We are developing AUREMOL1 (www.auremol.de), which goal is the reliable and automatic structure determination of biological macro molecules such as proteins from NMR data. For a fully automatic sequential NOESY assignment the tool ASSIGN2 has been developed. The required input consists of a homologous structure for a NOESY spectrum simulation and the experimental NOESY spectrum. ASSIGN fits the simulated NOE signals to the experimental spectrum. The fit quality given by a probability depends on the line shapes and volumes of the signals. The assignment is varied by moving or swapping spin system assignments using a Monte Carlo approach. A threshold accepting algorithm (TA3) is employed to find the
maximum of accordance.