PROTEAN: A New Method for Deriving Solution Structures of Proteins

Knowledge Systems Laboratory Computer Science Department Stanford University Stanford, CA 94305 Nuclear Overhauser Enhancement Spectroscopy (NOESY) is a powerful NMR technique for obtaining structural information on proteins in solution. 2DFT NOESY experiments readily provide information on dipole coupled protons, an indication of close spatial proximity. Unfortunately, quantitative interpretation of NOE measurements in terms of molecular structure is problematic because a rigorous interpretation requires prior knowledge of the structure. Nevertheless, a careful approximate analysis of the spectroscopic information can yield meaningful structural information if adequate precautions are applied. Here we outline a new strategy to take into account these limitations of the data. We also describe the PROTEAN system, a computer program under development to implement this strategy. Finally we provide a simple example of the use of PROTEAN to determine the solution structure of the lac-repressor headpiece.