Three-dimensional structure of IS4 segment of the rat brain sodium channel protein determined from NMR data in solution

<正> Two-dimensional H NMR techniques were used to determine the solution structure of IS4 which is a synthetic peptide from the rat brain sodium channel protein. Complete proton resonance assignment was obtained using 2D DQF-COSY, TOCSY and NOESY techniques. The cross-peak volumes in NOESY spectra were used to calculate the structure of IS4 and generated accurate proton-proton distance constraints employing the MARDIGRAS program. These data, combined with the φ angle constraints deduced from 3JHNα coupling constants, were used to obtain a set of 5 structures by program DIANA. These structures were refined by unrestrained energy minimization using standard minimization program. The results indicate that the conformation of IS4 in DMSO is of random coil.