Pmlbeta: a PyMOL extension for building β-amino acid insertions and β-peptide sequences

β-peptides are peptide-mimetics with wide biomedical and biotechnological applications. Their most 16 peculiar feature is their readiness to fold into various secondary structures not found in their natural 17 counterparts. Furthermore, β -amino acid insertions to natural polypeptides were found to provide 18 unique features and also increase enzymatic stability. This is due to the additional methylene group in 19 their backbone, which on the other hand makes it impossible to use the established algorithms and 20 computational tools developed for α-peptides and proteins. An extension to the PyMOL v2.x molecular 21 graphics environment is presented for β-peptides, which allows rapid graphical visualisation and greatly 22 simplified model building for computational studies, with special emphasis also put on direct formation 23 of diverse folding states.