Helical segment analysis of α-helical regions in proteins

The methods suggested earlier for the analysis and representation of protein structural data are now extended to the helical regions in finer details. These enable better handling of characterization of bends and distortions, for which statistical parameters are also developed. Using latest myoglobin data, best experimental parameters for the α-helix are deduced to be r_N = 1.55 (0.13) Å, r = 2.28 (0.12) Å, r_C′ = 1.70 (0.10) Å, r₀ = 2.02 (0.12) Å, ? = 100.5 (2.3)°, and t = 1.495 (0.055) Å.