Static and dynamic light scattering studies of collagen solutions

One of the important directions in medical biophysics nowadays is study of proteins both in crystallized form and in solutions. Solutions with protein macromolecules are quite unique for study using methods of molecular physics since mass of a macromolecule is well defined for each type of a protein and each protein molecule possesses definite surface charge, which can be changed by varying pH of the solution. One of the most important and abundant proteins is collagen. Collagens are major structural proteins in the extracellular matrix, making up about one-third of protein mass in a human body. About 40% of all the collagen in the body is found in skin, 10-20% in bone and teeth and 7-8% in the blood vessels [1]. This protein family is of interest because of the diversity of structural and morphogenetic roles. The triple helical structure of the collagen molecule is responsible for the vest majority of physical properties [2]. In this paper we address relationship between molecular parameters of collagen in solution (translational diffusion coefficient, coefficient of the intermolecular interactions) and concentration of collagen in solution, and pH of solution. Both static and dynamic light scattering methods are employed for study of collagen in solution.