Physical properties of type i collagen in solution: Structure of α‐Chains and β‐ and γ‐components and two‐component mixtures

The structure of thermally denatured Type I collagen has been studied using laser light scattering. The results indicate that the diffusion coefficients of α‐chains and β‐ and γ‐components are 1.550 ± 0.08 × 10 −7 , 1.000 ± 0.05 × 10 −7 , and 0.835 ± 0.04 × 10 −7 cm 2 /sec, respectively, at temperatures between 20 and 40°C. It is concluded from diffusion data that these species have hydrodynamic radii of about 13.8 nm (α‐chain), 21.5 nm (β‐component), and 25.7 nm (γ‐component), consistent with previous studies of thermal denaturation by light scattering. It is also concluded, based on volume calculations, that a large volume increase occurs when the triple helix unfolds. Homodyne correlation functions for two component mixtures of α‐chains and β‐and γ‐components appeared to decay exponentially. In all but one case discussed the correlation function could be fitted with a single component having a translational diffusion coefficient which was an intensity weighted average of the diffusion coefficient of each component present.