On the helix-coil transition in grafted chains

The helix-coil transition is modified by grafting to a surface. This modification is studied for short peptides capable of forming alpha-helices. Three factors are involved: i) the grafting can induce change of the boundary free energy of the helical domain ii) the van der Waals attraction between the helices and iii) the crowding-induced stretching of the coils. As a result, the helix-coil transition acquires "all or nothing" characteristics. In addition the transition temperature is elevated and the transition itself sharpens as the grafting density increases.