[Determination and comparative analysis of the conformation of bovine pancreatic trypsin inhibitor and trypsin inhibitors E and K from the data of two-dimensional 1H-NMR spectroscopy].

On the basis of joint consideration of distance dependences between amide proton NH and protons C alpha H, NH, C beta H of the preceding in amino acid sequence residue from the torsion angles phi psi, chi 1, the correlation diagram of these proton-proton distances with the regions of sterically allowed conformational space (phi, psi) is presented and the method for the determination of the L-amino acid residues backbone conformations is proposed. The diagram was used for the determination of backbone conformations of bovine pancreatic trypsin inhibitor and trypsin inhibitors E and K from Dendroaspis polylepis using the data from two-dimensional 1H-NMR spectroscopy. The analysis of backbone conformations was carried out. The individual elements of these protein molecules secondary structure were characterized and their high conformational homology was shown. The inference about qualitative coincidence of three protein molecules conformation in solution, preservation of secondary structure basic elements and their similarity with bovine pancreatic trypsin inhibitor crystalline structure was made.