Electronic structure of trypsin inhibitor from squash seeds in aqueous solution

The electronic structure of the trypsin inhibitor from seeds of the squash Cucurbita maxima (CMTI-I) in aqueous solution is obtained by ab initio, all -electron, full-potential calculations using the self-consistent cluster-em bedding (SCCE) method. The reactive site of the inhibitor is explained theo retically, which is in agreement with the experimental results. It is shown that the coordinates of oxygen atoms in the inhibitor, determined by nucle ar magnetic resonance and combination of distance geometry and dynamical si mulated annealing, are systematically less accurate than that of other kind s of heavy atoms.