A-C: 2D helical nets—i.e., projections of Cα atoms onto the surfaces of cylinders of appropriate radii—for a canonical polyproline-II helix (A), an α helix (B), and with these two overlaid showing ‘knobs-into-holes’ packing of the Pro and Tyr side chains (C). The paths of the backbones are shown as solid lines, while dashed lines outline the ‘holes’ presented by the α helix. Color key: Tyr, slate; Leu, yellow; Lys and Asp, orange; and Pro, green. D:
In silico model for the designed PPα-Tyr sequence, Table 1, after 100 ns of molecular-dynamics simulation in water.