Figure 4

Examples of processes involving protein dynamics. From the top row: (1) Conformational changes between folded and unfolded states, (2) ligand receptor interactions, (3) a representation of the effects of covalent modification of a protein, (4) the role of phosphorylation, (P), in stabilising one of several interconvertible forms and finally (5) transitions between structural sub-states of enzymes, on going from an inactive to an active, substrate-bound state are shown. The double arrows connect the interconvertible states with the longer arrows indicating the energetically favoured direction of the change. Percentages, where listed, give rough estimates of how much each state is populated. This is a simplified version of the scheme of Yuanpeng J. Huang and Gaetano T. Montelione (2005). News and views: Structural Biology: Proteins flex to function. Nature, 438, 36-37. It was reproduced with approval of the authors and Macmillan Publishers Ltd. in my forthcoming book in German: <Von Molekülen zu Zellen. 100 Jahre experimentelle Biologie. Betrachtungen eines Biochemikers>, and is shown here with permission of the GNT Verlag für Geschichte der Naturwissenschaften und der Technik. Diepholz. Stuttgart, Berlin.