Conformational preferences and the role of the statine residue in the crystal state.

The present paper is the result of an analysis of the available crystal structure data related to the statine amino acid so as to obtain information about bond lengths, bond angles, and preferential conformations. The number of configurations actually observed is small; nevertheless, some characteristic conformations should be pointed out for statine-containing peptides. The presence of two additional carbon atoms in the statine main chain enhances the peptide conformational degree of freedom and the statine-containing peptides are observed in a variety of different conformations including some usual secondary structure-types as beta-turns and beta-strands.