Premium
Investigation of molecular motion in collagen using the spin‐probe technique
Author(s) -
Nagamura T.,
Woodward A. E.
Publication year - 1977
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.1977.360160413
Subject(s) - chemistry , spin probe , analytical chemistry (journal) , electron paramagnetic resonance , spectral line , atmospheric temperature range , nuclear magnetic resonance , spin (aerodynamics) , thermodynamics , chromatography , physics , astronomy
The spin‐probe technique was employed to study molecular motion in collagen and modified collagen samples in the −160° to +200°C region. The effect of water content in the 0–30‐wt. % range, relative to vacuum dried samples, on the electron spin resonance spectrum of the probe was also investigated. The spectra at the lowest temperatures consisted of a broad asymmetric triplet. Narrowing of this triplet above −40° to −70°C and the appearance of additional lines in the spectrum, interpreted as due to a narrow triplet, at a temperature dependent on the water content were observed. For samples with low water contents [(0–0.4)%] the broad triplet was that expected for a glassy system up to 150–190°C; for these samples the narrow triplet appears at a temperature above 50°C, its intensity increasing with increasing temperature up to 70–100°C, then decreasing with a further temperature increase. For samples with water contents near 30%, the narrow triplet first completely appears at about 0°C, and reaches relative intensities of 35% at 30°C. The motion taking place in collagen and related samples is discussed in terms of these results.