## Abstract Dielectric measurements have been carried out on partially hydrated collagen in the frequency ranges 100 kHzβ5 MHz, 100 MHzβ1 GHz, and 8β23 GHz. In the lowβfrequency range, a dispersion was observed around 100 kHz which results from inhomogeneous conductivity of the samples. A dielectri
The molecular details of collagen hydration
β Scribed by J. Raul Grigera; Herman J. C. Berendsen
- Publisher
- Wiley (John Wiley & Sons)
- Year
- 1979
- Tongue
- English
- Weight
- 593 KB
- Volume
- 18
- Category
- Article
- ISSN
- 0006-3525
No coin nor oath required. For personal study only.
β¦ Synopsis
Nuclear magnetic resonance and dielectric data on hydrated collagen are interpreted in terms of Ramachandran's hydration model. It is found that all data are compatible with this model, indicating two specific binding sites per three amino acids in the threefold collagen helix. Sorption data have been interpreted according to the multilayer theory of Guggenheim and used to derive the fraction of bound water in the primary sites. From magnetic resonance anisotropies structural details of the position of the water molecules can be derived under the assumption that both sites are equally occupied. The residence time of a water molecule in one of these sites in moderately hydrated collagen (45 g H20/100 g collagen) is 1.2 X sec. The remainder of the water is weakly bound and consists of rapidly exchanging species with rotational correlation time shorter than 10-l0 sec. The sites are 50% occupied at a water content of 10 g/lOO g collagen and may contribute significantly to the stability of the collagen threefold helix.
π SIMILAR VOLUMES
Over the past 10 years calorimetric studies of collagen have been performed by several It is known that about 0.45-0.55 g H20 per collagen cannot be frozen,'^^-^ even at very low temperature.6 The freezable part of water has a melting point somewhat below 0Β°C.5,6 It was estimated that the enthalpy o
& WIGLER, M. (1985). In yeast RAS proteins are controlling elements of adenylate cyclase.
## Abstract Two dielectric relaxation peaks were found in moist collagen by the time domain reflectometry. The lowβfrequency peak around 100 MHz moves little as the water content is varied. Its relaxation strength depends on the content and vanishes for completely dried collagen. This process is co
The temperature dependence of the humidity-sensitive spacing, d , related to the lateral packing of collagen molecules was measured for fully hydrated collagen. In the vicinity of O"C, a sudden change in d was observed, which was reversible with temperature. In the diffraction profile, below O"C, a