## Abstract The vacuum‐ultraviolet circular dichroism (VUCD) of chondroitin and chontroitin‐6‐sulfate has been measured to 160 nm for films and to 170 nm for D~2~O solutions. The pD‐dependent dichroic behavior of these glycosaminoglycans in D~2~O is similar above 200 nm and is in agreement with pre
Circular dichroism of collagen, gelatin, and poly(proline) II in the vacuum ultraviolet
✍ Scribed by Duane D. Jenness; Cindy Sprecher; W. Curtis Johnson Jr.
- Publisher
- Wiley (John Wiley & Sons)
- Year
- 1976
- Tongue
- English
- Weight
- 463 KB
- Volume
- 15
- Category
- Article
- ISSN
- 0006-3525
No coin nor oath required. For personal study only.
✦ Synopsis
Abstract
Circular dichroism spectra for acid‐soluble calfskin collagen, gelatin, and poly(proline) II in solution have been extended into the vacuum ultraviolet region. The extended spectrum of gelatin reveals that the circular dichroism of this unordered polymer is more closely related to the spectrum of charged polypeptides than might be evident from near ultraviolet work. A short‐wavelength band is found at about 172 nm, which corresponds in position, magnitude, and sign to a band recorded earlier for poly(L‐glutamic acid) at pH 8.0. This band is observed in a helical structure for the first time in the vacuum ultraviolet circular dichroism and absorption spectra of poly(proline) II. Both circular dichroism and absorption spectra point to the assignement of this band as the __n__σ*. Neither the __n__σ* nor the expected positive lobe of the ππ* helix band is observed in the extended circular dichroism spectrum of collagen. We postulate that these two bands cancel here in analogy to the case of α‐helical poly(L‐glutamic acid).
📜 SIMILAR VOLUMES
Tripeptidesserve as model systems for understanding the so-called random-coil state of peptides and proteins. While it is well known that polyproline or proline-rich polypeptides adopt the very regular polyproline-II (PPII) or left-handed 3(1)-helix conformation, it was thus far not clear whether th
## Abstract The positive circular dichroism band observed near 228 nm with poly(L‐proline) responds in a similar fashion to HCl and CaCl~2~. The spectra in the HCl solutions are compatible with a simple binding equation and a p__K__ near −2 for the dissociation of a proton from a protonated peptide
## Abstract In the presence of sodium poly(L‐glutamate) at pH = 7.5 the dye pseudoisocyanine in dilute aqueous solution (__C__~__d__~ = 1.10 × 10^−5^ __M__) and low P/D values exhibits an absorption spectrum with a very sharp red‐shifted J‐band. Under the same conditions circular dichroism (CD) in