Effects of Arginine Deimination and Citrulline Side-Chain Length on Peptide Secondary Structure Formation.

摘要: Post-translational modifications expand the chemical functionality of peptides and proteins beyond that originating from encoded amino acids, but studies on structural effects these have been limited. Arginine undergoes deimination to give citrulline (Cit), converting positively charged guanidinium moiety into a neutral urea group. Herein, we report effect Arg secondary structure formation. To understand reason for number methylene units in Cit, Cit side-chain length formation was also studied. Ala-based β-hairpin were used study α-helix β-sheet formation, respectively. Peptides containing analogues prepared by an orthogonal protecting group strategy coupled with solid-phase carbamylation. The CD data analyzed using modified Lifson-Roig theory, showing helix propensity decreased upon either shortening or lengthening propensity. NMR methods, minimal change strand energetics deimination. Altering did not affect either. These results should be useful preparation urea-bearing systems design incorporating residues varying length.