I suggest, to emphasize the 222/208 ratio not too much for that purpose.

This ratio is also a parameter for amount and type of a-helical structure.

You may also want to consider this (older) reference, where coiled coil structure is characterized by another CD parameter:

The CD of Two-Chain Coiled Coils: Experiments

on Tropomyosin and Tropomyosin Segments

in the Tyrosine / Disulfide Spectral Region

MARILYN EMERSON HOLTZER, SWATANTAR KUMAR,

ALFRED HOLTZER

Biopolymers, Vol. 28, 1597-1612 (1989)

Best regards,

Martin