PHYSICAL REASON FOR FAST FOLDING OF THE STABLE SPATIAL STRUCTURE OF PROTEINS - A SOLUTION OF THE LEVINTHAL PARADOX

Can a protein chain acquire its most stable structure in the minutes a llotted for its self-organization in nature? To answer this question, the kinetics of protein chain folding was considered in the neighborho od of the point of all-or-none thermodynamic phase transition between the disordered coil (the initial state of the chain) and the most stab le spatial structure (the final state of the chain). The characteristi c time for the protein chain folding to its most stable spatial struct ure was shown to be similar to exp(N-2/3) ns; i.e., a chain of N = 100 -150 residues should attain its most stable structure in a time on the order of a minute.