LAUSR

Protein unfolding, i.e. the loss of its native tertiary (quaternary) structure, is a part of many important biological processes [1,2] and plays a big role in various biomedical and biotechnological applications [3,4]. Protein unfolding may be induced by a number of physicochemical factors including addition of chemical substances (such as different salts, acids, alcohols, detergents), mechanical stress, change of pH, heating and adsorption on a surface [5,6]. Protein unfolding upon adsorption on a surface may be responsible for activating an immune system response (e.g., foreign body reaction) and other biochemical reactions in an organism [7]. The aim of this work was to obtain direct insight into surface-induced protein unfolding at the level of an individual protein molecule using atomic force microscopy (AFM). Several proteins such as ferritin, fibrinogen and RNA polymerases (RNAP) have been used in this study.