The use of helical net-diagrams to represent protein structures.

The arrangement of side chains in alpha-helical regions of protein can be represented by helical net-diagrams. The addition of quantitative indices of the character of the residue at each net-point facilitates a straightforward examination of the groupings of residues of different character. As such the method complements that of Schiffer and Edmundson (1967). In addition, the reasons for non-helicity in some regions may be seen to be correlated with particular side-chain distributions. The method is illustrated with respect to myoglobin and lysozyme.