Solution Structure of Bioactive Peptides In Biomimetic Media

NMR studies on the most commonly used solvents, water and DMSO, show that, owing to their comformational flexibility, it may be difficult to find a well defined solution structure for short linear peptides. At present the main methods employed to limit the accessible conformational space in solution are the following: the >>anisotropic<< solvent systems, such as micelles and liposomes, complexation with suitable agents, the use of low temperatures and the combination of low temperatures with viscous solvent mixtures. The key note of all these methods is to choose a solution medium as close as possible to that in which the biological action takes place. In this article it is shown that the use of cryoprotective mixtures at a low temperature can be considered as an >>environmental constraint<< of general applicability.