An infrared study of unordered poly-L-proline in CaCL2 solutions
β Scribed by Nancy Johnston; S. Krimm
- Publisher
- Wiley (John Wiley & Sons)
- Year
- 1971
- Tongue
- English
- Weight
- 535 KB
- Volume
- 10
- Category
- Article
- ISSN
- 0006-3525
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β¦ Synopsis
Infrared spectra have been obt,aiiied of poly-Lproline in aqueous CaCL solutions. As the salt concentration is increased, the C=O stretching band develops a component at, the frequency found in the solid state while the CH, bending band broadens to higher frequency. Since circular dichroism spectra indicate progressive disordering of the chain with increasing salt, concentration, we associate the infrared spectral changes with the same phenomenon. Our interpretatiori of these changes, particularly in the CHZ bending modes, is that disordering is associated primarily with an increase in the range of accessible C"-C' (=O) rotation angles rather than with the random introduction of cis imide bonds in the chain.
π SIMILAR VOLUMES
The infrared absorption of poly-L-proline in concentrated aqueous salt solutions was measured in the fundanierital region. Of primary interest were the carbonyl absorption of the peptide linkage and the methylene C-H bending absorption of the pyrrolidine ring. These spectral regions each show an add
## Abstract The far infrared spectra of poly(Lβproline) I (190β35 cm^β1^) and II (400β35 cm^β1^) were obtained in the solid state at both 300Β° and 110Β°K. A significant difference in the region below 100 cm^β1^ was observed. A very intense band located at 60 cm^β1^ in the infrared spectrum of form I
## Abstract Xβray diffraction studies have been made on the polytripeptide poly(LβprolylβLβΞ±βphenylglycylβLβproline). Its structure has been found to be helical, with a poly(Lβproline) II conformation, packed in an orthorhombic lattice, space group P2~1~2~1~2, with __a__ = 14.3 Γ , __b__ = 13.5 Γ , a