| Abstract: | 1H-n.m.r. studies at 500MHz have been performed on a trypsin inhibitor (CMTI-III) found in squash seed (Cucurbita maxima). The sequential resonance assignments have been made using two-dimensional techniques. The chemical shifts for the assigned protons are reported at 30°, pH 2.8 and form a basis for the determination of the solution structure of CMTI-III. Analysis of the NOE data, NH-αCH vicinal coupling constants and pattern of slowly exchanging amide protons indicates that the predominant feature of the solution conformation is a triple stranded β sheet consisting of residues 8-10, 21-23, and 26-29. Residues 12-15 appear to form a β turn. |
