THE CONCEPT OF A RANDOM COIL - RESIDUAL STRUCTURE IN PEPTIDES AND DENATURED PROTEINS

Non-native states of proteins are of increasing interest because of th eir relevance to issues such as protein folding, translocation and sta bility. A framework for interpreting the wealth of experimental data f or nonnative states emerging from rapid advances in experimental techn iques involves comparison with a 'random coil' state, which possesses no structure except that inherent in the local interactions. We review here the concept of a random coil, from its global to its local prope rties. tn particular, we focus on the description of a random coil in terms of statistical distributions in phi,psi space. We show that such a model, in combination with experimental data, provides insight into the structural properties of polypeptide chains and has significance for understanding protein folding and for molecular design. (C) Curren t Biology Ltd