egg whiteUltrasound-assisted extraction process of proteins in the binding media of polychrome artworks was studied. A good extractant was selected from five reagents in common use for proteins extraction. Response surface methodology (RSM) was used to optimize the ultrasound-assisted extraction process of proteins in the binding media of polychrome artworks.Chapter 3:Proteomic study of chicken egg whiteMALDI-TOF-MS was used to characterization of proteins in the free-range and barn-raised chicken egg white. The effects of three factors (trypsin volume, pH of tryptic digestion and incubation time) on tryptic digestion process of extracted proteins were investigated.Chapter 4:Analysis and characterization egg proteins and its model samples by MALDI-TOF-MSThe determination conditions of proteins from model samples of egg white and egg yolk and interference elimination were investigated. The peptide mass fingerprints of the binding media of egg white and egg yolk were set up.Chapter 5:Extraction and MALDI-TOF-MS analysis of proteins from model sample of animal glue binding mediaRSM was used to optimize the ultrasound-assisted extraction process of proteins in the animal glue binding media of polychrome artworks which were characterized by MALDI-TOF-MS. The peptide mass fingerprints of the binding media of animal glue were set up.