Enzymes seen by restorers eyes or the ingenious gentleman Don Quixote of La Mancha

This paper deals with potential utilization of enzymes for removing of undesirable compounds evoking material destruction and distortion of esthetic characteristics of painting. Criteria of enzyme selectivity for clearing, specificity of restoration methods that should comply exact balance of conditions required for enzymes activity and security of painting are discussed. The enzymes properties are analyzed from the viewpoint of their attractiveness and undesirability in restoration. The enzymes effectivity, specificity, nontoxicity and rapid results obtaining make enzymatic clearing very attractive. This approach is more magnetic than traditional methods of clearing with utilization of acids, alkaline or organic solvents and therefore corresponds to the modern trend of minimal meddling in the work of art. However, some enzymes properties restrict their utilization. For instance, all enzymes are very labile and require high degree of purification. All enzymes can be utilized only under strict conditions such as temperature and pH. Finally, after enzymatic clearing additional steps of washing with surfactants and light organic solvents are required.