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Changement de structure de la poly‐ L ‐proline à l'état solide par hydratation: Etude par spectrométrie infra‐rouge
Author(s) -
De Lozé C.,
Josien M. L.
Publication year - 1969
Publication title -
biopolymers
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.556
H-Index - 125
eISSN - 1097-0282
pISSN - 0006-3525
DOI - 10.1002/bip.1969.360080403
Subject(s) - chemistry , polymer chemistry , stereochemistry , proline , solid state , infrared spectroscopy , crystallography , hydrogen bond , molecule , organic chemistry , amino acid , biochemistry
Films of poly‐ L ‐proline I and II have been hy drated by water vapor and their infrared spectra analysed between 1250 and 3500 cm −1 . Forms I and II behave differently. Water binds to the carbonyl of form II through hydrogen bridges and, when released by drying, leaves the polypeptide conformation unchanged. In form I, complex formation with water seems to proceed through a different mechanism involving more than the carbonyls. Hydration of form I yields a partial irreversible transition to form II. Successive hydration and drying of the film brings the transition to completion. This I → II transition in the solid state has a cooperative character; its mechanism is discussed. Poly‐ L ‐prolines I and II also absorb vapors of aliphatic alcohols but not change in conformation is observed.