| Abstract: | Solutions of native collagen extracted from rat tail tendons in neutral salt solution have been studied by dynamic light scattering. The spectra obtained are consistent with the presence in solution of both single rod-shaped collagen molecules and aggregates of molecules. No contribution to the spectrum has been detected at any scattering angle from rotational diffusion of single molecules, although a measurable broadening effect is expected at high angles. The translational diffusion coefficient D of single molecules, calculated from the broader spectral component, shows an anomalous dependence on collagen concentration with a maximum value of D20,w = 8.6 ± 0.2 × 10?12 m2/sec near the concentration 0.04% by weight. Above 0.05% D falls linearly with increasing concentration and takes the value D 20,w = 8.1 ± 0.2 × 10?12 m2/sec at 0.064% collagen. |
