Optical properties of the poly‐L‐proline and collagen helices

Abstract
Poly‐L‐proline I and II, polyphydroxy‐L‐proline II, polysarcosine, and collagen, as well as two model amides have been examined by far ultraviolet spectrophotometry. Absorption spectral data are presented. Neither in solution nor in oriented films of poly‐L‐proline I and II is there any indication of excition resonance splitting of the peptide absorption band. In collagen there is some, in the poly‐L‐prolines only minimal, hypochromicity. These observations, at least in poly‐L‐proline II, run counter to theory. Optical rotatory dispersion measurements in the ultraviolet indicate simple dispersion in collagen and poly‐L‐proline II down to at least 232 mμ. The Cotton effect (trough at 233 mμ) observed in α‐helical polypeptides and proteins is absent. The implications of these findings are discussed.

This publication has 24 references indexed in Scilit: